Actinic ray-sensitive or radiation-sensitive resin composition

Abstract

The present invention addresses the problem of providing an actinic ray-sensitive or radiation-sensitive resin composition capable of forming a fine pattern by dry development. An actinic ray-sensitive or radiation-sensitive resin composition according to the present invention is used in a pattern forming method including dry development, and contains: a resin containing a repeating unit represented by formula (1); and a solvent.

Description

Actinic ray-sensitive or radiation-sensitive resin composition

[0001] The present invention relates to an actinic ray-sensitive or radiation-sensitive resin composition.

[0002] Conventionally, in the manufacturing process of semiconductor devices such as ICs (Integrated Circuits) and LSIs (Large Scale Integrations), microfabrication has been performed by lithography using actinic ray-sensitive or radiation-sensitive compositions. In recent years, with the increasing integration density of integrated circuits, there has been a demand for the formation of ultrafine patterns in the submicron or quarter-micron range. Accordingly, there has been a trend toward shorter exposure wavelengths, from g-line to i-line and then to KrF excimer laser light, and currently, exposure machines using ArF excimer lasers with a wavelength of 193 nm as a light source have been developed. Furthermore, in addition to excimer laser light, development of lithography using electron beams (EB), X-rays, extreme ultraviolet rays (EUV), and the like is also currently underway. Accordingly, compositions that are effectively sensitive to various types of actinic rays or radiation have been developed.

[0003] As a composition used in the above-mentioned lithography, for example, Patent Document 1 discloses a composition containing a resin having a predetermined structure, a radiation-sensitive acid generator, and a solvent.

[0004] International Publication No. 2021 / 157354

[0005] In the lithography process, when developing an actinic ray- or radiation-sensitive resin composition (hereinafter also simply referred to as a "resist composition") that has been pattern-exposed, wet development is often used, in which exposed or unexposed areas are removed using a developer to form a pattern, as in the method described in Patent Document 1, and the composition is designed to be optimized for wet development. However, wet development has a problem in that pattern collapse is likely to occur due to capillary force and the like that occurs between patterns when the developer is dried and removed. Dry development is a useful method because it is less likely to cause such pattern collapse, but few resin compositions are known that can form fine patterns by dry development, and the development of a new resin composition has been desired.

[0006] Therefore, an object of the present invention is to provide an actinic ray-sensitive or radiation-sensitive resin composition that can form a fine pattern by dry development.

[0007] As a result of extensive research into solving the above problems, the present inventors have found that the problems can be solved by the following configuration.

[0008] [1] An actinic ray-sensitive or radiation-sensitive resin composition used in a pattern formation method including dry development, the actinic ray-sensitive or radiation-sensitive resin composition comprising a resin containing a repeating unit represented by formula (1) described below and a solvent. [2] The actinic ray-sensitive or radiation-sensitive resin composition according to [1], wherein the dry development is thermal development or steam exposure development. [3] The actinic ray-sensitive or radiation-sensitive resin composition according to [1] or [2], wherein the dry development does not include plasma treatment. [4] The actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [3], wherein the dry development includes at least one treatment selected from the group consisting of steam exposure treatment, treatment of contacting a film formed from the actinic ray-sensitive or radiation-sensitive resin composition with a treatment liquid, and treatment of exposing a film formed from the actinic ray-sensitive or radiation-sensitive resin composition to ultraviolet light. [5] The actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [4], wherein the dry development is the steam exposure development. [6] The actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [5], further comprising a photoacid generator. [7] The actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [6], wherein the resin is a resin that generates a polar group by the action of an acid. [8] The actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [7], wherein the resin has a group that generates a carboxy group by the action of an acid. [9] The actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [8], comprising a compound B that generates an amine compound by the action of heat or an acid.

[10] The actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [9], comprising a compound C having a structure that reduces the number of carboxy groups by exposure.

[0009] According to the present invention, it is possible to provide an actinic ray-sensitive or radiation-sensitive resin composition that can form a fine pattern by dry development.

[0010] 1 is a schematic diagram illustrating one embodiment of a pattern forming method using a resist composition of the present invention. 2 is a schematic diagram illustrating one embodiment of a pattern forming method using a resist composition of the present invention.

[0011] The present invention will be described in detail below. The following description of the components may be based on representative embodiments of the present invention, but the present invention is not limited to such embodiments.

[0012] In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​written before and after "to" as the lower and upper limits. Furthermore, in this specification, when two or more types of a certain component are present, the "content" of that component means the total content of those two or more components. In this specification, in a numerical range described in stages, the upper or lower limit value described in a certain numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in a numerical range described in this specification, the upper or lower limit value described in a certain numerical range may be replaced with a value shown in the Examples. In this specification, a combination of two or more preferred embodiments is a more preferred embodiment.

[0013] In this specification, "actinic rays" or "radiation" refers to, for example, the bright line spectrum of a mercury lamp, far ultraviolet rays typified by excimer lasers, extreme ultraviolet rays (EUV), X-rays, soft X-rays, and electron beams (EB). In this specification, "light" refers to actinic rays or radiation. In this specification, "exposure" refers to not only exposure using the bright line spectrum of a mercury lamp, far ultraviolet rays typified by excimer lasers, extreme ultraviolet rays, and X-rays, but also drawing using particle beams such as electron beams and ion beams, unless otherwise specified.

[0014] In this specification, the weight average molecular weight (Mw), number average molecular weight (Mn), and dispersity (also referred to as molecular weight distribution) (Mw / Mn) of a resin are defined as polystyrene-equivalent values ​​measured by Gel Permeation Chromatography (GPC) using a GPC apparatus (HLC-8120GPC manufactured by Tosoh Corporation) (solvent: tetrahydrofuran, flow rate (sample injection amount): 10 μL, column: TSK gel Multipore HXL-M manufactured by Tosoh Corporation, column temperature: 40° C., flow rate: 1.0 mL / min, detector: differential refractive index detector).

[0015] In this specification, the term "organic group" refers to a group containing at least one carbon atom. Unless otherwise specified, the substituent is preferably a monovalent substituent. Examples of the substituent include a monovalent nonmetallic atomic group excluding a hydrogen atom, and can be selected from the following substituents T.

[0016] (Substituent T) Examples of the substituent T include halogen atoms such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom; alkoxy groups such as a methoxy group, an ethoxy group, and a tert-butoxy group; a cycloalkyloxy group; an aryloxy group such as a phenoxy group and a p-tolyloxy group; an alkoxycarbonyl group such as a methoxycarbonyl group and a butoxycarbonyl group; a cycloalkyloxycarbonyl group; an aryloxycarbonyl group such as a phenoxycarbonyl group; an acyloxy group such as an acetoxy group, a propionyloxy group, and a benzoyloxy group; an acetyl group, a benzoyl group, an isobutyryl group, an acryloyl group, a methoxy group, a methyl ... Examples of the substituent T include acyl groups such as an acrylyl group and a methoxalyl group; a sulfanyl group; alkylsulfanyl groups such as a methylsulfanyl group and a tert-butylsulfanyl group; arylsulfanyl groups such as a phenylsulfanyl group and a p-tolylsulfanyl group; alkylsulfonyl groups; arylsulfonyl groups; alkyl groups; alkenyl groups; cycloalkyl groups; aryl groups; heteroaryl groups; hydroxy groups; carboxy groups; formyl groups; sulfo groups; cyano groups; alkylaminocarbonyl groups; arylaminocarbonyl groups; sulfonamide groups; silyl groups; amino groups; carbamoyl groups; etc. In addition, when these substituents can further have one or more substituents, examples of the substituent T also include groups having one or more substituents selected from the above-mentioned substituents as the further substituents (e.g., a monoalkylamino group, a dialkylamino group, an arylamino group, a trifluoromethyl group, etc.).

[0017] In this specification, the bonding direction of a divalent group is not limited unless otherwise specified. For example, when Y is -COO- in a compound represented by the formula "X-Y-Z", Y may be -CO-O- or -O-CO-. The compound may be either "X-CO-O-Z" or "X-O-CO-Z".

[0018] In this specification, the acid dissociation constant (pKa) refers to the pKa in an aqueous solution, and specifically, is a value determined by calculation using the following software package 1 based on a database of Hammett's substituent constants and known literature values. All pKa values ​​described in this specification are values ​​determined by calculation using this software package. Software package 1: Advanced Chemistry Development (ACD / Labs) Software V8.14 for Solaris (1994-2007 ACD / Labs).

[0019] The pKa can also be calculated by molecular orbital calculation. A specific method for this is to calculate the pKa of H in an aqueous solution based on the thermodynamic cycle. ＋ One method is to calculate the dissociation free energy. ＋ The dissociation free energy can be calculated by, for example, DFT (density functional theory), but various other methods have been reported in the literature, and the method is not limited to these. There are several software programs that can perform DFT, and Gaussian 16 is an example.

[0020] In this specification, pKa refers to a value calculated based on a database of Hammett's substituent constants and publicly known literature values ​​using software package 1, as described above, but if pKa cannot be calculated by this method, a value obtained by Gaussian 16 based on DFT (density functional theory) will be adopted. In this specification, pKa refers to "pKa in aqueous solution" as described above, but if pKa in aqueous solution cannot be calculated, "pKa in dimethyl sulfoxide (DMSO) solution" will be adopted.

[0021] In this specification, the term "solid content" refers to components contained in a composition (e.g., a resist composition) that form a film (e.g., a resist film), and does not include solvents. Furthermore, any component contained in a composition that forms a film is considered to be a solid content even if it is in a liquid state.

[0022] [Actinic Ray- or Radiation-Sensitive Resin Composition] The actinic ray- or radiation-sensitive resin composition of the present invention (hereinafter also referred to as "the present resist composition") is an actinic ray- or radiation-sensitive resin composition used in a pattern formation method including dry development, and contains a resin containing a repeating unit represented by formula (1) (hereinafter also referred to as "specific resin") and a solvent. That is, the present resist composition is used in a pattern formation method including a dry development step.

[0023] [Pattern Forming Method] As described above, the present resist composition is used in a pattern forming method including dry development. The pattern formed by the pattern forming method using the present resist composition may be either a positive pattern or a negative pattern. The pattern forming method typically includes a pattern exposure step and a development step, and the development step includes dry development. The pattern forming method may include dry development, and may also include a step using a processing liquid such as a developer as part of the process. In terms of achieving superior effects of the present invention, it is preferable that the development treatment used to develop the pattern finally obtained by the pattern forming method is dry development. It is also preferable that the pattern forming method using the present resist composition does not include plasma treatment. The present resist composition may be used in a pattern forming method including dry development, and may be used in any step from pattern exposure to development to form a final pattern. The present resist composition may be, for example, a composition that forms a pattern by dry development, or a composition that forms a pattern on a different resist film (e.g., an undercoat film) by dry development using a pattern formed by the present resist composition.

[0024] The patterned exposure step is preferably a step of pattern-exposing the present resist composition.

[0025] The development step preferably includes at least one treatment selected from the group consisting of a steam exposure treatment described below, a treatment of contacting the resist film with a treatment liquid, and a treatment of exposing the resist film to ultraviolet light (UV light) (UV exposure treatment). The treatment of contacting the resist film with a treatment liquid is preferably performed before dry development. Examples of treatment liquids include a treatment liquid containing a compound that acts on the resist film to change its vaporizability or sublimability (e.g., compound A described below or compound C described below), a treatment liquid that dissolves a portion of the resist film (e.g., a developer described below), and a treatment liquid containing a material that forms a film that is removed by dry development (e.g., a filling agent described below). Specific embodiments of the treatment liquid will be described later. The UV exposure treatment is preferably performed simultaneously with or before dry development. The UV exposure treatment preferably changes the vaporizability or sublimability of at least a portion of the resist film.

[0026] <Dry Development> As dry development, heat development or vapor exposure development is preferred, and vapor exposure development is more preferred. Note that the dry development is intended to be a development method different from wet development, in which a developer is brought into direct contact with a resist film to remove exposed or unexposed areas of the resist film, and the developer is volatilized to obtain a pattern.

[0027] The thermal development is a dry development method in which at least a portion of a resist film is vaporized or sublimated by heating and removed from a substrate to form a pattern. For example, by heating a resist film in which the vaporization or sublimation properties of the exposed and unexposed portions differ, one of the exposed and unexposed portions is selectively removed to form a pattern. In thermal development, the vaporization or sublimation properties of the resist film may change simultaneously with the removal of the resist film. The heating temperature for the thermal development can be selected appropriately depending on the development target and pressure, but is often 60°C or higher, preferably 90°C or higher, and more preferably 120°C or higher. The upper limit is not particularly limited, but is often 400°C or lower, preferably 200°C or lower. The heating time for the thermal development can be selected appropriately, but is often 30 minutes or less, preferably 60 seconds to 5 minutes. The thermal development may be performed under high pressure, normal pressure, or reduced pressure.

[0028] The steam exposure development is a dry development method that includes contacting a resist film with steam (steam exposure treatment). For example, the interaction between the exposed or unexposed portions of the resist film and the steam changes the volatility or sublimation of the resist film, thereby selectively removing one of the exposed and unexposed portions to form a pattern. The steam can be appropriately selected depending on the resist film to be developed, and examples thereof include low-molecular-weight organic compounds, water, ammonia, and hydrogen halides. The low-molecular-weight organic compounds are preferably volatile or sublimable, and examples thereof include organic solvents, organic acids, and nitrogen-containing organic compounds. Known organic solvents can be used, such as hydrocarbon solvents, alcohol solvents, ester solvents, ether solvents, ketone solvents, and amide solvents. Known organic acids can be used, such as carboxylic acids and sulfonic acids. Known nitrogen-containing compounds can be used, such as amines and aromatic nitrogen-containing compounds. Examples of hydrocarbon solvents include saturated hydrocarbon solvents such as hexane, cyclohexane, heptane, octane, nonane, decane, undecane, and dodecane, and aromatic hydrocarbon solvents such as benzene, toluene, and xylene. Examples of alcohol solvents include ethanol, n-propanol, isopropanol, n-butanol, n-pentanol, diacetone alcohol, 4-methyl-2-pentanol, and propylene glycol monomethyl ether. Examples of ester solvents include methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, propyl acetate, isoamyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, 3-methoxybutyl acetate, ethyl lactate, butyl lactate, propyl lactate, butyl butyrate, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether propionate, propylene glycol monoethyl ether acetate (PGMEA), methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, and γ-butyrolactone.Examples of ether solvents include diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, tetrahydrofuran, dioxane, dimethoxyethane, and diethylene glycol dimethyl ether. Examples of ketone solvents include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, and acetylacetone. Examples of amide solvents include N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone. Examples of carboxylic acids include formic acid, acetic acid, propionic acid, butyric acid, pentanoic acid, 2-ethylhexanoic acid, benzoic acid, salicylic acid, and phthalic acid. Examples of sulfonic acids include methanesulfonic acid, ethanesulfonic acid, and benzenesulfonic acid. Examples of amines include methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, tributylamine, aniline, N,N-dimethylaniline, piperidine, morpholine, ethylenediamine, tetraethylethylenediamine, and 1,8-diazabicyclo[5.4.0]-7-undecene. Examples of aromatic nitrogen-containing compounds include pyridine, pyrimidine, pyrazine, indole, quinoline, isoquinoline, imidazole, benzimidazole, and benzotriazole. The vapor is also preferably a vapor containing a gaseous developer or reactant. Examples of developers and reactants include the low-molecular-weight organic compounds described above, water, ammonia, and hydrogen halides. The vapor may contain only one type of gas, or two or more types of gases. Examples of combinations of two or more types of gases include a combination of PGMEA and acetic acid. In addition to the above, the vapor may also contain He, Ne, Ar, Xe, and N. ２ The vapor may contain an inert gas and a carrier gas such as oxygen, nitrogen, carbon dioxide, and the like. In addition to the above, the vapor may also contain air (e.g., containing at least one selected from the group consisting of oxygen, nitrogen, carbon dioxide, and water vapor). Suitable combinations of resist film and vapor will be described later.

[0029] The temperature during the steam exposure treatment is often 60°C or higher, preferably 90°C or higher, and more preferably 120°C or higher. There is no particular upper limit, but it is often 400°C or lower, and preferably 200°C or lower. The exposure time during the steam exposure treatment can be selected appropriately, but is often 30 minutes or shorter, and preferably 60 seconds to 5 minutes. The steam exposure treatment may be carried out under high pressure, normal pressure, or reduced pressure.

[0030] In the steam exposure development, the process of removing at least a portion of the resist film to form a pattern may be a dry method, such as a heating treatment, a decompression treatment, or a combination thereof, and preferably includes a heating treatment. The process of removing a portion of the resist film to form a pattern (preferably a heating treatment) may be performed after the steam exposure treatment or simultaneously with the steam exposure treatment. In addition to the steam exposure treatment and the pattern formation treatment, the steam exposure development may also include a treatment (e.g., a UV exposure treatment) that changes the vaporizability or sublimability of the steam-exposed resist film, and the vaporizability or sublimability of the resist film may be changed simultaneously with the pattern formation treatment.

[0031] It should be noted that the steam exposure development is intended to be a development method different from the above-mentioned thermal development, and in this specification, when a steam exposure treatment is included between pattern exposure and pattern formation, it is considered to be steam exposure development even if it includes a treatment of removing the resist film by heat treatment.

[0032] It is also preferable that the dry development does not include plasma treatment. Note that the above-mentioned thermal development and vapor exposure development are intended to be development methods different from plasma development and do not include plasma treatment.

[0033] [Specific Resin] The present resist composition contains a specific resin having a repeating unit (specific unit) represented by formula (1). The resin composition is useful as a resist composition in that it has a wide range of design possibilities and is easy to handle.

[0034]

[0035] In formula (1), R ａ represents a hydrogen atom, a halogen atom, a nitro group, or an organic group.ａ The organic group represented by the formula (I) is preferably an alkyl group. The alkyl group preferably has 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 to 3 carbon atoms. The alkyl group may have a substituent. Examples of the substituent include the above-mentioned substituent T, and a halogen atom, a hydroxy group, a carboxy group, an amino group, an amide group, a thiol group, an alkoxy group, or an acetoxy group is preferred.

[0036] In formula (1), R ｂ each independently represents a hydrogen atom or an organic group, with a hydrogen atom being preferred. The organic group is preferably an alkyl group. The alkyl group preferably has 1 to 12 carbon atoms, more preferably 1 to 6, and even more preferably 1 to 3. The alkyl group may have a substituent. Examples of the substituent include the above-mentioned substituent T, with a halogen atom, a hydroxy group, a carboxy group, an amino group, an amide group, a thiol group, an alkoxy group, or an acetoxy group being preferred.

[0037] In formula (1), X represents an oxygen atom, a sulfur atom, or —NR ｃ - represents. ｃ represents a hydrogen atom or an organic group, preferably a hydrogen atom. The organic group is preferably an alkyl group. The alkyl group preferably has 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 to 3 carbon atoms. The alkyl group may have a substituent. Examples of the substituent include the above-mentioned substituent T, and a halogen atom, a hydroxy group, a carboxy group, an amino group, an amide group, a thiol group, or an acetoxy group is preferred.

[0038] In formula (1), A represents an organic group. The number of carbon atoms in the organic group is preferably 1 to 30, and more preferably 1 to 20. The organic group is not particularly limited, but is preferably an alkyl group, an aryl group, or an aralkyl group. The alkyl group, aryl group, and aralkyl group may have a substituent. Examples of the substituent include the substituent T described above, and preferred are a halogen atom, a hydroxy group, a carboxy group, an amino group, an amide group, a thiol group, an acetoxy group, an alkoxy group, an aryloxy group, an acyl group, an alkyloxycarbonyl group, an aryloxycarbonyl group, an alkylthio group, an arylthio group, or an aliphatic heterocyclic group.

[0039] Specific examples of the specific resin are shown below, but the present invention is not limited to these.

[0040]

[0041]

[0042]

[0043]

[0044] The specific unit may be used alone or in combination of two or more. The specific resin may have a repeating unit other than the specific unit. Detailed preferred embodiments of the specific resin and the specific unit will be described later.

[0045] [Solvent] The solvent contained in the resist composition is not particularly limited as long as it can dissolve or disperse the specific resin and the various components contained in the resist composition. Examples of the solvent include water and organic solvents. Known organic solvents can be used as the organic solvent. The solvent preferably contains (M1) propylene glycol monoalkyl ether carboxylate and (M2) at least one selected from the group consisting of propylene glycol monoalkyl ether, lactate ester, acetate ester, alkoxypropionate ester, linear ketone, cyclic ketone, lactone, and alkylene carbonate. The solvent may further contain components other than components (M1) and (M2). Details of components (M1) and (M2) are described in paragraphs

[0218] to

[0226] of WO 2020 / 004306, the contents of which are incorporated herein by reference. The content of the solvent in the resist composition is preferably set so that the solids concentration is 0.5 to 30 mass %, and more preferably 1 to 20 mass %. When the solvent further contains components other than components (M1) and (M2), the content of the components other than components (M1) and (M2) is preferably 5 to 30 mass % based on the total amount of the solvent.

[0046] The resist composition may contain components other than the specific resin and the solvent. Examples of the other components include a photoacid generator, an acid diffusion controller, a compound A that interacts with a functional group derived from the specific resin (described later), a compound B that generates compound A under the action of heat or acid, a compound C having a structure that reduces carboxy groups (described later), and a surfactant. Details of each component will be described later.

[0047] [Preferred Embodiments] The present resist composition is not particularly limited as long as it contains a specific resin and a solvent and is a composition that can be used for pattern formation that includes the above-mentioned dry development. However, for example, the following embodiments are preferred depending on the target pattern and the mechanism of action of dry development.

[0048] <Resist Composition for Positive Pattern Formation> Aspect XA: A resist composition comprising a specific resin whose main chain decomposes upon exposure to reduce its molecular weight, and which forms a positive pattern by dry development. Aspect XB: A resist composition comprising a specific resin that generates functional groups under the action of acid, and which increases the vaporizability or sublimability of the specific resin in exposed areas by reaction with a compound that reacts with the functional groups, thereby forming a positive pattern by dry development. Aspect XC: A resist composition comprising a specific resin that generates carboxy groups under the action of acid, and which increases the vaporizability or sublimability of the specific resin in exposed areas by reduction of the carboxy groups under the action of a compound having a structure that reduces the carboxy groups, thereby forming a positive pattern by dry development. Aspect XD: A resist composition that can be applied to an underlayer from which exposed areas are removed by dry development, and which can form a positive pattern.

[0049] <Resist composition for forming a negative pattern> Aspect YB: A resist composition comprising a specific resin that generates a functional group under the action of an acid, wherein the vaporizability or sublimability of the specific resin in exposed areas is reduced by reaction with a compound that reacts with the functional group, thereby forming a negative pattern by dry development. Aspect YD: A resist composition that can be applied to an underlayer from which exposed areas are removed by dry development, thereby forming a negative pattern. Aspect YE: A resist composition that can form a negative pattern by dissolving unexposed areas with a treatment liquid, replacing the treatment liquid with a filling agent, and removing the filling agent by dry development.

[0050] Each embodiment of the resist composition will be described in detail below.

[0051] <<Aspect XA>> [Resist Composition XA] The resist composition of Aspect XA (resist composition XA) contains a specific resin (specific resin XA) whose main chain decomposes upon exposure, resulting in a decrease in molecular weight. In resist composition XA, the main chain of the specific resin in the exposed areas decomposes upon exposure, reducing the molecular weight and increasing the vaporizability or sublimability of the exposed areas, and the exposed areas are then removed by dry development to form a positive pattern. In other words, resist composition XA is a resist composition that forms a pattern by dry development. Resist composition XA is suitable for use in the pattern formation method including thermal development described above.

[0052] Components that may be contained in resist composition XA will be described in detail below.

[0053] <Specific Resin XA> Resist composition XA contains specific resin XA that has the specific unit represented by formula (1) above, and whose main chain is decomposed by exposure to reduce its molecular weight.

[0054] (Specific Unit XA1) The specific resin XA preferably contains, as a specific unit, a specific unit XA1 represented by formula (A1).

[0055]

[0056] In formula (A1), R ａ１ represents a halogen atom or a fluorinated alkyl group, with a halogen atom being preferred. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a chlorine atom being preferred in terms of providing better effects for the present invention. The number of carbon atoms in the fluorinated alkyl group is preferably 1 to 12, more preferably 1 to 6, even more preferably 1 to 3, and particularly preferably 1. The number of fluorine atoms in the fluorinated alkyl group may be one or more, but is preferably a perfluoroalkyl group in terms of providing better effects for the present invention.

[0057] In formula (A1), R ｂ１ each independently represents a hydrogen atom or an organic group, preferably a hydrogen atom. The organic group is preferably an alkyl group. The alkyl group preferably has 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 to 3 carbon atoms. The alkyl group may have a substituent. Examples of the substituent include a halogen atom, a hydroxy group, a carboxy group, an amino group, an amide group, a thiol group, and an acyloxy group.

[0058] In formula (1), A １represents an organic group. Examples of the organic group include an alkyl group, an aryl group, and an aralkyl group, with an alkyl group being preferred. The alkyl group may be linear, branched, or cyclic. The alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 10, and even more preferably 1 to 6. The aryl group may be monocyclic or polycyclic. The aryl group preferably has 6 to 20 carbon atoms, more preferably 6 to 15, and even more preferably 6 to 10. Among these, the aryl group is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. The aralkyl group is preferably a group in which one of the hydrogen atoms in the alkyl group is substituted with the aryl group. The aralkyl group preferably has 7 to 20 carbon atoms, more preferably 7 to 15. The alkyl group, aryl group, and aralkyl group may have a substituent. Examples of the substituent include a halogen atom, a hydroxy group, a carboxy group, an amino group, an amide group, a thiol group, an alkoxycarbonyl group, and an acyloxy group, and a halogen atom or a hydroxy group is preferred.

[0059] Examples of the specific unit XA1 include the repeating units described in paragraph

[0116] of WO 2021 / 153466, the disclosure of which is incorporated herein by reference.

[0060] The specific unit XA1 may be used alone or in combination of two or more. The content of the specific unit XA1 is preferably 10.0 mol% or more, more preferably 20.0 mol% or more, based on the total repeating units of the specific resin XA. The upper limit is 100.0 mol%, and preferably 80.0 mol% or less.

[0061] The specific resin XA may have a repeating unit other than the specific unit XA1. Examples of the repeating unit other than the specific unit XA1 include a repeating unit XA2 having an acid group and a repeating unit XA3 whose polarity changes upon the action of an acid. Note that the repeating unit other than the specific unit XA1 may be the specific unit.

[0062] (Repeating unit XA2 having an acid group) The acid group contained in the repeating unit XA2 is preferably a carboxy group, a phenolic hydroxy group, a fluorinated alcohol group (preferably a hexafluoroisopropanol group), a sulfonic acid group, a sulfonamide group, or an isopropanol group, and more preferably a phenolic hydroxy group. As the repeating unit XA2, a repeating unit represented by the following formula (Pa1) is preferred.

[0063]

[0064] In formula (Pa1), R ａ１ and R ａ２ R each independently represents a hydrogen atom or a substituent. ａ１ and R ａ２ The substituent represented by the formula (I) is not particularly limited, but is preferably an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group. The alkyl group may be either linear or branched. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 to 10, more preferably 1 to 5, and even more preferably 1 to 3. The number of carbon atoms in the cycloalkyl group is not particularly limited, but is preferably 3 to 20, and more preferably 5 to 15. The cycloalkyl group may be either monocyclic or polycyclic. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom or an iodine atom being preferred. The alkyl group contained in the alkoxycarbonyl group may be either linear or branched. The number of carbon atoms in the alkyl group contained in the alkoxycarbonyl group is not particularly limited, but is preferably 1 to 5, and more preferably 1 to 3. The alkyl group, cycloalkyl group, and alkoxycarbonyl group may have a substituent.

[0065] In formula (Pa1), L ａ１ represents a single bond or a divalent linking group. Examples of the divalent linking group include -COO- and -CONR ａ３ -, an alkylene group (preferably having 1 to 8 carbon atoms), or a group formed by combining two or more of these groups. ａ３ represents a hydrogen atom or an alkyl group (preferably having 1 to 8 carbon atoms).

[0066] In formula (Pa1), Ar ａ１ represents an (m+n+1)-valent aromatic ring group. The aromatic ring group may be either an aromatic hydrocarbon group or an aromatic heterocyclic group. The aromatic hydrocarbon group is preferably a group containing an aromatic hydrocarbon having 6 to 18 carbon atoms, such as benzene, naphthalene, anthracene, or naphthacene. The aromatic heterocyclic group preferably contains at least one heteroatom selected from a nitrogen atom, an oxygen atom, and a sulfur atom as a ring member atom. The aromatic heterocyclic group is preferably a group containing an aromatic heterocycle having 4 to 20 ring member atoms, such as thiophene, furan, pyridine, pyrrole, benzothiophene, benzofuran, benzopyrrole, triazine, imidazole, benzimidazole, triazole, thiadiazole, or thiazole.

[0067] Ar ａ１ And, R ａ２ or L ａ１ may be bonded to via a single bond or a linking group. Examples of the linking group include —O—, —S—, —CO—, and —CO ２ -, -SO-, -SO ２ -, alkylene groups (preferably having 1 to 5 carbon atoms), alkenylene groups (preferably having 2 to 5 carbon atoms), and groups formed by combining two or more of these. The alkylene groups and alkenylene groups may have a substituent.

[0068] In formula (Pa1), R Ｘ represents a substituent other than a hydroxy group. Ｘ Examples of the substituent represented by R include a carboxy group, a sulfo group, a cyano group, a halogen atom, a hydrocarbon group, an amino group, a nitro group, and a group formed by combining two or more of these. Ｘ Examples of the hydrocarbon group represented by R include an alkyl group (preferably having 1 to 10 carbon atoms), a cycloalkyl group (preferably having 5 to 15 carbon atoms), and an alkenyl group (preferably having 2 to 10 carbon atoms). Ｘ The hydrocarbon group represented by R may have a substituent. Ｘ The hydrocarbon group represented by is -CH ２ When it contains -, -CH２ At least one of - is -O-, -CO-, -S- and -SO ２ - may be replaced with at least one selected from the group consisting of

[0069] In formula (Pa1), n ​​represents an integer of 1 to 9, preferably an integer of 1 to 5, and more preferably an integer of 1 to 4. m represents an integer of 0 to 8, and preferably an integer of 0 to 4.

[0070] Examples of the repeating unit XA2 include the repeating units described in paragraphs

[0079] to

[0110] of WO 2022 / 024928, which are incorporated herein by reference.

[0071] The repeating unit XA2 may be used singly or in combination of two or more. When the specific resin XA contains the repeating unit XA2, the content of the repeating unit XA2 is preferably 10.0 to 80.0 mol %, more preferably 15.0 to 70.0 mol %, based on the total repeating units of the specific resin XA.

[0072] (Repeating unit XA3 having a group whose polarity changes under the action of acid) The group whose polarity changes under the action of acid contained in the repeating unit XA3 is a group whose polarity increases or decreases upon decomposition by the action of acid, and is typically a group that decomposes under the action of acid to produce a polar group. The acid-decomposable group preferably has a structure in which the polar group is protected by a group that leaves under the action of acid (leaving group). Examples of the polar group include a carboxy group, a phenolic hydroxy group, a fluorinated alcohol group, a sulfonic acid group, a phosphate group, a sulfonamide group, a sulfonylimide group, a (alkylsulfonyl) (alkylcarbonyl) methylene group, a (alkylsulfonyl) (alkylcarbonyl) imide group, a bis(alkylcarbonyl) methylene group, a bis(alkylcarbonyl) imide group, a bis(alkylsulfonyl) methylene group, a bis(alkylsulfonyl) imide group, a tris(alkylcarbonyl) methylene group, and an acidic group such as a tris(alkylsulfonyl) methylene group, and an alcoholic hydroxy group, among which a carboxy group, a phenolic hydroxy group, a fluorinated alcohol group (preferably a hexafluoroisopropanol group), or a sulfonic acid group is preferred, and a carboxy group is more preferred. That is, the repeating unit XA3 preferably has a group that generates a carboxy group under the action of an acid.

[0073] Examples of the leaving group that is eliminated by the action of an acid include a group represented by any one of formulas (Y1), (Y2), and (Y3). Formula (Y1): —C(Rx １ ) (Rx ２ ) (Rx ３ ) Formula (Y2): -C(R ３６ ) (R ３７ ) (OR ３８ ) Formula (Y3): -C(Rn)(H)(Ar)

[0074] In formula (Y1), Rx １ ~Rx ３ Rx each independently represents an alkyl group (linear or branched), a cycloalkyl group (monocyclic or polycyclic), an alkenyl group (linear or branched), an alkynyl group, a cycloalkenyl group (monocyclic or polycyclic), or an aryl group (monocyclic or polycyclic). １ ~Rx３ When all of Rx are alkyl groups (linear or branched), １ ~Rx ３ At least two of Rx are preferably methyl groups. １ ~Rx ３ each independently preferably represents a linear or branched alkyl group, and Rx １ ~Rx ３ More preferably, Rx each independently represents a linear alkyl group. １ ~Rx ３ may be bonded to form a monocyclic or polycyclic ring. １ ~Rx ３ The alkyl group of Rx is preferably an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, or a t-butyl group. １ ~Rx ３ The cycloalkyl group of Rx is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group. １ ~Rx ３ The alkenyl group of Rx is preferably a vinyl group. １ ~Rx ３ The alkynyl group of Rx is preferably an ethynyl group or a propargyl group. １ ~Rx ３ The cycloalkenyl group of Rx is preferably a structure containing a double bond in a part of a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group. １ ~Rx ３ The aryl group is preferably an aryl group having 6 to 10 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthryl group.

[0075] Rx １ ~Rx ３ The ring formed by combining the two is preferably a cycloalkane. １ ~Rx ３The cycloalkane formed by bonding the two is preferably a monocyclic cycloalkane such as a cyclopentane ring or a cyclohexane ring, or a polycyclic cycloalkyl group such as a norbornane ring, a tetracyclodecane ring, a tetracyclododecane ring, or an adamantane ring, and more preferably a monocyclic cycloalkane having 5 to 6 carbon atoms. １ ~Rx ３ In the cycloalkane formed by bonding these two, one of the methylene groups constituting the ring may be replaced with a heteroatom such as an oxygen atom, a group containing a heteroatom such as a carbonyl group, or a vinylidene group. In these cycloalkanes, one or more of the ethylene groups constituting the ring may be replaced with a vinylene group. The group represented by formula (Y1) can be, for example, Rx １ is a methyl group or an ethyl group, and Rx ２ and Rx ３ and bond to form the above-mentioned cycloalkane.

[0076] In formula (Y2), R ３６ ~R ３８ R each independently represents a hydrogen atom or a monovalent organic group. ３７ and R ３８ may be bonded to each other to form a ring. Examples of the monovalent organic group include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group, and an alkynyl group. ３６ is also preferably a hydrogen atom. The alkyl group, cycloalkyl group, aryl group, alkenyl group, and alkynyl group may contain a heteroatom such as an oxygen atom and / or a group containing a heteroatom such as a carbonyl group. For example, in the alkyl group, cycloalkyl group, aryl group, and aralkyl group, one or more methylene groups may be replaced with a heteroatom such as an oxygen atom and / or a group containing a heteroatom such as a carbonyl group. R ３８ may bond with another substituent on the main chain of the repeating unit to form a ring. ３８ The group formed by bonding together the repeating unit and another substituent carried by the main chain of the repeating unit is preferably an alkylene group such as a methylene group.

[0077] In formula (Y3), Ar represents an aromatic ring group. Rn represents an alkyl group, a cycloalkyl group, or an aryl group. Rn and Ar may be bonded to each other to form a non-aromatic ring. Ar is preferably an aryl group.

[0078] From the viewpoint of excellent acid decomposability, when a non-aromatic ring is directly bonded to the polar group (or a residue thereof) in a leaving group protecting a polar group, it is also preferable that a ring atom in the non-aromatic ring adjacent to the ring atom directly bonded to the polar group (or a residue thereof) does not have a halogen atom such as a fluorine atom as a substituent.

[0079] The group that is eliminated by the action of an acid may also be a 2-cyclopentenyl group having a substituent (such as an alkyl group), such as a 3-methyl-2-cyclopentenyl group, or a cyclohexyl group having a substituent (such as an alkyl group), such as a 1,1,4,4-tetramethylcyclohexyl group.

[0080] The repeating unit XA3 is also preferably a repeating unit represented by formula (A).

[0081]

[0082] In formula (A), L １ represents a divalent linking group which may have a fluorine atom or an iodine atom, R １ represents a hydrogen atom, a fluorine atom, an iodine atom, an alkyl group which may have a fluorine atom or an iodine atom, or an aryl group which may have a fluorine atom or an iodine atom; R ２ represents a leaving group which is eliminated by the action of an acid and which may have a fluorine atom or an iodine atom. １ , R １ and R ２ At least one of L has a fluorine atom or an iodine atom. １ Examples of the divalent linking group which may have a fluorine atom or an iodine atom and is represented by the formula: ２-, hydrocarbon groups which may have a fluorine atom or an iodine atom (for example, alkylene groups, cycloalkylene groups, alkenylene groups, arylene groups, etc.), and linking groups in which a plurality of these groups are linked together. １ As the alkylene group, -CO-, an arylene group, or -arylene group-alkylene group having a fluorine atom or an iodine atom- is preferred, and -CO- or -arylene group-alkylene group having a fluorine atom or an iodine atom- is more preferred. As the arylene group, a phenylene group is preferred. The alkylene group may be linear or branched. The number of carbon atoms in the alkylene group is not particularly limited, but is preferably 1 to 10, and more preferably 1 to 3. The total number of fluorine atoms and iodine atoms contained in the alkylene group having a fluorine atom or an iodine atom is not particularly limited, but is preferably 2 or more, more preferably 2 to 10, and even more preferably 3 to 6.

[0083] In formula (A), R １ The alkyl group represented by R may be linear or branched. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 to 10, and more preferably 1 to 3. １ The total number of fluorine atoms and iodine atoms contained in the alkyl group having a fluorine atom or an iodine atom, represented by the formula (I), is not particularly limited, but is preferably 1 or more, more preferably 1 to 5, and even more preferably 1 to 3. １ The alkyl group represented by the formula (I) may contain a heteroatom other than a halogen atom, such as an oxygen atom.

[0084] In formula (A), R ２ Examples of the leaving group represented by the formula (Y1), (Y2), or (Y3) above, which may have a fluorine atom or an iodine atom, include leaving groups represented by the formula (Y1), (Y2), or (Y3) above, which have a fluorine atom or an iodine atom.

[0085] The repeating unit XA3 is also preferably a repeating unit represented by formula (AI).

[0086]

[0087] In formula (AI), Xa １represents a hydrogen atom or an alkyl group which may have a substituent. T represents a single bond or a divalent linking group. Rx １ ~Rx ３ Rx each independently represents an alkyl group (linear or branched), a cycloalkyl group (monocyclic or polycyclic), an alkenyl group (linear or branched), an alkynyl group, a cycloalkenyl group (monocyclic or polycyclic), or an aryl group (monocyclic or polycyclic). １ ~Rx ３ When all of Rx are alkyl groups (linear or branched), １ ~Rx ３ Preferably, at least two of Rx are methyl groups. １ ~Rx ３ may be bonded to form a monocyclic or polycyclic ring (such as a monocyclic or polycyclic cycloalkyl group).

[0088] In formula (AI), Xa １ Examples of the alkyl group represented by the formula (I) which may have a substituent include a methyl group or a —CH ２ -R １１ Examples of the group include a group represented by R １１ represents a halogen atom (such as a fluorine atom), a hydroxy group, or a monovalent organic group. １１ Examples of the monovalent organic group represented by the formula (I) include an alkyl group having 5 or less carbon atoms which may be substituted with a halogen atom, an acyl group having 5 or less carbon atoms which may be substituted with a halogen atom, and an alkoxy group having 5 or less carbon atoms which may be substituted with a halogen atom, and an alkyl group having 3 or less carbon atoms is preferred, and a methyl group is more preferred. １ is preferably a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.

[0089] In formula (AI), examples of the divalent linking group represented by T include an alkylene group, an aromatic ring group, a -COO-Rt- group, and a -O-Rt- group. In the formula, Rt represents an alkylene group or a cycloalkylene group. T is preferably a single bond or a -COO-Rt- group. When T represents a -COO-Rt- group, Rt is preferably an alkylene group having 1 to 5 carbon atoms, and is preferably a -CH ２ -, -(CH２ ) ２ - or -(CH ２ ) ３ - is more preferable.

[0090] In formula (AI), Rx １ ~Rx ３ A preferred embodiment of the formula (Y1) is Rx １ ~Rx ３ is the same as

[0091] When each of the above groups has a substituent, examples of the substituent include an alkyl group (having 1 to 4 carbon atoms), a halogen atom, a hydroxy group, an alkoxy group (having 1 to 4 carbon atoms), a carboxy group, and an alkoxycarbonyl group (having 2 to 6 carbon atoms). The number of carbon atoms of the substituent is preferably 8 or less.

[0092] The repeating unit represented by formula (AI) may be an acid-decomposable (meth)acrylic acid tertiary alkyl ester repeating unit (Xa １ represents a hydrogen atom or a methyl group, and T represents a single bond. Examples of the repeating unit XA3 include the repeating units described in paragraphs

[0029] to

[0071] of WO 2022 / 024928, the contents of which are incorporated herein by reference.

[0093] The repeating unit XA3 may be used singly or in combination of two or more. When the specific resin XA contains the repeating unit XA3, the content of the repeating unit XA3 is preferably 1.0 to 70.0 mol %, more preferably 5.0 to 60.0 mol %, based on the total repeating units of the specific resin XA.

[0094] The specific resin XA may have a repeating unit other than those described above. The other repeating unit is not particularly limited, and may, for example, have a repeating unit that may be contained in a specific resin contained in another embodiment of the resist composition described below. In addition, for example, the descriptions of paragraphs

[0141] to

[0143] and

[0169] to

[0170] of WO 2022 / 024928 can also be referenced, and the above descriptions are incorporated herein by reference.

[0095] The specific resin XA may be used alone or in combination of two or more. The content of the specific resin XA is preferably 30.0 to 100.0 mass %, more preferably 40.0 to 100.0 mass %, and even more preferably 60.0 to 90.0 mass %, based on the total solid content of the resist composition XA.

[0096] <Solvent> Resist composition XA contains a solvent. Preferred embodiments of the solvent contained in resist composition XA are as described above.

[0097] <Photoacid Generator> Resist composition XA preferably further contains a photoacid generator. The photoacid generator is not particularly limited as long as it is a compound that generates an acid upon irradiation with actinic rays or radiation (hereinafter also simply referred to as "exposure"). The photoacid generator preferably generates an acid with a pKa of less than 0 upon exposure. The pKa of the acid generated from the photoacid generator upon exposure is preferably -0.1 or less, more preferably -0.5 or less. The pKa of the acid generated from the photoacid generator upon exposure is preferably -5.0 or more, more preferably -4.5 or more. The photoacid generator may be in the form of a low molecular weight compound or may be incorporated into a part of the resin, with a low molecular weight compound being preferred. When the photoacid generator is in the form of a low molecular weight compound, the molecular weight of the photoacid generator is not particularly limited, but is preferably 500 to 3,000, more preferably 600 to 2,500, and even more preferably 700 to 2,000. When the photoacid generator is incorporated into a part of a resin, it may be incorporated into a part of the specific resin XA, or may be incorporated into a resin different from the specific resin XA.

[0098] Examples of the photoacid generator include "M ＋ X － ", and it is preferably a compound that generates an organic acid upon exposure. Examples of the organic acid include sulfonic acids (aliphatic sulfonic acids, aromatic sulfonic acids, camphorsulfonic acids, etc.), carboxylic acids (aliphatic carboxylic acids, aromatic carboxylic acids, aralkyl carboxylic acids, etc.), carbonylsulfonylimido acids, bis(alkylsulfonyl)imido acids, and tris(alkylsulfonyl)methido acids.

[0099] "M ＋ X － In the compound represented by the formula ", M ＋ represents a cation, preferably an organic cation. The cation may have a valence of monovalent or divalent or higher. The cation is preferably a sulfonium cation represented by formula (ZaI) (hereinafter also referred to as "cation (ZaI)") or an iodonium cation represented by formula (ZaII) (hereinafter also referred to as "cation (ZaII)").

[0100]

[0101] In the above formula (ZaI), R ２０１ , R ２０２ , and R ２０３ R each independently represents an organic group. ２０１ , R ２０２ , and R ２０３The number of carbon atoms in the organic group is preferably 1 to 30, more preferably 1 to 20. Examples of the organic group include an aryl group, an alkyl group, and a cycloalkyl group. The aryl group is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. The aryl group may also be an aryl group having a heterocycle containing an oxygen atom, a nitrogen atom, or a sulfur atom. Examples of the skeleton of an aryl group having a heterocycle include pyrrole, furan, thiophene, indole, benzofuran, and benzothiophene. The alkyl group and cycloalkyl group are preferably an alkyl group having 1 to 15 carbon atoms or a cycloalkyl group having 3 to 15 carbon atoms, and more preferably an alkyl group having 1 to 5 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms. The aryl group, alkyl group, cycloalkyl group, and aralkyl group may have a substituent. Preferred examples of the substituent include alkyl groups (e.g., having 1 to 15 carbon atoms), cycloalkyl groups (e.g., having 3 to 15 carbon atoms), aryl groups (e.g., having 6 to 14 carbon atoms), alkoxy groups (e.g., having 1 to 15 carbon atoms), cycloalkylalkoxy groups (e.g., having 1 to 15 carbon atoms), halogen atoms (e.g., fluorine and iodine), hydroxy groups, carboxy groups, ester groups, sulfinyl groups, sulfonyl groups, alkylthio groups, phenylthio groups, and alkyloxycarbonylalkyleneoxy groups. The above substituents may further have a substituent if possible, and it is also preferred that the alkyl group has a halogen atom as a substituent to form a halogenated alkyl group such as a trifluoromethyl group. It is also preferred that the above substituents form an acid-decomposable group in any combination. The acid-decomposable group is a group that decomposes under the action of acid to increase its polarity, and preferably has a structure in which a polar group is protected by a group that is eliminated under the action of acid.

[0102] R ２０１ ~R ２０３ Two of these may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester group, an amide group, or a carbonyl group. ２０１ ~R ２０３Examples of groups formed by combining two of these include alkylene groups (e.g., butylene and pentylene groups) and —CH ２ -CH ２ -O-CH ２ -CH ２ When the resist composition of the present invention is used as an EUV resist, R ２０１ ~R ２０５ preferably contains a fluorine atom or an iodine atom as a substituent.

[0103] A preferred embodiment of the cation represented by formula (ZaI) is R ２０１ ~R ２０３ An arylsulfonium cation in which at least one of R is an aryl group is preferred. ２０１ ~R ２０３ may all be aryl groups, and R ２０１ ~R ２０３ A part of R may be an aryl group, and the rest may be an organic group other than an aryl group (for example, an alkyl group or a cycloalkyl group), ２０１ ~R ２０３ one of which is an aryl group, and R ２０１ ~R ２０３ Two of the groups may be bonded to form a ring structure. Examples of the arylsulfonium cation include triarylsulfonium cations, diarylalkylsulfonium cations, diarylcycloalkylsulfonium cations, aryldialkylsulfonium cations, and aryldicycloalkylsulfonium cations.

[0104] In formula (ZaII), R ２０４ and R ２０５ R each independently represents an aryl group, an alkyl group, or a cycloalkyl group. ２０４ and R ２０５The aryl group in R is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. Alternatively, it may be an aryl group having a heterocycle containing an oxygen atom, a nitrogen atom, a sulfur atom, or the like. Examples of the skeleton of the aryl group having a heterocycle include pyrrole, furan, thiophene, indole, benzofuran, and benzothiophene. ２０４ and R ２０５ The alkyl group and cycloalkyl group are preferably a linear alkyl group having 1 to 10 carbon atoms, a branched alkyl group having 3 to 10 carbon atoms (e.g., methyl, ethyl, propyl, butyl, or pentyl), or a cycloalkyl group having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, or norbornyl).

[0105] R ２０４ and R ２０５ The aryl group, alkyl group, and cycloalkyl group in R may each independently have a substituent. ２０４ and R ２０５ Examples of the substituent that the aryl group, alkyl group, and cycloalkyl group may have include an alkyl group (e.g., having 1 to 15 carbon atoms), a cycloalkyl group (e.g., having 3 to 15 carbon atoms), an aryl group (e.g., having 6 to 15 carbon atoms), an alkoxy group (e.g., having 1 to 15 carbon atoms), a halogen atom, a hydroxy group, and a phenylthio group.

[0106] Specific examples of the cation are shown below, but the present invention is not limited to these.

[0107]

[0108]

[0109] "M ＋ X － In the compound represented by the formula "X －represents an anion, preferably an organic anion. The valence of the anion may be monovalent or divalent or more. The anion is preferably an anion having a significantly low ability to cause a nucleophilic reaction, more preferably a non-nucleophilic anion. Examples of non-nucleophilic anions include sulfonate anions (aliphatic sulfonate anions, aromatic sulfonate anions, camphorsulfonate anions, etc.), carboxylate anions (aliphatic carboxylate anions, aromatic carboxylate anions, aralkyl carboxylate anions, etc.), sulfonylimide anions, bis(alkylsulfonyl)imide anions, and tris(alkylsulfonyl)methide anions.

[0110] Preferred non-nucleophilic anions include aliphatic sulfonate anions in which at least the α-position of the sulfonic acid is substituted with a fluorine atom, aromatic sulfonate anions substituted with a fluorine atom or a group having a fluorine atom, bis(alkylsulfonyl)imide anions in which an alkyl group is substituted with a fluorine atom, and tris(alkylsulfonyl)methide anions in which an alkyl group is substituted with a fluorine atom. Among these, perfluoroaliphatic sulfonate anions (preferably having 4 to 8 carbon atoms) and benzenesulfonate anions having a fluorine atom are more preferred, and nonafluorobutanesulfonate anion, perfluorooctanesulfonate anion, pentafluorobenzenesulfonate anion, and 3,5-bis(trifluoromethyl)benzenesulfonate anion are even more preferred.

[0111] Specific examples of the anion are shown below, but the present invention is not limited to these.

[0112]

[0113]

[0114] For details of the photoacid generator, please refer to the contents described in paragraphs

[0164] to

[0215] and paragraphs

[0188] to

[0235] of WO 2019 / 188455, the contents of which are incorporated herein by reference. Furthermore, as the photoacid generator, for example, the photoacid generators described in paragraphs

[0144] to

[0173] of JP 2019-045864 A and the onium salt compounds described in paragraphs

[0231] to

[0239] of WO 2019 / 188455 A can be suitably used.

[0115] The content of the photoacid generator is preferably 0.5 to 50.0 mass %, more preferably 1.0 to 45.0 mass %, and even more preferably 5.0 to 40.0 mass %, based on the total solid content of the resist composition XA.

[0116] <Acid Diffusion Controller> Resist composition XA may further contain an acid diffusion controller. The acid diffusion controller is a compound different from the specific resin and the photoacid generator. The acid diffusion controller can trap excess acid generated from the photoacid generator upon irradiation (exposure) with actinic rays or radiation, and act as a quencher that suppresses reaction in unexposed areas due to the excess acid.

[0117] The type of acid diffusion controller is not particularly limited, and examples thereof include compounds selected from basic compounds (CA), low molecular weight compounds (CB) having a nitrogen atom and a group that is cleaved by the action of an acid, and compounds (CC) whose acid diffusion control ability is reduced or eliminated by irradiation with actinic rays or radiation.

[0118] Specific examples of the basic compound (CA) include the compounds described in paragraphs

[0132] to

[0136] of WO 2020 / 066824, the disclosure of which is incorporated herein by reference. Specific examples of the low molecular weight compound (CB) having a nitrogen atom and a group that is cleaved by the action of an acid include the compounds described in paragraphs

[0156] to

[0163] of WO 2020 / 066824, the disclosure of which is incorporated herein by reference.

[0119] Specific examples of the compound (CC) include onium salt compounds (CD) of acids that are weaker acids than the compound (N) and the photoacid generator, and basic compounds (CE) whose basicity is reduced or eliminated by irradiation with actinic rays or radiation. The compound (CD) is preferably an onium salt compound composed of an anion and a cation. The compound (CD) may be a compound that generates an acid upon exposure. Furthermore, the compound (CD) is preferably a compound that generates an acid whose pKa is 1.00 or more higher than that of the acid generated by the photoacid generator. The difference between the pKa of the acid generated by the compound (CD) and the pKa of the acid generated by the photoacid generator (the value obtained by subtracting the pKa of the acid generated by the photoacid generator from the pKa of the acid generated by the compound (CD)) is preferably 1.00 or more, more preferably 1.00 to 10.00, even more preferably 1.00 to 5.00, and particularly preferably 1.00 to 3.00. Compound (CD) is also preferably a compound that generates an acid having a pKa of 0 or more. In particular, the pKa of the acid generated from compound (CD) is, for example, preferably 0.50 to 10.00, more preferably 0.80 to 5.00, and even more preferably 1.00 to 5.00.

[0120] Specific examples of the basic compound (CE) whose basicity is reduced or eliminated by irradiation with actinic rays or radiation include those described in paragraphs

[0137] to

[0155] of WO 2020 / 066824 and those described in paragraph

[0164] of WO 2020 / 066824. Specific examples of the onium salt compound (CD) that is a weaker acid relative to the photoacid generator include those described in paragraphs

[0305] to

[0314] of WO 2020 / 158337, the descriptions of which are incorporated herein by reference.

[0121] In addition to the above-mentioned compounds, known compounds disclosed in, for example, U.S. Patent Application Publication No. 2016 / 0070167A1, paragraphs

[0627] to

[0664] , U.S. Patent Application Publication No. 2015 / 0004544A1, paragraphs

[0095] to

[0187] , U.S. Patent Application Publication No. 2016 / 0237190A1, paragraphs

[0403] to

[0423] , and U.S. Patent Application Publication No. 2016 / 0274458A1, paragraphs

[0259] to

[0328] , can also be suitably used as the acid diffusion controller, and the descriptions above are incorporated herein by reference.

[0122] Specific examples of the acid diffusion controller are shown below, but the present invention is not limited to these.

[0123]

[0124]

[0125] The molecular weight of the acid diffusion controller is not particularly limited, but is preferably from 100 to 3,000, more preferably from 150 to 2,500, and even more preferably from 200 to 2,000.

[0126] The acid diffusion controller may be used alone or in combination of two or more. The content of the acid diffusion controller is not particularly limited, but is preferably 0.1 to 30.0 mass %, more preferably 0.5 to 20.0 mass %, and even more preferably 1.0 to 10.0 mass %, relative to the total solids content of resist composition XA.

[0127] <Other Additives> Resist composition XA may contain other additives in addition to those described above. Examples of other additives include surfactants. The surfactant is preferably a fluorine-based and / or silicon-based surfactant. Examples of fluorine-based and / or silicon-based surfactants include the surfactants disclosed in paragraphs

[0218] and

[0219] of WO 2018 / 193954.

[0128] The surfactant may be used alone or in combination of two or more. The content of the surfactant is preferably from 0.0001 to 2.0 mass %, more preferably from 0.0005 to 1.0 mass %, and even more preferably from 0.1 to 1.0 mass %, relative to the total solid content of the resist composition XA.

[0129] Resist composition XA may further contain, as other additives, at least one selected from the group consisting of a dissolution inhibiting compound, a dye, a plasticizer, a photosensitizer, a light absorber, and a compound that promotes solubility in a developer (for example, a phenolic compound having a molecular weight of 1000 or less, or an alicyclic or aliphatic compound containing a carboxy group). The "dissolution inhibiting compound" is a compound having a molecular weight of 3000 or less that decomposes under the action of an acid and thereby reduces its solubility in an organic solvent-based developer.

[0130] The content of the other additives is not particularly limited, but may be 20.0 mass % or less, 10.0 mass % or less, or 5.0 mass % or less, relative to the total solid content of the resist composition XA.

[0131] [Pattern Forming Method] Examples of pattern forming methods to which the resist composition XA can be applied include a method including a step XA1 of forming a resist film XA using the resist composition XA, a step XA2 of patternwise exposing the resist film XA, and a step XA3 of dry-developing the patternwise exposed resist film XA to form a pattern.

[0132] (Step XA1) In step XA1, a known method can be used to form a resist film XA using the resist composition XA, such as coating the resist composition XA on a substrate. If necessary, the resist composition XA is preferably filtered through a filter before coating. The pore size of the filter is preferably 0.1 μm or less, more preferably 0.03 μm or less, even more preferably 0.01 μm or less, and particularly preferably 0.005 μm or less. The lower limit of the pore size of the filter is not particularly limited, but may be 0.001 μm or more. The material of the filter is not particularly limited, but when it is a polymer, it preferably includes polyolefins (including high density and ultra-high molecular weight) such as polyethylene (PE) and polypropylene (PP); polyamides such as nylon 6 and nylon 66; polyimides (PI); polyamideimides; polyesters such as polyethylene terephthalate; polyethersulfone; cellulose; polyfluorocarbons such as polytetrafluoroethylene (PTFE) and perfluoroalkoxyalkanes; derivatives of the above polymers; and more preferably at least one selected from the group consisting of polyolefins, polyamides, polyimides, polyamideimides, polyesters, polysulfones, cellulose, polyfluorocarbons, and derivatives thereof. In addition to resins, diatomaceous earth, glass, etc. may also be used.

[0133] The filter used to filter the resist composition XA may be one filter, or two or more filters may be used in combination. When two or more filters are used, they may be the same filter or different filters. Furthermore, the resist composition XA may be circulated and repeatedly filtered using the same filter.

[0134] Resist composition XA can be applied onto a substrate (e.g., silicon, silicon coated with silicon dioxide, etc.) such as those used in the manufacture of integrated circuit elements by an appropriate application method such as a spinner or coater. Spin application using a spinner is preferred. The rotation speed during spin application using a spinner is preferably 1,000 to 3,000 rpm (rotations per minute). After application of resist composition XA, the substrate may be dried to form resist film XA. If necessary, various undercoating films (inorganic film, organic film, anti-reflective film, etc.) may be formed below resist film XA.

[0135] An example of a drying method is a method of drying by heating. Heating can be performed by means provided in at least one of a normal exposure machine and a developing machine, and may be performed using a hot plate or the like. The heating temperature is not particularly limited, but is preferably 80 to 150°C, more preferably 80 to 140°C, and even more preferably 80 to 130°C. The heating time is not particularly limited, but is preferably 30 to 1,000 seconds, more preferably 60 to 800 seconds, and even more preferably 60 to 600 seconds.

[0136] The thickness of the resist film XA is not particularly limited, but is preferably 10 to 120 nm in order to enable the formation of a finer pattern with higher precision.

[0137] (Step XA2) Step XA2 is a step of patternwise exposing the resist film XA formed in Step XA1. Examples of a method for patternwise exposure include irradiating the formed resist film XA with actinic rays or radiation through a predetermined mask. Examples of actinic rays or radiation include infrared light, visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light, X-rays, and electron beams. Examples of such radiation include far ultraviolet light with a wavelength of preferably 250 nm or less, more preferably 220 nm or less, and particularly preferably 1 to 200 nm, specifically KrF excimer laser (248 nm), ArF excimer laser (193 nm), and F ２ These include excimer laser (157 nm), EUV (13.5 nm), X-ray, and electron beam (EB).

[0138] (Step XA3) Step XA3 is a step of forming a pattern by dry development of the exposed resist film XA obtained in Step XA2. Thermal development is preferred as the dry development. By thermal development, the exposed portions of the resist film XA containing the specific resin XA whose molecular weight has been reduced by the exposure in Step XA2 are selectively vaporized or sublimated and removed, forming a positive pattern. The heating temperature for the thermal development is not particularly limited, but is preferably 80 to 160°C, more preferably 100 to 150°C, and even more preferably 120 to 150°C. The heating time for the thermal development is not particularly limited, but is preferably 10 to 1,000 seconds, more preferably 10 to 180 seconds, and even more preferably 30 to 120 seconds.

[0139] <<Aspect XB>> [Resist Composition XB] The resist composition of aspect XB (resist composition XB) contains a specific resin (specific resin XB) that generates functional groups under the action of acid. Upon exposure, functional groups are generated in the specific resin XB in the exposed areas, and the functional groups interact with a compound (hereinafter also referred to as "compound A") that interacts with the functional groups, increasing the vaporizability or sublimability of the specific resin XB. The exposed areas are then removed by dry development, forming a positive pattern. That is, resist composition XB is a resist composition that forms a pattern by dry development. Resist composition XB is suitable for use in the pattern formation methods including the above-mentioned thermal development or vapor exposure development.

[0140] Examples of the functional group generated by the action of the acid include polar groups. Examples of the polar group include carboxy groups, phenolic hydroxy groups, fluorinated alcohol groups, sulfonic acid groups, phosphoric acid groups, sulfonamide groups, sulfonylimide groups, (alkylsulfonyl) (alkylcarbonyl) methylene groups, (alkylsulfonyl) (alkylcarbonyl) imide groups, bis(alkylcarbonyl) methylene groups, bis(alkylcarbonyl) imide groups, bis(alkylsulfonyl) methylene groups, bis(alkylsulfonyl) imide groups, tris(alkylcarbonyl) methylene groups, and acidic groups such as tris(alkylsulfonyl) methylene groups, as well as alcoholic hydroxy groups. Preferred are carboxy groups, phenolic hydroxy groups, fluorinated alcohol groups (preferably hexafluoroisopropanol groups), or sulfonic acid groups, and more preferably carboxy groups. In other words, the specific resin XB preferably has a group that generates a polar group under the action of an acid, and more preferably has a group that generates a carboxy group under the action of an acid.

[0141] The compound A interacts with the functional group to increase the vaporization or sublimation of the specific resin XB. The mode of the interaction is not particularly limited, and examples thereof include the formation of a chemical bond. The compound A preferably has an interactive group that interacts with the functional group. Examples of the interactive group include an amino group and an epoxy group, and an amino group (preferably a primary amino group or a secondary amino group) is preferred.

[0142] The number of the interactive groups possessed by Compound A in Aspect XB is 1 or more, and preferably 1. That is, in Aspect XB, Compound A is preferably a monofunctional compound. Compound A in Aspect XB is preferably an amine compound or an epoxy compound, more preferably an amine compound, and even more preferably a monofunctional amine compound.

[0143] The method for supplying compound A to specific resin XB in which the functional group has been generated is not particularly limited. For example, resist composition XB may be brought into contact with vapor containing compound A, or resist composition XB may be brought into contact with a treatment liquid containing compound A, or resist composition XB may contain compound A, or resist composition XB may contain compound B that generates compound A under the action of heat or acid, or a combination of two or more of these.

[0144] Each component that may be contained in resist composition XB will be described in detail below.

[0145] <Specific Resin XB> The resist composition XB contains a specific resin XB that has a specific unit represented by the above-mentioned formula (1) and has a group that generates a functional group when acted on by an acid.

[0146] (Specific Unit XB1) The specific resin XB preferably has a specific unit XB1 having a group that generates a functional group when acted upon by an acid. The specific unit XB1 is preferably a repeating unit represented by formula (B1).

[0147]

[0148] In formula (B1), R ａ２ represents a hydrogen atom or an organic group. ａ２ The organic group represented by the formula (I) is preferably an alkyl group. The number of carbon atoms in the alkyl group is preferably 1 to 12, more preferably 1 to 6, and even more preferably 1 to 3. The alkyl group may have a substituent. Examples of the substituent include the above-mentioned substituent T, and a halogen atom, a hydroxy group, a carboxy group, an amino group, an amide group, a thiol group, an alkoxy group, or an acetoxy group is preferred. R ｂ２ R each independently represents a hydrogen atom or an organic group, and is preferably a hydrogen atom. ｂ２ The definition and preferred embodiments of R in formula (1) are as follows: ｂ２ It is the same as ２ represents a leaving group which is eliminated by the action of an acid, or —Rt—COO—Y ２ Rt represents an alkylene group or a cycloalkylene group. Y ２ represents a leaving group which is eliminated by the action of an acid.２ and Y ２ Examples of the leaving group represented by the formula (Y1), (Y2) or (Y3) described above in Aspect XA include groups represented by the formula (Y1), (Y2) or (Y3), and the preferred embodiments are the same. Rt is preferably an alkylene group having 1 to 5 carbon atoms, and -CH ２ -, -(CH ２ ) ２ - or -(CH ２ ) ３ - is more preferable.

[0149] The specific unit XB1 may be used alone or in combination of two or more. The content of the specific unit XB1 is preferably 10.0 mol% or more, more preferably 20.0 mol% or more, based on the total repeating units of the specific resin XB. The upper limit is 100.0 mol%, and preferably 80.0 mol% or less.

[0150] (Other Repeating Units) The specific resin XB may have a repeating unit other than the specific unit XB1. Examples of repeating units other than the specific unit XB1 include a repeating unit XB2 having a group that generates a functional group upon the action of an acid, which is different from the specific unit XB1, and a repeating unit XB3 having an acid group. Note that a repeating unit other than the specific unit XB1 may be the specific unit.

[0151] Examples of the repeating unit XB2 include the repeating unit represented by formula (A) described above in embodiment XA. When specific resin XB has repeating unit XB2, the content of repeating unit XB2 is preferably 1.0 to 70.0 mol %, and more preferably 5.0 to 60.0 mol %, based on the total repeating units of specific resin XB.

[0152] Examples of the repeating unit XB3 having an acid group include the repeating unit XA2 having an acid group described above. When the specific resin XB has the repeating unit XB3, the content of the repeating unit XB3 is preferably 10.0 to 80.0 mol %, and more preferably 15.0 to 70.0 mol %, based on the total repeating units of the specific resin XB.

[0153] The specific resin XB may contain a repeating unit other than those described above. The other repeating unit is not particularly limited, and may, for example, contain a repeating unit that may be contained in the specific resin in other embodiments of the present resist composition.

[0154] The specific resin XB may be used alone or in combination of two or more. The content of the specific resin XB is preferably 30.0 to 100.0 mass %, more preferably 40.0 to 100.0 mass %, and even more preferably 60.0 to 90.0 mass %, based on the total solid content of the resist composition XB.

[0155] <Solvent> Resist composition XB contains a solvent. Preferred embodiments of the solvent contained in resist composition XB are as described above.

[0156] <Photoacid Generator> Resist composition XB preferably further contains a photoacid generator. Examples of the photoacid generator that may be contained in resist composition XB include the photoacid generators that may be contained in resist composition XA described above.

[0157] The content of the photoacid generator is preferably 0.5 to 50.0 mass %, more preferably 1.0 to 45.0 mass %, and even more preferably 5.0 to 40.0 mass %, based on the total solid content of the resist composition XB.

[0158] <Compound A and Compound B> It is also preferable that resist composition XB further contains at least one of compound A and compound B. Details of compound A and compound B are as described below. The above-mentioned compound A and compound B may each be used alone, or two or more types may be used in combination. When resist composition XB contains at least one of compound A and compound B, the total content of compound A and compound B is preferably 0.1 to 30.0 mass%, more preferably 0.5 to 20.0 mass%, and even more preferably 0.5 to 10.0 mass%, relative to the total solid content of resist composition XB.

[0159] <Other Additives> Resist composition XB may contain additives other than those described above. It is also preferable that resist composition XB further contains an acid diffusion controller. Examples of acid diffusion controllers that may be contained in resist composition XB include the acid diffusion controllers that may be contained in resist composition XA described above. The acid diffusion controllers may be used alone, or two or more may be used in combination. There are no particular restrictions on the content of the acid diffusion controller, but it is preferably 0.1 to 30.0 mass %, more preferably 0.5 to 20.0 mass %, and even more preferably 1.0 to 10.0 mass %, relative to the total solids content of resist composition XB.

[0160] Examples of additives other than the acid diffusion controller include the other additives that may be contained in resist composition XA, and preferred embodiments are also the same.

[0161] [Pattern Forming Method] Examples of pattern forming methods using resist composition XB include a method comprising: a step XB1 of forming a resist film XB using resist composition XB; a step XB2 of patternwise exposing the resist film XB; and a step XB3 of dry-developing the patternwise exposed resist film XB to remove the exposed portion to form a pattern. The methods of steps XA1 and XA2 described above can be used for steps XB1 and XB2, respectively, and the preferred embodiments are also the same.

[0162] The pattern formation method of Aspect XB also preferably includes baking (post-exposure bake, PEB) after step XB2 and before step XB3. PEB promotes the reaction of the exposed area, resulting in better sensitivity and pattern shape. The heating temperature in PEB is preferably lower than the heating temperature in step XB3. The heating temperature in PEB is preferably 80 to 150°C, more preferably 80 to 140°C, and even more preferably 80 to 130°C. The heating time in PEB is not particularly limited, but is preferably 10 to 1,000 seconds, more preferably 10 to 180 seconds, and even more preferably 30 to 120 seconds. The heating can be performed using a means provided in at least one of a conventional exposure machine and a developing machine, and may be performed using a hot plate or the like.

[0163] (Step XB3) Step XB3 is a step of forming a pattern by dry development of the exposed resist film XB obtained in Step XB2. In Step XB3, the dry development is preferably thermal development or vapor exposure development. Step XB3 is more preferably any of the following steps: A thermal development step XB3-1 in which a resist film XB formed using a resist composition XB containing at least one of compound A and compound B is heated for development; A thermal development step XB3-2 including a treatment of contacting the resist film XB with a treatment liquid containing compound A and a treatment of heating and developing the resist film XB that has been contacted with the treatment liquid; A vapor exposure development step XB3-3 including a vapor exposure treatment of contacting the resist film XB with vapor containing compound A.

[0164] The heating temperature in thermal development steps XB3-1 and XB3-2 is not particularly limited, but is often 60° C. or higher, preferably 90° C. or higher, and more preferably 120° C. or higher. There is no particular upper limit, but it is often 400° C. or lower, preferably 200° C. or lower. The heating time is not particularly limited, but is preferably 10 to 1,000 seconds, more preferably 10 to 180 seconds, and even more preferably 30 to 120 seconds.

[0165] The treatment liquid in the thermal development step XB3-2 contains compound A and a solvent. The solvent is preferably one that can dissolve compound A but does not dissolve resist film XB. Examples of the solvent include water and organic solvents. Known organic solvents can be used as the organic solvent, and examples include hydrocarbon solvents, alcohol solvents, ester solvents, ether solvents, ketone solvents, and amide solvents. The solvent may also be a mixed solvent containing two or more solvents. The content of compound A in the treatment liquid is not particularly limited, but is preferably 0.01 to 20% by mass, and more preferably 0.1 to 10% by mass, relative to the total mass of the treatment liquid. The treatment liquid may contain other components in addition to compound A and the solvent, as necessary.

[0166] The method for bringing the treatment liquid into contact with the resist film is not particularly limited, and examples thereof include a method of applying the treatment liquid to the resist film, a method of spraying the treatment liquid onto the surface of the resist film, and a method of immersing the resist film in the treatment liquid for a certain period of time. After bringing the resist film XB into contact with the treatment liquid, a drying treatment or a rinsing treatment may be performed as necessary.

[0167] The vapor in the vapor exposure development step XB3-3 contains compound A. The vapor containing compound A may contain another gas other than compound A. Examples of other gases that the vapor may contain are as described above. The contact time between the resist film XB and the vapor is not particularly limited, but is preferably 10 to 1,000 seconds, more preferably 10 to 180 seconds, and even more preferably 30 to 120 seconds.

[0168] The steam exposure development step XB3-3 preferably includes a process of removing the exposed portion of the resist film XB to form a pattern, and also includes a heat treatment of heating and developing the resist film XB. As described above, the heat treatment may be carried out simultaneously with the steam exposure treatment, or may be carried out after the steam exposure treatment. In other words, the steam exposure development step XB3-3 preferably includes a steam exposure step of contacting the resist film XB with steam containing compound A, and a heating step of heating and developing the resist film XB that has been contacted with the steam, or includes a step of heating and developing the resist film XB while contacting it with steam containing compound A. The heating temperature and heating time in the steam exposure development step XB3-3 can be the same as those in the thermal development step XB3-1.

[0169] The pattern formed in step XB3 may be used as a mask to perform etching of the underlying layer. For example, the pattern formed in step XB3 may be used as a mask to process the substrate and / or the underlayer, thereby forming a pattern on the substrate and / or the underlayer.

[0170] <<Aspect XC>> [Resist Composition XC] The resist composition of Aspect XC (resist composition XC) contains a specific resin (specific resin XC) that generates carboxy groups under the action of acid. Carboxy groups are generated in the specific resin XC in the exposed areas upon exposure, and these carboxy groups are reduced by compound C having a structure that reduces carboxy groups, thereby increasing the vaporizability or sublimability of the specific resin XC in the exposed areas, and the exposed areas are removed by dry development to form a positive pattern. In other words, resist composition XC is a resist composition that forms a pattern by dry development. Resist composition XC is suitable for use in the pattern formation methods that include the above-mentioned thermal development or steam exposure development.

[0171] The mechanism by which the compound C having a structure for reducing the carboxyl group reduces the amount of the carboxyl group is not particularly limited. For example, the compound C may cause a decarboxylation reaction of the carboxyl group (in other words, the carboxyl group derived from the specific resin XC may be converted to CO ２ The compound C may undergo a transition from the ground state to an excited state upon exposure to light, and in the excited state, may accept an electron from the carboxy group to convert the carboxy group to CO ２ That is, the compound C is preferably a compound having a structure that reduces the number of carboxy groups upon exposure to light.

[0172] Examples of compound C include nitrogen-containing aromatic compounds. The nitrogen-containing aromatic compound is a compound having an aromatic ring (nitrogen-containing aromatic ring) having one or more (e.g., 1 to 4) nitrogen atoms as ring member atoms. The nitrogen-containing aromatic ring may be either monocyclic or polycyclic, with polycyclic being preferred. When the nitrogen-containing aromatic ring is an aromatic ring formed by condensing multiple (e.g., 2 to 6) aromatic ring structures, it is sufficient that at least one of the multiple aromatic ring structures contains a nitrogen atom as a ring member atom. Furthermore, the nitrogen-containing aromatic ring may have a heteroatom other than a nitrogen atom (e.g., an oxygen atom and a sulfur atom) as a ring member atom. Furthermore, the nitrogen-containing aromatic compound may further have a substituent.

[0173] Examples of the nitrogen-containing aromatic compound include quinoline compounds (quinoline and quinoline derivatives), isoquinoline compounds (isoquinoline and isoquinoline derivatives), quinoxaline compounds (quinoxaline and quinoxaline derivatives), acridine compounds (acridine and acridine derivatives), phenanthroline compounds (phenanthroline and phenanthroline derivatives), and phenazine compounds (phenazine and phenazine derivatives), which have a higher molar absorption coefficient at 365 nm and excellent photosensitivity at 365 nm. Quinoline compounds, isoquinoline compounds, and quinoxaline compounds are preferred, and quinoline compounds are more preferred. The substituent that the nitrogen-containing aromatic compound may have is not particularly limited, and examples thereof include an alkyl group, an aryl group, a halogen atom, an acyl group, an alkoxycarbonyl group, an arylcarbonyl group, a carbamoyl group, a cyano group, and a nitro group.

[0174] Specific examples of the nitrogen-containing compound include quinoline compounds such as quinoline, 2-methylquinoline, 3-methylquinoline, 4-methylquinoline, 6-methylquinoline, 7-methylquinoline, 8-methylquinoline, 4-methoxyquinoline, 6-methoxyquinoline, 8-methoxyquinoline, 2,4-dimethylquinoline, 2,6-dimethylquinoline, 4-methyl-6-methoxyquinoline, 4-methyl-6,8-dimethoxyquinoline, 4-chloroquinoline, 4-phenylquinoline, and 4-(4-vinylphenyl)quinoline; quinoxaline compounds such as quinoxaline, 2-methylquinoxaline, 2,3-dimethylquinoxaline, and 5-methylquinoxaline; isoquinoline compounds such as isoquinoline and 1-methylisoquinoline; acridine compounds such as acridine and 9-methylacridine; and phenazine compounds such as phenazine.

[0175] The method for supplying compound C to specific resin XC in which a carboxy group has been generated is not particularly limited, and may involve bringing resist composition XC into contact with vapor containing compound C, bringing resist composition XC into contact with a treatment liquid containing compound C, or allowing resist composition XC to contain compound C, or a combination of these. Each component that resist composition XC may contain will be described in detail below.

[0176] <Specific Resin XC> Resist composition XC contains specific resin XC, which has the specific unit represented by the above-mentioned formula (1) and has a group that generates a carboxy group when acted on by an acid.

[0177] (Specific Unit XC1) The specific resin XC preferably has a specific unit that has a carboxyl group when acted on by an acid. The specific unit having a group that generates a carboxyl group when acted on by an acid is preferably the specific unit XC1 represented by formula (C1).

[0178]

[0179] In formula (C1), R ａ３ and R ｂ３ The definition and preferred embodiments of R in formula (B1) are respectively ａ２ and R ｂ２ It is the same as ３ represents a group that is eliminated by the action of an acid. Examples of the leaving group include groups represented by any one of formulas (Y1), (Y2), and (Y3) described above in embodiment XA, and preferred embodiments are also the same.

[0180] The specific unit XC1 may be used alone or in combination of two or more. The content of the specific unit XC1 is preferably 10.0 mol% or more, more preferably 20.0 mol% or more, based on the total repeating units of the specific resin XC. The upper limit is 100.0 mol%, and preferably 80.0 mol% or less.

[0181] (Other Repeating Units) The specific resin XC may have a repeating unit other than the specific unit XC1. Examples of the repeating unit other than the specific unit XC1 include a repeating unit XC2 that changes polarity under the action of an acid, which is different from the specific unit XC1, and a repeating unit XC3 that has an acid group. Note that the repeating unit other than the specific unit XC1 may be the specific unit.

[0182] Examples of the repeating unit XC2 include the repeating unit represented by formula (A) described above in embodiment XA. When specific resin XC contains repeating unit XC2, the content of repeating unit XC2 is preferably 1.0 to 70.0 mol %, and more preferably 5.0 to 60.0 mol %, based on the total repeating units of specific resin XC.

[0183] Examples and preferred embodiments of the repeating unit XC3 having an acid group are the same as those of the repeating unit XA2 having an acid group described above. When the specific resin XC contains the repeating unit XC3, the content of the repeating unit XC3 is preferably 10.0 to 80.0 mol %, and more preferably 15.0 to 70.0 mol %, based on the total repeating units of the specific resin XC.

[0184] Specific resin XC may contain repeating units other than those described above. The other repeating units are not particularly limited, and may, for example, contain repeating units that may be contained in specific resins in other embodiments of the present resist composition.

[0185] The specific resin XC may be used alone or in combination of two or more. The content of the specific resin XC is preferably 30.0 to 100.0 mass %, more preferably 40.0 to 100.0 mass %, and even more preferably 60.0 to 90.0 mass %, based on the total solid content of the resist composition XC.

[0186] <Solvent> Resist composition XC contains a solvent. Preferred embodiments of the solvent contained in resist composition XC are as described above.

[0187] <Photoacid Generator> Resist composition XC preferably further contains a photoacid generator. Examples of the photoacid generator that may be contained in resist composition XC include the photoacid generators that may be contained in resist composition XA described above.

[0188] The content of the photoacid generator is preferably 0.5 to 50.0 mass %, more preferably 1.0 to 45.0 mass %, and even more preferably 5.0 to 40.0 mass %, based on the total solid content of the resist composition XC.

[0189] <Compound C> Resist composition XC may further contain compound C. The definition and preferred embodiments of compound C are as described above. Compound C may be used alone, or two or more types may be used in combination. When resist composition XC contains compound C, the content of compound C is preferably 0.1 to 30.0 mass%, more preferably 0.5 to 20.0 mass%, and even more preferably 0.5 to 10.0 mass%, relative to the total solid content of resist composition XC.

[0190] <Other Additives> Resist composition XC may contain other additives in addition to those described above. It is also preferable that resist composition XC further contains an acid diffusion controller. Examples of the acid diffusion controller that may be contained in resist composition XC include the acid diffusion controllers that may be contained in resist composition XA described above.

[0191] The acid diffusion controller may be used alone or in combination of two or more. The content of the acid diffusion controller is not particularly limited, but is preferably 0.1 to 30.0 mass %, more preferably 0.5 to 20.0 mass %, and even more preferably 1.0 to 10.0 mass %, relative to the total solid content of resist composition XC.

[0192] Examples of additives other than the acid diffusion controller include the other additives that may be contained in resist composition XA, and preferred embodiments are also the same.

[0193] [Pattern Forming Method] Examples of pattern forming methods using resist composition XC include a method comprising: step XC1 of forming a resist film XC using resist composition XC; step XC2 of patternwise exposing the resist film XC; and step XC3 of dry-developing the patternwise exposed resist film XC to form a pattern. Steps XC1 and XC2 can be the same as the methods of steps XA1 and XA2 described above, respectively, and preferred embodiments are also the same.

[0194] In the pattern formation method of Aspect XC, it is also preferable to include PEB after Step XC2 and before Step XC3. PEB promotes the reaction of the exposed area, resulting in better sensitivity and pattern shape. The heating temperature in PEB is preferably lower than the heating temperature in Step XC3. The heating temperature in PEB is preferably 80 to 150°C, more preferably 80 to 140°C, and even more preferably 80 to 130°C. The heating time in PEB is not particularly limited, but is preferably 10 to 1,000 seconds, more preferably 10 to 180 seconds, and even more preferably 30 to 120 seconds. The heating can be performed using a means provided in at least one of a conventional exposure machine and a developing machine, and may be performed using a hot plate or the like.

[0195] (Step XC3) Step XC3 is a step of developing the exposed resist film obtained in Step XC2 by dry development to form a pattern. In Step XC3, the dry development is preferably thermal development or steam exposure development. Step XC3 preferably includes a treatment to reduce carboxy groups in the resist film XC. The treatment to reduce carboxy groups in the resist film XC may be carried out simultaneously with at least one of the treatment to remove at least a portion of the resist film to form a pattern and the steam exposure treatment. Among these, Step XC3 is more preferably any of the following steps. a thermal development step XC3-1 comprising a treatment of reducing carboxy groups in a resist film XC formed using a resist composition XC containing compound C, and a treatment of heating and developing the resist film XC; a thermal development step XC3-2 comprising a treatment of contacting the resist film XC with a treatment liquid containing compound C, a treatment of reducing carboxy groups in the resist film XC, and a treatment of heating and developing the resist film XC; and a vapor exposure development step XC3-3 comprising a vapor exposure treatment of contacting the resist film XC with vapor containing compound C, and a treatment of reducing carboxy groups in the resist film XC. In XC3-1 to XC3-3, the treatment of reducing carboxy groups in the resist film XC and the treatment of heating and developing the resist film XC may be carried out simultaneously; for example, the resist film XC may be heated while being exposed to light to form a pattern.

[0196] In step XC3, the treatment for reducing the carboxy groups in the resist film XC can be selected appropriately depending on the mechanism for reducing the carboxy groups in compound C. For example, a method of exposing the resist film XC to light with a wavelength that excites compound C can be used. The light source used for exposure can be selected appropriately as long as it irradiates light in a wavelength range that excites compound C (e.g., light in wavelength ranges of 254 nm, 313 nm, 365 nm, 405 nm, etc.). Specific examples include ultra-high pressure mercury lamps, high pressure mercury lamps, metal halide lamps, xenon lamps, and LEDs (light emitting diodes). Of these, a UV exposure treatment in which the resist film XC is exposed to UV light is preferred as the treatment for reducing the carboxy groups in the resist film XC. The exposure dose is 1 to 10 J / cm. ２ is preferred, and 2 to 10 J / cm ２ More preferably, 2 to 5 J / cm ２ The above exposure may be either a full-surface exposure or a pattern exposure.

[0197] The heating temperature in thermal development steps XC3-1 and XC3-2 is not particularly limited, but is often 60° C. or higher, preferably 90° C. or higher, and more preferably 120° C. or higher. There is no particular upper limit, but it is often 400° C. or lower, preferably 200° C. or lower. The heating time is not particularly limited, but is preferably 10 to 1,000 seconds, more preferably 10 to 180 seconds, and even more preferably 30 to 120 seconds.

[0198] The treatment liquid in the thermal development step XC3-2 contains compound C and a solvent. The solvent is preferably one that can dissolve compound C but not resist film XC. Examples of the solvent include water and organic solvents. Known organic solvents can be used, including hydrocarbon solvents, alcohol solvents, ester solvents, ether solvents, ketone solvents, and amide solvents. The solvent may also be a mixed solvent containing two or more solvents. The content of compound C in the treatment liquid is not particularly limited, but is preferably 0.01 to 20% by mass, and more preferably 0.1 to 10% by mass, based on the total mass of the treatment liquid. The method for contacting the treatment liquid with the resist film is not particularly limited, and examples include a method of applying the treatment liquid to the resist film, a method of spraying the treatment liquid on the surface of the resist film, and a method of immersing the resist film in the treatment liquid for a certain period of time. After contacting the resist film XC with the treatment liquid, a drying treatment or a rinsing treatment may be performed as needed.

[0199] The vapor in the vapor exposure development step XC3-3 contains compound C. The vapor containing compound C may contain other gases in addition to compound C. Examples of other gases that the vapor may contain are as described above. The contact time between the resist film XC and the vapor is not particularly limited, but is preferably 10 to 1,000 seconds, more preferably 10 to 180 seconds, and even more preferably 30 to 120 seconds.

[0200] The steam exposure development step XC3-3 preferably includes a process of removing the exposed portion of the resist film XC to form a pattern, and also includes a heat treatment of heating and developing the resist film XC. The steam exposure process of bringing the resist film XC into contact with steam and the process of reducing carboxy groups in the resist film XC may be performed simultaneously or separately. As described above, the process of reducing carboxy groups in the resist film XC and the heat treatment may be performed simultaneously or separately. The heating temperature and heating time in the steam exposure development step XC3-3 can be the same as those in the thermal development step XC3-1.

[0201] The pattern formed in step XC3 may be used as a mask to perform etching of the underlying layer. For example, the pattern formed in step XC3 may be used as a mask to process the substrate and / or the underlayer, thereby forming a pattern on the substrate and / or the underlayer.

[0202] <<Aspect XD>> [Resist Composition XD] The resist composition of aspect XD (resist composition XD) is a resist composition that can form a positive pattern, and is applied to an underlayer from which exposed portions are removed by dry development to form a pattern. Resist composition XD is a resist composition from which a pattern is formed by dry development or wet development. Resist composition XD can be suitably applied to the pattern formation method that includes the above-mentioned vapor exposure development.

[0203] Resist composition XD is a resist composition that contains a specific resin and that forms a positive pattern by dry development or wet development. Examples of resist compositions that form a positive pattern by dry development include the compositions exemplified as the resist compositions of Aspects XA to XC described above. The resist composition that forms a positive pattern by wet development is not particularly limited as long as it is a composition that increases its solubility in a developer upon exposure, and examples include chemically amplified resist compositions and non-chemically amplified resist compositions, with chemically amplified resist compositions being preferred. Examples of the non-chemically amplified resist composition include resist compositions that contain a specific resin whose main chain decomposes upon exposure, resulting in a decrease in molecular weight, and resist compositions that contain a specific resin that has an interactive group that interacts with ionic compounds.

[0204] The underlayer is a layer that is developed by removing a region (exposed portion) above the exposed portion where the resist film XD derived from the resist composition XD is not present by dry development. That is, a positive pattern of the underlayer is formed by dry development. The underlayer is not particularly limited as long as it is a composition layer that can be developed by dry development, and examples thereof include a layer formed from a composition for forming an underlayer, which will be described later.

[0205] Each component that may be contained in the resist composition XD will be described in detail below.

[0206] <Specific Resin XD> The resist composition XD contains a specific resin XD that includes a specific unit XD1 represented by the above-mentioned formula (1).

[0207] (Specific Unit XD1) In terms of ease of forming a fine pattern, the specific resin XD1 is preferably a resin whose polarity changes under the action of an acid, and more preferably has a specific unit having a group that is decomposed by the action of an acid to generate a polar group. As the specific unit having a group that is decomposed by the action of an acid to generate a polar group, a repeating unit represented by the above-mentioned formula (B1) is preferred.

[0208] The specific resin XD1 may be a specific resin whose main chain is decomposed by exposure to light to reduce its molecular weight, and it also preferably contains the specific unit represented by the above formula (A1).

[0209] The specific unit XD1 may be used alone or in combination of two or more. The content of the specific unit XD1 is preferably 10.0 mol% or more, more preferably 20.0 mol% or more, based on the total repeating units of the specific resin XD. The upper limit is 100.0 mol%, and preferably 80.0 mol% or less.

[0210] (Other Repeating Units) The specific resin XD may have a repeating unit other than the specific unit XD1. Examples of repeating units other than the specific unit XD1 include a repeating unit XD2 having a group that generates a functional group upon the action of an acid, which is different from the specific unit XD1, and a repeating unit XD3 having an acid group. Note that a repeating unit other than the specific unit XD1 may be the specific unit.

[0211] Examples of the repeating unit XD2 include the repeating unit represented by formula (A) described above in embodiment XA. When specific resin XD has repeating unit XD2, the content of repeating unit XD2 is preferably 1.0 to 70.0 mol %, and more preferably 5.0 to 60.0 mol %, based on the total repeating units of specific resin XD.

[0212] Examples and preferred embodiments of the repeating unit XD3 having an acid group are the same as those of the repeating unit XA2 having an acid group described above. When the specific resin XD contains the repeating unit XD3, the content of the repeating unit XD3 is preferably 10.0 to 80.0 mol %, and more preferably 15.0 to 70.0 mol %, based on the total repeating units of the specific resin XD.

[0213] The specific resin XD may contain repeating units other than those described above. The other repeating units are not particularly limited, and may, for example, contain repeating units that may be contained in the specific resins of other embodiments of the present resist composition.

[0214] The specific resin XD may be used alone or in combination of two or more. The content of the specific resin XD is preferably 30.0 to 100.0 mass %, more preferably 40.0 to 100.0 mass %, and even more preferably 60.0 to 90.0 mass %, based on the total solid content of the resist composition XD.

[0215] <Solvent> Resist composition XD contains a solvent. Preferred embodiments of the solvent contained in resist composition XD are as described above.

[0216] <Photoacid Generator> Resist composition XD preferably further contains a photoacid generator. Examples of the photoacid generator that may be contained in resist composition XD include the photoacid generators that may be contained in resist composition XA described above.

[0217] The content of the photoacid generator is preferably 0.5 to 50.0 mass %, more preferably 1.0 to 45.0 mass %, and even more preferably 5.0 to 40.0 mass %, based on the total solid content of the resist composition XD.

[0218] <Other Additives> Resist composition XD may contain other additives in addition to those described above. It is also preferable that resist composition XD further contains an acid diffusion controller. Examples of the acid diffusion controller that may be contained in resist composition XD include the acid diffusion controller that may be contained in resist composition XA described above.

[0219] The acid diffusion controller may be used alone or in combination of two or more. The content of the acid diffusion controller is not particularly limited, but is preferably 0.1 to 30.0 mass %, more preferably 0.5 to 20.0 mass %, and even more preferably 1.0 to 10.0 mass %, relative to the total solid content of the resist composition XD.

[0220] Examples of additives other than the acid diffusion controller include the other additives that may be contained in resist composition XA, and preferred embodiments are also the same.

[0221] [Underlayer-forming Composition] The underlayer-forming composition is not particularly limited as long as it is a composition that can form a patternable film by removing exposed portions by dry development. The underlayer-forming composition may be the resist composition of any of Aspects XA to XC described above, or may be a composition that does not contain a specific resin. An example of a underlayer-forming composition that does not contain a specific resin is a composition that contains an organometallic compound. An organometallic compound is a compound that has a metal atom and an organic group, and can, for example, undergo ligand exchange by contact with steam, thereby increasing vaporizability or sublimability.

[0222] [Pattern Forming Method] Examples of pattern forming methods to which the resist composition XD can be applied include a method comprising a step XD0 of forming an underlayer, a step XD1 of forming a resist film XD on the underlayer using the resist composition XD, a step XD2 of patternwise exposing the resist film XD, a step XD3 of developing the resist film XD, and a step XD4 of dry-developing the underlayer to form a pattern.

[0223] The pattern formation method of embodiment XD will be described with reference to FIG. 1 . In step XD2, as shown in FIG. 1( a), a laminate having an underlayer 430 and a resist film XD420 on a substrate 10, formed in steps XD0 and XD1, is irradiated with actinic rays or radiation through a mask 12 in predetermined areas as indicated by the arrows. Next, in step XD3, as shown in FIG. 1( b), the exposed portions of the resist film XD420 are removed to obtain a positive pattern 422 of the resist film XD on the substrate 10 and the underlayer 430. Next, in step XD4, as shown in FIG. 1( c), the underlayer 430 is dry-developed using the positive pattern 422 of the resist film XD as a mask, thereby forming a positive pattern 422 of the resist film XD and a positive pattern 432 of the underlayer on the substrate 10.

[0224] (Step XD0) The method for forming the underlayer in the above step XD0 includes a method for forming an underlayer using the above-mentioned composition for forming an underlayer. For example, the method in the above-mentioned step XA1 can be used as the method for forming the underlayer. The thickness of the underlayer is not particularly limited, but is preferably 5 to 50 nm.

[0225] The definitions and preferred embodiments of the above steps XD1 and XD2 can be used for the methods of the above steps XA1 and XA2, respectively, and the preferred embodiments are also the same.

[0226] In the pattern formation method of Aspect XD, it is also preferable to include PEB after Step XD2 and before Step XD3. PEB promotes the reaction of the exposed area, resulting in better sensitivity and pattern shape. The PEB heating temperature is preferably 80 to 150°C, more preferably 80 to 140°C, and even more preferably 80 to 130°C. The PEB heating time is not particularly limited, but is preferably 10 to 1,000 seconds, more preferably 10 to 180 seconds, and even more preferably 30 to 120 seconds. The heating can be performed using a means provided in at least one of a conventional exposure machine and a developing machine, and may be performed using a hot plate or the like.

[0227] (Step XD3) Step XD3 is a step of developing the pattern-exposed resist film XD to form a positive pattern. The developing step may be either dry development or wet development. The dry development in step XD3 may be the above-mentioned thermal development or vapor exposure development, or may be plasma development.

[0228] As a method for the wet development, for example, a method of contacting the resist film XD with a developer can be used. The developer in the wet development may be either an organic solvent developer or an alkaline developer, and a developer capable of forming a positive pattern can be appropriately selected depending on the resist composition XD. For example, when the polarity of the exposed portion of the resist composition XD increases, a positive pattern can be formed by using an alkaline developer as the developer.

[0229] The organic solvent developer is preferably a developer containing at least one organic solvent selected from the group consisting of ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents, and hydrocarbon solvents. The organic solvents may be mixed together, or may be mixed with a solvent other than the organic solvents or with water. The water content of the organic solvent developer as a whole is preferably less than 50% by mass, more preferably less than 20% by mass, and even more preferably less than 10% by mass, and it is particularly preferable that the developer contains substantially no water. The alkaline developer is preferably an aqueous alkaline solution containing an alkali. The type of alkaline aqueous solution is not particularly limited, but examples include aqueous alkaline solutions containing quaternary ammonium salts such as tetramethylammonium hydroxide, inorganic alkalis, primary amines, secondary amines, tertiary amines, alcohol amines, or cyclic amines. Among these, the alkaline developer is preferably an aqueous solution of a quaternary ammonium salt such as tetramethylammonium hydroxide (TMAH). Appropriate amounts of alcohols, surfactants, etc. may be added to the alkaline developer. The alkaline concentration of the alkaline developer is typically preferably 0.1 to 20% by mass. The pH of the alkaline developer is preferably from 10.0 to 15.0.

[0230] After step XD3, a rinsing treatment or a drying treatment may be performed as needed before step XD4. The rinsing liquid is not particularly limited as long as it does not dissolve the pattern, and a solution containing a common solvent can be used. The rinsing liquid preferably contains at least one organic solvent selected from the group consisting of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents.

[0231] (Process XD4) Process XD4 is a process for forming a pattern by dry-developing the exposed underlayer portion exposed by removing the upper resist film XD in process XD3. The dry development is preferably steam exposure development. That is, the dry development in process XD3 is preferably steam exposure development that includes a steam exposure treatment in which steam is brought into contact with the exposed underlayer portion exposed in process XD3.

[0232] When the underlayer is a layer formed using a resist composition of any one of Aspects XA to XC, the vapor can be the vapor generated when the resist composition of Aspects XA to XC is subjected to vapor exposure development. When the underlayer is a layer formed using a composition for forming an underlayer containing the above-mentioned organometallic compound, the vapor can be an organic compound having a coordinating group, hydrogen halide, boron oxychloride, ammonia, or the like. Examples of the coordinating group include a carboxy group, a carbonyl group, a thiocarboxy group, a hydroxy group, and an amino group. Examples of the organic compound having a coordinating group include carboxylic acids such as acetylacetone and acetic acid, halogenated carboxylic acids such as trifluoroacetic acid, trichloroacetic acid, monofluoroacetic acid, difluoroacetic acid, and chlorodifluoroacetic acid, acid anhydrides such as acetic anhydride and trifluoroacetic anhydride, thioacetic acid, thioglycolic acid, hexafluoroacetylacetone, alkyl halides, acyl halides such as acetyl chloride, thionyl halides, and carbonyl halides. Acetic acid or acetylacetone is preferred, and acetic acid is more preferred.

[0233] The vapor may contain two or more gases, or may contain the other gases described above. The vapor also preferably contains PGMEA. The contact time between the underlayer and the vapor is not particularly limited, but is preferably 10 to 1,000 seconds, more preferably 10 to 180 seconds, and even more preferably 30 to 120 seconds.

[0234] The vapor exposure development includes a process of removing exposed portions of the underlayer to form a pattern, and preferably includes a heat treatment of heating the underlayer for development. The heat treatment may be performed simultaneously with the vapor exposure process or after the vapor exposure process. In other words, process XD4 preferably includes a vapor exposure process of bringing the underlayer into contact with vapor and a heating process of heating the underlayer that has been contacted with the vapor for development, or includes a process of heating the underlayer while contacting it with vapor for development.

[0235] The heating temperature in the heat treatment is not particularly limited, but is often 60° C. or higher, preferably 90° C. or higher, and more preferably 120° C. or higher. There is no particular upper limit, but it is often 400° C. or lower, and preferably 200° C. or lower.

[0236] The pattern formed in step XD4 may be used as a mask to etch the underlying layer. For example, the pattern formed in step XD4 may be used as a mask to process the substrate, thereby forming a pattern on the substrate.

[0237] Aspect YB The resist composition of aspect YB (resist composition YB) contains a specific resin (specific resin YB) that generates functional groups under the action of an acid. Upon exposure, functional groups are generated in the specific resin YB in the exposed areas, and the functional groups interact with compound A, which interacts with the functional groups, reducing the vaporizability or sublimability of the specific resin YB. The unexposed areas are removed by dry development, forming a negative pattern. In other words, resist composition YB is a resist composition that forms a pattern by dry development. Resist composition YB is suitable for use in the pattern formation methods that include the above-mentioned thermal development or vapor exposure development.

[0238] The compound A interacts with the functional group to reduce the vaporization or sublimation of the specific resin YB. The mode of the interaction is not particularly limited, and examples thereof include the formation of a chemical bond and the formation of a salt structure. The compound A preferably has an interactive group that interacts with the functional group. Examples of the interactive group include an amino group and an epoxy group, and an amino group is preferred.

[0239] The number of the interactive groups possessed by compound A in aspect YB is 1 or more, preferably 2 or more. That is, compound A in aspect YB is preferably a polyfunctional compound. Compound A in aspect YB may also be a polymer compound such as polyallylamine. Examples of compound A in aspect YB include amine compounds and epoxy compounds, and polyfunctional amine compounds or polyfunctional epoxy compounds are preferred.

[0240] The method for supplying compound A to specific resin YB in which the above-mentioned functional group has been generated is not particularly limited, and may involve bringing resist composition YB into contact with vapor containing compound A, bringing resist composition YB into contact with a treatment liquid containing compound A, or the resist composition YB may contain compound A, or the resist composition YB may contain compound B that generates compound A under the action of heat or acid, or a combination of two or more of these.

[0241] The compound B is a compound that generates compound A upon the action of heat or acid. Compound B is preferably a compound that generates an amine compound upon the action of heat or acid. Examples of compound B include protected amine compounds in which the amino group is protected with a leaving group shown below.

[0242]

[0243] [Resist Composition YB] Each component that can be contained in resist composition YB will now be described in detail.

[0244] <Specific Resin YB> The resist composition YB preferably contains a specific unit having a group that generates a functional group upon the action of an acid. The definition and preferred embodiments of the specific resin YB are the same as those of the specific resin XB described above. The specific resin YB may be used alone or in combination of two or more types. The content of the specific resin YB is preferably 30.0 to 100.0 mass%, more preferably 40.0 to 100.0 mass%, and even more preferably 60.0 to 90.0 mass%, based on the total solids content of the resist composition.

[0245] <Solvent> Resist composition YB contains a solvent. Preferred embodiments of the solvent contained in resist composition YB are as described above.

[0246] <Photoacid Generator> Resist composition YB preferably further contains a photoacid generator. Examples of photoacid generators that may be contained in resist composition YB include the photoacid generators that may be contained in resist composition XA described above.

[0247] The content of the photoacid generator is preferably 0.5 to 50.0 mass %, more preferably 1.0 to 45.0 mass %, and even more preferably 5.0 to 40.0 mass %, based on the total solid content of the resist composition YB.

[0248] <Compound A and Compound B> It is also preferable that resist composition YB further contains at least one of compound A and compound B. The details of compound A and compound B are as described above. Each of compound A and compound B may be used alone, or two or more types may be used in combination. When resist composition YB contains at least one of compound A and compound B, the total content of compound A and compound B is preferably 0.1 to 30.0 mass%, more preferably 0.5 to 20.0 mass%, and even more preferably 0.5 to 10.0 mass%, relative to the total solid content of resist composition YB.

[0249] <Other Additives> Resist composition YB may contain additives other than those described above. It is also preferable that resist composition YB further contains an acid diffusion controller. Examples of acid diffusion controllers that may be contained in resist composition YB include the acid diffusion controllers that may be contained in resist composition XA described above. The acid diffusion controllers may be used alone, or two or more may be used in combination. There are no particular restrictions on the content of the acid diffusion controller, but it is preferably 0.1 to 30.0 mass %, more preferably 0.5 to 20.0 mass %, and even more preferably 1.0 to 10.0 mass %, relative to the total solids content of resist composition YB.

[0250] Examples of additives other than the acid diffusion controller include other additives that may be contained in the resist composition XA, and preferred embodiments are also the same.

[0251] [Pattern Forming Method] Examples of pattern forming methods using resist composition YB include a method comprising: a step YB1 of forming a resist film YB using resist composition YB; a step YB2 of patternwise exposing the resist film YB; and a step YB3 of dry-developing the patternwise exposed resist film YB to remove unexposed portions to form a pattern. The methods for steps YB1 and YB2 can be the same as those for steps XB1 and XB2 described above, respectively, and preferred embodiments are also the same.

[0252] In the pattern formation method of Aspect YB, it is also preferable to include PEB after Step YB2 and before Step YB3. PEB promotes the reaction of the exposed area, resulting in better sensitivity and pattern shape. The heating temperature in PEB is preferably lower than the heating temperature in Step YB3. The heating temperature in PEB is preferably 80 to 150°C, more preferably 80 to 140°C, and even more preferably 80 to 130°C. The heating time in PEB is not particularly limited, but is preferably 10 to 1,000 seconds, more preferably 10 to 180 seconds, and even more preferably 30 to 120 seconds. The heating can be performed using a means provided in at least one of a conventional exposure machine and a developing machine, and may be performed using a hot plate or the like.

[0253] (Step YB3) Step YB3 is a step of developing the exposed resist film YB obtained in step YB2 by dry development to remove unexposed areas. In step YB3, the dry development is preferably thermal development or vapor exposure development. Among these, step YB3 is more preferably any of the following steps: A thermal development step YB3-1 in which a resist film YB formed using a resist composition YB containing at least one of compound A and compound B is heated for development; A thermal development step YB3-2 including a step of contacting the resist film YB with a treatment liquid containing compound A and a step of heating and developing the resist film YB that has been contacted with the treatment liquid; A vapor exposure development step YB3-3 including a vapor exposure treatment in which the resist film YB is contacted with vapor containing compound A.

[0254] The heating temperature in the thermal development steps YB3-1 and YB3-2 is not particularly limited, but is preferably 100 to 400° C., more preferably 150 to 400° C., and even more preferably 200 to 400° C. The heating time is not particularly limited, but is preferably 10 to 1,000 seconds, more preferably 10 to 180 seconds, and even more preferably 30 to 120 seconds.

[0255] The treatment liquid in the thermal development step YB3-2 contains compound A and a solvent. The solvent is preferably one that can dissolve compound A but does not dissolve resist film YB. Examples of the solvent include water and organic solvents. Known organic solvents can be used as the organic solvent, and examples include hydrocarbon solvents, alcohol solvents, ester solvents, ether solvents, ketone solvents, and amide solvents. The solvent may also be a mixed solvent containing two or more solvents. The content of compound A is not particularly limited, but is preferably 0.01 to 20% by mass, and more preferably 0.1 to 10% by mass, relative to the total mass of the treatment liquid. The treatment liquid may contain other components in addition to compound A and the solvent, as necessary.

[0256] The method for contacting the resist film with the treatment liquid is not particularly limited, and examples thereof include a method of applying the treatment liquid to the resist film, a method of spraying the treatment liquid onto the surface of the resist film, and a method of immersing the resist film in the treatment liquid for a certain period of time. After contacting the resist film YB with the treatment liquid, a drying treatment or a rinsing treatment may be performed as necessary. The heating temperature and heating time for development in the thermal development step YB3-2 can be the same as those in the thermal development step YB3-1.

[0257] The vapor in the vapor exposure development step YB3-3 contains compound A. The vapor containing compound A may contain another gas other than compound A. Examples of other gases that the vapor may contain are as described above. The contact time between the resist film YB and the vapor is not particularly limited, but is preferably 10 to 1,000 seconds, more preferably 10 to 180 seconds, and even more preferably 30 to 120 seconds.

[0258] The steam exposure development step YB3-3 includes a step of removing unexposed areas of the resist film YB to form a pattern, and preferably includes a heat treatment in which the resist film YB is heated for development. The heat treatment may be carried out simultaneously with the steam exposure treatment, or may be carried out after the steam exposure treatment. In other words, the steam exposure development step YB3-3 preferably includes a steam exposure step of contacting the resist film YB with steam containing compound A, and a heating step of heating the resist film YB that has been contacted with the steam for development, or includes a step of heating the resist film YB while contacting it with steam containing compound A for development. The heating temperature and heating time in the steam exposure development step YB3-3 can be the same as those in the thermal development step YB3-1.

[0259] The pattern formed in step YB3 may be used as a mask to perform etching of the underlying layer. For example, the pattern formed in step YB3 may be used as a mask to process the substrate and / or the underlying layer, thereby forming a pattern on the substrate and / or the underlying layer.

[0260] <<Aspect YD>> [Resist Composition YD] The resist composition of aspect YD (resist composition YD) is a resist composition that can form a negative pattern, and is applied to an underlayer from which exposed portions are removed by dry development to form a pattern. Resist composition YD is a resist composition from which a pattern is formed by dry development or wet development. Resist composition YD can be suitably applied to the pattern formation method including the above-mentioned vapor exposure development.

[0261] Resist composition YD may be any resist composition that contains a specific resin and that forms a negative pattern by dry development or wet development, as described above. Examples of resist compositions that form a negative pattern by dry development include the compositions listed as the resist composition of aspect YB above. Resist compositions that form a negative pattern by wet development are not particularly limited as long as they are compositions whose solubility in a developer decreases upon exposure, but examples include chemically amplified resist compositions and non-chemically amplified resist compositions, with chemically amplified resist compositions being preferred. Examples of the non-chemically amplified resist compositions include specific resins that have crosslinking groups that crosslink upon exposure.

[0262] The underlayer is a layer that is developed by removing the region (exposed portion) of the unexposed portion where the resist film YD derived from the resist composition YD is not present by dry development. That is, a negative pattern of the underlayer is formed by dry development. The underlayer is not particularly limited as long as it is a composition layer that can be developed by dry development, and examples thereof include a layer formed by the underlayer-forming composition in the above-mentioned embodiment XD.

[0263] Each component that may be contained in the resist composition YD will be described in detail below.

[0264] <Specific Resin YD> The resist composition YD contains a specific resin YD that includes a specific unit YD1 represented by the above-mentioned formula (1).

[0265] (Specific Unit YD1) In terms of facilitating the formation of a fine pattern, the specific resin YD is preferably a resin whose polarity changes under the action of an acid, and more preferably has a specific unit having a group that is decomposed by the action of an acid to generate a polar group. As the specific unit having a group that is decomposed by the action of an acid to generate a polar group, a repeating unit represented by the above-mentioned formula (B1) is preferred.

[0266] The specific unit YD1 may be used alone or in combination of two or more. The content of the specific unit YD1 is preferably 10.0 mol% or more, more preferably 20.0 mol% or more, based on the total repeating units of the specific resin YD. The upper limit is 100.0 mol%, and preferably 80.0 mol% or less.

[0267] (Other Repeating Units) The specific resin YD may have a repeating unit other than the specific unit YD1. Examples of repeating units other than the specific unit YD1 include a repeating unit YD2 having a group that generates a functional group upon the action of an acid, which is different from the specific unit YD1, and a repeating unit YD3 having an acid group. Note that a repeating unit other than the specific unit YD1 may also be a specific unit. The definitions and preferred embodiments of the repeating unit YD2 and repeating unit YD3 are the same as those of the repeating unit XD2 and repeating unit XD3 described above, respectively.

[0268] The specific resin YD may contain repeating units other than those described above. The other repeating units are not particularly limited, and may, for example, contain repeating units that may be contained in the specific resins of other embodiments of the present resist composition.

[0269] The specific resin YD may be used alone or in combination of two or more. The content of the specific resin YD is preferably 30.0 to 100.0 mass %, more preferably 40.0 to 100.0 mass %, and even more preferably 60.0 to 90.0 mass %, based on the total solid content of the resist composition YD.

[0270] <Solvent> Resist composition YD contains a solvent. Preferred embodiments of the solvent contained in resist composition YD are as described above.

[0271] <Photoacid Generator> Resist composition YD preferably further contains a photoacid generator. Examples of the photoacid generator that may be contained in resist composition YD include the photoacid generators that may be contained in resist composition XA described above.

[0272] The content of the photoacid generator is preferably 0.5 to 50.0 mass %, more preferably 1.0 to 45.0 mass %, and even more preferably 5.0 to 40.0 mass %, based on the total solid content of the resist composition YD.

[0273] <Other Additives> Resist composition YD may contain other additives in addition to those described above. It is also preferable that resist composition YD further contains an acid diffusion controller. Examples of the acid diffusion controller that may be contained in resist composition YD include the acid diffusion controller that may be contained in resist composition XA described above.

[0274] Examples of additives other than the acid diffusion controller include the other additives that may be contained in resist composition XA, and preferred embodiments are also the same.

[0275] [Pattern Forming Method] Examples of pattern forming methods to which the resist composition YD can be applied include a method including a step YD0 of forming an underlayer, a step YD1 of forming a resist film YD on the underlayer using the resist composition YD, a step YD2 of pattern-exposing the resist film YD, a step XD3 of developing the resist film YD, and a step YD4 of dry-developing the underlayer to form a pattern.

[0276] The methods of the above-mentioned steps YD0, YD1, and YD2 can be the same as the methods of the above-mentioned steps XD0, XD1, and XD2, respectively, and the preferred embodiments are also the same.

[0277] (Process YD3) Process YD3 is a process of developing the pattern-exposed resist film YD to form a negative pattern. The developing process may be either dry development or wet development. The dry development in process YD3 may be the above-mentioned thermal development or vapor exposure development, or may be plasma development.

[0278] As a method for the wet development, a method of contacting the resist film XD with a developer can be used. The developer in the wet development can be either an organic solvent developer or an alkaline developer, and a developer capable of forming a negative pattern can be appropriately selected depending on the resist composition YD. For example, when the polarity of the exposed portion of the resist composition YD increases, a negative pattern can be formed by using an organic solvent developer as the developer. The organic solvent developer and alkaline developer can be the developers described above in embodiment XD.

[0279] After step YD3, at least one of a rinsing step and a heating step may be performed as needed before step YD4. Details of the rinsing step and the heating step are as described above in embodiment XD.

[0280] (Process YD4) Process YD4 is a process for forming a pattern by dry-developing the unexposed portions of the underlayer exposed by removing the upper resist film YD in process YD3. Steam exposure development is preferred as the dry development. That is, the dry development in process YD4 is preferably steam exposure development that includes a steam exposure treatment in which steam is brought into contact with the unexposed portions of the underlayer exposed in process YD3. The method of process XD4 described above can be used as the dry development method, and the preferred embodiments are the same.

[0281] The pattern formed in process YD4 may be used as a mask to etch the underlying layer. For example, the pattern formed in process YD4 may be used as a mask to process the substrate, thereby forming a pattern on the substrate.

[0282] Aspect YE [Resist Composition YE] The resist composition of aspect YE (resist composition YE) is a resist composition that can form a negative pattern by dissolving unexposed areas with a first treatment liquid, replacing the first treatment liquid with a filling agent, and removing the filling agent by dry development. Resist composition YE is suitable for use in the pattern formation method including the above-mentioned thermal development or vapor exposure development. The filling agent will be described in detail below.

[0283] Resist composition YE may be any resist composition as long as it contains a specific resin and reduces the solubility of the exposed area in the first processing liquid. Examples of resist compositions that reduce the solubility of the exposed area in the first processing liquid include chemically amplified resist compositions and non-chemically amplified resist compositions, with chemically amplified resist compositions being preferred. Examples of the non-chemically amplified resist compositions include specific resins having crosslinking groups that crosslink upon exposure. Each component that may be contained in resist composition YE is described in detail below.

[0284] <Specific Resin YE> The resist composition YE contains a specific resin YE that includes a specific unit YE1 represented by the above-mentioned formula (1).

[0285] (Specific Unit YE1) In terms of facilitating the formation of a fine pattern, the resist composition YE is preferably a resin whose polarity changes under the action of an acid, and more preferably contains a specific unit having a group that decomposes under the action of an acid to generate a polar group. As the specific unit having a group that decomposes under the action of an acid to generate a polar group, a repeating unit represented by the above-mentioned formula (B1) or a repeating unit represented by the above-mentioned formula (AI) in which T is a single bond or a -COO-Rt- group is preferred.

[0286] The specific unit YE1 may be used alone or in combination of two or more. The content of the specific unit YE1 is preferably 10.0 mol% or more, more preferably 20.0 mol% or more, based on the total repeating units of the specific resin YE. The upper limit is 100.0 mol%, and preferably 80.0 mol% or less.

[0287] (Other Repeating Units) The specific resin YE may have a repeating unit other than the specific unit YE. Examples of repeating units other than the specific unit YE1 include a repeating unit YE2 having a group that generates a functional group upon the action of an acid, which is different from the specific unit YE1, and a repeating unit YE3 having an acid group. Note that a repeating unit other than the specific unit YE1 may be the specific unit.

[0288] An example of the repeating unit YE2 is the repeating unit represented by formula (A) described above in embodiment XA. When the specific resin YE has the repeating unit YE2, the content of the repeating unit YE2 is preferably 1.0 to 70.0 mol %, and more preferably 5.0 to 60.0 mol %, based on the total repeating units of the specific resin YE.

[0289] Examples and preferred embodiments of the repeating unit YE3 having an acid group are the same as those of the repeating unit XA2 having an acid group described above. When the specific resin YE contains the repeating unit YE3, the content of the repeating unit YE3 is preferably 10.0 to 80.0 mol %, and more preferably 15.0 to 70.0 mol %, based on the total repeating units of the specific resin YE.

[0290] The specific resin YE may contain repeating units other than those described above. The other repeating units are not particularly limited, and may, for example, contain repeating units that may be contained in the specific resins of other embodiments of the present resist composition.

[0291] The specific resin YE may be used alone or in combination of two or more. The content of the specific resin YE is preferably 30.0 to 100.0 mass %, more preferably 40.0 to 100.0 mass %, and even more preferably 60.0 to 90.0 mass %, based on the total solid content of the resist composition YE.

[0292] <Solvent> Resist composition YE contains a solvent. Preferred embodiments of the solvent contained in resist composition YE are as described above.

[0293] <Photoacid Generator> It is also preferable that resist composition YE further contains a photoacid generator. Examples of the photoacid generator that may be contained in resist composition YE include the photoacid generators that may be contained in resist composition XA described above.

[0294] The content of the photoacid generator is preferably 0.5 to 50.0 mass %, more preferably 1.0 to 45.0 mass %, and even more preferably 5.0 to 40.0 mass %, based on the total solid content of resist composition YE.

[0295] <Other Additives> Resist composition XE may contain other additives in addition to those described above. It is also preferable that resist composition XE further contains an acid diffusion controller. Examples of the acid diffusion controller that may be contained in resist composition XE include the acid diffusion controller that may be contained in resist composition XA described above.

[0296] Examples of additives other than the acid diffusion controller include the other additives that may be contained in resist composition XA, and preferred embodiments are also the same.

[0297] [Filling Agent] The filling agent is not particularly limited as long as it is a composition that can be removed by dry development, but it is preferably formed using a second treatment liquid containing a material that forms the filling agent and a solvent, in order to easily replace the first treatment liquid. The second treatment liquid preferably contains, as the material that forms the filling agent, at least one compound E selected from the group consisting of, for example, an organometallic compound, a sublimable low-molecular-weight compound, a silicon-containing compound, and a depolymerizable compound.

[0298] The organometallic compound is a compound having a metal atom and an organic group. When the filling agent formed by the second treatment liquid containing the organometallic compound comes into contact with, for example, vapor having a ligand, the filling agent undergoes ligand exchange, increasing its volatility or sublimability, and can be removed by vapor exposure development. Examples of the vapor include the vapor used in the above-mentioned aspect XD.

[0299] Examples of the sublimable low molecular weight compound include sublimable polycyclic aromatic compounds such as naphthalene, anthracene, and phenanthrene, and sublimable aliphatic compounds, etc. The embedding agent formed by the second treatment liquid containing the sublimable low molecular weight compound can be removed by sublimation, for example, by thermal development.

[0300] Examples of the silicon-containing compound include hydrolyzable silane compounds, their hydrolyzates, and hydrolyzed condensates thereof. Examples of the hydrolyzable silane compound include alkoxysilanes, halogenated silanes, and aminosilanes.

[0301] The depolymerizable compound is a compound whose bonds are cleaved and whose molecular weight is reduced by the action of heat, exposure, acid, or base. The depolymerizable compound may be either a low-molecular-weight compound or a high-molecular-weight compound. The reduction in molecular weight may be due, for example, to decrosslinking or to cleavage of the main chain of the high-molecular-weight compound. Examples of the depolymerizable compound include the above-mentioned specific resin XA, polyester, polylactic acid, and polyacetal. The filling agent formed by the second treatment liquid containing the depolymerizable compound has increased vaporizability or sublimability when depolymerized to a low molecular weight, and can be removed by thermal development or steam exposure development.

[0302] The compound E may be used alone or in combination of two or more. The content of compound E is preferably 30.0 to 100.0 mass%, more preferably 50.0 to 100.0 mass%, based on the total solid content of the second treatment liquid. The content of compound E is preferably 0.01 to 20 mass%, more preferably 0.1 to 10 mass%, based on the total mass of the second treatment liquid.

[0303] The solvent contained in the second treatment liquid may be water or an organic solvent. Examples of the organic solvent include the organic solvents listed as the solvent contained in the resist composition. The above solvents may be used alone or in combination of two or more. That is, the above solvents may be mixed solvents.

[0304] The second treatment liquid may contain components other than those described above, such as the additives that may be contained in the present resist composition.

[0305] [Pattern Forming Method] As a pattern forming method to which the resist composition YE is applied, for example, a pattern forming method using the resist composition YE includes a process YE1 of forming a resist film YE, a process YE2 of patternwise exposing the resist film YE, a process YE3 of supplying a first processing liquid to the resist film YE, a process YE4 of replacing the first processing liquid with a filling agent, and a process YE5 of removing the filling agent by dry development to form a pattern.

[0306] The pattern forming method of embodiment YE will be described with reference to FIG. 2. In step XE2, as shown in FIG. 2(a), the laminate having the resist film YE 520 on the substrate 10 formed in step XD1 is irradiated with actinic rays or radiation through a mask 12 in predetermined areas, as indicated by the arrows. Next, in step XE3, as shown in FIG. 2(b), a first processing liquid 530 is supplied to dissolve the unexposed portions of the resist film YE. This results in a state in which a negative pattern 522 of the resist film YE and the first processing liquid 530 are present on the substrate 10. Next, in step XE4, as shown in FIG. 2(c), the first processing liquid 530 is replaced with a filling agent 540. This results in a laminate in which the exposed negative pattern 522 of the resist film YE and the filling agent 540 are present on the substrate 10. Next, in step YE5, as shown in FIG. 2(d), the filling agent 540 is removed by dry development, thereby forming a negative pattern 522 of the resist film YE on the substrate 10.

[0307] The above-mentioned steps XA1 and XA2 can be used as the steps YE1 and YE2, respectively, and the preferred embodiments are also the same.

[0308] (Process YE3) Process YE3 is a process of supplying a first processing liquid to the exposed resist film YE to dissolve the unexposed portions of the resist film YE1. That is, process YE3 includes a process of contacting the resist film YE with the first processing liquid. Note that no drying process is performed between process YE3 and process YE4. In other words, process YE4 is performed in a state where at least the first processing liquid is present in the unexposed portions of the resist film YE. By performing process YE4 without removing the first processing liquid from the pattern, pattern collapse is suppressed.

[0309] The first treatment liquid is not particularly limited as long as it can dissolve the unexposed areas of the resist film YE1 but not the exposed areas, and for example, the developer described above in embodiment XD can be used. The developer may be either an organic solvent-based developer or an alkaline developer, and can be selected appropriately depending on the resist composition YE. For example, when the polarity of the exposed areas of the resist composition YE increases, the unexposed areas can be selectively dissolved by using an organic solvent-based developer as the developer.

[0310] (Process YE4) Process YE4 is a process of replacing the first processing liquid with a filling agent. As described above, the filling agent is preferably filled into the unexposed areas using a second processing liquid containing a material and a solvent for forming the filling agent. In other words, process YE4 is preferably a process of supplying a second processing liquid to the resist film YE to replace the first processing liquid with the second processing liquid, and forming a filling agent using the second processing liquid. That is, process YE4 preferably includes a step of contacting the resist film YE with the second processing liquid. The method of forming the filling agent using the second processing liquid is not particularly limited, and examples include a method of forming a coating film of the second processing liquid and a method of drying the coating film.

[0311] (Step YE5) Step YE5 is a step of forming a pattern by removing the filling agent by dry development. The dry development can be appropriately selected depending on the filling agent, and heat development or vapor exposure development is preferred.

[0312] The heating temperature for the thermal development is not particularly limited, but is often 60° C. or higher, preferably 90° C. or higher, and more preferably 120° C. or higher. There is no particular upper limit, but it is often 400° C. or lower, preferably 200° C. or lower. The heating time is not particularly limited, but is preferably 10 to 1,000 seconds, more preferably 10 to 180 seconds, and even more preferably 30 to 120 seconds.

[0313] The vapor used in the vapor exposure development can be appropriately selected depending on the filling agent, and specific examples are as described above. The vapor exposure development includes a step of removing the filling agent to form a pattern, and preferably includes a heat treatment for heating and removing the resist film YE and the filling agent. The heat treatment may be performed simultaneously with the vapor exposure treatment or after the vapor exposure treatment. The heating temperature and heating time in the heat treatment can be, for example, the same conditions as those for the thermal development.

[0314] The resist composition, as well as the developer, composition, and other materials used in the pattern formation method using the resist composition, preferably do not contain impurities such as metals. The content of impurities contained in these materials is preferably 1 mass ppm (parts per million) or less, more preferably 10 mass ppb (parts per billion) or less, even more preferably 100 mass ppt (parts per trillion) or less, particularly preferably 10 mass ppt or less, and most preferably 1 mass ppt or less. The lower limit of the impurity content is not particularly limited and may be 0 mass ppt or more. Here, examples of metal impurities include Na, K, Ca, Fe, Cu, Mg, Al, Li, Cr, Ni, Sn, Ag, As, Au, Ba, Cd, Co, Pb, Ti, V, W, and Zn. When the material contains an organometallic compound, it is preferable that the content of the metal other than the organometallic compound falls within the above range.

[0315] Methods for reducing impurities such as metals contained in various materials include, for example, selecting raw materials with low metal content as raw materials for the various materials, filtering the raw materials for the various materials, and lining the inside of the apparatus with Teflon (registered trademark) to perform distillation under conditions that minimize contamination. Details of filtration using a filter are described in paragraph

[0321] of WO 2020 / 004306.

[0316] In addition to filter filtration, impurities may be removed using an adsorbent, or a combination of filter filtration and an adsorbent may be used. Known adsorbents can be used as the adsorbent, including inorganic adsorbents such as silica gel and zeolite, and organic adsorbents such as activated carbon. In order to reduce impurities such as metals contained in the various materials, it is necessary to prevent the incorporation of metal impurities during the manufacturing process. Whether metal impurities have been sufficiently removed from the manufacturing equipment can be confirmed by measuring the content of metal components contained in the cleaning solution used to clean the manufacturing equipment. The content of metal components contained in the used cleaning solution is preferably 100 ppt by mass or less, more preferably 10 ppt by mass or less, and even more preferably 1 ppt by mass or less. There is no particular lower limit, and a content of 0 ppt by mass or more is preferred.

[0317] [Applications] As described above, the present resist composition can be used in a pattern formation method that includes dry development. The application of the pattern formed by dry development using the present resist composition is not particularly limited, but it is preferably used in electronic devices. Preferred embodiments of the electronic device herein include those that are installed in electrical and electronic devices (such as home appliances, OA (Office Automation), media-related devices, optical devices, and communication devices).

[0318] The present invention will be described in more detail below with reference to the following examples. The materials, amounts used, ratios, treatment details, and treatment procedures shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the following examples.

[0319] [Components used in the present resist composition and pattern formation] [Present resist composition] The present resist composition was prepared based on the components and formulation shown in the table below. The contents of the resin (A), photoacid generator (B), acid diffusion controller (C), and additive (D) shown in the table below are the contents (units: wt %) relative to the solid content of each resist composition. The solvent contents shown in the table below are the contents (units: parts by mass) when the mass of the solid content of each resist composition is taken as 100 parts by mass. Table 2 is a continuation of Table 1. For example, the present resist composition Res-06 of Example 7 contains Pol-03 as the resin (A), PAG-02 as the photoacid generator (B), PQ-01 as the acid diffusion controller (B), X-01 as the additive (D), and a PGMEA / PGME mixed solvent as the solvent (F).

[0320]

[0321]

[0322] Details of each component contained in the resist compositions of the Examples and Comparative Examples are shown below.

[0323] <Specific Resin (A) or Comparative Resin (A)> A specific resin having the composition ratio shown in the table below is used. Each specific resin can be synthesized by a known method. In the table below, the "Content (mol %)" column of the specific resin (A) column indicates the content of each repeating unit (unit: mol %). In addition, in the table below, the "Mw" column indicates the weight average molecular weight, and the "PDI" column indicates the polydispersity (Mw / Mn). The Mw and PDI of the specific resin can be measured by GPC (carrier: tetrahydrofuran (THF)) (values ​​converted into polystyrene). The composition ratio (molar ratio) of the resin is １３ It can be measured by C-NMR (Nuclear Magnetic Resonance).

[0324] The structures of the repeating units in the specific resin are shown below: Repeating units R-1 and R-3 correspond to the specific units.

[0325]

[0326] As a comparative resin, the following resin Pol-X was used.

[0327]

[0328] <Photoacid Generator (B)>

[0329]

[0330] <Acid Diffusion Controller (C)>

[0331]

[0332] <Other additives (D)> X-01: The following compound, which corresponds to compound B

[0333]

[0334] ・X-02: Quinoline, corresponds to Compound C

[0335] <Solvent (F)> PGMEA: propylene glycol monomethyl ether acetate PGME: propylene glycol monomethyl ether

[0336] [Components used in pattern formation] Tetraethylethylenediamine Polyallylamine (Mw=500) MIBC: 4-methyl-2-pentanol Decane nBA: n-butyl acetate Compound Z: sublimable low molecular weight compound, compound of the following structure

[0337]

[0338] ・MeSn(OBu) ３ : Organometallic compounds, acetic acid

[0339] [Pattern Formation] [Examples 1 to 3] An organic film AL412 (manufactured by Brewer Science) was applied to a silicon wafer and baked at 205°C for 60 seconds to form a 5 nm thick base film. Each resist composition shown in Tables 1 and 2 was applied to the base film and baked at 90°C for 60 seconds (PB: Pre-Bake) to form a 50 nm thick resist film. The wafer on which the resist film was formed was subjected to pattern exposure using an ELIONIX EB exposure system (ELS-BODEN) to write a line and space pattern with a half pitch of 50 nm (exposed area 50 nm, exposed area: unexposed area = 1:1). The wafer was then heated at 150°C for 60 seconds using a hot plate for thermal development. This resulted in a positive line and space pattern with a half pitch of 50 nm.

[0340] Examples 4-5: An organic film AL412 (manufactured by Brewer Science) was applied to a silicon wafer and baked at 205°C for 60 seconds to form a 5-nm-thick undercoat film. Each resist composition shown in Tables 1 and 2 was applied to the undercoat film and baked at 90°C for 60 seconds (PB) to form a 50-nm-thick resist film. The wafer with the resist film thus formed was subjected to pattern exposure using an ELIONIX EB exposure system (ELS-BODEN) to write a line-and-space pattern with a half pitch of 50 nm (exposed area: 50 nm, exposed area: unexposed area = 1:1). The wafer was then heated (PEB) at 100°C for 60 seconds using a hot plate. Next, a first treatment solution shown in Table 3 was sprayed onto the resist film for 20 seconds using a spin coater. After spin drying, the resist film was heated at 400°C for 60 seconds for thermal development. As a result, a negative line and space pattern with a half pitch of 50 nm is obtained.

[0341] Example 6: An organic film AL412 (manufactured by Brewer Science) was applied to a silicon wafer and baked at 205°C for 60 seconds to form a 5 nm thick base film. A resist composition shown in Tables 1 and 2 was applied to the base film and baked at 90°C for 60 seconds (PB) to form a 50 nm thick resist film. The wafer with the resist film formed thereon was subjected to pattern exposure by EB writing to form a line and space pattern with a half pitch of 50 nm (exposed area 50 nm, exposed area: unexposed area = 1:1) using an ELIONIX EB exposure system (ELS-BODEN). The wafer was then heated at 100°C for 60 seconds (PEB). The wafer was then heated to 400°C and exposed to the gasified compound listed in Table 3 for 60 seconds, resulting in vapor exposure development. This resulted in a negative line and space pattern with a half pitch of 50 nm.

[0342] Example 7: An organic film AL412 (manufactured by Brewer Science) was applied to a silicon wafer and baked at 205°C for 60 seconds to form a 5 nm thick undercoat film. A resist composition shown in Tables 1 and 2 was applied to the undercoat film and baked at 90°C for 60 seconds (PB) to form a 50 nm thick resist film. The wafer with the resist film formed thereon was subjected to pattern exposure by EB writing to form a line and space pattern with a half pitch of 50 nm (exposed area 50 nm, exposed area: unexposed area = 1:1) using an ELIONIX EB exposure system (ELS-BODEN). The wafer was then heated at 100°C for 60 seconds (PEB) using a hot plate. The wafer was then further exposed to the gasified compound shown in Table 3 for 60 seconds, followed by heating at 400°C for 60 seconds for vapor exposure development. This resulted in a negative line and space pattern with a half pitch of 50 nm.

[0343] Example 8: An organic film AL412 (manufactured by Brewer Science) was applied to a silicon wafer and baked at 205°C for 60 seconds to form a 5 nm thick base film. A resist composition shown in Tables 1 and 2 was applied to the base film and baked at 90°C for 60 seconds (PB) to form a 50 nm thick resist film. The wafer with the resist film formed thereon was subjected to pattern exposure using an ELIONIX EB exposure system (ELS-BODEN) to write a line and space pattern with a half pitch of 50 nm (exposed area 50 nm, exposed area:unexposed area = 1:1). The wafer was then heated at 100°C for 60 seconds (PEB) using a hot plate. Next, a first treatment solution shown in Table 3 was dispensed onto the resist film for 20 seconds using a spin coater. After spin drying, the resist film was irradiated with a UV lamp for 60 seconds and then heated at 150°C for 60 seconds for thermal development. As a result, a positive line and space pattern with a half pitch of 50 nm is obtained.

[0344] Example 9: An organic film AL412 (manufactured by Brewer Science) was applied to a silicon wafer and baked at 205°C for 60 seconds to form a 5 nm thick undercoat film. The resist compositions shown in Tables 1 and 2 were applied to the undercoat film and baked at 90°C for 60 seconds (PB) to form a 50 nm thick resist film. The wafer with the resist film formed thereon was subjected to pattern exposure using an ELIONIX EB exposure system (ELS-BODEN) to write a line and space pattern with a half pitch of 50 nm (exposed area 50 nm, exposed area: unexposed area = 1:1). The wafer was then heated at 100°C for 60 seconds (PEB) using a hot plate. The wafer was then exposed to the gasified compound listed in Table 3 for 60 seconds, irradiated with a UV lamp for 60 seconds, and then heated at 150°C for 60 seconds for thermal development. This resulted in a positive-tone line and space pattern with a half pitch of 50 nm.

[0345] Example 10: An organic film AL412 (manufactured by Brewer Science) was applied to a silicon wafer and baked at 205°C for 60 seconds to form a 5 nm thick undercoat film. The resist compositions shown in Tables 1 and 2 were applied to the undercoat film and baked at 90°C for 60 seconds (PB) to form a 50 nm thick resist film. The wafer with the resist film formed thereon was subjected to pattern exposure by EB writing to form a line and space pattern with a half pitch of 50 nm (exposed area 50 nm, exposed area: unexposed area = 1:1) using an ELIONIX EB exposure system (ELS-BODEN). The wafer was then heated at 100°C for 60 seconds (PEB) using a hot plate. The wafer was then irradiated with a UV lamp for 60 seconds and heated at 150°C for 60 seconds for thermal development. This resulted in a positive-tone line and space pattern with a half pitch of 50 nm.

[0346] Example 11: An organic film AL412 (manufactured by Brewer Science) was applied to a silicon wafer and baked at 205°C for 60 seconds to form a 5-nm-thick undercoat film. A resist composition shown in Tables 1 and 2 was applied to the undercoat film and baked at 90°C for 60 seconds (PB) to form a 50-nm-thick resist film. The wafer with the resist film formed thereon was subjected to pattern exposure using an ELIONIX EB exposure system (ELS-BODEN) to write a line-and-space pattern with a half pitch of 50 nm (exposed area: 50 nm, exposed area: unexposed area = 1:1). The wafer was then heated (PEB) at 100°C for 60 seconds using a hot plate. Next, a first treatment liquid shown in Table 3 was dispensed for 20 seconds using a spin coater. Before the first treatment liquid dried, the second treatment liquid shown in Table 3 was supplied and replaced, followed by spin drying. This replaces a portion of the resist film with a film formed by the second processing liquid. Thereafter, the resist film is heated at 150° C. for 60 seconds for thermal development, thereby obtaining a negative line-and-space pattern with a half pitch of 50 nm.

[0347] Example 12: An organic film AL412 (manufactured by Brewer Science) was applied to a silicon wafer and baked at 205°C for 60 seconds to form a 5-nm-thick undercoat film. A resist composition shown in Tables 1 and 2 was applied to the undercoat film and baked at 90°C for 60 seconds (PB) to form a 50-nm-thick resist film. The wafer with the resist film formed thereon was subjected to pattern exposure using an ELIONIX EB exposure system (ELS-BODEN) to write a line-and-space pattern with a half pitch of 50 nm (exposed area: 50 nm, exposed area: unexposed area = 1:1). The wafer was then heated (PEB) at 100°C for 60 seconds using a hot plate. Next, a first treatment liquid shown in Table 3 was dispensed for 20 seconds using a spin coater. Before the first treatment liquid dried, the second treatment liquid shown in Table 3 was supplied and replaced, followed by spin drying. This replaces a portion of the resist film with a film formed by the second treatment liquid. The resist is then heated to 150° C. and exposed to a gasified compound shown in Table 3 for 60 seconds for vapor exposure development. This results in a negative line-and-space pattern with a half pitch of 50 nm.

[0348] Comparative Example 1: An organic film AL412 (manufactured by Brewer Science) is applied to a silicon wafer and baked at 205°C for 60 seconds to form a 5 nm thick base film. The resist compositions shown in Tables 1 and 2 are applied to the base film and baked at 90°C for 60 seconds (PB: Pre-Bake) to form a 50 nm thick resist film. The wafer with the resist film formed thereon is subjected to pattern exposure using an ELIONIX EB exposure system (ELS-BODEN) to EB-print a line and space pattern with a half pitch of 50 nm (exposed area 50 nm, exposed area: unexposed area = 1:1). The resulting resist film is then thermally developed by heating at 160°C for 60 seconds using a hot plate.

[0349] The pattern formation conditions are shown in Table 3 below.

[0350]

[0351] [Evaluation] The patterns obtained by the above pattern formation method were checked for pattern resolution using a CDSEM S-9380II manufactured by Hitachi High-Technologies Corporation. If at least one of collapse, bridge, and disconnection was observed, the pattern was deemed non-resolved. If the line and space pattern with a half pitch of 50 nm was resolved, the resolution was rated as A, and if the line and space pattern with a half pitch of 50 nm was not resolved, the resolution was rated as B. The evaluation results are shown in Table 4.

[0352]

[0353] As shown in Table 4, it can be confirmed that the resist composition of the present invention makes it possible to form a fine pattern by dry development.

[0354] REFERENCE SIGNS LIST 10 Substrate 12 Mask 420 Resist film XD 422 Positive pattern of resist film XD 430 Underlayer 432 Positive pattern of underlayer 520 Resist film YE 522 Negative pattern of resist film YE 530 First processing liquid 540 Filling agent

Claims

1. An actinic ray-sensitive or radiation-sensitive resin composition for use in a pattern formation method including dry development, the actinic ray-sensitive or radiation-sensitive resin composition comprising a resin containing a repeating unit represented by formula (1) and a solvent. In formula (1), R ａ represents a hydrogen atom, a halogen atom, a nitro group, or an organic group. ｂ each independently represents a hydrogen atom or an organic group; X represents an oxygen atom, a sulfur atom, or —NR ｃ - represents. ｃ represents a hydrogen atom or an organic group. A represents an organic group.

2. The actinic ray-sensitive or radiation-sensitive resin composition according to claim 1, wherein the dry development is thermal development or steam exposure development.

3. The actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 or 2, wherein the dry development does not include plasma treatment.

4. The actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 or 2, wherein the dry development includes at least one treatment selected from the group consisting of a steam exposure treatment, a treatment of contacting a film formed from the actinic ray-sensitive or radiation-sensitive resin composition with a treatment liquid, and a treatment of exposing a film formed from the actinic ray-sensitive or radiation-sensitive resin composition to ultraviolet light.

5. The actinic ray-sensitive or radiation-sensitive resin composition according to claim 2, wherein the dry development is the steam exposure development.

6. The actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 or 2, further comprising a photoacid generator.

7. The actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 or 2, wherein the resin is a resin that generates a polar group upon the action of an acid.

8. The actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 or 2, wherein the resin has a group that generates a carboxyl group upon the action of an acid.

9. The actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 or 2, which contains compound B which generates an amine compound upon the action of heat or acid.

10. The actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 or 2, which contains a compound C having a structure that reduces the number of carboxy groups upon exposure.

Images