Photosensitive resin composition, production method therefor, resist film, pattern formation method, and method for producing electronic device

Abstract

To provide a photosensitive resin composition which has excellent linearity of a pattern obtained even in a case where the photosensitive resin composition is used after the lapse of time since the preparation thereof.SOLUTION: The present invention provides: a photosensitive resin composition including an ethylenically unsaturated compound, a resin having its polarity increase by the action of an acid, and metal atoms, in which a total content of the metal atoms is from 1 ppt to 30 ppb inclusive with respect to a total mass of the photosensitive resin composition, and a content of the ethylenically unsaturated compound is from 0.0001 mass% to 1 mass% inclusive with respect to the total mass of the photosensitive resin composition; a method for producing the same; and a resist film, a pattern forming method, and a method for manufacturing an electronic device, each of which uses the photosensitive resin composition.

Description

[Technical field]

[0001] The present disclosure relates to a photosensitive resin composition and a method for producing the same, a resist film, a pattern forming method, and a method for producing an electronic device. [Background technology]

[0002] Since resists for KrF excimer lasers (248 nm), a pattern formation method using chemical amplification has been used to compensate for the loss of sensitivity due to light absorption. For example, in a positive-type chemical amplification method, a photoacid generator contained in an exposed area is first decomposed by light irradiation to generate an acid. Then, in a post-exposure bake (PEB) process or the like, the generated acid acts as a catalyst to convert an alkali-insoluble group contained in the photosensitive composition into an alkali-soluble group. Then, development is performed using, for example, an alkaline solution. This removes the exposed area to obtain a desired pattern. In the above-mentioned method, various types of alkaline developers have been proposed, for example, an aqueous alkaline developer containing 2.38% by mass of TMAH (tetramethylammonium hydroxide) is widely used.

[0003] In order to miniaturize semiconductor elements, the wavelength of the exposure light source has become shorter and the numerical aperture (NA) of the projection lens has become higher, and currently, an exposure machine using an ArF excimer laser with a wavelength of 193 nm as a light source has been developed. As a technology to further increase the resolution, there is a method in which a liquid with a high refractive index (hereinafter also referred to as "immersion liquid") is filled between the projection lens and the sample (i.e., the liquid immersion method). Furthermore, as conventional photosensitive resin compositions and resins used in photosensitive resin compositions, for example, those described in Patent Documents 1 to 4 are known.

[0004] Patent Document 1 describes a method for purifying a photoresist resin, characterized in that the photoresist resin in a resin solution containing the photoresist resin and a solvent is purified by column chromatography. Patent Document 2 describes a method for producing a polymer compound for photoresist, which has a structure that is decomposed at least by an acid to become alkali-soluble, and an alicyclic hydrocarbon group that contains a polar group that has adhesion to a semiconductor substrate, characterized in that a monomer is polymerized with a polymerization initiator, the polymerization solution is added to a poor solvent, and the resulting polymer compound precipitate is decanted to remove unreacted monomer without using a filtration operation.

[0005] Patent Document 3 describes a protective film-forming composition for immersion exposure, which contains (A) a water-insoluble and alkali-soluble resin and (B) a solvent, and has a metal impurity content of 100 ppb or less. Patent Document 4 describes a radiation-sensitive resin composition that contains [A] a fluorine-containing polymer having a structural unit (f) containing a base-dissociable group, and has a total metal content of 30 ppb or less by mass.

[0006] Patent Document 1: JP 2010-13531 A Patent Document 2: Japanese Patent Application Laid-Open No. 2006-137829 Patent Document 3: JP 2006-30603 A Patent Document 4: JP 2012-88574 A Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present disclosure is to provide a photosensitive resin composition that gives a pattern with excellent linearity even when the photosensitive resin composition has been aged after preparation. Another problem to be solved by another embodiment of the present disclosure is to provide a method for producing a photosensitive resin composition that gives a pattern with excellent linearity even when a photosensitive resin composition that has been aged after preparation is used. A problem to be solved by still another embodiment of the present invention is to provide a resist film, a pattern forming method, and a method for manufacturing an electronic device, which use the above-mentioned photosensitive resin composition. [Means for solving the problem]

[0008] Means for solving the above problems include the following aspects. <1> A photosensitive resin composition comprising an ethylenically unsaturated compound, a resin whose polarity increases under the action of an acid, and a metal atom, the total content of the metal atoms being 1 ppt or more and 30 ppb or less relative to the total mass of the photosensitive resin composition, and the content of the ethylenically unsaturated compound being 0.0001 mass% or more and 1 mass% or less relative to the total mass of the photosensitive resin composition. <2> The content of the above metal atoms is 1 ppt or more and 10 ppb or less. <1> The photosensitive resin composition according to claim 1. <3> The content of the above metal atoms is 1 ppt or more and 1,000 ppt or less. <1> or <2> The photosensitive resin composition according to claim 1. <4> The content of the ethylenically unsaturated compound is 0.0001% by mass or more and 0.5% by mass or less based on the total mass of the photosensitive resin composition. <1> ~ <3> 10. The photosensitive resin composition according to claim 9 . <5> The content of the ethylenically unsaturated compound is 0.0001% by mass or more and 0.1% by mass or less based on the total mass of the photosensitive resin composition. <1> ~ <4> 10. The photosensitive resin composition according to claim 9 . <6> Further containing an organic solvent <1> ~ <5> 10. The photosensitive resin composition according to claim 9 . <7> Further contains a photoacid generator <1> ~ <6> 10. The photosensitive resin composition according to claim 9 . <8> Further contains an acid diffusion control agent <1> ~ <7> 10. The photosensitive resin composition according to claim 9 . <9> The method includes a step of mixing a resin whose polarity increases under the action of an acid, the total content of metal atoms in the resin is 1 ppt or more and 30 ppb or less with respect to the total mass of the resin, and the content of the ethylenically unsaturated compound contained in the resin is 0.001 mass% or more and 10 mass% or less with respect to the total mass of the resin. <1> ~ <8> 13. A method for producing the photosensitive resin composition according to claim 12. <10> The mixing step is a step of mixing at least the resin with an organic solvent having a total content of metal atoms of 1 ppt or more and 30 ppb or less. <9> A method for producing the photosensitive resin composition according to claim 1. <11> The mixing step is a step of mixing at least the resin with a photoacid generator having a total content of metal atoms of 1 ppt or more and 1,000 ppb or less. <9> or <10> A method for producing the photosensitive resin composition according to claim 1. <12> The mixing step is a step of mixing at least the resin with an acid diffusion control agent having a total metal atom content of 1 ppt or more and 1,000 ppb or less. <9> ~ <11> 13. A method for producing the photosensitive resin composition according to claim 12. <13> <1> ~ <8> 2. A resist film which is a solidified product of the photosensitive resin composition according to claim 1. <14> <13> 2. A pattern forming method comprising the steps of exposing the resist film according to claim 1 to light and developing the exposed resist film. <15> <14> A method for manufacturing an electronic device, comprising the pattern forming method according to claim 1. Effect of the Invention

[0009] According to the embodiments of the present disclosure, a photosensitive resin composition that gives a pattern with excellent linearity can be provided even when a photosensitive resin composition that has been aged after preparation is used. According to another embodiment of the present disclosure, it is possible to provide a method for producing a photosensitive resin composition that gives a pattern with excellent linearity even when using a photosensitive resin composition that has been aged after preparation. According to still another embodiment of the present invention, it is possible to provide a resist film, a pattern forming method, and a method for manufacturing an electronic device, which use the above-mentioned photosensitive resin composition. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The contents of the present disclosure will be described in detail below. The following description of the components may be based on a representative embodiment of the present disclosure, but the present disclosure is not limited to such an embodiment. The following description of the configuration features may be based on representative embodiments of the present invention, but the present disclosure is not limited to such embodiments. In the present specification, when a group (atomic group) is described without specifying whether it is substituted or unsubstituted, it includes both those that have no substituent and those that have a substituent. For example, an "alkyl group" includes not only an alkyl group that has no substituent (unsubstituted alkyl group) but also an alkyl group that has a substituent (substituted alkyl group). In addition, in the present specification, an "organic group" refers to a group that contains at least one carbon atom. In this specification, "actinic rays" or "radiation" refers to, for example, the bright line spectrum of a mercury lamp, far ultraviolet light represented by an excimer laser, extreme ultraviolet light (EUV light: extreme ultraviolet), X-rays, and electron beams (EB: electron beams), etc. In this specification, "light" refers to actinic rays or radiation, unless otherwise specified. In this specification, unless otherwise specified, "exposure" includes not only exposure to the emission line spectrum of a mercury lamp, far ultraviolet light represented by an excimer laser, extreme ultraviolet light, X-rays, EUV light, and the like, but also exposure to particle beams such as electron beams and ion beams. In this specification, the symbol "to" is used to mean that the numerical values ​​before and after it are included as the lower limit and upper limit.

[0011] In this specification, (meth)acrylate refers to acrylate and methacrylate, and (meth)acrylic refers to acrylic and methacrylic. 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 the resin component are defined as polystyrene-equivalent values ​​measured using a Gel Permeation Chromatography (GPC) device (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: refractive index detector).

[0012] In this specification, the amount of each component in a composition means, when a plurality of substances corresponding to each component are present in the composition, the total amount of the corresponding substances present in the composition, unless otherwise specified. In this specification, the term "process" includes not only an independent process but also a process that cannot be clearly distinguished from other processes as long as the intended purpose of the process is achieved. In this specification, the term "total solid content" refers to the total mass of the components excluding the solvent from the entire composition of the composition. As described above, the term "solid content" refers to the components excluding the solvent, and may be, for example, solid or liquid at 25°C. In this specification, "mass %" and "weight %" are synonymous, and "parts by mass" and "parts by weight" are synonymous. Also herein, a combination of two or more preferred embodiments is a more preferred embodiment.

[0013] (Photosensitive resin composition) The photosensitive resin composition according to the present disclosure comprises an ethylenically unsaturated compound, a resin whose polarity increases under the action of an acid, and a metal atom, the total content of the metal atoms being 1 ppt or more and 30 ppb or less, relative to the total mass of the photosensitive resin composition, and the content of the ethylenically unsaturated compound being 0.0001 mass% or more and 1 mass% or less, relative to the total mass of the photosensitive resin composition.

[0014] As a result of extensive investigations, the present inventors have found that by adopting the above-mentioned constitution, it is possible to provide a photosensitive resin composition which gives a pattern with excellent linearity even after aging. The mechanism by which the above-mentioned composition provides an excellent effect is not clear, but is presumed to be as follows. It is presumed that if metal atoms are present in high concentrations in each material when preparing a photosensitive resin composition, over time, the ethylenically unsaturated compound contained in the resin will associate with the metal atom or a compound having a metal atom and the ethylenically unsaturated compound, forming small particles that cannot be completely removed even by filtration, etc. It is presumed that the particles are too small to be removed from the photosensitive resin composition, and that when the photosensitive resin composition is applied and exposed to light to form a pattern, the linearity of the resulting pattern will be poor. In the photosensitive resin composition according to the present disclosure, the total content of metal atoms is 1 ppt or more and 30 ppb or less, relative to the total mass of the photosensitive resin composition, and the content of the ethylenically unsaturated compound is 0.0001 mass% or more and 1 mass% or less, relative to the total mass of the photosensitive resin composition. This is presumably why, even after the photosensitive resin composition is produced and aged, generation of the above particles is suppressed and the resulting pattern has excellent linearity. In addition, the present inventors have found that if the amount of metal atoms or the ethylenically unsaturated compound in the photosensitive resin composition is small, the acid diffusibility during heating after exposure is insufficient, and the linearity of the resulting pattern is poor. Regarding this phenomenon, it is presumed that the total content of metal atoms in the photosensitive resin composition according to the present disclosure is 1 ppt or more relative to the total mass of the photosensitive resin composition, and the content of the ethylenically unsaturated compound is 0.0001 mass% or more relative to the total mass of the photosensitive resin composition, so that the amount of the particles produced contributes, and the presence of an appropriate amount of the particles induces appropriate acid diffusibility in the photosensitive resin composition, resulting in excellent linearity of the resulting pattern.

[0015] The photosensitive resin composition according to the present disclosure is preferably a resist composition, and may be a positive resist composition or a negative resist composition. In addition, it may be a resist composition for alkaline development or a resist composition for organic solvent development. The photosensitive resin composition according to the present disclosure is preferably a chemically amplified photosensitive resin composition. Hereinafter, each component contained in the photosensitive resin composition (also simply referred to as the "composition") according to the present disclosure will be described in detail.

[0016] <Metal atom content> The photosensitive resin composition according to the present disclosure has a total content of metal atoms (also simply referred to as "metal content") of 1 ppt or more and 30 ppb or less based on the total mass of the photosensitive resin composition. In this disclosure, a "metal atom" refers to Li, Na, Mg, Al, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Rb, Sr, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Cs, Ba, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, and Bi. These metal atoms are metal atoms that can be contained in the photosensitive resin composition in the course of normal operations. The total content of the metal atoms is the total content of these metals. Furthermore, the form in which the metal atoms are contained in the photosensitive resin composition according to the present disclosure is not particularly limited, and the metal atoms may be contained in the form of a compound such as a salt, a simple substance, or an ion.

[0017] From the viewpoint of the linearity of a pattern obtained after aging, the total content of metal atoms in the photosensitive resin composition according to the present disclosure is preferably from 1 ppt to 10 ppb, more preferably from 1 ppt to 5 ppb, even more preferably from 1 ppt to 1,000 ppt, and particularly preferably from 5 ppt to 100 ppt, relative to the total mass of the photosensitive resin composition.

[0018] The content of metal atoms in the photosensitive resin composition and the above-mentioned resin in the present disclosure is measured by the method shown below. The content of metal atoms in the photosensitive resin composition can be measured, for example, by using ICP-MS (inductively coupled plasma mass spectrometry). The metal atom may be added to the photosensitive resin composition, or may be mixed unintentionally into the photosensitive resin composition during the manufacturing process of the photosensitive resin composition. Examples of unintentional mixing during the manufacturing process of the photosensitive resin composition include a case where the metal atom is contained in a raw material (e.g., an organic solvent) used in the manufacturing of the photosensitive resin composition, and a case where the metal atom is mixed during the manufacturing process of the photosensitive resin composition, but are not limited to the above.

[0019] <Ethylenically unsaturated compounds and resins whose polarity increases under the action of acid> The photosensitive resin composition according to the present disclosure contains an ethylenically unsaturated compound and a resin (hereinafter also referred to as "resin (A)") whose polarity increases under the action of an acid, and the content of the ethylenically unsaturated compound is 0.0001 mass % or more and 1 mass % or less with respect to the total mass of the photosensitive resin composition. In the photosensitive resin composition according to the present disclosure, it is presumed that by setting the content of the ethylenically unsaturated compound within the above range, association of a metal atom or a compound having a metal atom with the ethylenically unsaturated compound and the formation of particles having a small particle size that cannot be completely removed even by filtration or the like is suppressed, and the linearity of the pattern obtained after aging is excellent. The ethylenically unsaturated compound in the photosensitive resin composition according to the present disclosure preferably includes the ethylenically unsaturated compound used during polymerization of the resin, and the amount of the ethylenically unsaturated compound used during polymerization of the resin is preferably 50 mass% or more, more preferably 80 mass% or more, even more preferably 90 mass% or more, and particularly preferably 100 mass%, based on the total mass of the ethylenically unsaturated compounds contained in the photosensitive resin composition. Whether or not the resin corresponds to the above-mentioned ethylenically unsaturated compound is determined by performing a structural analysis of the resin, and determining whether or not it corresponds to a corresponding ethylenically unsaturated compound based on constituent units such as monomer units, and determining whether or not it corresponds to the ethylenically unsaturated compound used during polymerization of the resin. The above ethylenically unsaturated compound preferably has 1 to 4 ethylenically unsaturated bonds, and more preferably has 1. Furthermore, the above ethylenically unsaturated compound is preferably a monomer of a monomer. The molecular weight of the ethylenically unsaturated compound is preferably 28-1,000, more preferably 50-800, and particularly preferably 100-600.

[0020] As the ethylenically unsaturated compound, an ethylenically unsaturated compound other than the one used during polymerization of the resin may be used, and for example, a known ethylenically unsaturated compound may be used.

[0021] The content of the ethylenically unsaturated compound is from 0.0001% by mass to 1% by mass, relative to the total mass of the photosensitive resin composition. From the viewpoint of the linearity of the pattern obtained after aging, the content is preferably from 0.0001% by mass to 0.5% by mass, more preferably from 0.0001% by mass to 0.4% by mass, even more preferably from 0.0001% by mass to 0.2% by mass, particularly preferably from 0.0001% by mass to 0.1% by mass, and most preferably from 0.0001% by mass to 0.08% by mass.

[0022] The content of the ethylenically unsaturated compound in the photosensitive resin composition of the present disclosure is measured by the method shown below. The content of the ethylenically unsaturated compound can be measured using a gas chromatography mass spectrometry (GCMS). The ethylenically unsaturated compound may be added to the photosensitive resin composition, or may be mixed unintentionally into the photosensitive resin composition during the manufacturing process of the photosensitive resin composition. Examples of the case where the ethylenically unsaturated compound is mixed unintentionally during the manufacturing process of the photosensitive resin composition include the case where the compound is contained in the raw material (e.g., monomer during resin manufacturing) used in the manufacturing of the photosensitive resin composition, and the case where the compound is mixed during the manufacturing process of the photosensitive resin composition, but are not limited to the above.

[0023] The resin (resin (A)) whose polarity increases under the action of an acid is preferably a resin obtained by polymerizing at least an ethylenically unsaturated compound. Moreover, the resin whose polarity increases under the action of an acid preferably has an acid-decomposable group, and more preferably has a structural unit having an acid-decomposable group. In this case, in the pattern formation method according to the present disclosure described below, when an alkaline developer is used as the developer, a positive pattern is preferably formed, and when an organic developer is used as the developer, a negative pattern is preferably formed.

[0024] [Structural Unit Having an Acid-Decomposable Group] The resin (A) preferably has a structural unit having an acid-decomposable group.

[0025] As the resin (A), a known resin can be appropriately used. For example, the known resins disclosed in paragraphs 0055 to 0191 of US Patent Application Publication No. 2016 / 0274458, paragraphs 0035 to 0085 of US Patent Application Publication No. 2015 / 0004544, and paragraphs 0045 to 0090 of US Patent Application Publication No. 2016 / 0147150 can be suitably used as the resin (A).

[0026] The acid-decomposable group preferably has a structure in which a polar group is protected with a group (leaving group) that is decomposed and eliminated by the action of an acid. Examples of the polar group include acidic groups (groups that dissociate in a 2.38% by mass aqueous solution of tetramethylammonium hydroxide) such as a carboxy group, a phenolic hydroxyl group, a sulfonic acid group, a sulfonamide group, a sulfonylimide group, an (alkylsulfonyl)(alkylcarbonyl)methylene group, an (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 a tris(alkylsulfonyl)methylene group, as well as an alcoholic hydroxyl group.

[0027] The alcoholic hydroxyl group refers to a hydroxyl group bonded to a hydrocarbon group other than a hydroxyl group (phenolic hydroxyl group) directly bonded to an aromatic ring, and excludes aliphatic alcohols (e.g., hexafluoroisopropanol group) in which the α-position of the hydroxyl group is substituted with an electron-withdrawing group such as a fluorine atom. The alcoholic hydroxyl group is preferably a hydroxyl group having a pKa (acid dissociation constant) of 12 or more and 20 or less.

[0028] Preferred polar groups include a carboxy group, a phenolic hydroxyl group, and a sulfonic acid group.

[0029] Preferred as the acid-decomposable group are groups in which the hydrogen atom of the above groups is substituted with a group that is eliminated by the action of an acid (a leaving group). Examples of the group that is eliminated by the action of an acid (leaving group) include -C(R 36 )(R 37 )(R 38 ), -C(R 36 )(R 37 )(OR 39 ), and -C(R 01 )(R 02 )(OR 39 ) etc. In the formula, R 36 ~R 39 R each independently represents an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group. 36 and R37 may be bonded to each other to form a ring. R 01 and R 02 each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group.

[0030] R 36 ~R 39 , R 01 and R 02 The alkyl group is preferably an alkyl group having 1 to 8 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a hexyl group, and an octyl group. R 36 ~R 39 , R 01 and R 02 The cycloalkyl group may be monocyclic or polycyclic. As the monocyclic group, a cycloalkyl group having 3 to 8 carbon atoms is preferable, and examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group. As the polycyclic group, a cycloalkyl group having 6 to 20 carbon atoms is preferable, and examples thereof include an adamantyl group, a norbornyl group, an isobornyl group, a camphanyl group, a dicyclopentyl group, an α-pinel group, a tricyclodecanyl group, a tetracyclododecyl group, and an androstanyl group. At least one carbon atom in the cycloalkyl group may be substituted with a heteroatom such as an oxygen atom. R 36 ~R 39 , R 01 and R 02 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. R 36 ~R 39 , R 01 and R 02 The aralkyl group is preferably an aralkyl group having 7 to 12 carbon atoms, and examples thereof include a benzyl group, a phenethyl group, and a naphthylmethyl group. R 36 ~R 39, R 01 and R 02 The alkenyl group is preferably an alkenyl group having 2 to 8 carbon atoms, and examples thereof include a vinyl group, an allyl group, a butenyl group, and a cyclohexenyl group. R 36 and R 37 The ring formed by bonding with each other is preferably a cycloalkyl group (monocyclic or polycyclic). As the cycloalkyl group, monocyclic cycloalkyl groups such as cyclopentyl and cyclohexyl groups, or polycyclic cycloalkyl groups such as norbornyl, tetracyclodecanyl, tetracyclododecanyl, and adamantyl groups are preferred.

[0031] As the acid-decomposable group, a cumyl ester group, an enol ester group, an acetal ester group, a tertiary alkyl ester group, or the like is preferred, and an acetal group or a tertiary alkyl ester group is more preferred.

[0032] From the viewpoints of latitude in depth of focus and pattern linearity, the resin (A) preferably has a structural unit represented by the following formula AI as a structural unit having an acid-decomposable group.

[0033] [ka]

[0034] In formula AI, Xa 1 represents a hydrogen atom, a halogen atom other than a fluorine atom, or a monovalent organic group; T represents a single bond or a divalent linking group; Rx 1 ~Rx 3 Rx each independently represents an alkyl group or a cycloalkyl group; 1 ~Rx 3 Any two of these may or may not be bonded to form a ring structure.

[0035] Examples of the divalent linking group of T include an alkylene group, an arylene group, -COO-Rt-, and -O-Rt-, in which Rt represents an alkylene group, a cycloalkylene group, or an arylene group; T is preferably a single bond or -COO-Rt-. Rt is preferably a chain alkylene group having 1 to 5 carbon atoms, more preferably -CH2-, -(CH2)2-, or -(CH2)3-. T is more preferably a single bond.

[0036] Xa 1 is preferably a hydrogen atom or an alkyl group. Xa 1 The alkyl group may have a substituent, and examples of the substituent include a hydroxyl group and a halogen atom other than a fluorine atom. Xa 1 The alkyl group of Xa preferably has 1 to 4 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, and a hydroxymethyl group. 1 The alkyl group is preferably a methyl group.

[0037] Rx 1 , Rx 2 and Rx 3 The alkyl group of Rx may be linear or branched, and preferable examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a t-butyl group. The number of carbon atoms of the alkyl group is preferably 1 to 10, more preferably 1 to 5, and further preferably 1 to 3. 1 , Rx 2 and Rx 3 In the alkyl group, some of the carbon-carbon bonds may be double bonds. Rx 1 , Rx 2 and Rx 3 The cycloalkyl group 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.

[0038] Rx1 , Rx 2 and Rx 3 The ring structure formed by combining the two is preferably a monocyclic cycloalkane ring such as a cyclopentyl ring, a cyclohexyl ring, a cycloheptyl ring, or a cyclooctane ring, or a polycyclic cycloalkyl ring such as a norbornane ring, a tetracyclodecane ring, a tetracyclododecane ring, or an adamantane ring. A cyclopentyl ring, a cyclohexyl ring, or an adamantane ring is more preferred. 1 , Rx 2 and Rx 3 As the ring structure formed by combining the above two, the structure shown below is also preferred.

[0039] [ka]

[0040] Specific examples of monomers corresponding to the structural unit represented by formula AI are given below, but the present disclosure is not limited to these specific examples. 1 corresponds to the case where Xa is a methyl group, 1 can be optionally substituted with a hydrogen atom, a halogen atom other than a fluorine atom, or a monovalent organic group.

[0041] [ka]

[0042] It is also preferable that the resin (A) has a structural unit having an acid-decomposable group, which is a structural unit described in paragraphs 0336 to 0369 of US Patent Application Publication No. 2016 / 0070167.

[0043] Furthermore, the resin (A) may have, as a structural unit having an acid-decomposable group, a structural unit containing a group that decomposes under the action of an acid to generate an alcoholic hydroxyl group, as described in paragraphs 0363 to 0364 of U.S. Patent Application Publication No. 2016 / 0070167.

[0044] The resin (A) may contain one type of structural unit having an acid-decomposable group alone, or may contain two or more types.

[0045] The content of the structural units having an acid-decomposable group contained in the resin (the total content when a plurality of structural units having an acid-decomposable group are present) is preferably 10 mol % to 90 mol %, more preferably 20 mol % to 80 mol %, and even more preferably 30 mol % to 70 mol %, based on all the structural units of the resin (A). In this disclosure, when the content of the "structural unit" is specified by a molar ratio, the "structural unit" is synonymous with the "monomer unit." In addition, in this disclosure, the "monomer unit" may be modified after polymerization by a polymer reaction or the like. The same applies hereinafter.

[0046] [Structural Unit Having at Least One Structure Selected from the Group Consisting of Lactone Structure, Sultone Structure, and Carbonate Structure] The resin (A) preferably has a structural unit having at least one structure selected from the group consisting of a lactone structure, a sultone structure, and a carbonate structure.

[0047] As the lactone structure or sultone structure, any structure having a lactone structure or sultone structure can be used, but a 5- to 7-membered lactone structure or a 5- to 7-membered sultone structure is preferred, and a 5- to 7-membered lactone structure is more preferred in which another ring structure is condensed to form a bicyclo structure or a spiro structure, or a 5- to 7-membered sultone structure is more preferred in which another ring structure is condensed to form a bicyclo structure or a spiro structure. It is more preferred to have a structural unit having a lactone structure represented by any one of the following formulae LC1-1 to LC1-21, or a sultone structure represented by any one of the following formulae SL1-1 to SL1-3. The lactone structure or sultone structure may be directly bonded to the main chain. Preferred structures are LC1-1, LC1-4, LC1-5, LC1-8, LC1-16, LC1-21, and SL1-1.

[0048] [ka]

[0049] The lactone structure portion or the sultone structure portion is a substituent (Rb 2 ) may or may not be present. 2 Examples of the substituent (Rb) include an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 2 to 8 carbon atoms, a carboxyl group, a halogen atom other than a fluorine atom, a hydroxyl group, a cyano group, and an acid-decomposable group. More preferred are an alkyl group having 1 to 4 carbon atoms, a cyano group, and an acid-decomposable group. n2 represents an integer of 0 to 4. When n2 is 2 or more, a plurality of substituents (Rb 2 ) may be the same or different. In addition, when multiple substituents (Rb 2 ) may be bonded to each other to form a ring.

[0050] From the viewpoints of the latitude of the focal depth and the pattern linearity, the constitutional unit having a lactone structure or a sultone structure is preferably a constitutional unit represented by the following formula III. Moreover, from the viewpoints of the tolerance of the focal depth and the pattern linearity, it is preferable that the resin having a structural unit having an acid-decomposable group contains a structural unit represented by the following formula III.

[0051] [ka]

[0052] In the above formula III, A represents an ester bond (a group represented by -COO-) or an amide bond (a group represented by -CONH-). n is -R 0 It is the number of repetitions of the structure represented by -Z-, and represents an integer of 0 to 5, preferably 0 or 1, and more preferably 0. When n is 0, -R 0 -Z- does not exist, A and R 8 and are bonded by a single bond. R 0R represents an alkylene group, a cycloalkylene group, or a combination thereof. 0 When there are a plurality of them, each independently represents an alkylene group, a cycloalkylene group, or a combination thereof. Z represents a single bond, an ether bond, an ester bond, an amide bond, a urethane bond or a urea bond. When there are multiple Z's, each independently represents a single bond, an ether bond, an ester bond, an amide bond, a urethane bond or a urea bond. R 8 represents a monovalent organic group having a lactone structure or a sultone structure. R 7 represents a hydrogen atom, a halogen atom other than a fluorine atom, or a monovalent organic group (preferably a methyl group).

[0053] R 0 The alkylene group or cycloalkylene group may have a substituent. Z is preferably an ether bond or an ester bond, more preferably an ester bond.

[0054] Specific examples of monomers corresponding to the structural unit represented by formula III and the structural unit represented by formula A-1 described below are given below, but the present disclosure is not limited to these specific examples. 7 and R in Formula A-1 described below. A 1 corresponds to the case where R is a methyl group, 7 and R A 1 can be optionally substituted with a hydrogen atom, a halogen atom other than a fluorine atom, or a monovalent organic group.

[0055] [ka]

[0056] In addition to the above monomers, the following monomers are also suitably used as raw materials for the resin (A).

[0057] [ka]

[0058] The resin (A) may have a structural unit having a carbonate structure. The carbonate structure is preferably a cyclic carbonate ester structure. The structural unit having a cyclic carbonate structure is preferably a structural unit represented by the following formula A-1.

[0059] [ka]

[0060] In formula A-1, R A 1 represents a hydrogen atom, a halogen atom other than a fluorine atom, or a monovalent organic group (preferably a methyl group), n represents an integer of 0 or more, R A 2 R represents a substituent. A 2 When n is 2 or more, each independently represents a substituent, A represents a single bond or a divalent linking group, and Z represents an atomic group forming a monocyclic structure or a polycyclic structure together with the group represented by -O-C(=O)-O- in the formula.

[0061] Resin (A) also preferably has a structural unit described in paragraphs 0370 to 0414 of U.S. Patent Application Publication No. 2016 / 0070167 as a structural unit having at least one type selected from the group consisting of a lactone structure, a sultone structure, and a carbonate structure.

[0062] The resin (A) preferably has a structural unit (a) having at least two lactone structures (hereinafter also referred to as "structural unit (a)"). The at least two lactone structures may be, for example, a structure in which at least two lactone structures are condensed, or a structure in which at least two lactone structures are linked by a single bond or a linking group. The lactone structure of the structural unit (a) is not particularly limited, but may be a 5- to 7-membered lactone. A lactone structure is preferred, and a 5- to 7-membered lactone structure is preferred to form a bicyclo structure or a spiro structure. Preferably, the ring structure is condensed with another ring structure. Preferred examples of the lactone structure include the lactone structures represented by any of the above-mentioned LC1-1 to LC1-21.

[0063] The structural unit having at least two lactone structures (hereinafter also referred to as "structural unit (a)") is preferably a structural unit represented by the following formula L-1.

[0064] [ka]

[0065] In formula L-1, Ra represents a hydrogen atom or an alkyl group, and Rb represents a partial structure having two or more lactone structures.

[0066] The alkyl group of Ra is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and particularly preferably a methyl group. The alkyl group of Ra may be substituted. Examples of the substituent include halogen atoms such as fluorine atom, chlorine atom, and bromine atom, mercapto group, hydroxy group, alkoxy group such as methoxy group, ethoxy group, isopropoxy group, t-butoxy group, and benzyloxy group, and acyl group such as acetyl group and propionyl group. Ra is preferably a hydrogen atom, a methyl group, a trifluoromethyl group, and a hydroxymethyl group.

[0067] Examples of the lactone structure contained in the Rb partial structure include the lactone structures described above. The partial structure of Rb having two or more lactone structures is preferably, for example, a structure in which at least two lactone structures are linked by a single bond or a linking group, and a structure in which at least two lactone structures are condensed. The structural unit (a1) having a structure in which at least two lactone structures are condensed, and the structural unit (a2) having a structure in which at least two lactone structures are linked by a single bond or a linking group are each described below.

[0068] -Structural unit (a1) having a structure in which at least two lactone structures are condensed-ring The structure in which at least two lactone structures are fused is preferably a structure in which two or three lactone structures are fused, and more preferably a structure in which two lactone structures are fused. An example of a structural unit having a structure in which at least two lactone structures are fused together (hereinafter, also referred to as "structural unit (a1)") is a structural unit represented by the following formula L-2.

[0069] [ka]

[0070] In formula L-2, Ra has the same meaning as Ra in formula L-1, Re1 to Re8 each independently represent a hydrogen atom or an alkyl group, Me1 represents a single bond or a divalent linking group, and Me2 and Me3 each independently represent a divalent linking group.

[0071] The alkyl group of Re1 to Re8 preferably has, for example, 5 or less carbon atoms, and more preferably has 1 carbon atom. Examples of the alkyl group having 5 or less carbon atoms for Re1 to Re8 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, an isopentyl group, an s-pentyl group, and a t-pentyl group. Among these, Re1 to Re8 are preferably hydrogen atoms.

[0072] Examples of the divalent linking group for Me1 include an alkylene group, a cycloalkylene group, -O-, -CO-, -COO-, -OCO-, and a combination of two or more of these groups. The alkylene group of Me1 preferably has, for example, 1 to 10 carbon atoms, and more preferably has 1 or 2 carbon atoms, and the alkylene group having 1 or 2 carbon atoms is preferably, for example, a methylene group or an ethylene group. The alkylene group of Me1 may be linear or branched, and examples thereof include a methylene group, an ethane-1,1-diyl group, an ethane-1,2-diyl group, a propane-1,1-diyl group, a propane-1,3-diyl group, a propane-2,2-diyl group, a pentane-1,5-diyl group, and a hexane-1,6-diyl group. The cycloalkylene group of Me1 preferably has 5 to 10 carbon atoms, and more preferably has 5 or 6 carbon atoms, for example. Examples of the cycloalkylene group of Me1 include a cyclopentylene group, a cyclohexylene group, a cycloheptylene group, a cyclooctylene group, and a cyclodecylene group. As the divalent linking group of Me1, the group combining the above two or more groups is preferably, for example, a group combining an alkylene group with -COO-, and a group combining -OCO- with an alkylene group.Moreover, the group combining the above two or more groups is more preferably a group combining a methylene group with -COO-, and a group combining a -COO- with a methylene group.

[0073] Examples of the divalent linking group of Me2 and Me3 include an alkylene group, -O-, etc. The divalent linking group of Me2 and Me3 is preferably a methylene group, an ethylene group, or -O-, and more preferably -O-.

[0074] A monomer corresponding to the structural unit (a1) can be synthesized, for example, by the method described in JP-A-2015-160836.

[0075] Specific examples of the structural unit (a1) are shown below, but the present disclosure is not limited thereto. In each of the following formulas, R9 represents a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group, and * represents the bonding position to other structural units.

[0076] [ka]

[0077] [ka]

[0078] [ka]

[0079] -Structural unit (a2) having a structure in which at least two lactone structures are linked by a single bond or a linking group- The structure in which at least two lactone structures are linked by a single bond or a linking group is preferably a structure in which two to four lactone structures are linked by a single bond or a linking group, and more preferably a structure in which two lactone structures are linked by a single bond or a linking group. Examples of the linking group include the same groups as those exemplified as the linking group of M2 in formula L-3 described below. An example of a structural unit having a structure in which two or more lactone structures are linked via a single bond or a linking group (hereinafter also referred to as "structural unit (a2)") includes a structural unit represented by the following formula L-3.

[0080] [ka]

[0081] In formula L-3, Ra has the same meaning as Ra in formula L-1 above, M1 and M2 each independently represent a single bond or a linking group, and Lc1 and Lc2 each independently represent a group having a lactone structure.

[0082] Examples of the linking group for M1 include an alkylene group, a cycloalkylene group, -O-, -CO-, -COO-, -OCO-, and a combination of two or more of these groups. The alkylene group of M1 preferably has 1 to 10 carbon atoms, for example. The alkylene group of M1 may be linear or branched, and examples thereof include a methylene group, an ethane-1,1-diyl group, an ethane-1,2-diyl group, a propane-1,1-diyl group, a propane-1,3-diyl group, a propane-2,2-diyl group, a pentane-1,5-diyl group, and a hexane-1,6-diyl group. The cycloalkylene group of M1 preferably has 5 to 10 carbon atoms, for example. Examples of the cycloalkylene group of M1 include a cyclopentylene group, a cyclohexylene group, a cycloheptylene group, a cyclooctylene group, and a cyclodecylene group. As the linking group of M1, the group combining the above two or more groups is preferably, for example, a group combining an alkylene group with -COO-, and a group combining -OCO- with an alkylene group.Moreover, the group combining the above two or more groups is more preferably a group combining a methylene group with -COO-, and a group combining a -COO- with a methylene group. Examples of the linking group for M2 include the same groups as those exemplified as the linking group for M1.

[0083] The lactone structure of Lc1 is preferably, for example, a 5- to 7-membered ring lactone structure, and preferably a 5- to 7-membered ring lactone structure to which another ring structure is condensed to form a bicyclo structure or a spiro structure. The lactone structure is more preferably a lactone structure represented by any one of the above LC1-1 to LC1-21. More preferred lactone structures include LC1-1, LC1-4, LC1-5, LC1-6, LC1-13, LC1-14 and LC1-17. The lactone structure of Lc1 may contain a substituent. The substituent that the structure may contain is, for example, the same as the substituent (Rb2) of the lactone structure described above. The same substituents are mentioned. The lactone structure of Lc2 may be, for example, any of the lactone structures listed for Lc1. The structure is the same as the methionine structure.

[0084] The structural unit (a2) is preferably a structural unit represented by the following formula L-4 as the structural unit represented by the above formula L-3.

[0085] [ka]

[0086] In formula L-4, Ra has the same meaning as Ra in formula L-1 above, Mf1 and Mf2 each independently represent a single bond or a linking group, Rf1, Rf2, and Rf3 each independently represent a hydrogen atom or an alkyl group, Mf1 and Rf1 may be bonded to each other to form a ring, and Mf2 and Rf2 or Rf3 may each be bonded to each other to form a ring.

[0087] The linking group of Mf1 has the same meaning as the linking group of M1 in the above formula L-3. The linking group of Mf2 has the same meaning as the linking group of M2 in the above formula L-3. Examples of the alkyl group of Rf1 include alkyl groups having 1 to 4 carbon atoms. The alkyl group of Rf1 having 1 to 4 carbon atoms is preferably a methyl group or an ethyl group, more preferably a methyl group. The alkyl group of Rf1 may have a substituent. Examples of the substituent that the alkyl group of Rf1 may have include alkoxy groups such as a hydroxy group, a methoxy group, and an ethoxy group, a cyano group, and a halogen atom such as a fluorine atom. The alkyl groups of Rf2 and Rf3 have the same meaning as the alkyl group of Rf1.

[0088] Mf1 and Rf1 may be bonded to each other to form a ring. Examples of the structure in which Mf1 and Rf1 are bonded to each other to form a ring include the lactone structures represented by LC1-13, LC1-14, or LC1-17 among the lactone structures described above. Mf2 and Rf2 or Rf3 may be bonded to each other to form a ring. Examples of the structure in which Mf2 and Rf2 are bonded to each other to form a ring include the lactone structures represented by LC1-7, LC1-8, or LC1-15 among the above-mentioned lactone structures. Examples of the structure in which Mf2 and Rf3 are bonded to each other to form a ring include the lactone structures represented by any of the above-mentioned LC1-3 to LC1-6 among the above-mentioned lactone structures. Specific examples of the structural unit (a2) are shown below, but the present disclosure is not limited thereto. * indicates the bonding position to other structural units.

[0089] [ka]

[0090] A structural unit having at least two lactone structures usually has optical isomers, and any of the optical isomers may be used. In addition, one type of optical isomer may be used alone, or a mixture of multiple optical isomers may be used. When one type of optical isomer is mainly used, the optical purity (ee) is preferably 90% or more, more preferably 95% or more.

[0091] The content of the structural unit having at least two lactone structures is preferably 10 mol % to 60 mol %, more preferably 20 mol % to 50 mol %, and even more preferably 30 mol % to 50 mol %, based on all structural units in the resin (A). In order to enhance the effects of the present disclosure, it is also possible to use two or more types of constitutional units having at least two lactone structures in combination. When two or more types of repeating units having at least two lactone structures are contained, it is preferable that the total content of the constitutional units having at least two lactone structures is within the above-mentioned range.

[0092] The resin (A) may contain one type of structural unit having at least one type selected from the group consisting of a lactone structure, a sultone structure, and a carbonate structure, or may contain two or more types of structural units in combination.

[0093] The content of the structural units having at least one selected from the group consisting of lactone structures, sultone structures, and carbonate structures contained in the resin (the total content when there are a plurality of structural units having at least one selected from the group consisting of lactone structures, sultone structures, and carbonate structures) is preferably 5 mol % to 70 mol %, more preferably 10 mol % to 65 mol %, and even more preferably 20 mol % to 60 mol %, based on the total structural units of the resin (A).

[0094] [Structural Unit Having a Polar Group] The resin (A) preferably has a structural unit having a polar group. Examples of the polar group include a hydroxyl group, a cyano group, and a carboxy group. The structural unit having a polar group is preferably a structural unit having an alicyclic hydrocarbon structure substituted with a polar group. The structural unit having a polar group is preferably free of an acid-decomposable group. The alicyclic hydrocarbon structure in the alicyclic hydrocarbon structure substituted with a polar group is preferably an adamantyl group or a norbornyl group.

[0095] Specific examples of monomers corresponding to structural units having a polar group are given below, but the present disclosure is not limited to these specific examples. In addition, the following specific examples are described as methacrylic acid ester compounds, but may be acrylic acid ester compounds.

[0096] [ka]

[0097] Other specific examples of structural units having a polar group include the structural units disclosed in paragraphs 0415 to 0433 of US Patent Application Publication No. 2016 / 0070167. The resin (A) may contain one type of structural unit having a polar group on its own, or may contain two or more types in combination. The content of the structural unit having a polar group is preferably from 5 mol % to 40 mol %, more preferably from 5 mol % to 30 mol %, and even more preferably from 10 mol % to 25 mol %, based on all structural units in the resin (A).

[0098] [Structural Unit Having Neither an Acid-Decomposable Group nor a Polar Group] The resin (A) may further have a structural unit having neither an acid decomposable group nor a polar group. The structural unit having neither an acid decomposable group nor a polar group preferably has an alicyclic hydrocarbon structure. Examples of the structural unit having neither an acid decomposable group nor a polar group include the structural units described in paragraphs 0236 to 0237 of US Patent Application Publication No. 2016 / 0026083. Preferred examples of monomers corresponding to the structural unit having neither an acid decomposable group nor a polar group are shown below.

[0099] [ka]

[0100] In addition, specific examples of structural units having neither an acid-decomposable group nor a polar group include the structural units disclosed in paragraph 0433 of U.S. Patent Application Publication No. 2016 / 0070167. The resin (A) may contain one type of structural unit having neither an acid-decomposable group nor a polar group, or may contain two or more types of structural units in combination. The content of the structural units having neither an acid-decomposable group nor a polar group is preferably from 5 to 40 mol %, more preferably from 5 to 30 mol %, and even more preferably from 5 to 25 mol %, based on all the structural units in the resin (A).

[0101] In addition to the above structural units, the resin (A) may have various structural units for the purpose of adjusting dry etching resistance, suitability for a standard developer, substrate adhesion, resist profile, and furthermore, general required properties of a resist, such as resolution, heat resistance, sensitivity, etc. Examples of such structural units include, but are not limited to, structural units corresponding to other monomers.

[0102] Examples of the other monomers include compounds having one addition-polymerizable unsaturated bond selected from acrylic acid esters, methacrylic acid esters, acrylamides, methacrylamides, allyl compounds, vinyl ethers, and vinyl esters. In addition, any addition-polymerizable unsaturated compound that is copolymerizable with the monomers corresponding to the various structural units described above may be copolymerized. In the resin (A), the molar ratio of each constituent unit is appropriately set in order to adjust various properties.

[0103] When the photosensitive resin composition according to the present disclosure is for argon fluoride (ArF) laser exposure, from the viewpoint of the transmittance of ArF light, it is preferable that the resin (A) does not substantially have an aromatic group. More specifically, among all the structural units of the resin (A), structural units having an aromatic group are preferably 5 mol% or less of the total, more preferably 3 mol% or less, and ideally 0 mol%, that is, it is even more preferable that there is no structural unit having an aromatic group. In addition, it is preferable that the resin (A) has a monocyclic or polycyclic alicyclic hydrocarbon structure.

[0104] It is preferable that all of the structural units of the resin (A) are (meth)acrylate-based structural units. In this case, any of those in which all of the structural units are methacrylate-based structural units, all of the structural units are acrylate-based structural units, and all of the structural units are a combination of methacrylate-based structural units and acrylate-based structural units can be used, but it is preferable that the acrylate-based structural units account for 50 mol% or less of the total structural units of the resin (A).

[0105] When the photosensitive resin composition according to the present disclosure is for krypton fluoride (KrF) exposure, electron beam (EB) exposure, or extreme ultraviolet (EUV) exposure, the resin (A) preferably contains a structural unit having an aromatic hydrocarbon group, and more preferably contains a structural unit having a phenolic hydroxyl group. Examples of the structural unit having a phenolic hydroxyl group include a structural unit derived from hydroxystyrene and a structural unit derived from hydroxystyrene (meth)acrylate. When the photosensitive resin composition according to the present disclosure is for KrF exposure, EB exposure, or EUV exposure, the resin (A) preferably has a structure in which the hydrogen atom of the phenolic hydroxyl group is protected with a group (leaving group) that is decomposed and eliminated by the action of an acid. The content of the structural units having an aromatic hydrocarbon group contained in the resin (A) is preferably 30 mol% to 100 mol%, more preferably 40 mol% to 100 mol%, and even more preferably 50 mol% to 100 mol%, based on all structural units in the resin (A).

[0106] The weight average molecular weight of the resin (A) is preferably from 1,000 to 200,000, more preferably from 2,000 to 20,000, further preferably from 3,000 to 15,000, and particularly preferably from 3,000 to 11,000. The dispersity (Mw / Mn) is preferably from 1.0 to 3.0, more preferably from 1.0 to 2.6, further preferably from 1.0 to 2.0, and particularly preferably from 1.1 to 2.0.

[0107] Specific examples of the resin (A) include resins A-1 to A-14 and A-21 to A-43 used in the examples, but are not limited thereto.

[0108] The resin (A) may be used alone or in combination of two or more kinds. The content of the resin having a structural unit having an acid-decomposable group is preferably 20% by mass or more, more preferably 40% by mass or more, even more preferably 60% by mass or more, and particularly preferably 80% by mass or more, based on the total solid content of the photosensitive resin composition according to the present disclosure. The upper limit is not particularly limited, but is preferably 99.5% by mass or less, more preferably 99% by mass or less, and even more preferably 97% by mass or less.

[0109] [Alkali-soluble resin having a phenolic hydroxyl group] When the photosensitive resin composition according to the present disclosure contains a crosslinking agent (G) described later, the photosensitive resin composition according to the present disclosure preferably contains an alkali-soluble resin having a phenolic hydroxyl group (hereinafter, also referred to as "resin (C)"). The resin (C) preferably has a structural unit having a phenolic hydroxyl group. In this case, typically, a negative pattern is preferably formed. The crosslinking agent (G) may be in a form supported on the resin (C). Among the resins (C), those that correspond to resins whose polarity increases under the action of an acid are treated as resins whose polarity increases under the action of an acid. In that case, the photosensitive resin composition according to the present disclosure preferably contains at least a resin (C) other than the resin whose polarity increases under the action of an acid and a resin whose polarity increases under the action of an acid. The resin (C) may contain the above-mentioned acid-decomposable group. The structural unit having a phenolic hydroxyl group contained in the resin (C) is not particularly limited, but is preferably a structural unit represented by the following formula (II).

[0110] [ka]

[0111] In formula (II), R2 represents a hydrogen atom, an alkyl group which may have a substituent (preferably a methyl group), or a halogen atom (preferably a fluorine atom), B' represents a single bond or a divalent linking group, Ar' represents an aromatic ring group, and m represents an integer of 1 or greater.

[0112] The resin (C) may be used alone or in combination of two or more kinds. The content of the resin (C) in the total solid content of the photosensitive resin composition according to the present disclosure is preferably 30% by mass or more, more preferably 40% by mass or more, and even more preferably 50% by mass or more. There is no particular upper limit, but it is preferably 99% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less. As the resin (C), the resins disclosed in paragraphs 0142 to 0347 of US Patent Application Publication No. 2016 / 0282720 can be suitably used.

[0113] [Hydrophobic resin] The photosensitive resin composition according to the present disclosure preferably contains a hydrophobic resin (also referred to as "hydrophobic resin (E)"). The photosensitive resin composition according to the present disclosure preferably contains at least a hydrophobic resin (E) other than the resin whose polarity increases by the action of an acid, and a resin whose polarity increases by the action of an acid. The photosensitive resin composition according to the present disclosure contains a hydrophobic resin (E), which allows the static / dynamic contact angle on the surface of the actinic ray-sensitive or radiation-sensitive film to be controlled, thereby making it possible to improve development characteristics, suppress outgassing, improve immersion liquid tracking in immersion exposure, and reduce immersion defects. The hydrophobic resin (E) is preferably designed so as to be unevenly distributed on the surface of the resist film. However, unlike a surfactant, it does not necessarily have to have a hydrophilic group in the molecule, and does not necessarily have to contribute to uniformly mixing polar / non-polar substances. In the present disclosure, a resin having a fluorine atom is treated as a hydrophobic resin and a fluorine-containing resin described later. In addition, the resin having a structural unit having an acid-decomposable group preferably does not have a fluorine atom.

[0114] From the viewpoint of uneven distribution on the membrane surface layer, the hydrophobic resin (E) is preferably a resin containing a structural unit having at least one selected from the group consisting of a "fluorine atom", a "silicon atom", and a "CH3 partial structure contained in a side chain portion of the resin". When the hydrophobic resin (E) contains a fluorine atom or a silicon atom, the fluorine atom or silicon atom in the hydrophobic resin (E) may be contained in the main chain or in a side chain of the resin.

[0115] The hydrophobic resin (E) preferably has at least one group selected from the group consisting of (x) to (z) below. (x) Acid group (y) A group that is decomposed by the action of an alkaline developer to increase the solubility in the alkaline developer (hereinafter also referred to as a polarity conversion group). (z) Groups that decompose when subjected to the action of acid

[0116] Examples of the acid group (x) include a phenolic hydroxyl group, a carboxylic acid group, a fluorinated alcohol group, a sulfonic acid group, a sulfonamide group, a sulfonylimide group, an (alkylsulfonyl)(alkylcarbonyl)methylene group, an (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 a tris(alkylsulfonyl)methylene group. The acid group is preferably a fluorinated alcohol group (preferably hexafluoroisopropanol), a sulfonimide group, or a bis(alkylcarbonyl)methylene group.

[0117] Examples of the group (y) that is decomposed by the action of an alkaline developer to increase its solubility in an alkaline developer include a lactone group, a carboxylate group (-COO-), an acid anhydride group (-C(O)OC(O)-), an acid imide group (-NHCONH-), a carboxylate thioester group (-COS-), a carbonate group (-OC(O)O-), a sulfate group (-OSO-), and a sulfonate group (-SOO-), and the like are mentioned, with a lactone group or a carboxylate group (-COO-) being preferred. The structural unit containing these groups is a structural unit in which these groups are directly bonded to the main chain of the resin, and examples thereof include structural units of acrylic acid ester and methacrylic acid ester. In this structural unit, these groups may be bonded to the main chain of the resin via a linking group. Alternatively, this structural unit may be introduced to the end of the resin by using a polymerization initiator or chain transfer agent having these groups during polymerization. Examples of structural units having a lactone group include the same structural units having a lactone structure as those explained above in the section on resin (A).

[0118] The content of the structural unit having a group (y) that is decomposed by the action of an alkaline developer to increase the solubility in the alkaline developer is preferably from 1 to 100 mol %, more preferably from 3 to 98 mol %, and even more preferably from 5 to 95 mol %, based on all structural units in the hydrophobic resin (E).

[0119] In the hydrophobic resin (E), the structural unit having a group (z) decomposed by the action of an acid may be the same as the structural unit having an acid decomposable group exemplified in the resin (A). The structural unit having a group (z) decomposed by the action of an acid may have at least one of a fluorine atom and a silicon atom. The content of the structural unit having a group (z) decomposed by the action of an acid is preferably 1 mol% to 80 mol%, more preferably 10 mol% to 80 mol%, and even more preferably 20 mol% to 60 mol%, based on the total structural units in the resin (E).

[0120] The hydrophobic resin (E) may further have a structural unit other than the structural units described above.

[0121] The fluorine atom-containing structural unit preferably accounts for 10 mol% to 100 mol%, more preferably 30 mol% to 100 mol%, of all structural units contained in the hydrophobic resin (E), and the silicon atom-containing structural unit preferably accounts for 10 mol% to 100 mol%, more preferably 20 mol% to 100 mol%, of all structural units contained in the hydrophobic resin (E).

[0122] On the other hand, particularly when the hydrophobic resin (E) contains a CH3 partial structure in the side chain portion, the hydrophobic resin (E) is preferably substantially free of fluorine atoms and silicon atoms. Also, the hydrophobic resin (E) is preferably substantially composed of structural units composed only of atoms selected from carbon atoms, oxygen atoms, hydrogen atoms, nitrogen atoms, and sulfur atoms.

[0123] The weight average molecular weight of the hydrophobic resin (E) in terms of standard polystyrene is preferably from 1,000 to 100,000, and more preferably from 1,000 to 50,000.

[0124] The total content of residual monomer and oligomer components contained in the hydrophobic resin (E) is preferably 0.01% by mass to 5% by mass, more preferably 0.01% by mass to 3% by mass, and the dispersity (Mw / Mn) is preferably in the range of 1 to 5, more preferably 1 to 3.

[0125] As the hydrophobic resin (E), known resins can be appropriately selected and used alone or as a mixture thereof. For example, known resins disclosed in paragraphs 0451-0704 of US Patent Application Publication No. 2015 / 0168830 and paragraphs 0340-0356 of US Patent Application Publication No. 2016 / 0274458 can be suitably used as the hydrophobic resin (E). In addition, the structural units disclosed in paragraphs 0177-0258 of US Patent Application Publication No. 2016 / 0237190 are also preferred as structural units constituting the hydrophobic resin (E).

[0126] -Fluorine-containing resin- The hydrophobic resin (E) is preferably a resin containing fluorine atoms (also referred to as a "fluorine-containing resin"). When the hydrophobic resin (E) contains a fluorine atom, it is preferable that the hydrophobic resin (E) is a resin having, as a partial structure having a fluorine atom, an alkyl group having a fluorine atom, a cycloalkyl group having a fluorine atom, or an aryl group having a fluorine atom.

[0127] The alkyl group having a fluorine atom is a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and preferably has 1 to 10 carbon atoms, more preferably 1 to 4 carbon atoms. The cycloalkyl group having a fluorine atom is a monocyclic or polycyclic cycloalkyl group in which at least one hydrogen atom is substituted with a fluorine atom. Examples of aryl groups having a fluorine atom include aryl groups such as a phenyl group and a naphthyl group in which at least one hydrogen atom is substituted with a fluorine atom.

[0128] As the alkyl group having a fluorine atom, the cycloalkyl group having a fluorine atom, and the aryl group having a fluorine atom, groups represented by the formulae F2 to F4 are preferred.

[0129] [ka]

[0130] In formulas F2 to F4, R 57 ~R 68 each independently represents a hydrogen atom, a fluorine atom, or an alkyl group (linear or branched), provided that R 57 ~R 61 At least one of R 62 ~R 64 At least one of, and R 65 ~R 68 At least one of each independently represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom. R 57 ~R 61 and R 65 ~R 67 It is preferable that all of R are fluorine atoms. 62 , R 63 and R 68 R is preferably an alkyl group (preferably having 1 to 4 carbon atoms) in which at least one hydrogen atom is substituted with a fluorine atom, and more preferably a perfluoroalkyl group having 1 to 4 carbon atoms. 62 and R 63 may be linked to each other to form a ring.

[0131] In particular, in terms of achieving better effects according to the present disclosure, it is preferable for the fluorine-containing resin to be alkali-decomposable. The term "fluorine-containing resin is alkali decomposable" means that 30 mol % or more of the total amount of decomposable groups in the fluorine-containing resin is hydrolyzed after 10 minutes when 100 mg of the fluorine-containing resin is added to a mixture of 2 mL of a pH 10 buffer solution and 8 mL of THF and allowed to stand at 40° C. The decomposition rate can be calculated from the ratio of the raw material and the decomposed product by NMR analysis.

[0132] From the viewpoints of improving the latitude of focal depth, pattern linearity, development characteristics, suppressing outgassing, improving the immersion liquid followability in immersion exposure, and reducing immersion defects, the fluorine-containing resin preferably has a constitutional unit represented by formula X. In addition, from the viewpoints of improving the latitude of focal depth, pattern linearity, development characteristics, suppressing outgassing, improving immersion liquid tracking in immersion exposure, and reducing immersion defects, it is preferable that the photosensitive resin composition according to the present disclosure further contains a fluorine-containing resin having a constitutional unit represented by formula X.

[0133] [ka]

[0134] In the formula X, Z is a halogen atom, R 11 A group represented by OCH2- or R 12 R represents a group represented by OC(=O)CH2-. 11 and R 12 each independently represents a substituent, X represents an oxygen atom or a sulfur atom, L represents a (n+1)-valent linking group, R 10 represents a group having a group which is decomposed by the action of an alkaline aqueous solution to increase the solubility of the fluororesin in the alkaline aqueous solution, n represents a positive integer, and when n is 2 or more, a plurality of R 10 may be the same or different from each other.

[0135] Examples of the halogen atom represented by Z include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable. R 11 and R 12 Examples of the substituent as R include an alkyl group (preferably having 1 to 4 carbon atoms), a cycloalkyl group (preferably having 6 to 10 carbon atoms), and an aryl group (preferably having 6 to 10 carbon atoms). 11 and R 12The substituent as may further have a substituent, and such further substituent includes an alkyl group (preferably having 1 to 4 carbon atoms), a halogen atom, a hydroxyl group, an alkoxy group (preferably having 1 to 4 carbon atoms), and a carboxy group. The linking group represented by L is preferably a divalent or trivalent linking group (in other words, n is preferably 1 or 2), and more preferably a divalent linking group (in other words, n is preferably 1). The linking group represented by L is preferably a linking group selected from the group consisting of an aliphatic group, an aromatic group, and a combination thereof. For example, when n is 1 and the linking group as L is a divalent linking group, examples of the divalent aliphatic group include an alkylene group, an alkenylene group, an alkynylene group, and a polyalkyleneoxy group. Among these, an alkylene group or an alkenylene group is preferable, and an alkylene group is more preferable. The divalent aliphatic group may have a chain structure or a cyclic structure, but a chain structure is more preferable than a cyclic structure, and a straight chain structure is more preferable than a branched chain structure. The divalent aliphatic group may have a substituent, and examples of the substituent include a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), a hydroxyl group, a carboxyl group, an amino group, a cyano group, an aryl group, an alkoxy group, an aryloxy group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxy group, a monoalkylamino group, a dialkylamino group, an arylamino group, and a diarylamino group. The divalent aromatic group may be an arylene group, of which a phenylene group and a naphthylene group are preferred. The divalent aromatic group may have a substituent, and examples of the substituent in the divalent aliphatic group include an alkyl group. Furthermore, L may be a divalent group obtained by removing two hydrogen atoms at any position from the structure represented by the above formulae LC1-1 to LC1-21 or SL1-1 to SL-3. When n is 2 or more, specific examples of the (n+1)-valent linking group include groups obtained by removing any (n-1) hydrogen atoms from the specific examples of the divalent linking groups mentioned above. Specific examples of L include the following linking groups.

[0136] [ka]

[0137] As described above, these linking groups may further have a substituent.

[0138] R 10 is preferably a group represented by the following formula W. -YR 20 formula W

[0139] In the above formula W, Y represents a group that is decomposed by the action of an alkaline aqueous solution and has an increased solubility in the alkaline aqueous solution. 20 represents an electron-withdrawing group.

[0140] Examples of Y include a carboxylate group (-COO- or OCO-), an acid anhydride group (-C(O)OC(O)-), an acid imide group (-NHCONH-), a carboxylate thioester group (-COS-), a carbonate group (-OC(O)O-), a sulfate group (-OSO-), and a sulfonate group (-SOO-), and a carboxylate group is preferred.

[0141] The electron-withdrawing group is preferably a partial structure represented by the following formula EW: In formula EW, * represents a bond directly bonded to group Y in formula W.

[0142] [ka]

[0143] In the formula EW, n ew -C(R ew1 )(R ew2 n is the number of repetitions of the linking group represented by -, and represents an integer of 0 or 1. ew If is 0, it represents a single bond, and Y ew1indicates that the bond is Y ew1 is a halogen atom, a cyano group, a nitro group, or -C(R f1 )(R f2 )-R f3 Examples of the halo(cyclo)alkyl group include a haloaryl group, an oxy group, a carbonyl group, a sulfonyl group, a sulfinyl group, and combinations thereof. (Note that Y ew1 is a halogen atom, a cyano group, or a nitro group, n ew is 1.) R ew1 and R ew2 each independently represents an arbitrary group, for example, a hydrogen atom, an alkyl group (preferably having 1 to 8 carbon atoms), a cycloalkyl group (preferably having 3 to 10 carbon atoms) or an aryl group (preferably having 6 to 10 carbon atoms). R ew1 , R ew2 and Y ew1 At least two of these may be linked to each other to form a ring. The term "halo(cyclo)alkyl group" refers to an alkyl group or cycloalkyl group which is at least partially halogenated, and the term "haloaryl group" refers to an aryl group which is at least partially halogenated.

[0144] Y ew1 Examples of the halogen atom include -C(R f1 )(R f2 )-R f3 A halo(cyclo)alkyl group represented by the following formula: or a haloaryl group is preferred.

[0145] R f1 represents a halogen atom, a perhaloalkyl group, a perhalocycloalkyl group, or a perhaloaryl group, preferably a fluorine atom, a perfluoroalkyl group, or a perfluorocycloalkyl group, more preferably a fluorine atom or a trifluoromethyl group. R f2 and R f3 each independently represents a hydrogen atom, a halogen atom, or an organic group; R f2 and R f3and may be linked to form a ring. Examples of the organic group include an alkyl group, a cycloalkyl group, and an alkoxy group, which may be substituted with a halogen atom (preferably a fluorine atom). R f2 and R f3 R is preferably a (halo)alkyl group or a (halo)cycloalkyl group. f2 is R f1 or R f3 It is more preferable that they are linked to form a ring. R f2 and R f3 Examples of the ring formed by linking these include a (halo)cycloalkyl ring.

[0146] R f1 ~R f3 The (halo)alkyl group in the formula (I) may be either linear or branched, and the linear (halo)alkyl group preferably has 1 to 30 carbon atoms, and more preferably has 1 to 20 carbon atoms.

[0147] R f1 ~R f3 In or R f2 and R f3 The (halo)cycloalkyl group in the ring formed by linking and may be a monocyclic or polycyclic group. In the case of a polycyclic group, the (halo)cycloalkyl group may be a bridged group. That is, in this case, the (halo)cycloalkyl group may have a bridged structure. Examples of these (halo)cycloalkyl groups include those represented by the following formulae and halogenated versions of these: In addition, some of the carbon atoms in the cycloalkyl group may be substituted with heteroatoms such as oxygen atoms.

[0148] [ka]

[0149] R f2 and R f3 In or R f2 and R f3As the (halo)cycloalkyl group in the ring formed by linking with (n) F (2n-2) Preferred is a fluorocycloalkyl group represented by H. Here, the carbon number n is not particularly limited, but is preferably 5 to 13, and more preferably 6.

[0150] Y ew1 In or R f1 The (per)haloaryl group in the formula (I) is -C (n) F (n-1) Here, the carbon number n is not particularly limited, but is preferably 5 to 13, and more preferably 6.

[0151] R ew1 , R ew2 and Y ew1 The ring which may be formed by combining at least two of these is preferably a cycloalkyl group or a heterocyclic group.

[0152] Each group and each ring constituting the partial structure represented by the above formula EW may further have a substituent.

[0153] In the above formula W, R 20 is preferably an alkyl group substituted with one or more selected from the group consisting of a halogen atom, a cyano group, and a nitro group, more preferably an alkyl group substituted with a halogen atom (haloalkyl group), and even more preferably a fluoroalkyl group. The alkyl group substituted with one or more selected from the group consisting of a halogen atom, a cyano group, and a nitro group preferably has 1 to 10 carbon atoms, and more preferably has 1 to 5 carbon atoms. More specifically, R 20 is -C(R' 1 )(R' f1 )(R' f2 ) or -C(R' 1 )(R' 2 )(R' f1 R' is preferably an atomic group represented by the formula: 1 and R' 2R' each independently represents a hydrogen atom or an alkyl group that is not substituted with an electron-withdrawing group (preferably unsubstituted). f1 and R' f2 each independently represents a halogen atom, a cyano group, a nitro group, or a perfluoroalkyl group. R' 1 and R' 2 The alkyl group as the radical may be linear or branched, and preferably has 1 to 6 carbon atoms. R' f1 and R' f2 The perfluoroalkyl group may be linear or branched, and preferably has 1 to 6 carbon atoms. R 20 Preferred specific examples of the above include -CF3, -C2F5, -C3F7, -C4F9, -CF(CF3)2, -CF(CF3)C2F5, -CF2CF(CF3)2, -C(CF3)3, -C5F 11 , -C6F 13 , -C7F 15 , -C8F 17 , -CH2CF3, -CH2C2F5, -CH2C3F7, -CH(CF3)2, -CH(CF3)C2F5, -CH2CF(CF3)2, and -CH2CN. Among them, -CF3, -C2F5, -C3F7, -C4F9, -CH2CF3, -CH2C2F5, -CH2C3F7, -CH(CF3)2, or -CH2CN is preferred, -CH2CF3, -CH2C2F5, -CH2C3F7, -CH(CF3)2, or -CH2CN is more preferred, -CH2C2F5, -CH(CF3)2, or -CH2CN is even more preferred, and -CH2C2F5 or -CH(CF3)2 is particularly preferred.

[0154] As the constitutional unit represented by formula X, a constitutional unit represented by the following formula X-1 or formula X-2 is preferable, and a constitutional unit represented by formula X-1 is more preferable.

[0155] [ka]

[0156] In formula X-1, R20 represents an electron-withdrawing group, L 2 represents a divalent linking group; X 2 represents an oxygen atom or a sulfur atom, Z 2 represents a halogen atom. In formula X-2, R 20 represents an electron-withdrawing group, L 3 represents a divalent linking group; X 3 represents an oxygen atom or a sulfur atom, Z 3 represents a halogen atom.

[0157] L 2 and L 3 Specific examples and preferred examples of the divalent linking group as are the same as those explained for L as the divalent linking group in formula X above. R 2 and R 3 The electron-withdrawing group as is preferably a partial structure represented by the above formula EW, and specific examples and preferred examples are as described above, but a halo(cyclo)alkyl group is more preferred.

[0158] In the above formula X-1, L 2 and R 2 and do not bond to each other to form a ring, and in the above formula X-2, L 3 and R 3 do not bond to each other to form a ring.

[0159] X 2 and X 3 is preferably an oxygen atom. Z 2 and Z 3 is preferably a fluorine atom or a chlorine atom, and more preferably a fluorine atom.

[0160] As the constitutional unit represented by the formula X, a constitutional unit represented by the formula X-3 is also preferred.

[0161] [ka]

[0162] In formula X-3, R 20 represents an electron-withdrawing group, R 21 represents a hydrogen atom, an alkyl group, or an aryl group; L 4 represents a divalent linking group; X 4 represents an oxygen atom or a sulfur atom, and m represents 0 or 1.

[0163] L 4 Specific examples and preferred examples of the divalent linking group as are the same as those explained for L as the divalent linking group of formula X. R 4 The electron-withdrawing group as is preferably a partial structure represented by the above formula EW, and specific and preferred examples are as described above, but is more preferably a halo(cyclo)alkyl group.

[0164] In the above formula X-3, L 4 and R 4 do not bond to each other to form a ring. X 4 is preferably an oxygen atom.

[0165] As the structural unit represented by formula X, a structural unit represented by formula Y-1 or a structural unit represented by formula Y-2 is also preferred.

[0166] [ka]

[0167] In formula Y-1 and formula Y-2, Z is a halogen atom, R 11 A group represented by OCH2- or R 12 R represents a group represented by OC(=O)CH2-. 11 and R 12 each independently represents a substituent; R 20 represents an electron-withdrawing group.

[0168] R 20The electron-withdrawing group as is preferably a partial structure represented by the above formula EW, and specific and preferred examples are as described above, but is more preferably a halo(cyclo)alkyl group.

[0169] Z as halogen atom, R 11 A group represented by OCH2- and R 12 Specific and preferred examples of the group represented by OC(=O)CH2- are the same as those explained in formula 1 above.

[0170] The content of the constitutional unit represented by formula X is preferably from 10 mol % to 100 mol %, more preferably from 20 mol % to 100 mol %, and further preferably from 30 mol % to 100 mol %, based on all constitutional units of the fluorine-containing resin.

[0171] Preferred examples of the structural units constituting the hydrophobic resin (E) are shown below. Preferred examples of the hydrophobic resin (E) include resins containing any combination of these structural units, and resins E-1 to E-23 used in the examples, but are not limited to these.

[0172] [ka]

[0173] [ka]

[0174] The hydrophobic resin (E) may be used alone or in combination of two or more kinds. It is preferable to use a mixture of two or more hydrophobic resins (E) having different surface energies from the viewpoint of achieving both immersion liquid followability in immersion exposure and development characteristics. The content of the hydrophobic resin (E) in the composition is preferably 0.01 mass % to 10 mass %, and more preferably 0.05 mass % to 8 mass %, based on the total solid content of the photosensitive resin composition according to the present disclosure.

[0175] <Photoacid generator> The composition according to the present disclosure preferably contains a photoacid generator (hereinafter also referred to as "photoacid generator (B)"). A photoacid generator is a compound that generates an acid when exposed to actinic rays or radiation. The photoacid generator is preferably a compound that generates an organic acid upon irradiation with actinic rays or radiation, such as a sulfonium salt compound, an iodonium salt compound, a diazonium salt compound, a phosphonium salt compound, an imide sulfonate compound, an oxime sulfonate compound, a diazodisulfone compound, a disulfone compound, and an o-nitrobenzylsulfonate compound.

[0176] As the photoacid generator, a known compound that generates an acid by irradiation with actinic rays or radiation can be appropriately selected and used alone or as a mixture thereof. For example, the known compounds disclosed in paragraphs 0125 to 0319 of US Patent Application Publication No. 2016 / 0070167, paragraphs 0086 to 0094 of US Patent Application Publication No. 2015 / 0004544, and paragraphs 0323 to 0402 of US Patent Application Publication No. 2016 / 0237190 can be suitably used as the photoacid generator (B).

[0177] [Compounds represented by formulae ZI, ZII and ZIII] Suitable embodiments of the photoacid generator (B) include, for example, compounds represented by the following formulae ZI, ZII, and ZIII.

[0178] [ka]

[0179] In the above formula ZI, R 201 , R 202 and R 203 each independently represents an organic group. R 201 , R 202 and R 203 The organic group as the substituent preferably has 1 to 30 carbon atoms, and more preferably has 1 to 20 carbon atoms. Also, 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 bond, an amide bond, or a carbonyl group. 201 ~R 203 Examples of the group formed by combining two of these groups include an alkylene group (for example, a butylene group, a pentylene group) and -CH2-CH2-O-CH2-CH2-. Z - represents an anion.

[0180] [Cation in the compound represented by formula ZI] Suitable embodiments of the cation in formula ZI include the corresponding groups in the compounds (ZI-1), (ZI-2), (ZI-3) and (ZI-4) described below. The photoacid generator (C) may be a compound having a plurality of structures represented by formula ZI. For example, R 201 ~R 203 and R of another compound represented by formula ZI. 201 ~R 203 and at least one of the above may be bonded via a single bond or a linking group.

[0181] -Compound ZI-1- First, the compound (ZI-1) will be described. Compound (ZI-1) is a compound represented by the formula ZI 201 ~R 203 At least one of the above is an aryl group, that is, an arylsulfonium compound, that is, a compound having an arylsulfonium cation. Arylsulfonium compounds are R 201 ~R 203 may all be aryl groups, or R 201 ~R 203 A part of the group may be an aryl group, and the remainder may be an alkyl group or a cycloalkyl group. Examples of the arylsulfonium compound include triarylsulfonium compounds, diarylalkylsulfonium compounds, aryldialkylsulfonium compounds, diarylcycloalkylsulfonium compounds, and aryldicycloalkylsulfonium compounds.

[0182] The aryl group of the arylsulfonium compound is preferably a phenyl group or a naphthyl group, more preferably a phenyl group. The aryl group may be an aryl group having a heterocyclic structure with an oxygen atom, a nitrogen atom, or a sulfur atom. Examples of the heterocyclic structure include a pyrrole residue, a furan residue, a thiophene residue, an indole residue, a benzofuran residue, and a benzothiophene residue. When the arylsulfonium compound has two or more aryl groups, the two or more aryl groups may be the same or different. The alkyl group or cycloalkyl group that the arylsulfonium compound may have as needed is preferably a linear alkyl group having 1 to 15 carbon atoms, a branched alkyl group having 3 to 15 carbon atoms, or a cycloalkyl group having 3 to 15 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a t-butyl group, a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group.

[0183] R 201 ~R 203 The aryl group, alkyl group, and cycloalkyl group may each independently have 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 14 carbon atoms), an alkoxy group (e.g., having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, or a phenylthio group as a substituent.

[0184] -Compound ZI-2- Next, the compound (ZI-2) will be described. Compound (ZI-2) is a compound represented by the formula ZI 201 ~R 203are each independently an organic group having no aromatic ring. Here, the aromatic ring also includes an aromatic ring containing a hetero atom. R 201 ~R 203 The organic group having no aromatic ring as the aromatic ring preferably has 1 to 30 carbon atoms, and more preferably has 1 to 20 carbon atoms. R 201 ~R 203 are each independently preferably an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, more preferably a linear or branched 2-oxoalkyl group, a 2-oxocycloalkyl group, or an alkoxycarbonylmethyl group, and further preferably a linear or branched 2-oxoalkyl group.

[0185] R 201 ~R 203 The alkyl group and cycloalkyl group preferably include a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms (e.g., a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group), and a cycloalkyl group having 3 to 10 carbon atoms (e.g., a cyclopentyl group, a cyclohexyl group, and a norbornyl group). R 201 ~R 203 may be further substituted with a halogen atom, an alkoxy group (eg, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.

[0186] -Compound ZI-3- Next, the compound (ZI-3) will be described. Compound (ZI-3) is represented by the following formula ZI-3, and is a compound having a phenacylsulfonium salt structure.

[0187] [ka]

[0188] In formula ZI-3, R 1c ~R 5ceach independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, a cycloalkylcarbonyloxy group, a halogen atom, a hydroxyl group, a nitro group, an alkylthio group, or an arylthio group; R 6c and R 7c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an aryl group; R x and R y each independently represents an alkyl group, a cycloalkyl group, a 2-oxoalkyl group, a 2-oxocycloalkyl group, an alkoxycarbonylalkyl group, an allyl group, or a vinyl group.

[0189] R 1c ~R 5c Any two or more of the following, R 5c and R 6c , R 6c and R 7c , R 5c and R x , and R x and R y may be bonded to each other to form a ring structure, and each of these ring structures may independently contain an oxygen atom, a sulfur atom, a ketone group, an ester bond, or an amide bond. Examples of the ring structure include aromatic or non-aromatic hydrocarbon rings, aromatic or non-aromatic heterocyclic rings, and polycyclic condensed rings formed by combining two or more of these rings. Examples of the ring structure include 3- to 10-membered rings, preferably 4- to 8-membered rings, and more preferably 5- or 6-membered rings.

[0190] R 1c ~R 5c Any two or more of the following, R 6c and R 7c , and R x and R y Examples of the group formed by bonding include a butylene group and a pentylene group. R 5c and R 6c , and R 5c and R xThe group formed by bonding is preferably a single bond or an alkylene group. Examples of the alkylene group include a methylene group and an ethylene group. Zc - represents an anion.

[0191] -Compound ZI-4- Next, the compound (ZI-4) will be described. The compound (ZI-4) is represented by the following formula ZI-4.

[0192] [ka]

[0193] In formula ZI-4, l represents an integer of 0 to 2, r represents an integer of 0 to 8, R 13 represents a hydrogen atom, a fluorine atom, a hydroxyl group, an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, or a group having a cycloalkyl group, and these groups may have a substituent; R 14 each independently represents a group having a hydroxyl group, an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylsulfonyl group, a cycloalkylsulfonyl group, or a cycloalkyl group, and these groups may have a substituent; R 15 each independently represents an alkyl group, a cycloalkyl group, or a naphthyl group, and these groups may have a substituent; 15 may be bonded to each other to form a ring. The Two R's 15 When R are bonded to each other to form a ring, the ring structure may contain heteroatoms such as oxygen or nitrogen atoms. 15 are preferably alkylene groups and are bonded to each other to form a ring structure. Z - represents an anion.

[0194] In formula ZI-4, R 13 , R 14 and R 15The alkyl group is linear or branched and preferably has 1 to 10 carbon atoms, more preferably a methyl group, an ethyl group, an n-butyl group, a t-butyl group, or the like.

[0195] [Cation in the compound represented by formula ZII or formula ZIII] Next, formulae ZII and ZIII will be explained. In formulas ZII and ZIII, R 204 ~R 207 each independently represents an aryl group, an alkyl group, or a cycloalkyl group. R 204 ~R 207 The aryl group of R is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. 204 ~R 207 The aryl group may be an aryl group having a heterocyclic structure containing an oxygen atom, a nitrogen atom, a sulfur atom, etc. Examples of the skeleton of the aryl group having a heterocyclic structure include pyrrole, furan, thiophene, indole, benzofuran, and benzothiophene. R 204 ~R 207 The alkyl group and cycloalkyl group preferably include a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms (e.g., a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group), and a cycloalkyl group having 3 to 10 carbon atoms (e.g., a cyclopentyl group, a cyclohexyl group, and a norbornyl group).

[0196] R 204 ~R 207 The aryl group, alkyl group, and cycloalkyl group in R may each independently have a substituent. 204 ~R 207 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 hydroxyl group, and a phenylthio group. Z - represents an anion.

[0197] [Anions in the compounds represented by formulae ZI to ZIII] Z in the formula ZI - , Z in formula ZII - , Zc in formula ZI-3 - and Z in formula ZI-4 - is preferably an anion represented by the following formula An-1.

[0198] [ka]

[0199] In formula An-1, pf represents an integer of 0 to 10, qf represents an integer of 0 to 10, rf represents an integer of 1 to 3, each Xf independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom, and when rf is an integer of 2 or more, multiple -C(Xf)2- may be the same or different, and R 4 and R 5 each independently represents a hydrogen atom, a fluorine atom, an alkyl group, or an alkyl group substituted with at least one fluorine atom, and when pf is an integer of 2 or more, a plurality of -CR 4f R 5f - may be the same or different, L f represents a divalent linking group, and when qf is an integer of 2 or more, a plurality of L f may be the same or different, and W represents an organic group containing a cyclic structure.

[0200] Xf represents a fluorine atom or an alkyl group substituted with at least one fluorine atom. The number of carbon atoms in this alkyl group is preferably 1 to 10, more preferably 1 to 4. In addition, the alkyl group substituted with at least one fluorine atom is preferably a perfluoroalkyl group. Xf is preferably a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms. Xf is more preferably a fluorine atom or CF3. It is particularly preferable that both Xf are fluorine atoms.

[0201] R 4f and R 5f Each of R independently represents a hydrogen atom, a fluorine atom, an alkyl group, or an alkyl group substituted with at least one fluorine atom. 4f and R 5f may be the same or different. R 4f and R 5f The alkyl group represented by R may have a substituent and preferably has 1 to 4 carbon atoms. 4f and R 5f is preferably a hydrogen atom. Specific examples and preferred embodiments of the alkyl group substituted with at least one fluorine atom are the same as the specific examples and preferred embodiments of Xf in formula An-1.

[0202] L f represents a divalent linking group, and when a plurality of L f may be the same or different. Examples of the divalent linking group include -COO-(-C(=O)-O-), -OCO-, -CONH-, -NHCO-, -CO-, -O-, -S-, -SO-, -SO2-, an alkylene group (preferably having 1 to 6 carbon atoms), a cycloalkylene group (preferably having 3 to 15 carbon atoms), an alkenylene group (preferably having 2 to 6 carbon atoms), and a divalent linking group formed by combining a plurality of these. Among these, -COO-, -OCO-, -CONH-, -NHCO-, -CO-, -O-, -SO2-, -COO-alkylene group-, -OCO-alkylene group-, -CONH-alkylene group-, or -NHCO-alkylene group- are preferred, and -COO-, -OCO-, -CONH-, -SO2-, -COO-alkylene group-, or -OCO-alkylene group- are more preferred.

[0203] W represents an organic group containing a cyclic structure. Among these, a cyclic organic group is preferable. Examples of the cyclic organic group include an alicyclic group, an aryl group, and a heterocyclic group. The alicyclic group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic group include monocyclic cycloalkyl groups such as cyclopentyl, cyclohexyl, and cyclooctyl. Examples of the polycyclic alicyclic group include polycyclic cycloalkyl groups such as norbornyl, tricyclodecanyl, tetracyclodecanyl, tetracyclododecanyl, and adamantyl. Among them, alicyclic groups having a bulky structure with 7 or more carbon atoms, such as norbornyl, tricyclodecanyl, tetracyclodecanyl, tetracyclododecanyl, and adamantyl, are preferred.

[0204] The aryl group may be monocyclic or polycyclic and includes, for example, phenyl, naphthyl, phenanthryl and anthryl groups. The heterocyclic group may be monocyclic or polycyclic. The polycyclic group can suppress the diffusion of the acid more effectively. The heterocyclic group may have aromaticity or may not have aromaticity. Examples of heterocyclic rings having aromaticity include furan ring, thiophene ring, benzofuran ring, benzothiophene ring, dibenzofuran ring, dibenzothiophene ring, and pyridine ring. Examples of heterocyclic rings not having aromaticity include tetrahydropyran ring, lactone ring, sultone ring, and decahydroisoquinoline ring. Examples of lactone ring and sultone ring include the lactone structure and sultone structure exemplified in the above-mentioned resin. As the heterocyclic ring in the heterocyclic group, a furan ring, a thiophene ring, a pyridine ring, or a decahydroisoquinoline ring is particularly preferable.

[0205] The cyclic organic group may have a substituent. Examples of the substituent include an alkyl group (which may be linear or branched, and preferably has 1 to 12 carbon atoms), a cycloalkyl group (which may be monocyclic, polycyclic, or spirocyclic, and preferably has 3 to 20 carbon atoms), an aryl group (which preferably has 6 to 14 carbon atoms), a hydroxyl group, an alkoxy group, an ester group, an amide group, a urethane group, a ureido group, a thioether group, a sulfonamide group, and a sulfonate ester group. The carbon that constitutes the cyclic organic group (the carbon that contributes to the ring formation) may be a carbonyl carbon.

[0206] The anion represented by the formula An-1 is SO3 - -CF2-CH2-OCO-(L f )q'-W, SO3 - -CF2-CHF-CH2-OCO-(L f )q'-W, SO3 - -CF2-COO-(L f )q'-W, SO3 - -CF2-CF2-CH2-CH2-(L f ) qf -W, SO3 - -CF2-CH(CF3)-OCO-(L f )q'-W is preferred. f , qf and W are the same as in formula An-1. q' represents an integer of 0 to 10.

[0207] In one embodiment, Z in formula ZI - , Z in formula ZII - , Zc in formula ZI-3 - and Z in formula ZI-4 - The anion represented by the following formula 4 is also preferred.

[0208] [ka]

[0209] In formula 4, X B1 and X B2Each of X independently represents a hydrogen atom or a monovalent organic group that does not contain a fluorine atom. B1 and X B2 is preferably a hydrogen atom. X B3 and X B4 Each of X independently represents a hydrogen atom or a monovalent organic group. B3 and X B4 At least one of X is preferably a fluorine atom or a monovalent organic group having a fluorine atom, B3 and X B4 It is more preferable that both of X are fluorine atoms or monovalent organic groups having fluorine atoms. B3 and X B4 It is more preferable that both of the above are fluorine-substituted alkyl groups. L f , qf and W are the same as in Equation 3.

[0210] Z in the formula ZI - , Z in formula ZII - , Zc in formula ZI-3 - and Z in formula ZI-4 - is preferably an anion represented by the following formula 5.

[0211] [ka]

[0212] In formula 5, each Xa independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom, and each Xb independently represents a hydrogen atom or an organic group having no fluorine atom. 4f , R 5f , L f The definitions and preferred embodiments of and W are the same as those of formula 3.

[0213] Z in the formula ZI - , Z in formula ZII - , Zc in formula ZI-3 - and Z in formula ZI-4 -may be a benzenesulfonate anion, preferably a benzenesulfonate anion substituted with a branched alkyl or cycloalkyl group.

[0214] Z in the formula ZI - , Z in formula ZII - , Zc in formula ZI-3 - and Z in formula ZI-4 - Also preferred as the anion is an aromatic sulfonate anion represented by the following formula SA1.

[0215] [ka]

[0216] In formula SA1, Ar represents an aryl group, and the sulfonate anion and -(DR B ) may further have a substituent other than the above. Examples of the substituent that may further be had include a fluorine atom and a hydroxyl group.

[0217] n represents an integer of 0 or more. n is preferably 1 to 4, more preferably 2 to 3, and particularly preferably 3.

[0218] D represents a single bond or a divalent linking group. Examples of the divalent linking group include an ether group, a thioether group, a carbonyl group, a sulfoxide group, a sulfone group, a sulfonate group, an ester group, and a group consisting of a combination of two or more of these groups.

[0219] R B represents a hydrocarbon group.

[0220] Preferably, D is a single bond and R B is an aliphatic hydrocarbon structure. B is more preferably an isopropyl group or a cyclohexyl group.

[0221] Preferred examples of the sulfonium cation in formula ZI and the sulfonium or iodonium cation in formula ZII are shown below.

[0222] [ka]

[0223] Anion Z in formula ZI and formula ZII - , Zc in formula ZI-3 - and Z in formula ZI-4 - Preferred examples are shown below.

[0224] [ka]

[0225] Any combination of the above cations and anions can be used as a photoacid generator. In particular, it is preferable that the photoacid generator is an ionic compound containing a cation and an anion, and the anion contains an ion represented by any one of the above formula An-1, the following formula An-2, and the following formula An-3.

[0226] [ka]

[0227] In formulae An-2 and An-3, Rfa each independently represents a monovalent organic group having a fluorine atom, and multiple Rfa may be bonded to each other to form a ring.

[0228] Rfa is preferably an alkyl group substituted with at least one fluorine atom. The number of carbon atoms in this alkyl group is preferably 1 to 10, more preferably 1 to 4. In addition, the alkyl group substituted with at least one fluorine atom is preferably a perfluoroalkyl group. In addition, a plurality of Rfa are preferably bonded to each other to form a ring.

[0229] The photoacid generator may be in the form of a low molecular weight compound, or may be incorporated into a part of a polymer. Also, the photoacid generator may be in the form of a low molecular weight compound and in the form of a polymer in combination. The photoacid generator is preferably in the form of a low molecular weight compound. When the photoacid generator is in the form of a low molecular weight compound, the molecular weight is preferably 3,000 or less, more preferably 2,000 or less, and even more preferably 1,000 or less. When the photoacid generator is in a form in which it is incorporated into a part of a polymer, it may be incorporated into a part of the above-mentioned resin (A), or may be incorporated into a resin different from the resin (A). The photoacid generator may be used alone or in combination of two or more kinds. The content of the photoacid generator in the composition (the total amount if multiple types are present) is preferably 0.1 mass % to 35 mass %, more preferably 0.5 mass % to 25 mass %, even more preferably 3 mass % to 20 mass %, and particularly preferably 3 mass % to 15 mass %, based on the total solid content of the composition. When the photoacid generator contains a compound represented by the above formula ZI-3 or ZI-4, the content of the photoacid generator contained in the composition (the total content when multiple types are present) is preferably 5% by mass to 35% by mass, more preferably 7% by mass to 30% by mass, based on the total solid content of the composition.

[0230] <Acid diffusion control agent> The photosensitive resin composition according to the present disclosure preferably contains an acid diffusion controller (also referred to as "acid diffusion controller (D)"). The acid diffusion controller (D) traps the acid generated from the acid generator etc. upon exposure and acts as a quencher to suppress the reaction of the acid-decomposable resin in the unexposed area due to excess acid generated. For example, a basic compound (DA), a basic compound (DB) whose basicity is reduced or eliminated by irradiation with actinic rays or radiation, an onium salt (DC) whose acidity is relatively weaker than that of the acid generator, a low molecular weight compound (DD) having a nitrogen atom and a group that is eliminated by the action of an acid, or an onium salt compound (DE) having a nitrogen atom in the cation moiety can be used as the acid diffusion controller. In particular, from the viewpoint of linearity of a pattern obtained after aging, the photosensitive resin composition according to the present disclosure preferably contains a nitrogen-containing compound, and more preferably contains a nitrogen-containing basic compound, as an acid diffusion controller. In the photosensitive resin composition according to the present disclosure, a known acid diffusion controller can be appropriately used. For example, the known compounds disclosed in paragraphs 0627-0664 of US Patent Application Publication No. 2016 / 0070167, paragraphs 0095-0187 of US Patent Application Publication No. 2015 / 0004544, paragraphs 0403-0423 of US Patent Application Publication No. 2016 / 0237190, and paragraphs 0259-0328 of US Patent Application Publication No. 2016 / 0274458 can be suitably used as the acid diffusion controller (D).

[0231] [Basic compounds (DA)] Preferred examples of the basic compound (DA) include compounds having structures represented by the following formulae A to E.

[0232] [ka]

[0233] In formula A and formula E, R 200 , R 201 and R 202may be the same or different, and each independently represents a hydrogen atom, an alkyl group (preferably having 1 to 20 carbon atoms), a cycloalkyl group (preferably having 3 to 20 carbon atoms), or an aryl group (preferably having 6 to 20 carbon atoms). R 201 and R 202 may be bonded to each other to form a ring. R 203 , R 204 , R 205 and R 206 may be the same or different, and each independently represents an alkyl group having 1 to 20 carbon atoms.

[0234] The alkyl groups in formulae A and E may be substituted or unsubstituted. Regarding the above alkyl group, the alkyl group having a substituent is preferably an aminoalkyl group having 1 to 20 carbon atoms, a hydroxyalkyl group having 1 to 20 carbon atoms, or a cyanoalkyl group having 1 to 20 carbon atoms. More preferably, the alkyl groups in formulae A and E are unsubstituted.

[0235] The basic compound (DA) is preferably guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine, piperidine, or the like, and more preferably a compound having an imidazole structure, a diazabicyclo structure, an onium hydroxide structure, an onium carboxylate structure, a trialkylamine structure, an aniline structure or a pyridine structure, an alkylamine derivative having a hydroxyl group and / or an ether bond, or an aniline derivative having a hydroxyl group and / or an ether bond.

[0236] [Basic compounds (DB) whose basicity decreases or disappears when exposed to actinic rays or radiation] A basic compound (DB) (hereinafter, also referred to as "compound (DB)") whose basicity is reduced or eliminated by irradiation with actinic rays or radiation is a compound that has a proton acceptor functional group and is decomposed by irradiation with actinic rays or radiation, and the proton acceptor property is reduced or eliminated, or the proton acceptor property is changed from a proton acceptor property to an acidic property.

[0237] A proton acceptor functional group is a group that can interact electrostatically with a proton or a functional group having electrons, and for example, it means a functional group having a macrocyclic structure such as a cyclic polyether, or a functional group having a nitrogen atom with a non-bonding electron pair that does not contribute to π-conjugation. A nitrogen atom with a non-bonding electron pair that does not contribute to π-conjugation is, for example, a nitrogen atom having a partial structure represented by the following formula.

[0238]

Chemical formula

[0239] Preferred partial structures of the proton acceptor functional group include, for example, crown ether, azacrown ether, primary to tertiary amines, pyridine, imidazole, and pyrazine structures.

[0240] Compound (DB) decomposes upon irradiation with actinic rays or radiation to generate a compound in which the proton acceptor property decreases or disappears, or changes from a proton acceptor property to acidity. Here, the decrease or disappearance of the proton acceptor property, or the change from the proton acceptor property to acidity, is a change in the proton acceptor property caused by the addition of a proton to the proton acceptor functional group. Specifically, when a proton adduct is formed from a compound (DB) having a proton acceptor functional group and a proton, it means that the equilibrium constant in the chemical equilibrium decreases. The proton acceptor property can be confirmed by measuring the pH.

[0241] The acid dissociation constant pKa of the compound generated by the decomposition of compound (DB) upon irradiation with actinic rays or radiation preferably satisfies pKa < -1, more preferably -13 < pKa < -1, and even more preferably -13 < pKa < -3.

[0242] The acid dissociation constant pKa refers to the acid dissociation constant pKa in an aqueous solution, and is defined, for example, in Chemistry Handbook (II) (revised 4th edition, 1993, edited by the Chemical Society of Japan, Maruzen Co., Ltd.). The lower the value of the acid dissociation constant pKa, the greater the acid strength. Specifically, the acid dissociation constant pKa in an aqueous solution can be measured by measuring the acid dissociation constant at 25°C using an infinitely diluted aqueous solution. Alternatively, the value can be calculated based on a database of Hammett's substituent constants and known literature values ​​using the following software package 1. All pKa values ​​described in this specification are values ​​calculated using this software package.

[0243] Software package 1: Advanced Chemistry Development (ACD / Labs) Software V8.14 for Solaris (1994-2007 ACD / Labs).

[0244] [Onium salts (DC) that are weak acids relative to photoacid generators] In the photosensitive resin composition according to the present disclosure, an onium salt (DC) that is a relatively weak acid compared to the photoacid generator can be used as another acid diffusion controller. When a photoacid generator is used in combination with an onium salt that generates an acid that is weaker than the acid generated by the photoacid generator, when the acid generated by the photoacid generator upon irradiation with actinic rays or radiation collides with an onium salt having an unreacted weak acid anion, the weak acid is released by salt exchange to generate an onium salt having a strong acid anion. In this process, the strong acid is exchanged for a weak acid with a lower catalytic activity, and the acid appears to be deactivated, thereby enabling control of acid diffusion.

[0245] From the viewpoints of depth of focus latitude and pattern linearity, the photosensitive resin composition according to the present disclosure preferably further contains at least one compound selected from the group consisting of compounds represented by formulas d1-1 to d1-3.

[0246] [ka]

[0247] In formulas d1-1 to d1-3, R 51 represents a hydrocarbon group which may have a substituent; Z 2c represents a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent, and a fluorine atom is not bonded to the carbon atom adjacent to the S atom; R 52 represents an organic group, and Y 3 represents a linear, branched or cyclic alkylene group or arylene group, Rf represents a hydrocarbon group containing a fluorine atom, M + each independently represents an ammonium cation, a sulfonium cation, or an iodonium cation.

[0248] M + Preferred examples of the sulfonium cation or iodonium cation represented by the formula ZI and the iodonium cation represented by the formula ZII can be mentioned.

[0249] The onium salt (DC) which is a weak acid relative to the photoacid generator may be a compound having a cationic moiety and an anionic moiety in the same molecule, and in which the cationic moiety and the anionic moiety are linked by a covalent bond (hereinafter, also referred to as "compound (DCA)"). The compound (DCA) is preferably a compound represented by any one of the following formulas C-1 to C-3.

[0250] [ka]

[0251] In formulas C-1 to C-3, R 1 , R 2 , and R 3 each independently represents a substituent having 1 or more carbon atoms. L 1 represents a divalent linking group or a single bond that links a cationic moiety and an anionic moiety. -X - -COO -, -SO3 - , -SO2 - , and -N - -R 4 R represents an anionic moiety selected from 4 represents a monovalent substituent having at least one of a carbonyl group (-C(=O)-), a sulfonyl group (-S(=O)2-), and a sulfinyl group (-S(=O)-) at the bonding site with the adjacent N atom. R 1 , R 2 , R 3 , R 4 , and L 1 may be bonded to each other to form a ring structure. 1 ~R 3 Two of these may be combined to represent one divalent substituent, which may be bonded to the N atom via a double bond.

[0252] R 1 ~R 3 Examples of the substituent having one or more carbon atoms in the formula (I) include an alkyl group, a cycloalkyl group, an aryl group, an alkyloxycarbonyl group, a cycloalkyloxycarbonyl group, an aryloxycarbonyl group, an alkylaminocarbonyl group, a cycloalkylaminocarbonyl group, and an arylaminocarbonyl group. An alkyl group, a cycloalkyl group, or an aryl group is preferable.

[0253] L as a divalent linking group 1 L includes a linear or branched alkylene group, a cycloalkylene group, an arylene group, a carbonyl group, an ether bond, an ester bond, an amide bond, a urethane bond, a urea bond, and a group formed by combining two or more of these. 1 is preferably an alkylene group, an arylene group, an ether bond, an ester bond, or a group formed by combining two or more of these.

[0254] [Low molecular weight compound (DD) having a nitrogen atom and a group that is cleaved by the action of an acid] The low molecular weight compound (DD) having a nitrogen atom and a group that can be eliminated by the action of an acid (hereinafter also referred to as "compound (DD)") is preferably an amine derivative having, on the nitrogen atom, a group that can be eliminated by the action of an acid. The group which is eliminated by the action of an acid is preferably an acetal group, a carbonate group, a carbamate group, a tertiary ester group, a tertiary hydroxyl group, or a hemiaminal ether group, more preferably a carbamate group or a hemiaminal ether group. The molecular weight of the compound (DD) is preferably from 100 to 1,000, more preferably from 100 to 700, and even more preferably from 100 to 500. Compound (DD) may have a carbamate group having a protecting group on the nitrogen atom. The protecting group constituting the carbamate group can be represented by the following formula d-1.

[0255] [ka]

[0256] In formula d-1, R b R each independently represents a hydrogen atom, an alkyl group (preferably having 1 to 10 carbon atoms), a cycloalkyl group (preferably having 3 to 30 carbon atoms), an aryl group (preferably having 3 to 30 carbon atoms), an aralkyl group (preferably having 1 to 10 carbon atoms), or an alkoxyalkyl group (preferably having 1 to 10 carbon atoms). b may be linked to each other to form a ring. R b The alkyl group, cycloalkyl group, aryl group, and aralkyl group represented by R may each independently be substituted with a functional group such as a hydroxy group, a cyano group, an amino group, a pyrrolidino group, a piperidino group, a morpholino group, or an oxo group, an alkoxy group, or a halogen atom. b The same applies to the alkoxyalkyl group represented by the formula:

[0257] R bAs the alkyl group, a linear or branched alkyl group, a cycloalkyl group, or an aryl group is preferable, and a linear or branched alkyl group, or a cycloalkyl group is more preferable. The Two R's b Examples of the ring formed by linking together include alicyclic hydrocarbons, aromatic hydrocarbons, heterocyclic hydrocarbons, and derivatives thereof. Specific examples of the group represented by formula d-1 include, but are not limited to, the structures disclosed in paragraph 0466 of US Patent Application Publication No. 2012 / 0135348.

[0258] The compound (DD) preferably has a structure represented by the following formula 6.

[0259] [ka]

[0260] In Equation 6, l represents an integer of 0 to 2, m represents an integer of 1 to 3, and l+m=3 is satisfied. R a represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or an aralkyl group. When l is 2, two R a can be the same or different, and the two R a may be linked together to form a heterocycle together with the nitrogen atom in the formula. This heterocycle may contain heteroatoms other than the nitrogen atom in the formula. R b is R in the above formula d-1 b The same applies to preferred examples. In formula 6, R a The alkyl group, cycloalkyl group, aryl group, and aralkyl group represented by R b The alkyl group, cycloalkyl group, aryl group, and aralkyl group as the optionally substituted group may be substituted with the same groups as those mentioned above as the optionally substituted group.

[0261] Above R aSpecific examples of the alkyl group, cycloalkyl group, aryl group, and aralkyl group (which may be substituted with the above groups) include R b The same groups as those specifically mentioned above can be mentioned. In the present disclosure, a specific structure of the particularly preferred compound (DD) is, but is not limited to, the compound disclosed in paragraph 0475 of U.S. Patent Application Publication No. 2012 / 0135348.

[0262] The onium salt compound (DE) having a nitrogen atom in the cationic moiety (hereinafter also referred to as "compound (DE)") is preferably a compound having a basic moiety containing a nitrogen atom in the cationic moiety. The basic moiety is preferably an amino group, more preferably an aliphatic amino group. It is further preferable that all atoms adjacent to the nitrogen atom in the basic moiety are hydrogen atoms or carbon atoms. Furthermore, from the viewpoint of improving basicity, it is preferable that an electron-withdrawing functional group (such as a carbonyl group, a sulfonyl group, a cyano group, or a halogen atom) is not directly bonded to the nitrogen atom. A preferred specific structure of compound (DE) may include, but is not limited to, the compound disclosed in paragraph 0203 of US Patent Application Publication No. 2015 / 0309408.

[0263] Other preferred examples of the acid diffusion controller are given below.

[0264] [ka]

[0265] [ka]

[0266] [ka]

[0267] In the photosensitive resin composition according to the present disclosure, the other acid diffusion controllers may be used alone or in combination of two or more. The content of the acid diffusion controller in the composition (the total content when multiple types are present) is preferably 0.1 to 10 mass %, more preferably 0.1 to 5 mass %, based on the total solid content of the composition.

[0268] <Solvent> The photosensitive resin composition according to the present disclosure preferably contains a solvent (also referred to as "solvent (F)"), and more preferably contains an organic solvent. In the photosensitive resin composition according to the present disclosure, known resist solvents can be appropriately used. For example, known solvents disclosed in paragraphs 0665-0670 of US Patent Application Publication No. 2016 / 0070167, paragraphs 0210-0235 of US Patent Application Publication No. 2015 / 0004544, paragraphs 0424-0426 of US Patent Application Publication No. 2016 / 0237190, and paragraphs 0357-0366 of US Patent Application Publication No. 2016 / 0274458 can be suitably used. Examples of solvents that can be used when preparing the composition include organic solvents such as alkylene glycol monoalkyl ether carboxylates, alkylene glycol monoalkyl ethers, alkyl lactates, alkyl alkoxypropionates, cyclic lactones (preferably having 4 to 10 carbon atoms), monoketone compounds which may have a ring (preferably having 4 to 10 carbon atoms), alkylene carbonates, alkyl alkoxyacetates, and alkyl pyruvates.

[0269] As the organic solvent, a mixed solvent obtained by mixing a solvent containing a hydroxyl group in the structure with a solvent not containing a hydroxyl group may be used. The solvent containing a hydroxyl group and the solvent not containing a hydroxyl group can be appropriately selected from the above-mentioned exemplary compounds. As the solvent containing a hydroxyl group, an alkylene glycol monoalkyl ether, an alkyl lactate, or the like is preferable, and propylene glycol monomethyl ether (PGME), propylene glycol monoethyl ether (PGEE), methyl 2-hydroxyisobutyrate, or ethyl lactate is more preferable. In addition, as the solvent not containing a hydroxyl group, alkylene glycol monoalkyl ether acetate, alkyl alkoxypropionate, monoketone compound which may contain a ring, cyclic lactone, alkyl acetate, etc. are preferred, among which propylene glycol monomethyl ether acetate (PGMEA), ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, cyclopentanone or butyl acetate are more preferred, and propylene glycol monomethyl ether acetate, γ-butyrolactone, ethyl ethoxypropionate, cyclohexanone, cyclopentanone or 2-heptanone are even more preferred. As the solvent not containing a hydroxyl group, propylene carbonate is also preferred. Among these, from the viewpoint of uniformity of the layer to be formed, it is particularly preferred that the solvent contains γ-butyrolactone. The mixing ratio (mass ratio) of the solvent containing a hydroxyl group to the solvent not containing a hydroxyl group is 1 / 99 to 99 / 1, preferably 10 / 90 to 90 / 10, and more preferably 20 / 80 to 60 / 40. A mixed solvent containing 50 mass % or more of a solvent not containing a hydroxyl group is preferred from the viewpoint of coating uniformity. The solvent preferably contains propylene glycol monomethyl ether acetate, and may be a solvent containing propylene glycol monomethyl ether acetate alone or a mixed solvent containing propylene glycol monomethyl ether acetate.

[0270] The solid content concentration of the photosensitive resin composition according to the present disclosure is not particularly limited, but is preferably 0.5% by mass to 50% by mass, more preferably 1.0% by mass to 20% by mass, and even more preferably 1.0% by mass to 15% by mass.

[0271] <Crosslinking agent> The photosensitive resin composition according to the present disclosure may contain a compound that crosslinks a resin by the action of an acid (hereinafter, also referred to as a crosslinking agent (G)). As the crosslinking agent (G), a known compound can be appropriately used. For example, the known compounds disclosed in paragraphs 0379 to 0431 of US Patent Application Publication No. 2016 / 0147154 and paragraphs 0064 to 0141 of US Patent Application Publication No. 2016 / 0282720 can be suitably used as the crosslinking agent (G). The crosslinking agent (G) is a compound having a crosslinkable group capable of crosslinking a resin. Examples of the crosslinkable group include a hydroxymethyl group, an alkoxymethyl group, an acyloxymethyl group, an alkoxymethyl ether group, an oxirane ring, and an oxetane ring. The crosslinkable group is preferably a hydroxymethyl group, an alkoxymethyl group, an oxirane ring, or an oxetane ring. The crosslinking agent (G) is preferably a compound (including a resin) having two or more crosslinkable groups. The crosslinking agent (G) is more preferably a phenol derivative, a urea compound (a compound having a urea structure), or a melamine compound (a compound having a melamine structure) having a hydroxymethyl group or an alkoxymethyl group. The crosslinking agent may be used alone or in combination of two or more kinds. The content of the crosslinking agent (G) is preferably from 1 to 50% by mass, more preferably from 3 to 40% by mass, and even more preferably from 5 to 30% by mass, based on the total solid content of the composition.

[0272] <Surfactant> The photosensitive resin composition according to the present disclosure may or may not contain a surfactant (also referred to as "surfactant (H)"). When a surfactant is contained, it is preferable to contain at least one of a fluorine-based and a silicone-based surfactant (specifically, a fluorine-based surfactant, a silicone-based surfactant, or a surfactant having both a fluorine atom and a silicon atom).

[0273] By containing a surfactant in the photosensitive resin composition according to the present disclosure, a resist pattern with good sensitivity and resolution, excellent adhesion and few development defects can be obtained when an exposure light source having a wavelength of 250 nm or less, particularly 220 nm or less, is used. Examples of fluorine-based or silicone-based surfactants include those described in paragraph 0276 of US Patent Application Publication No. 2008 / 0248425. Also, surfactants other than fluorine-based or silicone-based surfactants described in paragraph 0280 of US Patent Application Publication No. 2008 / 0248425 can be used.

[0274] These surfactants may be used alone or in combination of two or more. When the photosensitive resin composition according to the present disclosure contains a surfactant, the content of the surfactant is preferably 0.0001 mass % to 2 mass %, and more preferably 0.0005 mass % to 1 mass %, based on the total solid content of the composition. On the other hand, by making the content of the surfactant 0.0001% by mass or more based on the total solid content of the composition, the hydrophobic resin is more unevenly distributed on the surface, which makes the surface of the actinic ray-sensitive or radiation-sensitive film more hydrophobic and improves water tracking during immersion exposure.

[0275] <Other additives> The photosensitive resin composition according to the present disclosure may further contain other known additives. Other additives include acid amplifiers, dyes, plasticizers, photosensitizers, light absorbers, alkali-soluble resins, dissolution inhibitors, and dissolution promoters.

[0276] (Method for producing photosensitive resin composition) The method for producing the photosensitive resin composition according to the present disclosure is not particularly limited, but from the viewpoint of easily producing the photosensitive resin composition according to the present disclosure, it preferably includes a step of mixing a resin whose polarity increases under the action of an acid, the total content of metal atoms in the resin being 1 ppt or more and 30 ppb or less with respect to the total mass of the resin, and the content of the ethylenically unsaturated compound contained in the resin being 0.001 mass% or more and 10 mass% or less with respect to the total mass of the resin, and it is more preferable that the mixing step is a step of mixing a resin whose polarity increases under the action of an acid with an organic solvent, and it is even more preferable that the mixing step is a step of at least mixing the resin with an organic solvent whose total content of metal atoms is 1 ppt or more and 30 ppb or less. Moreover, from the viewpoint of easily producing the photosensitive resin composition according to the present disclosure, the mixing step is preferably a step of mixing at least the resin with a photoacid generator having a total metal atom content of 1 ppt or more and 1,000 ppb or less. From the viewpoint of easily producing the photosensitive resin composition according to the present disclosure, the mixing step is preferably a step of mixing at least the resin and an acid diffusion control agent having a total metal atom content of 1 ppt or more and 1,000 ppb or less.

[0277] Among these, from the viewpoint of easily producing the photosensitive resin composition according to the present disclosure, the mixing step is more preferably a step of mixing at least the resin, an organic solvent having a total metal atom content of 1 ppt or more and 30 ppb or less, and a photoacid generator having a total metal atom content of 1 ppt or more and 1,000 ppb or less, and is particularly preferably a step of mixing at least the resin, an organic solvent having a total metal atom content of 1 ppt or more and 30 ppb or less, a photoacid generator having a total metal atom content of 1 ppt or more and 1,000 ppb or less, and an acid diffusion controller having a total metal atom content of 1 ppt or more and 1,000 ppb or less.

[0278] From the viewpoint of the linearity of the pattern obtained after aging, the total content of metal atoms in the resin used in the mixing step is preferably 1 ppt or more and 10 ppb or less, more preferably 1 ppt or more and 5 ppb or less, even more preferably 1 ppt or more and 1,000 ppt or less, and particularly preferably 5 ppt or more and 100 ppt or less, relative to the total mass of the resin. From the viewpoint of the linearity of the pattern obtained after aging, the total content of metal atoms in the organic solvent used in the mixing step is preferably from 1 ppt to 10 ppb, more preferably from 1 ppt to 5 ppb, even more preferably from 1 ppt to 1,000 ppt, and particularly preferably from 5 ppt to 100 ppt, relative to the total mass of the organic solvent.

[0279] From the viewpoint of the linearity of the pattern obtained after aging, the total content of metal atoms in the photoacid generator used in the mixing step is preferably from 1 ppt to 500 ppb, more preferably from 1 ppt to 100 ppb, even more preferably from 1 ppt to 10 ppb, and particularly preferably from 5 ppt to 1,000 ppt, relative to the total mass of the photoacid generator. From the viewpoint of the linearity of the pattern obtained after aging, the total content of metal atoms in the acid diffusion control agent used in the mixing step is preferably from 1 ppt to 500 ppb, more preferably from 1 ppt to 100 ppb, even more preferably from 1 ppt to 10 ppb, and particularly preferably from 5 ppt to 1,000 ppt, relative to the total mass of the acid diffusion control agent.

[0280] As a method for removing impurities such as metal atoms from the various materials, for example, filtration using a filter can be mentioned. The filter pore size is preferably 10 nm or less, more preferably 5 nm or less, and even more preferably 3 nm or less. The filter material is preferably a filter made of polytetrafluoroethylene, polyethylene, or nylon. The filter may be washed in advance with an organic solvent. In the filter filtration process, multiple types of filters may be connected in series or parallel. When multiple types of filters are used, filters having at least one different pore size and material may be used in combination. In addition, various materials may be filtered multiple times, and the process of filtering multiple times may be a circulation filtration process. As the filter, one with reduced elution as disclosed in JP2016-201426A is preferable. In addition to filtration, impurities may be removed by an adsorbent, or a combination of filtration and an adsorbent may be used. As the adsorbent, a known adsorbent may be used, for example, an inorganic adsorbent such as silica gel or zeolite, or an organic adsorbent such as activated carbon. As the metal adsorbent, for example, those disclosed in JP 2016-206500 A may be used. In addition, methods for removing impurities such as metal atoms contained in the various materials include selecting raw materials with a low content of metal atoms as the raw materials constituting the various materials, filtering the raw materials constituting the various materials, or lining the inside of the apparatus with Teflon (registered trademark) to perform distillation under conditions that suppress the metal content in the various materials as much as possible. The preferred conditions for filtering the raw materials constituting the various materials are the same as those described above.

[0281] In order to prevent the inclusion of impurities, the above various materials are preferably stored in containers as described in U.S. Patent Application Publication No. 2015 / 0227049, Japanese Patent Application Publication No. 2015-123351, Japanese Patent Application Publication No. 2017-13804, etc.

[0282] The order of mixing in the mixing step is not particularly limited, and the ingredients may be mixed in any order. For example, two or more ingredients may be added and mixed at once, or all ingredients may be added and mixed at once. The total amount of each component may be added at once or in two or more portions. For example, each component may be prepared as a solution in an organic solvent, and the solutions may be mixed.

[0283] In addition, after the mixing step, it is preferable to include a step of filtering the obtained photosensitive resin composition, and it is more preferable to include a step of filtering the obtained photosensitive resin composition through a filter. The photosensitive resin composition according to the present disclosure is preferably used, for example, by coating on a predetermined support (substrate) after the mixing step or the filtering step. The pore size (hole diameter) of the filter used for filtration is preferably 0.1 μm or less, more preferably 0.05 μm or less, and even more preferably 0.03 μm or less. When the solid content of the photosensitive resin composition is high (for example, 25 mass % or more), the pore size of the filter used for filtration is preferably 3 μm or less, more preferably 0.5 μm or less, and even more preferably 0.3 μm or less. The filter is preferably made of polytetrafluoroethylene, polyethylene, or nylon. In the filter filtration, for example, as disclosed in JP-A-2002-62667, circulatory filtration may be performed, or multiple types of filters may be connected in series or parallel to perform filtration. The composition may also be filtered multiple times. Furthermore, the composition may be subjected to degassing treatment before or after filter filtration.

[0284] The thickness of the resist film made of the photosensitive resin composition according to the present disclosure is not particularly limited, but from the viewpoint of improving resolution, it is preferably 90 nm or less, more preferably 85 nm or less. Such a thickness can be achieved by setting the solid content concentration in the composition within an appropriate range to provide a suitable viscosity and improve coatability or film-forming property.

[0285] <Application> The photosensitive resin composition according to the present disclosure is a photosensitive resin composition whose properties change when it reacts with light irradiation. More specifically, the photosensitive resin composition according to the present disclosure relates to an actinic ray-sensitive or radiation-sensitive resin composition used in a semiconductor manufacturing process such as an IC (Integrated Circuit), manufacturing a circuit board such as a liquid crystal or thermal head, making a mold structure for imprinting, other photofabrication processes, or manufacturing a lithographic printing plate or an acid-curable composition. The resist pattern formed by the photosensitive resin composition according to the present disclosure can be used in an etching process, an ion implantation process, a bump electrode forming process, a rewiring forming process, and MEMS (Micro Electro Mechanical Systems), etc.

[0286] (resist film) The resist film according to the present disclosure is a solidified product of the photosensitive resin composition according to the present disclosure. The solidified product in the present disclosure may be a product obtained by removing at least a part of the solvent from the photosensitive resin composition according to the present disclosure. Specifically, the resist film according to the present disclosure can be obtained, for example, by applying the photosensitive resin composition according to the present disclosure onto a support such as a substrate, and then drying the applied composition. The above-mentioned drying refers to removing at least a portion of the solvent contained in the photosensitive resin composition according to the present disclosure. The drying method is not particularly limited, and a known method can be used, including drying by heating (for example, 70° C. to 130° C., for 30 to 300 seconds). The heating method is not particularly limited, and any known heating means can be used, including, for example, a heater, an oven, a hot plate, an infrared lamp, and an infrared laser.

[0287] The components contained in the resist film according to the present disclosure are the same as the components contained in the photosensitive resin composition according to the present disclosure excluding the solvent, and preferred aspects are also the same. The content of each component contained in the resist film according to the present disclosure corresponds to the content of each component other than the solvent in the photosensitive resin composition according to the present disclosure, where the term "total solids content" is replaced with "total mass of the resist film."

[0288] The thickness of the resist film according to the present disclosure is not particularly limited, but is preferably from 50 nm to 150 nm, and more preferably from 80 nm to 130 nm. Furthermore, when it is desired to form a thick resist film in association with the three-dimensionalization of memory devices, the thickness is preferably, for example, 2 μm or more, more preferably 2 μm to 50 μm, and even more preferably 2 μm to 20 μm.

[0289] (Pattern formation method) The pattern forming method according to the present disclosure includes the steps of: A step of exposing the resist film according to the present disclosure to active light (exposure step); and The method includes a step of developing the resist film after the exposure step using a developer (development step). The pattern forming method according to the present disclosure includes a step of forming a resist film on a support using the photosensitive resin composition according to the present disclosure (film formation step); a step of exposing the resist film to actinic radiation (exposure step); and The method may also include a step of developing the resist film after the exposure step using a developer (development step).

[0290] <Film formation process> The pattern forming method according to the present disclosure may include a film forming step. Examples of the method for forming a resist film in the film forming step include the method for forming a resist film by drying described above in the section on resist film.

[0291] [Support] The support is not particularly limited, and may be a substrate generally used in the manufacturing process of semiconductors such as ICs, or in the manufacturing process of circuit boards such as liquid crystal or thermal heads, as well as in other lithography processes for photofabrication, etc. Specific examples of the support include inorganic substrates such as silicon, SiO2, and SiN.

[0292] <Exposure process> The exposure step is a step of exposing the resist film to light. The exposure method may be immersion exposure. The pattern formation method according to the present disclosure may include the exposure step multiple times. The type of light (actinic rays or radiation) used for exposure may be selected in consideration of the properties of the photoacid generator and the desired pattern shape, and examples of the light include infrared light, visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light (EUV), X-rays, and electron beams, with far ultraviolet light being preferred. For example, actinic rays having a wavelength of 250 nm or less are preferred, 220 nm or less is more preferred, and 1 to 200 nm is even more preferred. Specific examples of light used include KrF excimer laser (248 nm), ArF excimer laser (193 nm), F2 excimer laser (157 nm), X-rays, EUV (13 nm), and electron beams, with ArF excimer laser, EUV, and electron beams being preferred. Among these, the exposure in the exposure step is preferably performed by immersion exposure using an argon fluoride laser. The exposure dose was 5 mJ / cm 2 ~200mJ / cm 2 and preferably 10 mJ / cm 2 ~100mJ / cm 2 It is more preferable that:

[0293] <Developing process> The developer used in the development step may be an alkaline developer or a developer containing an organic solvent (hereinafter also referred to as an organic developer), and is preferably an alkaline aqueous solution.

[0294] [Alkaline developer] As the alkaline developer, a quaternary ammonium salt such as tetramethylammonium hydroxide is preferably used, but other alkaline aqueous solutions of inorganic alkali, primary to tertiary amines, alkanolamines, cyclic amines, and the like can also be used. Furthermore, the alkaline developer may contain at least one of alcohols and surfactants in an appropriate amount. The alkaline developer preferably has an alkali concentration of 0.1% by mass to 20% by mass. The alkaline developer preferably has a pH of 10 to 15. The time for developing using an alkaline developer is preferably 10 seconds to 300 seconds. The alkali concentration and pH of the alkaline developer and the developing time can be appropriately adjusted depending on the pattern to be formed.

[0295] [Organic Developer] The organic developer is preferably a developer containing at least one organic solvent selected from the group consisting of ketone-based solvents, ester-based solvents, alcohol-based solvents, amide-based solvents, ether-based solvents, and hydrocarbon-based solvents.

[0296] -Ketone-based solvents- Examples of ketone solvents include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 2-heptanone (methyl amyl ketone), 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetyl carbinol, acetophenone, methyl naphthyl ketone, isophorone, and propylene carbonate.

[0297] -Ester-based solvent- Examples of ester-based solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, pentyl acetate, isopentyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, butyl butanoate, methyl 2-hydroxyisobutyrate, isoamyl acetate, isobutyl isobutyrate, and butyl propionate.

[0298] -Other solvents- As the alcohol-based solvent, the amide-based solvent, the ether-based solvent, and the hydrocarbon-based solvent, the solvents disclosed in paragraphs 0715 to 0718 of US Patent Application Publication No. 2016 / 0070167 can be used.

[0299] The above solvents may be mixed in combination, or may be mixed with a solvent other than the above solvents or with water. The water content of the 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 particularly preferably substantially free of water. The content of the organic solvent in the organic developer is preferably 50% by mass or more and 100% by mass or less, more preferably 80% by mass or more and 100% by mass or less, still more preferably 90% by mass or more and 100% by mass or less, and particularly preferably 95% by mass or more and 100% by mass or less, based on the total amount of the developer.

[0300] -Surfactants- The organic developer may contain a suitable amount of a known surfactant, if necessary. The content of the surfactant is preferably from 0.001% by mass to 5% by mass, more preferably from 0.005% by mass to 2% by mass, and further preferably from 0.01% by mass to 0.5% by mass, based on the total mass of the developer.

[0301] -Acid diffusion control agent- The organic developer may contain the above-mentioned acid diffusion controller.

[0302] [Developing method] Examples of the developing method that can be applied include a method of immersing a substrate in a tank filled with a developing solution for a certain period of time (dip method), a method of piling up a developing solution on the substrate surface by surface tension and leaving it to stand for a certain period of time (paddle method), a method of spraying the developing solution on the substrate surface (spray method), and a method of continuously discharging the developing solution while scanning a developing solution discharge nozzle at a constant speed onto a substrate rotating at a constant speed (dynamic dispense method).

[0303] A step of developing using an alkaline aqueous solution (alkaline developing step) and a step of developing using a developer containing an organic solvent (organic solvent developing step) may be combined. This allows pattern formation without dissolving only the areas with intermediate exposure intensity, making it possible to form finer patterns.

[0304] <Pre-baking process, post-exposure baking process> The pattern formation method according to the present disclosure preferably includes a pre-bake (PB) step prior to the exposure step. The pattern formation method according to the present disclosure may include the pre-heating step multiple times. The pattern formation method according to the present disclosure preferably includes a post-exposure bake (PEB) step after the exposure step and before the development step. The pattern formation method according to the present disclosure may include the post-exposure baking step multiple times. The heating temperature is preferably from 70°C to 130°C, more preferably from 80°C to 120°C, in both the pre-bake step and the post-exposure bake step. The heating time in both the pre-heating step and the post-exposure heating step is preferably from 30 seconds to 300 seconds, more preferably from 30 seconds to 180 seconds, and even more preferably from 30 seconds to 90 seconds. Heating can be performed by means provided in the exposure device and the development device, and may be performed using a hot plate or the like.

[0305] <Resist underlayer film formation process> The pattern forming method according to the present disclosure may further include a step of forming a resist underlayer film (resist underlayer film forming step) prior to the film forming step. The resist underlayer film forming step is a step of forming a resist underlayer film (e.g., SOG (Spin On Glass), SOC (Spin On Carbon), anti-reflective film, etc.) between the resist film and the support. As the resist underlayer film, a known organic or inorganic material can be appropriately used.

[0306] <Protective film formation process> The pattern forming method according to the present disclosure may further include a step of forming a protective film (protective film forming step) prior to the development step. The protective film forming step is a step of forming a protective film (topcoat) on the upper layer of the resist film. As the protective film, a known material can be appropriately used. For example, the protective film forming composition disclosed in US Patent Application Publication No. 2007 / 0178407, US Patent Application Publication No. 2008 / 0085466, US Patent Application Publication No. 2007 / 0275326, US Patent Application Publication No. 2016 / 0299432, US Patent Application Publication No. 2013 / 0244438, and International Publication No. 2016 / 157988 can be suitably used. As the protective film forming composition, one containing the above-mentioned acid diffusion controller is preferable. A protective film may be formed on the resist film containing the hydrophobic resin described above.

[0307] <Rinse process> The pattern forming method according to the present disclosure preferably includes a step of washing with a rinse liquid (rinsing step) after the developing step.

[0308] [In the case of a development process using an alkaline developer] The rinse liquid used in the rinse step after the development step using an alkaline developer can be, for example, pure water. The pure water may contain an appropriate amount of a surfactant. In this case, after the development step or the rinse step, a treatment may be added to remove the developer or rinse liquid adhering to the pattern using a supercritical fluid. Furthermore, after the rinse treatment or the treatment using a supercritical fluid, a heat treatment may be performed to remove moisture remaining in the pattern.

[0309] [In the case of a development process using an organic developer] The rinse liquid used in the rinse step after the development step using a developer containing an organic solvent is not particularly limited as long as it does not dissolve the resist pattern, and a solution containing a general organic solvent can be used. As the rinse liquid, it is preferable to use a rinse liquid containing at least one organic solvent selected from the group consisting of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents. Specific examples of the hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents include those similar to those described in the developer containing an organic solvent. In this case, the rinse liquid used in the rinsing step is preferably a rinse liquid containing a monohydric alcohol.

[0310] The monohydric alcohol used in the rinsing step may be a linear, branched, or cyclic monohydric alcohol.Specific examples include 1-butanol, 2-butanol, 3-methyl-1-butanol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 1-hexanol, 4-methyl-2-pentanol, 1-heptanol, 1-octanol, 2-hexanol, cyclopentanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, and methylisobutylcarbinol.Examples of the monohydric alcohol having 5 or more carbon atoms include 1-hexanol, 2-hexanol, 4-methyl-2-pentanol, 1-pentanol, 3-methyl-1-butanol, and methylisobutylcarbinol.

[0311] Each component may be used in combination with a plurality of other components, or may be used in combination with an organic solvent other than those mentioned above. The water content in the rinse liquid is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less. By keeping the water content at 10% by mass or less, good development characteristics can be obtained.

[0312] The rinse solution may contain a suitable amount of a surfactant. In the rinsing step, the substrate developed using an organic developer is washed with a rinse solution containing an organic solvent. The method of the washing step is not particularly limited, but for example, a method of continuously discharging a rinse solution onto a substrate rotating at a constant speed (spin coating method), a method of immersing a substrate in a tank filled with a rinse solution for a certain period of time (dip method), or a method of spraying a rinse solution onto the substrate surface (spray method) can be applied. Among them, it is preferable to perform the washing step by the spin coating method, rotate the substrate after washing at a rotation speed of 2,000 rpm to 4,000 rpm (revolutions / min) and remove the rinse solution from the substrate. It is also preferable to include a heating step (Post Bake) after the rinsing step. The developing solution and the rinse solution remaining between and inside the patterns are removed by this heating step. In the heating step after the rinsing step, the heating temperature is preferably 40 to 160°C, more preferably 70 to 95°C. The heating time is preferably 10 seconds to 3 minutes, more preferably 30 seconds to 90 seconds.

[0313] <Improvement of surface roughness> A method for improving the surface roughness of a pattern may be applied to the pattern formed by the pattern forming method according to the present disclosure. For example, a method for improving the surface roughness of a pattern may be a method for treating a resist pattern with a plasma of a gas containing hydrogen, as disclosed in U.S. Patent Application Publication No. 2015 / 0104957. In addition, known methods such as those described in JP-A-2004-235468, U.S. Patent Application Publication No. 2010 / 0020297, and Proc. of SPIE Vol.8328 83280N-1 "EUV Resist Curing Technique for LWR Reduction and Etch Selectivity Enhancement" may be applied. Furthermore, the resist pattern formed by the above method can be used as a core in the spacer process disclosed in, for example, JP-A-03-270227 and US Patent Application Publication No. 2013 / 0209941.

[0314] (Electronic device manufacturing method) The method for manufacturing an electronic device according to the present disclosure includes the pattern formation method according to the present disclosure. An electronic device manufactured by the method for manufacturing an electronic device according to the present disclosure is suitable for use in electric and electronic devices (e.g., home appliances, OA (Office Automation) related devices, media related devices, optical devices, communication devices, etc.). EXAMPLES

[0315] The following examples further illustrate the embodiments of the present invention. The materials, amounts, ratios, processing contents, and processing procedures shown in the following examples can be changed as appropriate without departing from the spirit of the embodiments of the present invention. Therefore, the scope of the embodiments of the present invention is not limited to the specific examples shown below. Unless otherwise specified, "parts" and "%" are based on mass.

[0316] <Synthesis Example 1: Synthesis of Resin A-1> Under a nitrogen stream, 8.6 g of cyclohexanone was placed in a three-neck flask and heated to 80°C. Separately, 12.3 g of t-butyl methacrylate, 13.2 g of norbornane lactone methacrylate, and 8 mol% of a polymerization initiator V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) based on the total amount of these monomers were dissolved in 79 g of cyclohexanone to obtain a solution. Then, this solution was dropped into the three-neck flask over 6 hours. After the dropwise addition was completed, the mixture was further reacted at 80°C for 2 hours. After cooling, the reaction liquid was dropped into a mixture of 800 mL of hexane / 200 mL of ethyl acetate over 20 minutes, and the precipitated powder was filtered and dried to obtain 19 g of resin (A-1). The weight average molecular weight of the obtained resin was 11,000 in terms of standard polystyrene, and the degree of dispersion (Mw / Mn) was 1.5. In the same manner, other resins (A) shown below were synthesized.

[0317] The structures of the monomers used in the synthesis of the resin (A) used in the examples and comparative examples are shown below. Table 1 below also shows the molar ratio of the structural units, the weight average molecular weight (Mw), and the dispersity (Mw / Mn) of each resin.

[0318] [ka]

[0319] [ka]

[0320] [ka]

[0321] [Table 1]

[0322] <Synthesis Example 2: Synthesis of Resin E-1> 0.8g of compound (ME-3), 0.7g of compound (ME-4), and 0.03g of polymerization initiator V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) were dissolved in 2.33g of cyclohexanone to obtain a mixed solution. This mixed solution was added dropwise to 0.44g of cyclohexanone in a reaction vessel over 4 hours in a system at 85°C under a nitrogen gas atmosphere. After heating and stirring this reaction solution for 2 hours, it was allowed to cool to room temperature (25°C, the same below). The reaction solution was dropped into 30 g of methanol / water = 9 / 1 (mass ratio) to precipitate the polymer, and the precipitate was filtered. The filtered solid was washed with 6 g of methanol / water = 9 / 1 (mass ratio). The washed solid was then dried under reduced pressure to obtain 0.89 g of resin (E-1). In a similar manner, other hydrophobic resins (E) shown below were synthesized.

[0323] The structures of the monomers used in the synthesis of the hydrophobic resins (E) used in the examples and comparative examples are shown below. Table 2 below also shows the molar ratio of the structural units, the weight average molecular weight (Mw), and the dispersity (Mw / Mn) of each resin.

[0324] [ka]

[0325] [ka]

[0326] [Table 2]

[0327] The structures of the photoacid generators (C) used in the examples and comparative examples are shown below.

[0328] [ka]

[0329] The structure of the acid diffusion controller (D) used in the examples and comparative examples is shown below.

[0330] [ka]

[0331] The surfactants (H) used in the examples and comparative examples are shown below. H-1: Megafac F176 (DIC Corporation, fluorosurfactant) H-2: Megafac R08 (DIC Corporation, fluorine and silicone surfactant) H-3: PF656 (OMNOVA, fluorosurfactant) H-4: PF6320 (OMNOVA, fluorosurfactant) H-5: FC-4430 (Sumitomo 3M, fluorosurfactant)

[0332] The solvents (F) used in the examples and comparative examples are shown below. F-1: Propylene glycol monomethyl ether (PGME) F-2: Propylene glycol monomethyl ether acetate (PGMEA) F-3: Propylene glycol monoethyl ether (PGEE) F-4: Cyclohexanone F-5: Cyclopentanone F-6: 2-heptanone F-7: Ethyl lactate F-8: γ-butyrolactone F-9: Propylene carbonate

[0333] (Examples 1 to 16 and Comparative Examples 1 to 6) <Preparation of Photosensitive Resin Composition> Each material other than the solvent (F) shown in Table 3 was dissolved in a solvent to a concentration of 10 mass %. The obtained solution and the solvent (F) were filtered, in this order, first through a polyethylene filter having a pore size of 50 nm and then through a nylon filter having a pore size of 10 nm. Here, the content of metal atoms (metal content) contained in each material was appropriately adjusted by changing the number of times the filtration was repeated as shown on the left. Then, the components were mixed so that the solid content concentration was 6% by mass to prepare a photosensitive resin composition. The solid content here means all components other than the solvent (F). The photosensitive resin composition was first filtered through a polyethylene filter having a pore size of 50 nm, then a nylon filter having a pore size of 10 nm, and finally a polyethylene filter having a pore size of 5 nm, in that order. The obtained photosensitive resin composition was used in the examples and comparative examples.

[0334] [Table 3]

[0335] (Evaluation method) <Measurement of metal atom content (metal content) of each component and photosensitive resin composition> The content of metal atoms in each component and photosensitive resin composition shown in Table 4 was measured as follows. The content of metal atoms in the photosensitive resin composition was measured using a triple quadrupole inductively coupled plasma mass spectrometer (8800 manufactured by Agilent Corporation). N-methylpyrrolidone (NMP, electronic grade) was used as the solvent. Argon gas was used as the carrier gas, an argon / oxygen mixed gas was used as the make-up gas, and a helium / ammonia mixed gas was used as the reaction gas. Other conditions were set with reference to the description in JP-A-2006-184109, and measurements were performed.

[0336] <Measurement of the Content of Ethylenically Unsaturated Compounds in Resin or Photosensitive Resin Composition> The contents of ethylenically unsaturated compounds in the resins and photosensitive resin compositions shown in Table 4 were measured as follows. The content of ethylenically unsaturated compounds in the resin or photosensitive resin composition was measured by attaching a reversed-phase ODS (diethylhexyl group-bonded silica gel) column to a liquid chromatograph Prominence LC-20A manufactured by Shimadzu Corporation under gradient flow conditions using a methanol / water-based eluent.

[0337] <Pattern formation method (1): ArF immersion exposure, alkaline aqueous solution development> An organic anti-reflective coating composition ARC29SR (manufactured by Brewer Science) was applied onto a silicon wafer and baked at 205°C for 60 seconds to form an anti-reflective coating having a thickness of 98 nm. A photosensitive resin composition shown in Table 4 was applied thereon and baked at 100°C for 60 seconds to form a photosensitive film having a thickness of 90 nm. The photosensitive resin composition used was stored in a thermostatic chamber at 35°C for 6 months after preparation. The photosensitive film was exposed to light through a 6% halftone mask with a 1:1 line and space pattern of 45 nm line width using an ArF excimer laser immersion scanner (ASML; XT1950i, NA 1.35, C-Quad, outer sigma 0.930, inner sigma 0.730, XY deflection). Ultrapure water was used as the immersion liquid. The exposed photosensitive film was baked at 100°C for 60 seconds, developed with a tetramethylammonium hydroxide aqueous solution (TMAH, 2.38% by mass) for 30 seconds, and then rinsed with pure water for 30 seconds. It was then spin-dried to obtain a positive pattern.

[0338] <Pattern formation method (2): ArF immersion exposure, organic solvent development> An organic anti-reflective coating composition ARC29SR (manufactured by Brewer Science) was applied onto a silicon wafer and baked at 205°C for 60 seconds to form an anti-reflective coating having a thickness of 98 nm. A photosensitive resin composition shown in Table 4 was applied thereon and baked at 100°C for 60 seconds to form a photosensitive film having a thickness of 90 nm. The photosensitive resin composition used was stored in a thermostatic chamber at 35°C for 6 months after preparation. The photosensitive film was exposed to light through a 6% halftone mask with a 1:1 line and space pattern of 45 nm line width using an ArF excimer laser immersion scanner (ASML; XT1950i, NA 1.35, C-Quad, outer sigma 0.930, inner sigma 0.730, XY deflection). Ultrapure water was used as the immersion liquid. The exposed photosensitive film was baked at 100°C for 60 seconds, developed with n-butyl acetate for 30 seconds, rinsed with 4-methyl-2-pentanol for 30 seconds, and then spin-dried to obtain a negative pattern.

[0339] <Performance evaluation> [Evaluation of linearity of pattern obtained after aging (line width roughness (LWR value), unit: nm)] When observing a 45 nm (1:1) line and space resist pattern resolved with the optimal exposure dose from above using a critical dimension scanning electron microscope (SEM, Hitachi Ltd. CG-4100), the line width was observed at any point, and the measurement variation was evaluated at 3σ. The smaller the value, the better the performance.

[0340] The measured metal content, ethylenically unsaturated compound content, and LWR value in the photosensitive resin composition and each material are shown in Table 4.

[0341] [Table 4]

[0342] The metal atoms detected in the photosensitive resin compositions of Examples 1 to 16 were Li, Na, Mg, Al, K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Ag, Cd, Sn, W, Au, and Pb. As shown in Table 4, even when a photosensitive resin composition that had been aged after preparation was used, the photosensitive film formed in the above examples was exposed to light and then subjected to alkaline development or organic solvent development to form a pattern with good linearity.

[0343] <Synthesis of Resins K-1 and K-2> Resins K-1 and K-2 were each synthesized in the same manner as for Resin A-1, except that the amounts of monomers and structural units were changed to the molar ratios shown in Table 5. Table 5 below also shows the molar ratios of the structural units, weight average molecular weight (Mw), and dispersity (Mw / Mn) for each resin.

[0344] [Table 5]

[0345] The structures of the monomers listed in Table 5 are shown below.

[0346] [ka]

[0347] (Example 17 and Comparative Example 7: KrF Exposure) <Preparation of Photosensitive Resin Composition> The components shown in Table 6 were dissolved in a solvent in the ratios (mass % of the total mass of the composition) shown in Table 6 below to prepare resist solutions for each, which were then filtered through a UPE (ultra high molecular weight polyethylene) filter with a pore size of 0.1 μm, thereby preparing photosensitive resin compositions (resist compositions) with a solid content concentration of 7.5 mass %.

[0348] [Table 6]

[0349] <Pattern formation method (3): KrF exposure, alkaline aqueous solution development> A composition for forming an organic anti-reflective film DUV44 (manufactured by Brewer Science) was applied onto a silicon wafer and baked at 205°C for 60 seconds to form an anti-reflective film with a thickness of 70 nm. A photosensitive resin composition shown in Table 7 was applied thereon and baked at 120°C for 60 seconds to form a photosensitive film with a thickness of 300 nm. The photosensitive resin composition used was stored in a thermostatic chamber at 35°C for 6 months after preparation. The photosensitive film was exposed through a 6% halftone mask of a 1:1 line and space pattern with a line width of 150 nm using a KrF excimer laser scanner (NA 0.80, Dipole, outer sigma 0.89, inner sigma 0.65). The exposed photosensitive film was baked at 120°C for 60 seconds, developed with a tetramethylammonium hydroxide aqueous solution (TMAH, 2.38% by mass) for 30 seconds, and then rinsed with pure water for 30 seconds. It was then spin-dried to obtain a positive pattern.

[0350] <Evaluation of linearity of pattern obtained after aging (line width roughness (LWR value), unit: nm)> When observing a 150 nm (1:1) line and space resist pattern resolved with the optimal exposure dose from above using a critical dimension scanning electron microscope (SEM, Hitachi Ltd. CG-4100), the line width was observed at any point, and the measurement variation was evaluated at 3σ. The smaller the value, the better the performance.

[0351] [Table 7]

[0352] <Synthesis of Resins EB-1 and EB-2> Resins EB-1 and EB-2 were each synthesized in the same manner as for Resin A-1, except that the amounts of monomers and structural units were changed to the molar ratios shown in Table 8. Table 8 below also shows the molar ratios of the structural units, weight average molecular weight (Mw), and dispersity (Mw / Mn) for each resin.

[0353] [Table 8]

[0354] The structures of the monomers listed in Table 8 are shown below.

[0355] [ka]

[0356] (Example 18 and Comparative Example 8: EB Exposure) <Preparation of Photosensitive Resin Composition> The components shown in Table 9 below were dissolved in a solvent to prepare a solution with a solids concentration of 3.5 mass %, which was then precision filtered through a polytetrafluoroethylene filter having a pore size of 0.03 μm to obtain a resist solution.

[0357] [Table 9]

[0358] Incidentally, G-1 in Table 9 is the following compound.

[0359] [ka]

[0360] <Pattern formation method (4): EB exposure, negative resist pattern, alkaline aqueous solution development> A photosensitive resin composition shown in Table 10 was applied onto a 6-inch wafer using a spin coater Mark 8 manufactured by Tokyo Electron Ltd., and dried on a hot plate at 110°C for 90 seconds to obtain a resist film with a thickness of 80 nm. The photosensitive resin composition used was stored in a thermostatic chamber at 35°C for 6 months after preparation.

[0361] [Preparation of negative resist pattern] This resist film was patterned using an electron beam lithography system (ELS-7500, manufactured by Elionix Co., Ltd., accelerating voltage 50 KeV). After irradiation, the film was heated on a hot plate at 110°C for 90 seconds, immersed in a 2.38% by mass aqueous solution of tetramethylammonium hydroxide as a developer for 60 seconds, rinsed with pure water for 30 seconds, and dried.

[0362] <Evaluation of linearity of pattern obtained after aging (line width roughness (LWR value), unit: nm)> When observing a 100 nm (1:1) line and space resist pattern resolved with the optimal exposure dose from above using a critical dimension scanning electron microscope (SEM, Hitachi, Ltd. S-9220), the line width was observed at any point, and the measurement variation was evaluated at 3σ. The smaller the value, the better the performance.

[0363] [Table 10]

[0364] <Synthesis of Resins V-1 and V-2> Resins V-1 and V-2 were each synthesized in the same manner as for Resin A-1, except that the amounts of monomers and structural units were changed to the molar ratios shown in Table 11. Table 11 below also shows the molar ratios of the structural units, weight average molecular weight (Mw), and dispersity (Mw / Mn) for each resin.

[0365] [Table 11]

[0366] The structures of the monomers listed in Table 11 are shown below.

[0367] [ka]

[0368] (Example 19 and Comparative Example 9: EUV Exposure) <Preparation of Photosensitive Resin Composition> The components shown in Table 12 below were dissolved in a solvent to prepare a solution with a solid content concentration of 1.3 mass %, which was then precision-filtered through a polytetrafluoroethylene filter having a pore size of 0.03 μm to obtain a photosensitive resin composition.

[0369] [Table 12]

[0370] <Pattern formation method (5): EUV exposure, alkaline aqueous solution development> AL412 (manufactured by Brewer Science) was applied onto a silicon wafer and baked at 205°C for 60 seconds to form an underlayer film with a thickness of 30 nm. A photosensitive resin composition shown in Table 13 was applied thereon and baked at 120°C for 60 seconds to form a photosensitive film with a thickness of 30 nm. The photosensitive resin composition used was stored in a thermostatic chamber at 35°C for 6 months after preparation. The photosensitive film was irradiated with an EUV exposure device (Exitech, Micro Exposure Tool, NA 0.3, Quadrupol, outer sigma 0.68, inner sigma 0.36) to pattern the silicon wafer having the resist film. As the reticle, a mask with a line size of 20 nm and a line:space ratio of 1:1 was used. The exposed photosensitive film was baked at 120°C for 60 seconds (Post Exposure Bake; PEB), developed with a tetramethylammonium hydroxide aqueous solution (TMAH, 2.38% by mass) for 30 seconds, and then rinsed with pure water for 30 seconds. The silicon wafer was rotated at 4000 rpm for 30 seconds and further baked at 90°C for 60 seconds to obtain a line and space pattern with a pitch of 40 nm and a line width of 20 nm (space width of 20 nm).

[0371] <Evaluation of linearity of pattern obtained after aging (line width roughness (LWR value), unit: nm)> When observing a 20 nm (1:1) line and space resist pattern resolved with the optimal exposure dose from above using a critical dimension scanning electron microscope (SEM, Hitachi Ltd. CG-4100), the line width was observed at any point, and the measurement variation was evaluated at 3σ. The smaller the value, the better the performance.

[0372] [Table 13]

[0373] <Synthesis Example 3: Synthesis of Resins A-21 to A-43> Resins A-21 to A-43 were each synthesized in the same manner as in the synthesis of A-1, except that the monomers and the amounts used thereof were changed to those shown in Table 14 and the molar ratios thereof.

[0374] The structures of the monomers used in the synthesis of Resins A-21 to A-43 other than those mentioned above are shown below. Table 14 below shows the molar ratio of the structural units, the weight average molecular weight (Mw), and the dispersity (Mw / Mn) of each resin.

[0375] [ka]

[0376] [Table 14]

[0377] <Synthesis Example 4: Synthesis of Resins E-12 to E-23> Resins E-12 to E-23 were each synthesized in the same manner as in the synthesis of E-1, except that the monomers and the amounts used thereof were changed to those shown in Table 15 and the molar ratios thereof.

[0378] The structures of the monomers used in the synthesis of Resins E-12 to E-23 other than those mentioned above are shown below. Table 15 below shows the molar ratio of the structural units, the weight average molecular weight (Mw), and the dispersity (Mw / Mn) of each resin.

[0379] [ka]

[0380] [Table 15]

[0381] (Examples 20 to 157) <Preparation of Photosensitive Resin Composition> Photosensitive resin compositions were prepared in the same manner as in Example 1, except that the materials and their contents were changed to those shown in Tables 16 to 20. In addition, the obtained photosensitive resin composition was used to measure the metal content in the photosensitive resin composition and each material in the same manner as in Example 1. Furthermore, the LWR value was measured in the same manner as in Example 1, except that the pattern formation method was changed to those shown in Tables 21 to 25. The evaluation results are shown in Tables 21 to 25.

[0382] [Table 16]

[0383] [Table 17]

[0384] [Table 18]

[0385] [Table 19]

[0386] [Table 20]

[0387] [Table 21]

[0388] [Table 22]

[0389] [Table 23]

[0390] [Table 24]

[0391] [Table 25]

[0392] The metal atoms detected in the photosensitive resin compositions of Examples 20 to 157 were Li, Na, Mg, Al, K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Ag, Cd, Sn, W, Au, and Pb. As shown in Tables 21 to 25, even when a photosensitive resin composition that had been aged after preparation was used, a pattern with good linearity was formed by performing alkaline development or organic solvent development on the photosensitive film formed in the above examples after exposure to light.

[0393] The disclosure of Japanese Patent Application No. 2018-058907, filed on March 26, 2018, is incorporated herein by reference in its entirety. All publications, patent applications, and technical standards mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent application, or technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. The composition comprises an ethylenically unsaturated compound, a resin (A) whose polarity increases under the action of an acid, a metal atom, a photoacid generator, and an acid diffusion controller, The ethylenically unsaturated compound is contained in an amount of 0.0001% by mass or more and 0.58% by mass or less based on the total mass of the photosensitive resin composition, The ethylenically unsaturated compound contains an ethylenically unsaturated compound having a molecular weight of 100 to 600 in an amount of 0.0001% by mass or more and 0.58% by mass or less based on the total mass of the photosensitive resin composition, the total content of the metal atoms is 1 ppt or more and 10 ppb or less based on the total mass of the photosensitive resin composition, Among the metal atoms, the total content of Li, Na, Mg, Al, K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Ag, Cd, Sn, W, Au, and Pb is 1 ppt or more and 10 ppb or less based on the total mass of the photosensitive resin composition, The resin (A) has, as a structural unit, at least one of the monomers shown in the following MA-1 to MA-14 and at least one of the monomers shown in the following MB-2 to MB-12. Photosensitive resin composition. 【Chemistry 1】

2. A photosensitive resin composition as described in claim 1, wherein the resin (A) whose polarity increases due to the action of the acid further contains a structural unit having an aromatic hydrocarbon group.

3. The photosensitive resin composition described in claim 2, wherein the structural unit having an aromatic hydrocarbon group is a structural unit having a phenolic hydroxyl group.

4. A photosensitive resin composition as described in claim 3, wherein the structural unit having a phenolic hydroxyl group is a structural unit derived from hydroxystyrene.

5. The photosensitive resin composition according to claim 4, wherein the structural unit having a phenolic hydroxyl group is a structural unit represented by MV-1 below. 【Chemistry 2】

6. 6. The photosensitive resin composition according to claim 1, wherein the content of the metal atoms is from 1 ppt to 1,000 ppt.

7. The photosensitive resin composition according to any one of claims 1 to 6, wherein the content of the ethylenically unsaturated compound is 0.0001 mass% or more and 0.5 mass% or less with respect to the total mass of the photosensitive resin composition.

8. The photosensitive resin composition according to any one of claims 1 to 7, wherein the content of the ethylenically unsaturated compound is 0.0001 mass% or more and 0.1 mass% or less with respect to the total mass of the photosensitive resin composition.

9. The photosensitive resin composition according to any one of claims 1 to 8, further comprising an organic solvent.

10. The method includes at least a step of mixing the resin (A) whose polarity increases under the action of an acid, a photoacid generator, and an acid diffusion controller, The total content of metal atoms in the resin is 1 ppt or more and 30 ppb or less based on the total mass of the resin, The content of the ethylenically unsaturated compound contained in the resin is 0.001% by mass or more and 10% by mass or less with respect to the total mass of the resin. A method for producing the photosensitive resin composition according to any one of claims 1 to 9.

11. 11. The method for producing a photosensitive resin composition according to claim 10, wherein the mixing step is a step of mixing at least the resin (A), a photoacid generator, an acid diffusion controller, and an organic solvent having a total content of metal atoms of 1 ppt or more and 30 ppb or less.

12. 12. The method for producing a photosensitive resin composition according to claim 10, wherein in the mixing step, the photoacid generator is a photoacid generator having a total content of metal atoms of 1 ppt or more and 1,000 ppb or less.

13. 13. The method for producing a photosensitive resin composition according to claim 10, wherein in the mixing step, the acid diffusion control agent is an acid diffusion control agent having a total content of metal atoms of 1 ppt or more and 1,000 ppb or less.

14. A resist film which is a solidified product of the photosensitive resin composition according to any one of claims 1 to 9.

15. A pattern forming method comprising the steps of: exposing the resist film according to claim 14; and developing the exposed resist film.

16. A method for manufacturing an electronic device, comprising the pattern formation method according to claim 15.

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