Iodine-containing (METH)acrylate compound, iodine-containing (METH)acrylate (CO)polymer, lithography composition, resist composition, underlayer-film-forming composition, and method for producing iodine-containing (METH)acrylate compound

Abstract

This iodine-containing (meth)acrylate compound is represented by formula (1). [Chemical formula 1] (In formula (1): R1 represents a hydrogen atom, a methyl group, or a halogen atom; R2 and R3 each independently represent a C1-20 straight chain organic group, a C3-20 branched organic group, or a C3-20 cyclic organic group, and, with reference to the carbon atom to which R2 and R3 are bonded, at least one of a hydrogen atom or a halogen atom is bonded to the carbon atom at the α-position of at least one of R2 or R3; A represents a C1-30 aliphatic group; n1 represents 0 or 1; n2 represents an integer of 1-20; and, when n1 is 0, A is an aliphatic group in which a C3+ alkyl group having a main chain that is straight or branched is bonded to a carbon atom involved in a bond with the (meth)acrylate skeleton in formula (1).)

Description

Iodine-containing (meth)acrylate compound, iodine-containing (meth)acrylate (co)polymer, composition for lithography, resist composition, composition for forming underlayer film, and method for producing iodine-containing (meth)acrylate compound

[0001] The present invention relates to an iodine-containing (meth)acrylate compound, an iodine-containing (meth)acrylate (co)polymer, a composition for lithography, a resist composition, a composition for forming an underlayer film, and a method for producing the iodine-containing (meth)acrylate compound.

[0002] In recent years, advances in lithography technology have led to rapid advances in miniaturization of semiconductors (patterns) and pixels in the manufacture of semiconductor elements and liquid crystal display elements. A common method for miniaturizing pixels is to shorten the wavelength of the exposure light source. Specifically, while ultraviolet light, typically g-line and i-line, has traditionally been used, far-ultraviolet exposure using KrF excimer lasers (248 nm) and ArF excimer lasers (193 nm) has now become the norm for mass production, and extreme ultraviolet (EUV) lithography (13.5 nm) is also increasingly being introduced. Electron beams (EB) are also used to form fine patterns.

[0003] Conventional resist materials are polymeric resist materials capable of forming amorphous films. Examples include polymeric resist materials such as polymethyl methacrylate, and polyhydroxystyrene or polyalkyl methacrylate having an acid-dissociable group (see, for example, Non-Patent Document 1). Conventionally, a thin resist film is prepared by applying a solution of such a resist material onto a substrate, and then irradiating the thin resist film with ultraviolet light, far ultraviolet light, an electron beam, extreme ultraviolet light, or the like to form a line pattern of approximately 10 to 100 nm.

[0004] Furthermore, the reaction mechanism of electron beam or extreme ultraviolet lithography differs from that of conventional optical lithography. Furthermore, electron beam or extreme ultraviolet lithography aims to form fine patterns of several nanometers to several tens of nanometers. As resist pattern dimensions become smaller, resist materials with even higher sensitivity to the exposure light source are required. In particular, extreme ultraviolet lithography requires even higher sensitivity in terms of throughput. Inorganic resist materials containing metal elements such as titanium, tin, hafnium, and zirconium have been proposed as resist materials that address the above-mentioned problems (see, for example, Patent Document 1).

[0005] JP 2015-108781 A

[0006] Shinji Okazaki and 8 others, "40 Years of Lithography Technology," S&T Publishing, December 9, 2016

[0007] However, conventional resist compositions have problems such as insufficient sensitivity, insufficient resolution, many defects during pattern formation, insufficient etching resistance, and poor resist pattern quality. Among these, there is a particular demand for resist compositions that simultaneously achieve high sensitivity, high resolution, and reduced defects in the formed film.

[0008] In view of the above circumstances, an object of the present invention is to provide an iodine-containing (meth)acrylate compound or an iodine-containing (meth)acrylate (co)polymer that can simultaneously achieve high sensitivity, high resolution, and reduced defects during pattern formation.

[0009] As a result of intensive investigations to solve the above-mentioned problems, the present inventors have found that an iodine-containing (meth)acrylate compound and / or an iodine-containing (meth)acrylate (co)polymer having a specific structure can simultaneously achieve high sensitivity, high resolution, and reduced defects during pattern formation, and have thus completed the present invention.

[0010] [1] An iodine-containing (meth)acrylate compound represented by formula (1): (In formula (1), R １ represents a hydrogen atom, a methyl group, or a halogen atom;２ , R ３ are each independently a linear organic group having 1 to 20 carbon atoms, a branched organic group having 3 to 20 carbon atoms, or a cyclic organic group having 3 to 20 carbon atoms, and R ２ and R ３ When the carbon atom to which R is bonded is used as a reference, ２ and R ３ A represents an aliphatic group having 1 to 30 carbon atoms, and n １ represents 0 or 1; ２ represents an integer of 1 to 20, １ is 0, A is an aliphatic group in which a linear or branched alkyl group having 3 or more carbon atoms in its main chain is bonded to a carbon atom bonding to the (meth)acrylate skeleton in formula (1). [2] The iodine-containing (meth)acrylate compound according to [1], in which A has an alicyclic skeleton. [3] The iodine-containing (meth)acrylate compound according to [1] or [2], in which A has a polycyclic alicyclic skeleton. [4] The iodine-containing (meth)acrylate compound according to any one of [1] to [3], in which A has an adamantane skeleton. [5] The iodine-containing (meth)acrylate compound according to any one of [1] to [3], in which A has an adamantane skeleton. １ [6] The iodine-containing (meth)acrylate compound according to any one of [1] to [4], wherein n is 1. ２ represents an integer of 2 to 20. [7] The iodine-containing (meth)acrylate compound according to any one of [1] to [5], ２ The number of carbon atoms and R ３ [8] The iodine-containing (meth)acrylate compound according to any one of [1] to [6], wherein the total number of carbon atoms in R is 4 or more. ２ , the R ３ are each independently a linear organic group having 2 to 20 carbon atoms, a branched organic group having 3 to 20 carbon atoms, or a cyclic organic group having 3 to 20 carbon atoms, and R ２ and R ３ When the carbon atom to which R is bonded is used as a reference, ２ and R ３[9] The iodine-containing (meth)acrylate compound according to any one of [1] to [7], wherein R represents a group in which at least one of a hydrogen atom and a halogen atom is bonded to the carbon atom at the α-position of at least one of the R ２ and the number of carbon atoms in R ３

[10] An iodine-containing (meth)acrylate (co)polymer having a repeating unit represented by formula (2): (In formula (2), R １ represents a hydrogen atom, a methyl group, or a halogen atom; ２ , R ３ are each independently a linear organic group having 1 to 20 carbon atoms, a branched organic group having 3 to 20 carbon atoms, or a cyclic organic group having 3 to 20 carbon atoms, and R ２ and R ３ When the carbon atom to which R is bonded is used as a reference, ２ and R ３ A represents an aliphatic group having 1 to 30 carbon atoms, and n １ represents 0 or 1; ２ represents an integer of 1 to 20, １ is 0, A is an aliphatic group in which a linear or branched alkyl group having 3 or more carbon atoms in the main chain is bonded to a carbon atom bonding to the (meth)acrylate skeleton in formula (1), and the symbol * represents a bonding site to an adjacent repeating unit.

[11] The iodine-containing (meth)acrylate (co)polymer according to

[10] , in which A has an alicyclic skeleton.

[12] The iodine-containing (meth)acrylate (co)polymer according to

[10] or

[11] , in which A has a polycyclic alicyclic skeleton.

[13] The iodine-containing (meth)acrylate (co)polymer according to any one of

[10] to

[12] , in which A has an adamantane skeleton.

[14] The n １

[15] The iodine-containing (meth)acrylate (co)polymer according to any one of

[10] to

[13] , wherein n is 1.２ represents an integer of 2 to 20.

[16] The iodine-containing (meth)acrylate (co)polymer according to any one of

[10] to

[14] . ２ The number of carbon atoms and R ３

[17] The iodine-containing (meth)acrylate (co)polymer according to any one of

[10] to

[15] , wherein the total number of carbon atoms in R is 4 or more. ２ , the R ３ are each independently a linear organic group having 2 to 20 carbon atoms, a branched organic group having 3 to 20 carbon atoms, or a cyclic organic group having 3 to 20 carbon atoms, and R ２ and R ３ When the carbon atom to which R is bonded is used as a reference, ２ and R ３

[18] The iodine-containing (meth)acrylate (co)polymer according to any one of

[10] to

[16] , wherein R represents a group in which at least one of a hydrogen atom and a halogen atom is bonded to the carbon atom at the α-position of at least one of the R ２ and the number of carbon atoms in R ３ The iodine-containing (meth)acrylate (co)polymer according to any one of

[10] to

[17] , wherein the carbon numbers of the iodine-containing (meth)acrylate (co)polymers are different from each other.

[19] A composition for lithography, comprising the iodine-containing (meth)acrylate (co)polymer according to any one of

[10] to

[18] .

[20] A resist composition, comprising the iodine-containing (meth)acrylate (co)polymer according to any one of

[10] to

[18] .

[21] A composition for forming an underlayer film, comprising the iodine-containing (meth)acrylate (co)polymer according to any one of

[10] to

[18] .

[22] A method for producing the iodine-containing (meth)acrylate compound according to any one of [1] to [9], comprising an esterification step of reacting an iodine-containing hydroxy compound represented by formula (a) with a (meth)acrylic acid compound represented by formula (b). (In formula (a), R ２ , R ３ , A, n １ , n ２ is as defined in the above formula (1). (In formula (b), R １is as defined in the formula (1), Ｂ is selected from the group consisting of a hydroxyl group, a halogen atom, and a (meth)acryloyloxy group.)

[23] A method for producing an iodine-containing (meth)acrylate compound according to any one of [1] to [9], comprising: a first step of reacting a compound represented by formula (RM1) with a compound represented by formula (RGT21) or a compound represented by formula (RGT22); and a second step of reacting a product produced by the first step with a compound represented by formula (b). (In formula (RM1), A, n ２ is as defined in the formula (1), and R ４ is a hydrogen atom, a linear organic group having 1 to 20 carbon atoms, a branched organic group having 3 to 20 carbon atoms, or a cyclic organic group having 3 to 20 carbon atoms, and R ４ represents a group in which at least one of a hydrogen atom or a halogen atom is bonded to the carbon atom at the α-position relative to the carbon atom to which ２ (RGT21) (In formula (RGT21), X is a halogen atom, and R ２ is as defined in the above formula (1). ２ (RGT22) (In formula (RGT22), R ２ is as defined in the above formula (1). (In formula (b), R １ is as defined in the formula (1), Ｂ is selected from the group consisting of a hydroxyl group, a halogen atom, and a (meth)acryloyloxy group.

[0011] According to the present invention, it is possible to provide an iodine-containing (meth)acrylate compound or an iodine-containing (meth)acrylate (co)polymer that can simultaneously achieve high sensitivity, high resolution, and reduced defects during pattern formation.

[0012] Hereinafter, an embodiment of the present invention will be described (hereinafter also referred to as "the present embodiment"). Note that the present embodiment is an example for explaining the present invention, and the present invention is not limited to only the present embodiment.

[0013] In this specification, (meth)acrylate means acrylate and methacrylate. Other terms containing the term (meth) are also interpreted in the same manner as (meth)acrylate. In this specification, (co)polymer means homopolymer and copolymer.

[0014] 1. Iodine-Containing (Meth)acrylate Compound The iodine-containing (meth)acrylate compound of the present embodiment is a compound represented by the following formula (1). (In formula (1), R １ represents a hydrogen atom, a methyl group, or a halogen atom; ２ , R ３ are each independently a linear organic group having 1 to 20 carbon atoms, a branched organic group having 3 to 20 carbon atoms, or a cyclic organic group having 3 to 20 carbon atoms, and R ２ and R ３ When the carbon atom to which R is bonded is used as a reference, ２ and R ３ A represents an aliphatic group having 1 to 30 carbon atoms, and n １ represents 0 or 1; ２ represents an integer of 1 to 20, １ is 0, A is an aliphatic group in which a linear or branched alkyl group having 3 or more carbon atoms in the main chain is bonded to a carbon atom relating to the bond to the (meth)acrylate skeleton in formula (1).

[0015] The mechanism by which the iodine-containing (meth)acrylate compound of the present embodiment can simultaneously achieve high sensitivity, high resolution, and reduced defects during pattern formation is not particularly limited, but is thought to be, for example, as follows: The iodine-containing (meth)acrylate compound of the present embodiment has excellent sensitivity and resolution due to the inclusion of iodine, and １ is 1 or n １Even if A is 0, it is believed that by having a structure in which at least one alkyl group having 3 or more carbon atoms in the main chain is bonded to the carbon atom bonded to the (meth)acrylate skeleton in formula (1), the deprotection energy due to exposure is reduced, the solubility contrast is improved, and the resolution is excellent. At the same time, by increasing the bulkiness of the molecule, it is possible to suppress aggregate formation (hereinafter simply referred to as aggregate formation) caused by intermolecular interactions such as crystallization or similar packing effects that may occur during film formation, and it is believed that the occurrence of film defects after development caused by local aggregate formation can be prevented.

[0016] 1.1.R １ Structure of R １ R can be a hydrogen atom, a methyl group, or a halogen atom. Known atoms can be used as the halogen atom, and F, Cl, Br, I, etc. can be used appropriately. １ is preferably a methyl group or a halogen atom from the viewpoints of exposure sensitivity and material stability when the compound of this embodiment is used as a structural unit of a resin for a resist, and is more preferably a methyl group from the viewpoint of exposure sensitivity in particular.

[0017] 1.2.R ２ and R ３ Structure of R ２ , R ３ are each independently a linear organic group having 1 to 20 carbon atoms, a branched organic group having 3 to 20 carbon atoms, or a cyclic organic group having 3 to 20 carbon atoms, and R ２ and R ３ represents a group containing at least one of a hydrogen atom and a halogen atom as a substituent on the carbon atom at the α-position relative to the carbon atom to which R is bonded. ２ , R ３ are each independently a linear organic group having 1 to 20 carbon atoms, a branched organic group having 3 to 20 carbon atoms, or a cyclic organic group having 3 to 20 carbon atoms, and R ２ and R ３ When the carbon atom to which R is bonded is used as a reference, ２ and R ３At least one of the carbon atoms at the α-position of the above is bonded to at least one of a hydrogen atom and a halogen atom.

[0018] R ２ , R ３ From the viewpoint of high resolution and reduction of defects in the formed film, ２ The number of carbon atoms and R ３ It is preferable that the total number of carbon atoms in

[0019] Here, "R ２ and R ３ The carbon atom to which "R" is bonded in formula (1) refers to the carbon atom to which "R" is bonded. ２ , R ３ , which means the oxygen atom of the (meth)acrylate skeleton in formula (1) and the quaternary carbon atom relating to the bond with A, and "R ２ and R ３ The carbon atom at the α-position relative to the carbon atom to which R is bonded refers to the carbon atom at the α-position relative to the carbon atom to which R is bonded. ２ and R ３ means the carbon atoms of

[0020] In the present embodiment, the term "(meth)acrylate skeleton" refers not only to a skeleton derived from (meth)acrylic acid that constitutes an ester bond in an iodine-containing (meth)acrylate compound represented by formula (1), but also to a skeleton derived from R ２ and R ３ And, R ２ and R ３ and a quaternary carbon atom to which is attached.

[0021] R ２ and R ３ are each independently a linear organic group having 2 to 20 carbon atoms, a branched organic group having 3 to 20 carbon atoms, or a cyclic organic group having 3 to 20 carbon atoms, from the viewpoints of improving solubility contrast, improving resolution, and reducing defects during pattern formation, and R ２ and R ３ When the carbon atom to which R is bonded is used as a reference, ２ and R ３and more preferably a linear organic group having 2 to 20 carbon atoms or a branched organic group having 3 to 20 carbon atoms.

[0022] Here, R in this embodiment ２ , R ３ The number of carbon atoms in R ２ , R ３ The number of carbon atoms contained in the substituents is not included.

[0023] In the present embodiment, the solubility contrast refers to the difference in solubility or dissolution rate between an exposed portion and an unexposed portion in a developer, which is caused by the presence or absence of a deprotection reaction due to acid dissociation of the ester bond in formula (1) when a film is formed using a composition containing an iodine-containing (meth)acrylate compound and / or a polymer thereof and applied to lithography. As the developer, an alkaline developer or an organic solvent developer is generally used.

[0024] Also, R ２ and the number of carbon atoms in R ３ The number of carbon atoms in R may be different from each other, and is preferable, mainly from the viewpoint of reducing defects during pattern formation. ２ and the number of carbon atoms in R ３ When the number of carbon atoms in R is different, ２ The number of carbon atoms and R ３ The absolute value of the difference between the number of carbon atoms (|R ２ Number of carbon atoms - R ３ The number of carbon atoms (|) is preferably 1 or more, more preferably 2 or more, and even more preferably 3 or more, mainly from the viewpoint of reducing defects during pattern formation.

[0025] Here, R ２ , R ３ may have a substituent. ２ , R ３are each independently not particularly limited, and examples thereof include an alkyl group having 1 to 20 carbon atoms, 1 to 10 carbon atoms, or 1 to 6 carbon atoms, which may have a substituent; an alkenyl group having 2 to 20 carbon atoms, 2 to 10 carbon atoms, or 2 to 6 carbon atoms, which may have a substituent; an alkynyl group having 2 to 20 carbon atoms, 2 to 10 carbon atoms, or 2 to 6 carbon atoms, which may have a substituent; a cycloalkyl group having 3 to 20 carbon atoms, 3 to 10 carbon atoms, or 3 to 6 carbon atoms, which may have a substituent; a cycloalkenyl group having 3 to 20 carbon atoms, 3 to 10 carbon atoms, or 3 to 6 carbon atoms, which may have a substituent; a cycloalkynyl group having 3 to 20 carbon atoms, 3 to 10 carbon atoms, or 3 to 6 carbon atoms, which may have a substituent; an aryl group having 5 to 20 carbon atoms, 5 to 10 carbon atoms, or 5 to 6 carbon atoms, which may have a substituent; and combinations thereof. ２ , R ３ are each independently preferably an alkyl group having 1 to 6 carbon atoms which may have a substituent, more preferably an alkyl group having 1 to 6 carbon atoms which has no substituent, and further preferably an alkyl group having 1 to 4 carbon atoms which has no substituent, from the viewpoint of reducing defects during pattern formation, etc.

[0026] R ２ , R ３ Specific examples of the group include, but are not limited to, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, icosyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cycloicosyl, adamantyl, ethylene, propylene, butylene, phenyl, naphthyl, anthracene, phenanthrene, tetracene, chrysene, triphenylene, pyrene, benzopyrene, azulene, and fluorene, which may have a substituent. Among these, groups other than methyl are preferred from the viewpoint of improving solubility contrast and improving resolution. These groups may contain an ether bond, a ketone bond, or an ester bond.

[0027] Here, the exemplified groups include isomers, i.e., without any particular limitation, for example, a propyl group includes an n-propyl group and an isopropyl group, and a butyl group includes an n-butyl group, a sec-butyl group, an isobutyl group, and a tert-butyl group.

[0028] The substituent is not particularly limited, but examples thereof include a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, a thiol group, a heterocyclic group, a linear aliphatic hydrocarbon group, a branched aliphatic hydrocarbon group, a cyclic aliphatic hydrocarbon group, an aryl group, an aralkyl group, an alkoxy group, an alkenyl group, an acyl group, an alkoxycarbonyl group, an alkyloyloxy group, an aryloyloxy group, an alkylsilyl group, various crosslinkable groups, and acid-dissociable groups.

[0029] The term "crosslinkable group" refers to a group that crosslinks with the aid of an acid, an alkali, light, or heat, and that crosslinks in the presence or absence of a catalyst. The crosslinkable group is not particularly limited, and examples thereof include a group having an allyl group, a group having a (meth)acryloyl group, a group having an epoxy(meth)acryloyl group, a group having a urethane(meth)acryloyl group, a group having a hydroxyl group, a group having a glycidyl group, a group having a vinyl-containing phenylmethyl group, a group having a styrene group, a group having an alkynyl group, a group having a carbon-carbon double bond, a group having a carbon-carbon triple bond, and groups containing these groups.

[0030] The term "acid-dissociable group" refers to a group that cleaves in the presence of an acid to generate an alkali-soluble group (e.g., a phenolic hydroxyl group, a carboxyl group, a sulfonic acid group, a hexafluoroisopropanol group), etc. The acid-dissociable group is not particularly limited, and can be appropriately selected from those proposed for, for example, hydroxystyrene resins and (meth)acrylic acid resins used in chemically amplified resist compositions for KrF and ArF. Specific examples of the acid-dissociable group include those described in WO 2016 / 158168.

[0031] 1.3. Structure of A A is an aliphatic group having 1 to 30 carbon atoms. Here, A may have a substituent other than iodine. A is not particularly limited, but examples thereof include an aliphatic group having a non-alicyclic skeleton, an aliphatic group having an alicyclic skeleton, and a combination thereof.

[0032] The aliphatic group having a non-alicyclic skeleton is not particularly limited, and examples thereof include an alkane having 1 to 30, 1 to 20, 1 to 10, or 1 to 6 carbon atoms, which may have a substituent; an alkene having 2 to 30, 2 to 20, 2 to 10, or 2 to 6 carbon atoms, which may have a substituent; an alkyne having 2 to 30, 2 to 20, 2 to 10, or 2 to 6 carbon atoms, which may have a substituent; and combinations thereof. Furthermore, the aliphatic group having an alicyclic skeleton is not particularly limited, and examples thereof include optionally substituted cycloalkanes having 3 to 30, 3 to 20, 3 to 10, or 3 to 6 carbon atoms; optionally substituted cycloalkenes having 3 to 30, 3 to 20, 3 to 10, or 3 to 6 carbon atoms; optionally substituted cycloalkynes having 3 to 30, 3 to 20, 3 to 10, or 3 to 6 carbon atoms; and combinations thereof.

[0033] Among these, from the viewpoints of reducing the deprotection energy, improving the resolution, and reducing defects during pattern formation, A preferably has an alicyclic skeleton, more preferably has a polycyclic alicyclic skeleton, and further preferably has an adamantane skeleton, because the adamantane cation in particular has very high stability and is thought to be able to particularly reduce the deprotection energy.

[0034] Specific examples of the compound that forms the skeleton of A include, but are not limited to, optionally substituted methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane, decane, icosane, triacontane, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, cycloicosane, cyclotriacontane, adamantane, ethylene, propylene, butene, pentene, hexene, heptene, octene, nonene, decene, icosene, triacontene, and combinations thereof, which may contain an ether bond, a ketone bond, or an ester bond.

[0035] The substituent of the compound that forms the skeleton of A is not particularly limited, but examples thereof include a halogen atom (fluorine, chlorine, bromine), a hydroxyl group, a cyano group, a nitro group, an amino group, a thiol group, a heterocyclic group, a linear aliphatic hydrocarbon group, a branched aliphatic hydrocarbon group, a cyclic aliphatic hydrocarbon group, an aryl group, an aralkyl group, an alkoxy group, an alkenyl group, an acyl group, an alkoxycarbonyl group, an alkyloyloxy group, an aryloyloxy group, an alkylsilyl group, various crosslinkable groups, and acid-dissociable groups.

[0036] The "crosslinkable group" and "acid-dissociable group" are not particularly limited, but examples thereof include the above-mentioned R ２ The materials described in the description of the above can be used.

[0037] n １ represents 0 or 1, n １ When n is 0, A is an aliphatic group in which a linear or branched alkyl group having 3 or more carbon atoms in the main chain is bonded to the carbon atom bonding to the (meth)acrylate skeleton in formula (1). １ is preferably 1 from the viewpoint of reducing deprotection energy, improving resolution, and reducing defects during pattern formation. When n1 is 0, specifically, the iodine-containing (meth)acrylate compound of the present embodiment is not particularly limited, but is, for example, represented by the following formula (10). (In formula (10), R １ represents a hydrogen atom, a methyl group, or a halogen atom; Ａ１represents a linear or branched alkyl group having 3 or more carbon atoms in the main chain, R Ａ２ represents an aliphatic group having 1 to 25 carbon atoms which forms an alicyclic structure together with the carbon atom of the (meth)acrylate skeleton, ２ represents an integer from 1 to 20.

[0038] R Ａ２ From the viewpoint of reducing defects during pattern formation, the number of carbon atoms is preferably 5 or more, and more preferably 10 or more.

[0039] n ２ is an integer of 1 to 20, and from the viewpoint of improving sensitivity, is preferably an integer of 2 to 20, more preferably an integer of 2 to 10, and even more preferably an integer of 2 to 5. Also, from the viewpoint of improving reactivity, n ２ is preferably 1 to 4, more preferably 1 to 3, and even more preferably 1 or 2.

[0040] Specific examples of the iodine-containing (meth)acrylate compound of the present embodiment are not particularly limited, but include the compounds synthesized in the examples described below as well as the following compounds.

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050] 2. Method for Producing Iodine-Containing (Meth)acrylate Compound The iodine-containing (meth)acrylate compound represented by formula (1) of this embodiment is not particularly limited, but can be synthesized, for example, by the following method.

[0051] 2.1. Reaction of Iodine-Containing Hydroxy Compound with (Meth)acrylic Acid Compound (First Production Method) One embodiment of the method for producing an iodine-containing (meth)acrylate compound is not particularly limited, but may be, for example, a method including an esterification step of reacting an iodine-containing hydroxy compound represented by formula (a) with a (meth)acrylic acid compound represented by formula (b).

[0052] (In formula (a), R ２ , R ３ , A, n １ , n ２ is as defined in formula (1). (In formula (b), R １ is as defined in formula (1). Ｂ is selected from the group consisting of a hydroxyl group, a halogen atom, and a (meth)acryloyloxy group. Ｂ is preferably a halogen atom such as a chlorine atom.

[0053] The (meth)acrylic acid compound represented by formula (b) of this embodiment is not particularly limited, but examples thereof include the following. Of these (meth)acrylic acid compounds, (meth)acrylic acid chloride is preferred from the viewpoint of reactivity.

[0054] A method for synthesizing an iodine-containing hydroxy compound represented by formula (a) will be described. The synthesis of the iodine-containing hydroxy compound represented by formula (a) is not particularly limited, but for example, the compound can be synthesized by carrying out an iodine introduction reaction on a compound of formula (Sa1) or (Sa2). When carrying out an iodine introduction reaction on a compound of formula (Sa2), the method further includes a step of converting the iodine-introduced product into a compound of formula (a).

[0055] (In formula (Sa1), R ２ , R３ , A, n １ is as defined in formula (1), and n ２ represents an integer of 0 to 20. X can be selected from a hydroxyl group or a halogen atom (F, Cl, Br, I, etc.).

[0056] (In formula (Sa2), A, n ２ is as defined in formula (1). X is as defined in formula (Sa1). E is a hydrocarbon group having 1 to 30 carbon atoms and having at least one group selected from the group consisting of a hydroxyl group, an aldehyde group, a carboxyl group, an ether group, a thiol group, and an amino group.

[0057] The iodine introduction reaction is not particularly limited, and examples thereof include the Sandmeyer method, the Halex method, an iodine introduction method using an iodizing agent or a compound that serves as an iodine source, an iodine introduction method using an iodizing agent or a compound that serves as an iodine source and an oxidizing agent, an iodine introduction method using an iodizing agent or a compound that serves as an iodine source and a radical generator, an iodine introduction method using a system in which the catalytic activity is improved by using an iodizing agent or a compound that serves as an iodine source and a zeolite or the like, and a method in which iodination is performed by a substitution reaction of a functional group such as a hydroxyl group or a halogen atom. Examples of iodizing agents that can be used include iodine, potassium iodide, HI, iodine chloride, and N-iodosuccinimide. Examples of oxidizing agents that can be used include known oxidizing agents such as hydrogen peroxide, iodic acid, periodic acid, and sulfuric acid.

[0058] Next, the first production method for the iodine-containing (meth)acrylate compound represented by formula (1) will be described. The iodine-containing hydroxy compound represented by formula (a) is used in an amount of, for example, 0.1 to 100 molar equivalents, preferably 0.5 to 20 molar equivalents, more preferably 1.0 to 6 molar equivalents, and even more preferably 1.0 to 2.0 molar equivalents relative to the (meth)acrylic acid compound represented by formula (b). This range is preferred because it allows the reaction to proceed sufficiently and results in a high yield of the target iodine-containing (meth)acrylate compound represented by formula (1).

[0059] 2.2. Reaction of Iodine-Containing Carbonyl Compound with (Meth)Acrylic Acid Compound (Second Production Method) One embodiment of the production method for an iodine-containing (meth)acrylate compound is not particularly limited, but examples thereof include a method comprising: a first step of reacting a compound represented by formula (RM1) (hereinafter also referred to as an iodine-containing aldehyde compound) with a compound represented by formula (RGT21) or a compound represented by formula (RGT22); and a second step of reacting the product produced in the first step with a compound represented by formula (b). (In formula (RM1), A, n ２ is as defined in formula (1), and R ４ is a hydrogen atom, a linear organic group having 1 to 20 carbon atoms, a branched organic group having 3 to 20 carbon atoms, or a cyclic organic group having 3 to 20 carbon atoms, and R ４ represents a group in which at least one of a hydrogen atom or a halogen atom is bonded to the carbon atom at the α-position relative to the carbon atom to which ２ (RGT21) (In formula (RGT21), X is a halogen atom, and R ２ is as defined in formula (1). ２ (RGT22) (In formula (RGT22), R ２ is as defined in formula (1). (In formula (b), R １ is as defined in formula (1), and R Ｂ is selected from the group consisting of a hydroxyl group, a halogen atom, and a (meth)acryloyloxy group.

[0060] In formula (RM1), R ４ is not particularly limited, and may be, for example, a linear organic group having 1 to 20 carbon atoms. Examples of the linear organic group having 1 to 20 carbon atoms include, but are not particularly limited to, a linear alkyl group having 1 to 20, 1 to 10, or 1 to 5 carbon atoms, and a linear alkoxy group having 1 to 20, 1 to 10, or 1 to 5 carbon atoms.

[0061] The first step is a step of reacting a compound represented by formula (RM1) with a compound represented by formula (RGT21) or a compound represented by formula (RGT22). ４ is R ３ may be reacted with a compound represented by formula (RGT21) or a compound represented by formula (RGT22), and in this case, the compound represented by formula (1) may be reacted with a compound represented by formula (RGT21) or a compound represented by formula (RGT22) ２ and R derived from a compound represented by formula (RM1) ３ In addition, R in formula (RM1) ４ is a hydrogen atom or an alkoxy group, or the like, may be reacted with 2 equivalents of a compound represented by formula (RGT21) or a compound represented by formula (RGT22). In this case, the compound represented by formula (1) may be reacted with 2 equivalents of a compound represented by formula (RGT23). ２ =R ３ and R derived from the compound represented by formula (RGT21) or the compound represented by formula (RGT22) ２ has 2 equivalents.

[0062] The second step is a step of reacting the product produced in the first step with a compound represented by formula (b). In the second step, the reactive groups derived from the compound represented by formula (RGT21) or the compound represented by formula (RGT22) in the product produced in the first step are used in the reaction with the compound represented by formula (b) without quenching. This allows the quenching step to be omitted, making it possible to easily obtain an iodine-containing (meth)acrylate compound represented by formula (1). In this embodiment, the carbonyl group-derived site of formula (RM1) is activated by Mg or Li derived from formula (RGT21) or formula (RGT22) formed after the reaction in the first step, so that the reactive groups derived from the compound represented by formula (RGT21) or the compound represented by formula (RGT22) in the product produced in the first step can be used in the reaction with the compound represented by formula (b) without quenching.

[0063] A method for synthesizing an iodine-containing carbonyl compound represented by formula (RM1) will be described. Examples of synthesis methods for the iodine-containing carbonyl compound represented by formula (RM1) are not particularly limited, but for example, the compound can be synthesized by subjecting a compound of formula (SRM1-1) or (SRM1-2) to an iodine introduction reaction. When subjecting a compound of formula (SRM1-2) to an iodine introduction reaction, the method further includes a step of converting the iodine-introduced product into a compound of formula (SRM1-1).

[0064] (In formula (SRM1-1), R ４ , A, are as defined in formula (RM1), and n ２ represents an integer of 0 to 20. X can be selected from a hydroxyl group or a halogen atom (F, Cl, Br, I, etc.). (In formula (SRM1-2), A, X, n ２ is as defined in formula (SRM1-1). E is a hydrocarbon group having 1 to 30 carbon atoms and having at least one group selected from the group consisting of a hydroxyl group, an aldehyde group, a carboxyl group, an ether group, a thiol group, and an amino group.

[0065] In the second step, the (meth)acrylic acid compound represented by formula (b) may be the same as that in the first production method.

[0066] Other conditions are not particularly limited, but for example, the same conditions as those in the first production method can be used appropriately.

[0067] Next, the method for producing the iodine-containing (meth)acrylate compound represented by formula (1) by the second production method will be described. First, in the first step, the molar equivalent of the compound represented by formula (RGT21) or the compound represented by formula (RGT22) used with respect to the iodine-containing carbonyl compound represented by formula (RM1) is adjusted according to the stoichiometric number of organic groups to be introduced relative to the carbonyl carbon. This makes it possible to obtain an intermediate product having a reactive group derived from the compound represented by formula (RGT21) or the compound represented by formula (RGT22).

[0068] Subsequently, a (meth)acrylic acid compound represented by formula (b) is used in an amount of, for example, 0.1 to 100 molar equivalents, preferably 0.5 to 20 molar equivalents, more preferably 1.0 to 6.0 molar equivalents, and even more preferably 1.0 to 2.0 molar equivalents relative to the intermediate product. This range is preferred because the reaction proceeds sufficiently and the yield of the target iodine-containing (meth)acrylate compound represented by formula (1) is high.

[0069] As the solvent used in the first and second reactions, commonly available solvents can be used. While not particularly limited, for example, alcohols, ethers, hydrocarbons, aromatic solvents, halogenated solvents, etc. can be used appropriately as long as they do not inhibit the reactions. A mixture of multiple solvents can also be used as long as they do not inhibit the reactions. Since water inhibits the reactions, it is preferable to use a dehydrated solvent.

[0070] Furthermore, as the solvent used in producing the iodine-containing (meth)acrylate compound of this embodiment, a solvent with good solubility is preferably used for the purpose of improving the stability of the material and the efficiency of the process from reaction to obtaining the final compound. As a preferred solvent, γP and γH in the Hansen Solubility Parameters (Hansen Solubility Parameters: A User's Handbook, CRC Press, Boca Raton FL, 2007) can be used as indicators, and γP and γH can be determined from the compound structure. The lower the γP and γH, the better. A γP value of 6 or less is preferred, more preferably 4 or less, and even more preferably 2 or less. A γH value of 6 or less is preferred, more preferably 4 or less, and even more preferably 2 or less. Particularly preferred solvents include cyclic ether solvents such as tetrahydrofuran and 2-methyltetrahydrofuranbenzene, aromatic solvents such as benzene, toluene and xylene, aliphatic hydrocarbon solvents such as hexane, heptane and octane, and halogenated solvents such as dichloromethane and dichloroethane.

[0071] The reaction temperature and reaction time depend on the substrate concentration and the catalyst used, but generally the reaction temperature is −20° C. to 100° C., the reaction time is 1 to 10 hours, and the pressure is normal, reduced, or increased. The reaction can be carried out by any known method appropriately selected from the batch, semi-batch, and continuous systems.

[0072] A polymerization inhibitor may be added to the series of reactions, and a commercially available product that is generally available can be used. Examples of the polymerization inhibitor include, but are not limited to, nitroso compounds such as 2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxyl, N-nitrosophenylhydroxylamine ammonium salt, N-nitrosophenylhydroxylamine aluminum salt, N-nitroso-N-(1-naphthyl)hydroxylamine ammonium salt, N-nitrosodiphenylamine, N-nitroso-N-methylaniline, nitrosonaphthol, p-nitrosophenol, and N,N'-dimethyl-p-nitrosoaniline; sulfur-containing compounds such as phenothiazine, methylene blue, and 2-mercaptobenzimidazole; N,N'-diphenyl-p-phenylenediamine; Examples of the compound include amines such as N-phenyl-N'-isopropyl-p-phenylenediamine, 4-hydroxydiphenylamine, and aminophenol, quinones such as hydroxyquinoline, hydroquinone, methylhydroquinone, p-benzoquinone, and hydroquinone monomethyl ether, phenols such as p-methoxyphenol, 2,4-dimethyl-6-t-butylphenol, catechol, 3-s-butylcatechol, and 2,2-methylenebis-(6-t-butyl-4-methylphenol), imides such as N-hydroxyphthalimide, oximes such as cyclohexaneoxime and p-quinonedioxime, and dialkylthiodipropionates. The amount added is, for example, 0.001 to 10 parts by mass, and preferably 0.01 to 1 part by mass, relative to 100 parts by mass of the (meth)acrylic acid compound represented by formula (b).

[0073] The iodine-containing (meth)acrylate compound represented by formula (1) obtained by the reaction can be isolated and purified as a desired high-purity monomer by a known purification method such as filtration, concentration, distillation, extraction, crystallization, recrystallization, column chromatography, or a separation and purification method using activated carbon, or a combination of these methods.

[0074] 3. Iodine-Containing (Meth)acrylate (Co)Polymer The iodine-containing (meth)acrylate (co)polymer of this embodiment is a polymer containing an iodine-containing (meth)acrylate compound as a polymerization unit. A resist composition containing a polymer containing the compound of this embodiment as a structural unit as a resin component can achieve high sensitivity in a lithography process and high resolution due to an increased solubility contrast of the resin during development.

[0075] The weight average molecular weight of the iodine-containing (meth)acrylate (co)polymer is preferably 5,000 to 50,000, more preferably 7,000 to 30,000, and even more preferably 9,000 to 15,000, from the viewpoint of reducing defects during pattern formation.

[0076] The molecular weight distribution (also referred to as dispersity) of the iodine-containing (meth)acrylate (co)polymer is preferably 5.0 or less, more preferably 3.0 or less, and even more preferably 2.0 or less, from the viewpoint of reducing defects during pattern formation.

[0077] The ratio of the structural units derived from the iodine-containing (meth)acrylate compound to all structural units in the iodine-containing (meth)acrylate (co)polymer is preferably 20 to 80, more preferably 30 to 70, and even more preferably 40 to 60, from the viewpoint of reducing defects during pattern formation.

[0078] The iodine-containing (meth)acrylate (co)polymer of this embodiment has a repeating unit represented by formula (2). (In formula (2), R １ represents a hydrogen atom, a methyl group, or a halogen atom; ２ , R ３are each independently a linear organic group having 1 to 20 carbon atoms, a branched organic group having 3 to 20 carbon atoms, or a cyclic organic group having 3 to 20 carbon atoms, and R ２ and R ３ When the carbon atom to which R is bonded is used as a reference, ２ and R ３ A represents an aliphatic group having 1 to 30 carbon atoms, and n １ represents 0 or 1; ２ represents an integer of 1 to 20, １ is 0, A is an aliphatic group in which a linear or branched alkyl group having 3 or more carbon atoms in the main chain is bonded to a carbon atom relating to a bond to the (meth)acrylate skeleton in formula (1), and the symbol * represents a bonding site to an adjacent repeating unit.

[0079] R in formula (2) ２ , R ３ From the viewpoint of high resolution and reduction of defects in the formed film, ２ The number of carbon atoms and R ３ It is preferable that the total number of carbon atoms in

[0080] R in formula (2) ２ and R ３ are each independently a linear organic group having 2 to 20 carbon atoms, a branched organic group having 3 to 20 carbon atoms, or a cyclic organic group having 3 to 20 carbon atoms, from the viewpoints of improving solubility contrast, improving resolution, and reducing defects during pattern formation, and R ２ and R ３ When the carbon atom to which R is bonded is used as a reference, ２ and R ３ and more preferably a linear organic group having 2 to 20 carbon atoms or a branched organic group having 3 to 20 carbon atoms.

[0081] Furthermore, R in formula (2) ２ and the number of carbon atoms in R ３The numbers of carbon atoms in the groups are preferably different from each other, mainly from the viewpoint of reducing defects during pattern formation.

[0082] From the viewpoint of reducing the deprotection energy, improving the resolution, and reducing defects during pattern formation, A in formula (2) preferably has an alicyclic skeleton, more preferably has a polycyclic alicyclic skeleton, and further preferably has an adamantane skeleton, because adamantane cations in particular have very high stability and are thought to be able to particularly reduce the deprotection energy.

[0083] n in formula (2) １ is n １ is preferably 1 from the viewpoint of reducing the deprotection energy, improving the resolution, and reducing defects during pattern formation.

[0084] n in formula (2) ２ From the viewpoint of improving sensitivity, n is preferably an integer of 2 to 20, more preferably an integer of 2 to 10, and even more preferably an integer of 2 to 5. ２ is preferably 1 to 4, more preferably 1 to 3, and even more preferably 1 or 2.

[0085] In the present embodiment, it is preferable that A has an iodine atom bonded to a carbon atom adjacent to the carbon atom bonded to the (meth)acrylate skeleton in formula (2). The mechanism for this is not particularly limited, but for example, ２ and R ３ and are close to each other, and the aliphatic groups cannot easily adopt a conformation that is prone to aggregate formation. This is thought to make it possible to suppress excessive aggregate formation during film formation and prevent the occurrence of film defects after development that are due to local aggregate formation.

[0086] The iodine-containing (meth)acrylate (co)polymer represented by formula (2) can be obtained by polymerizing one or more iodine-containing (meth)acrylate compounds represented by formula (1) of the present embodiment, or by polymerizing one or more iodine-containing (meth)acrylate compounds represented by formula (1) of the present embodiment together with other monomers.

[0087] In this embodiment, R in formula (2) １ , R ２ , R ３ , A, n １ , and n ２ Unless otherwise specified, the meanings are the same as those of the iodine-containing (meth)acrylate compounds.

[0088] The repeating units other than the repeating unit represented by the formula (2) in the iodine-containing (meth)acrylate copolymer represented by the formula (2) are not particularly limited, and for example, those described in International Publication WO2016 / 125782, International Publication WO2015 / 115613, JP2015 / 117305, International Publication WO2014 / 175275, and JP2012 / 162498, or compounds represented by the following formulas (C1) and (C2) can be used. (In formula (C1), R Ｃ１１ represents a hydrogen atom or a methyl group; R Ｃ１２ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; R Ｃ１３ is R Ｃ１３ represents a cycloalkyl or heterocycloalkyl group having 4 to 20 carbon atoms that forms an alicyclic structure together with the carbon atom to which it is attached, and the dot * represents the bonding point to the adjacent repeating unit.

[0089] Preferably, R Ｃ１２ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R Ｃ１３ is R Ｃ１３ is a cycloalkyl group or heterocycloalkyl group having 4 to 10 carbon atoms, which together with the carbon atom to which R is attached forms an alicyclic structure. １３ may have a substituent (for example, an oxo group).

[0090] (In formula (C2), RＣ２１ represents a hydrogen atom or a methyl group; R Ｃ２２ and R Ｃ２３ each independently represents an alkyl group having 1 to 4 carbon atoms; Ｃ２４ represents an alkyl group having 1 to 4 carbon atoms or a cycloalkyl group having 5 to 20 carbon atoms; R Ｃ２２ ~R Ｃ２４ Two or three of these may form an alicyclic structure having 3 to 20 carbon atoms together with the carbon atoms to which they are attached, and the dot * indicates the bonding point to the adjacent repeating unit.) Preferably, R Ｃ２２ represents an alkyl group having 1 to 3 carbon atoms, and R Ｃ２４ is a cycloalkyl group having 5 to 10 carbon atoms. Ｃ２２ ~R Ｃ２４ The alicyclic structure formed by may contain a plurality of rings such as an adamantyl group, etc. The alicyclic structure may have a substituent (for example, a hydroxyl group or an alkyl group).

[0091] The monomer raw material for the repeating unit represented by formula (C2) is not particularly limited, and examples thereof include 2-methyl-2-(meth)acryloyloxyadamantane, 2-ethyl-2-(meth)acryloyloxyadamantane, 2-isopropyl-2-(meth)acryloyloxyadamantane, 2-n-propyl-2-(meth)acryloyloxyadamantane, 2-n-butyl-2-(meth)acryloyloxyadamantane, 1-methyl-1-(meth)acryloyloxycyclopentane, 1-ethyl-1-(meth)acryloyloxycyclopentane, 1-methyl Examples of such monomers include 1-(meth)acryloxycyclohexane, 1-ethyl-1-(meth)acryloxycyclohexane, 1-methyl-1-(meth)acryloxycycloheptane, 1-ethyl-1-(meth)acryloxycycloheptane, 1-methyl-1-(meth)acryloxycyclooctane, 1-ethyl-1-(meth)acryloxycyclooctane, 2-ethyl-2-(meth)acryloxydecahydro-1,4:5,8-dimethanonaphthalene, and 2-ethyl-2-(meth)acryloxynorbornane. Commercially available products can be used as these monomers.

[0092] Next, a method for producing an iodine-containing (meth)acrylate (co)polymer by polymerization reaction will be described. The polymerization reaction is carried out by dissolving the monomers that form the repeating units in a solvent, adding a catalyst, and heating or cooling the resulting mixture. The reaction conditions can be set as desired depending on the type of initiator, the initiation method (e.g., heat or light), temperature, pressure, concentration, solvent, additives, etc. The iodine-containing (meth)acrylate (co)polymer of this embodiment can be produced by known methods, such as radical polymerization using a radical generator such as azoisobutyronitrile or peroxide, or ionic polymerization using a catalyst such as an alkyllithium or a Grignard reagent.

[0093] The solvent used in the polymerization reaction may be a commercially available product that is generally available, and is not particularly limited, but various solvents such as alcohols, ethers, hydrocarbons, and halogenated solvents may be used as appropriate within the range that does not inhibit the reaction. A mixture of multiple solvents may also be used within the range that does not inhibit the reaction.

[0094] The iodine-containing (meth)acrylate (co)polymer obtained by the polymerization reaction can be purified by, for example, a known method, although not particularly limited thereto, specifically by a combination of ultrafiltration, crystallization, microfiltration, acid washing, washing with water having an electrical conductivity of 10 mS / m or less, and extraction.

[0095] 4. Compositions Containing Iodine-Containing (Meth)acrylate Compounds, etc. The composition of this embodiment contains the iodine-containing (meth)acrylate compound and / or the iodine-containing (meth)acrylate (co)polymer of this embodiment and is particularly suitable for lithography. The composition can be used for forming a film for lithography (i.e., a "lithography composition"), but is not particularly limited thereto. For example, the composition can be used for forming a resist film (i.e., a "resist composition"). Furthermore, the composition can be used for forming an upper layer film (i.e., a "composition for forming an upper layer film"), an intermediate layer (i.e., a "composition for forming an intermediate layer"), an underlayer film (i.e., a "composition for forming an underlayer film"), etc. The composition of this embodiment can form a film with high sensitivity and can also impart a good resist pattern shape.

[0096] The composition of this embodiment can also be used as a composition for forming optical components using lithography technology. Optical components are used in film or sheet form, and are useful as plastic lenses (prism lenses, lenticular lenses, microlenses, Fresnel lenses, viewing angle control lenses, contrast enhancement lenses, etc.), retardation films, electromagnetic wave shielding films, prisms, optical fibers, solder resists for flexible printed wiring, plating resists, interlayer insulating films for multilayer printed wiring boards, photosensitive optical waveguides, liquid crystal displays, organic electroluminescence (EL) displays, optical semiconductor (LED) elements, solid-state imaging elements, organic thin-film solar cells, dye-sensitized solar cells, and organic thin-film transistors (TFTs). The composition is particularly suitable for use as filling films and planarizing films on photodiodes, planarizing films before and after color filters, microlenses, and planarizing and conformal films on microlenses, which are components of solid-state imaging elements that require a high refractive index.

[0097] The composition of the present embodiment contains an iodine-containing (meth)acrylate compound and / or an iodine-containing (meth)acrylate (co)polymer (B), and may contain other components, such as a base material (A), a solvent (S), an acid generator (C), an acid diffusion controller (E), and a base generator (G), as necessary. Each component will be described below.

[0098] 4.1. Substrate (A) In this embodiment, the term "substrate (A)" refers to a compound (including a resin) other than an iodine-containing (meth)acrylate compound and / or an iodine-containing (meth)acrylate (co)polymer, and refers to a substrate (e.g., a substrate for lithography or a substrate for a resist) that is used as a resist for g-line, i-line, KrF excimer laser (248 nm), ArF excimer laser (193 nm), extreme ultraviolet (EUV) lithography (13.5 nm), or electron beam (EB). Any of these substrates can be used as the substrate (A) in this embodiment, without any particular limitation. Examples of the substrate (A) include phenol novolac resin, cresol novolac resin, hydroxystyrene resin, (meth)acrylic resin, hydroxystyrene-(meth)acrylic copolymer, cycloolefin-maleic anhydride copolymer, cycloolefin, vinyl ether-maleic anhydride copolymer, and inorganic resist materials containing metal elements such as titanium, tin, hafnium, and zirconium, as well as derivatives thereof. Among these, from the viewpoint of the shape of the resulting resist pattern, preferred are phenol novolac resins, cresol novolac resins, hydroxystyrene resins, (meth)acrylic resins, hydroxystyrene-(meth)acrylic copolymers, and inorganic resist materials containing metal elements such as titanium, tin, hafnium, and zirconium, as well as derivatives of these.

[0099] The derivative is not particularly limited, but examples thereof include those into which a dissociable group has been introduced, those into which a crosslinkable group has been introduced, etc. Derivatives into which a dissociable group or a crosslinkable group has been introduced can undergo a dissociation reaction or a crosslinking reaction by the action of light, acid, etc.

[0100] The term "dissociable group" refers to a characteristic group that cleaves to generate a functional group such as an alkali-soluble group that changes solubility. The alkali-soluble group is not particularly limited, but examples thereof include a phenolic hydroxyl group, a carboxyl group, a sulfonic acid group, and a hexafluoroisopropanol group. The phenolic hydroxyl group and the carboxyl group are preferred, and the phenolic hydroxyl group is particularly preferred.

[0101] The term "crosslinkable group" refers to a group that crosslinks in the presence or absence of a catalyst. The crosslinkable group is not particularly limited, but examples thereof include an alkoxy group having 1 to 20 carbon atoms, a group having an allyl group, a group having a (meth)acryloyl group, a group having an epoxy(meth)acryloyl group, a group having a hydroxyl group, a group having a urethane(meth)acryloyl group, a group having a glycidyl group, and a group having a vinyl-containing phenylmethyl group.

[0102] 4.2. Solvent (S) In the present embodiment, any known solvent can be used as appropriate, as long as it can dissolve at least the iodine-containing (meth)acrylate compound and / or the iodine-containing (meth)acrylate (co)polymer (B) described above.Specific examples of the solvent include, but are not limited to, ethylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono-n-propyl ether acetate, and ethylene glycol mono-n-butyl ether acetate; ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether; propylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monoethyl ether acetate, propylene glycol mono-n-propyl ether acetate, and propylene glycol mono-n-butyl ether acetate; propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether (PGME) and propylene glycol monoethyl ether; ester lactates such as methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, and n-amyl lactate. esters; aliphatic carboxylic acid esters such as methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, n-amyl acetate, n-hexyl acetate, methyl propionate, and ethyl propionate; methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, methyl 3-methoxy-2-methylpropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, butyl 3-methoxy-3-methylpropionate, 3-meth Examples of the ester include, but are not particularly limited to, other esters such as butyl oxy-3-methylbutyrate, methyl acetoacetate, methyl pyruvate, and ethyl pyruvate; aromatic hydrocarbons such as toluene and xylene; ketones such as acetone, 2-butanone, 2-heptanone, 3-heptanone, 4-heptanone, cyclopentanone (CPN), and cyclohexanone (CHN); amides such as N,N-dimethylformamide, N-methylacetamide, N,N-dimethylacetamide, and N-methylpyrrolidone; and lactones such as γ-lactone.The solvent used in the present embodiment is preferably a safe solvent, more preferably at least one selected from PGMEA, PGME, CHN, CPN, 2-heptanone, anisole, butyl acetate, and ethyl lactate, and even more preferably at least one selected from PGMEA, PGME, CHN, CPN, and ethyl lactate.

[0103] In this embodiment, the amounts of the solid component and the solvent are not particularly limited, but are preferably 1 to 80% by mass of the solid component and 20 to 99% by mass of the solvent, more preferably 1 to 50% by mass of the solid component and 50 to 99% by mass of the solvent, even more preferably 2 to 40% by mass of the solid component and 60 to 98% by mass of the solvent, and particularly preferably 2 to 10% by mass of the solid component and 90 to 98% by mass of the solvent. In this specification, the term "solid component" refers to components other than the solvent contained in the composition of this embodiment.

[0104] 4.3. Acid Generator (C) The composition of this embodiment preferably contains one or more acid generators (C) that generate an acid directly or indirectly upon irradiation with any radiation selected from visible light, ultraviolet light, excimer laser, electron beam, extreme ultraviolet light (EUV), X-rays, and ion beams. The acid generator (C) is not particularly limited, but examples thereof include those described in International Publication WO 2013 / 024778. The acid generators (C) may be used alone or in combination of two or more.

[0105] The amount of acid generator (C) used is preferably 0.001 to 49% by mass, more preferably 1 to 40% by mass, even more preferably 3 to 30% by mass, and particularly preferably 10 to 25% by mass, of the total mass of the solid components. Using the acid generator (C) within the above range tends to result in a pattern profile with high sensitivity and low edge roughness. In this embodiment, the method for generating acid is not particularly limited as long as an acid is generated in the system. Using an excimer laser instead of ultraviolet light such as g-line or i-line enables finer processing, and using an electron beam, extreme ultraviolet light, X-ray, or ion beam as a high-energy beam enables even finer processing.

[0106] 4.4. Base Generator (G) The case where the base generator (G) is a photobase generator will be described. The photobase generator is a compound that generates a base upon exposure to light, and is not particularly limited as long as it is inactive under normal conditions of room temperature and normal pressure, but generates a base (basic substance) upon exposure to electromagnetic waves and heating as external stimuli.

[0107] The photobase generator that can be used in the present embodiment is not particularly limited, and known photobase generators can be used, such as carbamate derivatives, amide derivatives, imide derivatives, α-cobalt complexes, imidazole derivatives, cinnamic acid amide derivatives, and oxime derivatives.

[0108] The basic substance generated from the photobase generator is not particularly limited, and examples thereof include compounds having an amino group, particularly polyamines such as monoamines and diamines, and amidines. From the viewpoints of sensitivity and resolution, the generated basic substance is preferably a compound having an amino group with a higher basicity (a higher pKa value of the conjugate acid). Examples of the photobase generator include base generators having a cinnamic acid amide structure as disclosed in JP 2009-80452 A and WO 2009 / 123122 A, base generators having a carbamate structure as disclosed in JP 2006-189591 A and JP 2008-247747 A, base generators having an oxime structure or a carbamoyloxime structure as disclosed in JP 2007-249013 A and JP 2008-003581 A, and compounds described in JP 2010-243773 A, but are not limited to these, and other known base generator structures can also be used.

[0109] The photobase generators may be used alone or in combination of two or more. The preferred content of the photobase generator is the same as the preferred content of the acid generator (C) described above.

[0110] 4.5. Acid Diffusion Controller (E) In this embodiment, the composition may contain an acid diffusion controller (E), which has the effect of controlling the diffusion of the acid generated from the acid generator upon irradiation in the resist film and preventing undesirable chemical reactions in unexposed areas. The use of the acid diffusion controller (E) tends to improve the storage stability of the composition of this embodiment. Furthermore, the use of the acid diffusion controller (E) tends to improve the resolution of the film formed using the composition of this embodiment, as well as suppress changes in the line width of the resist pattern due to variations in the exposure time before and after radiation exposure, thereby resulting in excellent process stability. The acid diffusion controller (E) is not particularly limited, and examples thereof include radiation-decomposable basic compounds such as nitrogen-containing basic compounds, basic sulfonium compounds, and basic iodonium compounds.

[0111] The acid diffusion controller (E) is not particularly limited, but for example, those described in International Publication WO 2013 / 024778 can be used. The acid diffusion controller (E) can be used alone or in combination of two or more.

[0112] The amount of the acid diffusion controller (E) is preferably 0.001 to 49% by mass, more preferably 0.01 to 10% by mass, even more preferably 0.01 to 5% by mass, and particularly preferably 0.01 to 3% by mass, based on the total mass of the solid components. When the amount of the acid diffusion controller (E) is within the above range, degradation of resolution, pattern shape, dimensional fidelity, and the like tends to be prevented. Furthermore, even if the exposure time between electron beam irradiation and post-exposure heating is long, degradation of the shape of the upper layer of the pattern can be suppressed. Furthermore, when the amount is 10% by mass or less, degradation of sensitivity, developability of unexposed areas, and the like tends to be prevented. Furthermore, the use of such an acid diffusion controller improves the storage stability and resolution of the resist composition, and also suppresses changes in the line width of the resist pattern due to variations in exposure time before and after radiation exposure, tending to result in excellent process stability.

[0113] 4.6. Other Components (F) If necessary, the composition of this embodiment may contain one or more of various additives as other components (F), such as a crosslinker, a dissolution promoter, a dissolution controller, a sensitizer, a surfactant, and an organic carboxylic acid, a phosphorus oxoacid, or a derivative thereof.

[0114] 4.6.1. Crosslinking Agent In this embodiment, the composition may contain one or more crosslinking agents. The crosslinking agent refers to a compound capable of crosslinking at least the substrate (A) or the iodine-containing (meth)acrylate compound and / or the iodine-containing (meth)acrylate (co)polymer (B). The crosslinking agent is preferably an acid crosslinking agent capable of intramolecularly or intermolecularly crosslinking the substrate (A) in the presence of an acid generated from the acid generator (C). Examples of such acid crosslinking agents include compounds having one or more groups (hereinafter referred to as "crosslinkable groups") capable of crosslinking the substrate (A).

[0115] Examples of the crosslinkable group include (i) hydroxyalkyl groups such as hydroxy (alkyl group having 1 to 6 carbon atoms), alkoxy (alkyl group having 1 to 6 carbon atoms), and acetoxy (alkyl group having 1 to 6 carbon atoms), or groups derived therefrom; (ii) carbonyl groups such as formyl group and carboxy (alkyl group having 1 to 6 carbon atoms), or groups derived therefrom; (iii) dimethylaminomethyl group, diethylaminomethyl group, dimethylolaminomethyl group, diethylolaminomethyl group, and the like. (iv) glycidyl group-containing groups such as a glycidyl ether group, a glycidyl ester group, and a glycidylamino group; (v) groups derived from aromatic groups such as allyloxy (alkyl groups having 1 to 6 carbon atoms) and aralkyloxy (alkyl groups having 1 to 6 carbon atoms) having 1 to 6 carbon atoms, such as a benzyloxymethyl group and a benzoyloxymethyl group; and (vi) polymerizable multiple bond-containing groups such as a vinyl group and an isopropenyl group. Examples of the crosslinkable group of the crosslinking agent in this embodiment include hydroxyalkyl groups and alkoxyalkyl groups, and particularly alkoxymethyl groups.

[0116] The crosslinking agent having a crosslinkable group is not particularly limited, and for example, the acid crosslinking agents described in International Publication WO 2013 / 024778 can be used. The crosslinking agents can be used alone or in combination of two or more.

[0117] In the present embodiment, the blending amount of the crosslinking agent is preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less, and particularly preferably 20% by mass or less, of the total mass of the solid components.

[0118] 4.6.2. Dissolution Accelerator A dissolution accelerator is a component that has the effect of increasing the solubility of a solid component in a developer when the solubility of the component is too low, thereby appropriately increasing the dissolution rate of the compound during development. Dissolution accelerators with low molecular weights are preferred, and examples thereof include low molecular weight phenolic compounds. Examples of low molecular weight phenolic compounds include bisphenols and tris(hydroxyphenyl)methane. These dissolution accelerators can be used alone or in combination of two or more.

[0119] The amount of the dissolution promoter to be added is adjusted appropriately depending on the type of solid component used, but is preferably 0 to 49% by mass, more preferably 0 to 5% by mass, even more preferably 0 to 1% by mass, and particularly preferably 0% by mass, of the total mass of the solid components.

[0120] Dissolution controllers are components that act to control the solubility of solid components in a developer when the solubility of the solid components is too high, thereby appropriately reducing the dissolution rate during development. Such dissolution controllers are preferably those that do not undergo chemical changes during processes such as baking, irradiation, and development of the resist film.

[0121] The dissolution controller is not particularly limited, but examples thereof include aromatic hydrocarbons such as phenanthrene, anthracene, and acenaphthene; ketones such as acetophenone, benzophenone, and phenyl naphthyl ketone; and sulfones such as methyl phenyl sulfone, diphenyl sulfone, and dinaphthyl sulfone. These dissolution controllers can be used alone or in combination of two or more.

[0122] The amount of the dissolution controller is adjusted appropriately depending on the type of the compound used, but is preferably 0 to 49% by mass, more preferably 0 to 5% by mass, even more preferably 0 to 1% by mass, and particularly preferably 0% by mass, of the total mass of the solid components.

[0123] 4.6.4. Sensitizer The sensitizer is a component that absorbs the energy of irradiated radiation and transfers that energy to the acid generator (C), thereby increasing the amount of acid produced and improving the apparent sensitivity of the resist. Examples of such sensitizers include, but are not limited to, benzophenones, biacetyls, pyrenes, phenothiazines, and fluorenes. These sensitizers can be used alone or in combination.

[0124] The amount of the sensitizer to be added is adjusted as appropriate depending on the type of the compound to be used, but is preferably 0 to 49 mass % of the total mass of the solid components, more preferably 0 to 5 mass %, even more preferably 0 to 1 mass %, and particularly preferably 0 mass %.

[0125] 4.6.5. Surfactant The surfactant is a component that has the effect of improving the coatability and striation of the composition of this embodiment, the developability of the resist, and the like. The surfactant may be any of anionic surfactants, cationic surfactants, nonionic surfactants, and amphoteric surfactants. Preferred surfactants include nonionic surfactants. Nonionic surfactants have good affinity with the solvent used in producing the composition of this embodiment, and can further enhance the effects of the composition of this embodiment. Examples of nonionic surfactants include, but are not limited to, polyoxyethylene higher alkyl ethers, polyoxyethylene higher alkyl phenyl ethers, and higher fatty acid diesters of polyethylene glycol. Examples of commercially available surfactants include, by trade name, F-TOP (manufactured by GEMCO), MEGAFAC (manufactured by Dainippon Ink and Chemicals, Inc.), FLORAAD (manufactured by Sumitomo 3M Limited), ASAHIGUARD, and SURFLOON (all manufactured by Asahi Glass Co., Ltd.), PEPOL (manufactured by Toho Chemical Industry Co., Ltd.), KP (manufactured by Shin-Etsu Chemical Co., Ltd.), and POLYFLOW (manufactured by Kyoeisha Yushi Kagaku Kogyo Co., Ltd.).

[0126] The amount of surfactant to be added is adjusted appropriately depending on the type of solid component to be used, but is preferably 0 to 49 mass % of the total mass of the solid components, more preferably 0 to 5 mass %, even more preferably 0 to 1 mass %, and particularly preferably 0 mass %.

[0127] 4.6.6. Organic Carboxylic Acid or Phosphorus Oxo Acid or Derivatives Thereof For the purpose of preventing sensitivity degradation or improving resist pattern shape and post-deposition stability, an organic carboxylic acid or a phosphorus oxo acid or a derivative thereof can be further included as an optional component. The organic carboxylic acid or the phosphorus oxo acid or a derivative thereof can be used in combination with an acid diffusion controller or alone. Suitable organic carboxylic acids include malonic acid, citric acid, malic acid, succinic acid, benzoic acid, and salicylic acid. Examples of phosphorus oxo acids or derivatives thereof include phosphoric acid, di-n-butyl phosphate, diphenyl phosphate, and other phosphoric acid or ester derivatives thereof; phosphonic acid, dimethyl phosphonate, di-n-butyl phosphonate, phenylphosphonic acid, diphenyl phosphonate, and other phosphonic acid or ester derivatives thereof; phosphinic acid, phenylphosphinic acid, and other phosphinic acid or ester derivatives thereof; and phosphonic acid, phenylphosphinic acid, and other ester derivatives thereof. Among these, phosphonic acid is particularly preferred.

[0128] The organic carboxylic acid, phosphorus oxo acid, or derivative thereof may be used alone or in combination of two or more. The amount of the organic carboxylic acid, phosphorus oxo acid, or derivative thereof is adjusted appropriately depending on the type of compound used, but is preferably 0 to 49% by mass, more preferably 0 to 5% by mass, even more preferably 0 to 1% by mass, and particularly preferably 0% by mass, of the total mass of the solid components.

[0129] 4.6.7. Other Additives Furthermore, the composition of this embodiment may contain one or more additives other than the components described above, as needed. Examples of such additives include dyes, pigments, and adhesion promoters. For example, the incorporation of a dye or pigment is preferred because it can visualize the latent image in the exposed area and mitigate the effects of halation during exposure. Furthermore, the incorporation of an adhesion promoter is preferred because it can improve adhesion to the substrate. Other additives include antihalation agents, storage stabilizers, antifoaming agents, shape modifiers, and the like, specifically 4-hydroxy-4'-methylchalcone.

[0130] In the composition of the present embodiment, the total amount of the other component (F) can be 0 to 99 mass% of the total mass of the solid components, preferably 0 to 49 mass%, more preferably 0 to 10 mass%, even more preferably 0 to 5 mass%, still more preferably 0 to 1 mass%, and particularly preferably 0 mass%.

[0131] To form a resist pattern from the composition of this embodiment, a solution of the composition is applied to a substrate, such as a silicon wafer, metal, plastic, glass, or ceramic, using a suitable coating method such as a spin coater, dip coater, or roller coater, to form a resist film. This may be pre-heated at a temperature of about 50°C to 200°C, and then exposed through a predetermined mask pattern. The thickness of the coating film is, for example, about 0.1 to 20 μm, preferably about 0.3 to 2 μm. Light beams of various wavelengths, such as ultraviolet light and X-rays, can be used for exposure. For example, light sources such as far ultraviolet light (e.g., F2 excimer laser (wavelength 157 nm), ArF excimer laser (wavelength 193 nm), and KrF excimer laser (wavelength 248 nm), extreme ultraviolet light (wavelength 13 nm), X-rays, and electron beams can be appropriately selected and used. Furthermore, exposure conditions, such as the exposure dose, are appropriately selected depending on the formulation of the resin and / or compound, the type of additive, and the like.

[0132] In this embodiment, in order to stably form a highly accurate fine pattern, it is preferable to perform a heat treatment at a temperature of 50 to 200°C for 30 seconds or more after exposure. In this case, if the temperature is less than 50°C, there is a risk of widening the variation in sensitivity depending on the type of substrate. Thereafter, the resist is developed using an alkaline developer typically at 10 to 50°C for 10 to 200 seconds, preferably at 20 to 25°C for 15 to 90 seconds, to form a predetermined resist pattern.

[0133] The alkaline developer is, for example, an alkaline aqueous solution in which an alkaline compound such as an alkali metal hydroxide, aqueous ammonia, alkylamines, alkanolamines, heterocyclic amines, tetraalkylammonium hydroxides, choline, 1,8-diazabicyclo-[5.4.0]-7-undecene, or 1,5-diazabicyclo-[4.3.0]-5-nonene is dissolved to a concentration of typically 1 to 10% by weight, preferably 1 to 3% by weight. A water-soluble organic solvent or a surfactant may also be added to the alkaline aqueous developer, as appropriate.

[0134] In this embodiment, in order to stably form a highly accurate fine pattern, after exposure and PEB, a development process can be performed using a developer containing an organic solvent as a main component to form a resist pattern. Various organic solvents are widely used as the organic solvent used in the developer, and examples of such organic solvents include ester-based solvents, ketone-based solvents, alcohol-based solvents, amide-based solvents, ether-based solvents, and hydrocarbon-based solvents. It is particularly preferred that the developer contain at least one solvent selected from ketone-based solvents, ester-based solvents, alcohol-based solvents, and ether-based solvents.

[0135] A basic compound, a water-soluble organic solvent, or a surfactant may be added to the developer comprising the organic solvent as described above.

[0136] Hereinafter, the present embodiment will be described in more detail with reference to examples and comparative examples, but the present embodiment is not limited to these examples in any way.

[0137] 1. Measurement Method (1) Compound Structure The compound structure was measured using a Bruker Advance 600II spectrometer under the following conditions: １ The product was confirmed by H-NMR measurement. Frequency: 600 MHz Solvent: CDCl ３ , or d ６ -DMSO Internal standard: TMS Measurement temperature: 23 ° C. Also, １３ C-NMR measurements were carried out using the same apparatus under the following conditions: Frequency: 150 MHz Solvent: CDCl ３ , or d ６ -DMSO Internal standard: Use the solvent used Measurement temperature: 23°C

[0138] 2. Synthesis of Iodine-Containing (Meth)acrylate Compound (Synthesis Example 1-72) Synthesis of 2nPAD2MA-1I A 1 L four-necked flask was prepared and, under a nitrogen flow, 27.7 g (0.1 mol) of 5-iodo-2-adamantanone (Mw 276.11) as the substrate was dissolved in 250 mL of dehydrated tetrahydrofuran. The flask was then immersed in an ice-water bath and the internal temperature was adjusted to -10°C. 110.4 mL of 1 M n-propylmagnesium bromide (Mw 147.3, 1.1 molar equivalents, tetrahydrofuran solution) as a Grignard reagent was slowly added dropwise over 30 minutes so that the liquid temperature remained below 5°C, followed by stirring for an additional 30 minutes. Subsequently, 15.8 g of methacrylic acid chloride (Mw 104.53, 1.5 molar equivalents) was slowly added over 30 minutes under conditions where the internal temperature was adjusted to -10°C. Subsequently, 1.2 g of 4-dimethylaminopyridine (Mw 122.17, 0.1 molar equivalent) was added while continuing stirring, and the mixture was further stirred for 6 hours while maintaining the internal temperature at -10°C. Subsequently, 100 mL of ice-cooled saturated aqueous ammonium chloride solution was added so that the internal temperature remained at 0°C, followed by stirring for 30 minutes. Subsequently, an extraction treatment was performed with 200 mL of ethyl acetate using a separatory funnel. The resulting organic phase consisting of the ethyl acetate solution was further washed with saturated saline, and then sodium sulfate was added to this organic phase for drying. The solvent was then distilled off under reduced pressure to obtain a crude product of 2nPAD2MA-1I. The resulting crude product of 2nPAD2MA-1I was purified by column chromatography to obtain 33.1 g (yield 85%) of 2nPAD2MA-1I shown below. Here, the term "molar equivalent" refers to the stoichiometric ratio relative to the number of moles of substrate.

[0139] The obtained compound (2nPAD2MA-1I) was analyzed under the above measurement conditions. １ H-NMR measurement revealed the following peaks, confirming that the compound had the chemical structure of the following formula (2nPAD2MA-1I): δ (ppm) (CDCl ３ ):6.5(1H,=CH ２ ), 6.4 (1H, =CH ２ ), 2.0 (3H, -CH ３ ), 1.0 (3H, -CH ３ ), 1.3 to 1.5 (4H, -CH ２-), 1.8 to 2.0 (2H, -CH-), 1.5 (1H, -CH-), 1.7 to 2.0 (2H, -CH ２ -), 2.6 to 2.9 (2H, -CH ２ -), 2.0 to 2.4 (2H, -CH ２ -), 1.3 to 1.9 (2H, -CH ２ -), 0.8 to 2.0 (2H, -CH ２ -)

[0140] The same procedures were carried out as in Synthesis Example 1-72, except that the substrate or Grignard reagent used was changed to that shown in Table 1, to synthesize the compounds shown in Table 1.

[0141] The specific structures of the compounds listed in Table 1 above are shown below.

[0142] Synthesis Example 2-39 Synthesis of DMADMA-3I A 1 L four-necked recovery flask was prepared and under a nitrogen flow, 32.1 g (0.1 mol) of methyl 3-iodoadamantanecarboxylate (Mw 320.17) as a substrate was dissolved in 250 ml of dehydrated tetrahydrofuran, and the flask was then immersed in an ice-water bath to bring the internal temperature to −10° C. 220.8 mL of 1 M methylmagnesium bromide (Mw 119.24, 2.2 molar equivalents, tetrahydrofuran (THF) solution) as a Grignard reagent was slowly added dropwise over 30 minutes so that the liquid temperature was 5° C. or less, and the mixture was then stirred for an additional 30 minutes. Thereafter, 15.8 g of methacrylic acid chloride (Mw 104.53, 1.5 molar equivalents) was slowly added over 30 minutes under the condition that the internal temperature was −10° C. Thereafter, 1.2 g of 4-dimethylaminopyridine (Mw After adding 122.17g of ammonium chloride (0.1 molar equivalents), the mixture was stirred for an additional 6 hours while maintaining the internal temperature at -10°C. Subsequently, 100mL of ice-cooled saturated aqueous ammonium chloride solution was added so as to maintain the internal temperature at 0°C, followed by stirring for 30 minutes. Subsequently, an extraction treatment was carried out with 200mL of ethyl acetate using a separatory funnel. The resulting organic phase consisting of the ethyl acetate solution was further washed with saturated saline, and sodium sulfate was added to this organic phase for drying. The solvent was then distilled off under reduced pressure to obtain a crude product of DMADMA-3I. The resulting crude product of DMADMA-3I was purified by column chromatography to obtain 28.2g (yield 85%) of DMADMA-3I shown below.

[0143] The obtained compound (DMADMA-3I) was measured under the above measurement conditions. １ H-NMR measurement revealed the following peaks, confirming that the compound had the chemical structure of the following formula (DMADMA-3I): δ (ppm) (CDCl ３ ):6.5(1H,=CH ２ ), 6.4 (1H, =CH ２ ), 2.0 (3H, -CH ３ ), 1.4 (6H, -CH ３ ), 1.7 to 1.9 (2H, -CH ２ -), 1.3 (2H, -CH ２ -), 1.0 to 1.1 (2H, -CH ２-), 1.5 (2H, -CH-), 1.3 to 1.9 (2H, -CH ２ -), 2.6 to 3.0 (2H, -CH ２ -), 2.0 to 2.4 (2H, -CH ２ -)

[0144] The same procedures were carried out as in Synthesis Example 2-39, except that the substrates and Grignard reagents used were changed to those shown in Table 2, to synthesize the compounds shown in Table 2.

[0145] The specific structures of the compounds listed in Table 2 above are shown below.

[0146] 3. Synthesis of Iodine-Containing (Meth)acrylate (Co)polymer (Resin Synthesis Example A72) Synthesis of P-2nPAD2MA-1I 7.06 g of 2nPAD2MA-1I, 1.24 g of γ-butyrolactone methacrylate, and 1.31 g of 4-vinylphenol were dissolved in 50 mL of tetrahydrofuran, and 0.20 g of azobisisobutyronitrile was added. After refluxing for 12 hours, the reaction solution was added dropwise to 2 L of n-heptane. The precipitated resin was filtered and dried under reduced pressure to obtain a white powdery resin represented by the following chemical formula (P-2nPAD2MA-1I). The molecular weight (Mw) of this resin was 12,500, and the dispersity (Mw / Mn) was 1.66. １３ As a result of C-NMR measurement, the composition ratio (molar ratio) in the following chemical formula (P-2nPAD2MA-1I) was found to be a:b:c = 20:30:50. Note that although the following chemical formula (P-2nPAD2MA-1I) is written in a simplified form to indicate the ratio of each structural unit, P-2nPAD2MA-1I is not a block copolymer in which each structural unit forms an independent block.

[0147]

[0148] Resin Synthesis Examples listed in Tables 3 and 4 were prepared in the same manner as in (Resin Synthesis Example A72), except that the types and amounts of compounds used were changed to those shown in Tables 3 and 4. The weight average molecular weight (Mw), dispersity, and monomer composition ratio a:b:c in the resin obtained are as shown in Tables 3 and 4.

[0149]

[0150]

[0151] Comparative Synthesis Example 1 A resin represented by the following chemical formula (P-AC-1) was obtained in the same manner as in Synthesis Example A72, except that 4.26 g of commercially available methyl adamantane methacrylate (manufactured by Osaka Organic Chemical Industry Ltd., product name EAMA(P)) was used as compound 1-76 instead of 2nPAD2MA-1I. The molecular weight (Mw) of this resin was 13,500, and the dispersity (Mw / Mn) was 1.95.

[0152]

[0153] In the formula (P-AC-1), "50", "20", and "30" represent the molar ratios of the respective structural units. Formula (P-AC-1) is written in a simplified manner to indicate the ratios of the respective structural units, but P-AC-1 is not a block copolymer in which the respective structural units form independent blocks.

[0154] 4. Evaluation 4.1. EB Writing (Evaluation of Sensitivity, Resolution, and Roughness) [Evaluation Using Resin Synthesis Example A72] A resin solution using Resin Synthesis Example A72 (P-2nPAD2MA-1I) was applied to a silicon wafer and baked at 110 to 130°C for 60 seconds to form a photoresist layer with a film thickness of 100 nm. The resin solution was prepared by blending 5 parts by mass of the resin of Resin Synthesis Example A72 (P-2nPAD2MA-1I), 1 part by mass of triphenylsulfonium nonafluoromethanesulfonate, 0.1 parts by mass of tributylamine, and 94 parts by mass of PGMEA. Furthermore, the prepared resin solution was filtered in a clean room using a filter line connected to a 15 nm pore size PTFE filter (manufactured by Entegris), to obtain a filtered resin solution.

[0155] The film was then exposed to light using an electron beam lithography system (ELS-7500, 100 keV, manufactured by Elionix), baked (PEB) at 105°C for 60 seconds, and puddle-developed with a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (TMAH) for 60 seconds. After rinsing with pure water, the film was rotated at 1500 rpm for 30 seconds, yielding a positive pattern. The resulting pattern was observed using an SEM (S4800, manufactured by Hitachi, Ltd.) to evaluate the resolution and sensitivity. The results are shown in Table 5.

[0156] The sensitivity was evaluated based on the lower limit of the exposure dose (mJ / cm) that allows formation of a pattern with a line width of 40 nm and a half pitch of 40 nm. ２ The results are shown in Table 5.

[0157] Regarding the resolution, a pattern with an L (line) / S (space) ratio of 1 / 1 was created using pattern layout conditions PL in which the half pitch was reduced by 1 nm from 60 nm, and the exposure dose was 60 mL / cm. ２ to 1 mJ / cm ２ Using condition D, in which the exposure dose was decreased each time, pattern formability was evaluated using a matrix of conditions PL and D, and the line width at which the resolution was minimized was determined. The results are shown in Table 5.

[0158] Furthermore, for any 10 of the obtained line patterns, the line width was measured at 30 points at 1 nm intervals per line, and the roughness value was evaluated as three times the standard deviation of the line width values. The results are shown in Table 5.

[0159] [Evaluation of Each Resin Synthesis Example] Photoresist layers were formed using the resins of each Synthesis Example in the same manner as when Resin Synthesis Example A72 was used, except that Resin Synthesis Example A72 was replaced with the resins shown in Tables 5 and 6. The results of EB sensitivity, resolution, and roughness value are shown in Tables 5 and 6.

[0160] 4.2. EUV Sensitivity Evaluation The sensitivity of each resin solution prepared above to an EUV light source was evaluated by the following method: Each prepared resin solution was applied to a separate silicon wafer using a spin coater, and then heat-treated on a hot plate at 105°C for 60 seconds to form a resist layer with a thickness of 100 nm.

[0161] Next, an extreme ultraviolet (EUV) exposure device "EUVES-7000" (product name, manufactured by LithoTech Japan Co., Ltd.) was used to expose the film to 1 mJ / cm ２ to 1 mJ / cm ２ 80 mJ / cm ２ After maskless shot exposure with the exposure dose increased to 1000, the entire surface of the silicon wafer was subjected to a 60-second bake (PEB) at 105°C and puddle development was performed for 60 seconds using a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (TMAH), yielding a wafer that had undergone 80 shot exposures on the wafer. For each of the resulting shot exposure areas, the film thickness was measured using an optical interference film thickness meter "VM3200" (product name, manufactured by SCREEN Semiconductor Solutions Co., Ltd.), profile data on the film thickness versus exposure dose was obtained, and the exposure dose at which the slope of the film thickness variation versus exposure dose was greatest was determined as the sensitivity value (mJ / cm). ２ ) and used as an index of the EUV sensitivity of the resist.

[0162] 4.3. Evaluation of Plain Film Exposure Defects The resin solution used in the EUV exposure sensitivity measurement was applied to a 12-inch silicon wafer with a 100 nm-thick oxide film formed on the outermost surface, and baked at 105°C for 60 seconds to form a 100 nm-thick photoresist layer. Next, using an extreme ultraviolet (EUV) exposure system "EUVES-7000" (product name, manufactured by Litho Tech Japan Co., Ltd.), the entire wafer was subjected to shot exposure at the same exposure dose as the EUV sensitivity value obtained in the EUV sensitivity evaluation described above. The wafer was then further baked at 105°C for 90 seconds (PEB) and paddle developed for 60 seconds using a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution, yielding a wafer that had been shot-exposed for 80 shots across the entire wafer.

[0163] The exposed wafer was then subjected to etching using a Telius SCCM (product name, manufactured by Tokyo Electron Ltd.). ４ / CF ４ Etching was performed using Ar / Ar gas until the oxide film was etched to a depth of 60 nm. The wafers produced by etching were subjected to defect evaluation using a defect inspection device "Surfscan SP3" (product name, manufactured by KLA Corporation), and the number of cone defects of 25 nm or more was determined as an index of etching defects. The measurement results are shown in Tables 5 and 6. (Evaluation criteria) S: Number of cone defects ≦ 5 A: 5 < Number of cone defects ≦ 20 B: 20 ​​< Number of cone defects ≦ 60 C: 60 < Number of cone defects ≦ 400 D: 400 < Number of cone defects

[0164]

[0165]

[0166] 5. Evaluation of Impurities in the Purified (Co)polymer Product [P1] 5.1. Treatment 1 (Acid Purification) 150 g of a solution (10% by mass) of Resin Synthesis Example A72 (P-2nPAD2MA-1I) dissolved in ethyl acetate / heptane (1 / 3) was placed in a 1000 mL four-neck flask (bottom-opening type) and stirred at 0°C for 1 hour. Next, 37.5 g of a 0.1% aqueous oxalic acid solution was added, stirred for 10 minutes, and then allowed to stand for 30 minutes. This resulted in separation into an oil phase and an aqueous phase, and the aqueous phase was removed. This operation was repeated twice, and then 37.5 g of ultrapure water was added to the resulting oil phase, stirred for 5 minutes, allowed to stand for 30 minutes, and the aqueous phase was removed. This operation was repeated 7 times. Thereafter, methoquinone was added to P-2nPAD2MA-1I so that the concentration was 100 ppm, followed by air bubbling while heating in a water bath at 40°C, and then the pressure inside the flask was reduced to 30 hPa or less to concentrate and distill off residual water, ethyl acetate, and heptane. Subsequently, EL-grade PGMEA (a reagent manufactured by Kanto Chemical Co., Ltd.) was diluted, and the concentration was adjusted to 10% by mass. A PTFE filter (15 nm PTFE filter) was used to filter out particles, yielding a PGMEA solution of compound P-2nPAD2MA-1I with a reduced metal content. Treatment 1 was also carried out in the same manner for other (co)polymers.

[0167] 5.2 Treatment 2 (treatment without using acid) A PGMEA solution of Resin Synthesis Example A72 (P-2nPAD2MA-1I) with a concentration adjusted to 10% by mass was obtained in the same manner as in Treatment 1 above, except that ultrapure water was used instead of the oxalic acid aqueous solution. Treatment 2 was also performed similarly on other (co)polymers.

[0168] 5.3. Treatment 3 (Metal Removal Filter Treatment) A PGMEA solution was prepared using Resin Synthesis Example A72 (P-2nPAD2MA-1I) and EL-grade PGMEA (manufactured by Kanto Chemical Co., Ltd.), the concentration of which was adjusted to 10% by mass. This was then subjected to metal removal filter treatment using a nylon filter (Polyfix Nylon (10 nm nylon filter), manufactured by Kitz Microfilter Co., Ltd.), and then particle removal filter treatment was performed using a PTFE filter (15 nm PTFE filter) to obtain a PGMEA solution of compound P-2nPAD2MA-1I. Treatment 3 was also performed similarly on other (co)polymers.

[0169] 5.4. Treatment 4 (no metal removal filter treatment) A PGMEA solution was prepared using Resin Synthesis Example A72 (P-2nPAD2MA-1I) adjusted to a concentration of 10% by mass and EL-grade PGMEA (a reagent manufactured by Kanto Chemical Co., Ltd.), and then the solution was subjected to a filter treatment to remove particles using a PTFE filter (40 nm PTFE filter) to obtain a PGMEA solution of compound P-2nPAD2MA-1I. The same treatment was also carried out on other (co)polymers.

[0170] 5.5. Evaluation of Various Metal Contents in P-2nPAD2MA-1I Purified Product Based on the above, the various metal contents were measured by ICP-MSMS (AG8900 manufactured by Agilent) for a 10 mass% PGMEA solution of P-2nPAD2MA-1I that had not been subjected to metal removal filter treatment, a 10 mass% PGMEA solution of P-2nPAD2MA-1I that had undergone treatment 1, a 10 mass% PGMEA solution of P-2nPAD2MA-1I that had undergone treatment 2, and a 10 mass% PGMEA solution of P-2nPAD2MA-1I that had undergone treatment 3. The details of the measurement conditions are as follows. The measurement results are shown in Table 7. <Measurement Conditions> - Apparatus: ICP-MSMS (Agilent 8900 manufactured by Agilent) - Dilution Conditions: 100-fold dilution, EL-grade NMP was distilled and used as the dilution solvent.

[0171]

[0172] 5.6. EUV Sensitivity of Purified Product and Evaluation of Solid Film Exposure Defects [E1] 5.6.1. EUV Sensitivity Evaluation 50 parts by mass of the PGMEA solution prepared in Example P1, 1 part by mass of triphenylsulfonium nonafluoromethanesulfonate, 0.1 part by mass of tributylamine, and 50 parts by mass of PGMEA were blended to prepare a resin solution. Furthermore, the prepared resin solution was filtered in a clean room using a PTFE filter (manufactured by Entegris) with a pore size of 15 nm to obtain a filtered resin solution. The composition was spin-coated on a silicon wafer and then baked at 105°C for 60 seconds to form a photoresist layer with a film thickness of 100 nm. Next, the resin solution was exposed to 1 mJ / cm using an extreme ultraviolet (EUV) exposure device "EUVES-7000" (product name, manufactured by LithoTech Japan Co., Ltd.). ２ to 1 mJ / cm ２ 80 mJ / cm ２ After maskless shot exposure with the exposure dose increased to 1000, the wafer was baked (PEB) at 110°C for 90 seconds and developed with a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution for 60 seconds, yielding a wafer with 80 shots of exposure on the wafer. For each of the resulting shot exposure areas, the film thickness was measured using an optical interference film thickness meter "VM3200" (product name, manufactured by SCREEN Semiconductor Solutions Co., Ltd.), profile data of the film thickness versus the exposure dose was obtained, and the exposure dose at which the slope of the film thickness variation versus the exposure dose was greatest was determined as the sensitivity value (mJ / cm). ２ ) and used as an index of the EUV sensitivity of the resist.

[0173] 5.6.2. Plain Film Exposure Defect Evaluation [P1] The resin solution used in the EUV exposure sensitivity measurement was applied to a 12-inch silicon wafer with a 100 nm-thick oxide film formed on its outermost surface, and baked at 105°C for 60 seconds to form a 100 nm-thick photoresist layer. The wafer was then subjected to a shot exposure across the entire surface using an extreme ultraviolet (EUV) exposure system "EUVES-7000" (product name, manufactured by Litho Tech Japan Co., Ltd.) at the same exposure dose as the EUV sensitivity value obtained in the EUV sensitivity evaluation described above. The wafer was then further baked at 110°C for 90 seconds (PEB) and developed for 60 seconds in a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (TMAH), yielding a wafer that had been shot-exposed across the entire surface for 80 shots.

[0174] The exposed wafer was then subjected to etching using a Telius SCCM (product name, manufactured by Tokyo Electron Ltd.). ４ / CF ４ Etching was performed using Ar / Ar gas until the oxide film was etched to 60 nm. The wafers produced by etching were subjected to defect evaluation using a defect inspection device "Surfscan SP3" (product name, manufactured by KLA Corporation), and the number of cone defects of 25 nm or more was determined as an index of etching defects. (Evaluation criteria) S: Number of cone defects ≦ 5 A: 5 < Number of cone defects ≦ 20 B: 20 ​​< Number of cone defects ≦ 60 C: 60 < Number of cone defects ≦ 400 D: 400 < Number of cone defects

[0175] The purified compound P-2nPAD2MA-1I was used to measure EUV exposure sensitivity and etching defects. The measurement results are shown in Table 8.

[0176]

[0177] Instead of Resin Synthesis Example A72 used in the test of [P1], each of the other Synthesis Examples was used, and the same purification treatment and evaluation as for [P1] were carried out. In all cases, the same results as for [P1] were obtained.

[0178] Furthermore, when the same evaluation as in [E1] was carried out using each of the other synthesis examples instead of Resin Synthesis Example A72 used in the test of [E1], the same results as in [E1] were obtained in all cases.

[0179] As described above, by using the iodine-containing (meth)acrylate compound and / or the iodine-containing (meth)acrylate (co)polymer of this embodiment, a composition capable of forming a lithography film with high resolution and high sensitivity can be obtained.

[0180] The present invention can provide a compound and composition capable of forming a film having high resolution and sensitivity, as well as a method for forming a resist pattern and a method for forming an insulating film using the same.

Claims

1. An iodine-containing (meth)acrylate compound represented by formula (1). (In formula (1), R １ represents a hydrogen atom, a methyl group, or a halogen atom; R ２ , R ３ are each independently a linear organic group having 1 to 20 carbon atoms, a branched organic group having 3 to 20 carbon atoms, or a cyclic organic group having 3 to 20 carbon atoms, and R ２ and R ３ When the carbon atom to which R is bonded is used as a reference, ２ and R ３ A represents an aliphatic group having 1 to 30 carbon atoms, and n １ represents 0 or 1; ２ represents an integer of 1 to 20, １ is 0, A is an aliphatic group in which a straight-chain or branched alkyl group having 3 or more carbon atoms in the main chain is bonded to a carbon atom relating to a bond to the (meth)acrylate skeleton in the formula (1).

2. The iodine-containing (meth)acrylate compound according to claim 1, wherein A has an alicyclic skeleton.

3. The iodine-containing (meth)acrylate compound according to claim 1, wherein A has a polycyclic alicyclic skeleton.

4. The iodine-containing (meth)acrylate compound according to claim 1, wherein A has an adamantane skeleton.

5. The above １ The iodine-containing (meth)acrylate compound according to claim 1 , wherein R 1 is 1.

6. The above ２ The iodine-containing (meth)acrylate compound according to claim 1 , wherein R represents an integer of 2 to 20.

7. The above R ２ The number of carbon atoms and R ３ The iodine-containing (meth)acrylate compound according to claim 1 , wherein the total number of carbon atoms in 8. The above R ２ , the R ３ are each independently a linear organic group having 2 to 20 carbon atoms, a branched organic group having 3 to 20 carbon atoms, or a cyclic organic group having 3 to 20 carbon atoms, and R ２ and R ３ When the carbon atom to which R is bonded is used as a reference, ２ and R ３ The iodine-containing (meth)acrylate compound according to claim 1 , wherein the iodine-containing (meth)acrylate compound according to claim 1 represents a group in which at least one of a hydrogen atom and a halogen atom is bonded to at least one α-position carbon atom of the formula (I).

9. The above R ２ and the number of carbon atoms in R ３ The iodine-containing (meth)acrylate compound according to claim 1 , wherein each of the carbon numbers of the following is different:

10. An iodine-containing (meth)acrylate (co)polymer having a repeating unit represented by formula (2). (In formula (2), R １ represents a hydrogen atom, a methyl group, or a halogen atom; R ２ , R ３ are each independently a linear organic group having 1 to 20 carbon atoms, a branched organic group having 3 to 20 carbon atoms, or a cyclic organic group having 3 to 20 carbon atoms, and R ２ and R ３ When the carbon atom to which R is bonded is used as a reference, ２ and R ３ A represents an aliphatic group having 1 to 30 carbon atoms, and n １ represents 0 or 1; ２ represents an integer of 1 to 20, １ is 0, A is an aliphatic group in which a straight-chain or branched alkyl group having 3 or more carbon atoms in the main chain is bonded to a carbon atom relating to a bond to the (meth)acrylate skeleton in the formula (1), and the symbol * represents a bonding site to an adjacent repeating unit.

11. The iodine-containing (meth)acrylate (co)polymer according to claim 10, wherein A has an alicyclic skeleton.

12. The iodine-containing (meth)acrylate (co)polymer according to claim 10, wherein A has a polycyclic alicyclic skeleton.

13. The iodine-containing (meth)acrylate (co)polymer according to claim 10, wherein A has an adamantane skeleton.

14. The above n １ The iodine-containing (meth)acrylate (co)polymer according to claim 10, wherein R 1 is 1.

15. The above ２ The iodine-containing (meth)acrylate (co)polymer according to claim 10, wherein represents an integer of 2 to 20.

16. The above R ２ The number of carbon atoms and R ３ The iodine-containing (meth)acrylate (co)polymer according to claim 10 , wherein the total number of carbon atoms in 17. The above R ２ , the R ３ are each independently a linear organic group having 2 to 20 carbon atoms, a branched organic group having 3 to 20 carbon atoms, or a cyclic organic group having 3 to 20 carbon atoms, and R ２ and R ３ When the carbon atom to which R is bonded is used as a reference, ２ and R ３ The iodine-containing (meth)acrylate (co)polymer according to claim 10, wherein the iodine-containing (meth)acrylate (co)polymer represents a group in which at least one of a hydrogen atom and a halogen atom is bonded to at least one α-position carbon atom of the formula (I).

18. The above R ２ and the number of carbon atoms in R ３ The iodine-containing (meth)acrylate (co)polymer according to claim 10 , wherein the carbon numbers of the following are different from each other.

19. A composition for lithography comprising the iodine-containing (meth)acrylate (co)polymer according to any one of claims 10 to 18.

20. A resist composition comprising the iodine-containing (meth)acrylate (co)polymer according to any one of claims 10 to 18.

21. A composition for forming an underlayer film, comprising the iodine-containing (meth)acrylate (co)polymer according to any one of claims 10 to 18.

22. A method for producing the iodine-containing (meth)acrylate compound according to any one of claims 1 to 9, comprising an esterification step of reacting an iodine-containing hydroxy compound represented by formula (a) with a (meth)acrylic acid compound represented by formula (b). (In formula (a), R ２ , R ３ , A, n １ , n ２ is as defined in the above formula (1). (In formula (b), R １ is as defined in the above formula (1), R Ｂ is selected from the group consisting of a hydroxyl group, a halogen atom, and a (meth)acryloyloxy group.

23. A method for producing an iodine-containing (meth)acrylate compound according to any one of claims 1 to 9, comprising: a first step of reacting a compound represented by formula (RM1) with a compound represented by formula (RGT21) or a compound represented by formula (RGT22); and a second step of reacting a product produced in the first step with a compound represented by formula (b). (In formula (RM1), A, n ２ is as defined in formula (1), R ４ is a hydrogen atom, a linear organic group having 1 to 20 carbon atoms, a branched organic group having 3 to 20 carbon atoms, or a cyclic organic group having 3 to 20 carbon atoms, and R ４ represents a group in which at least one of a hydrogen atom or a halogen atom is bonded to the carbon atom at the α-position relative to the carbon atom to which ２ (RGT21) (In formula (RGT21), X is a halogen atom, and R ２ is as defined in the above formula (1). ２ (RGT22) (In formula (RGT22), R ２ is as defined in the above formula (1). (In formula (b), R １ is as defined in the above formula (1), R Ｂ is selected from the group consisting of a hydroxyl group, a halogen atom, and a (meth)acryloyloxy group.