Iodine-containing compound, iodine-containing hydroxy compound, iodine-containing (CO)polymer, composition, pattern formation method, and production method for iodine-containing compound

Abstract

Provided are: an iodine-containing compound capable of forming a film having high resolution and high sensitivity; an iodine-containing hydroxy compound; an iodine-containing (co)polymer; a composition; a pattern formation method; and a production method for an iodine-containing compound. The iodine-containing compound according to the present invention is represented by formula (1).

Description

Iodine-containing compound, iodine-containing hydroxy compound, iodine-containing (co)polymer, composition, pattern forming method, and method for producing iodine-containing compound

[0001] The present invention relates to an iodine-containing compound, an iodine-containing hydroxy compound, an iodine-containing (co)polymer, a composition, a pattern forming method, and a method for producing an iodine-containing 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. Furthermore, extreme ultraviolet (EUV) lithography (13.5 nm) is 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, polyhydroxystyrene having an acid-dissociable group, or polyalkyl methacrylate (see, for example, Non-Patent Document 1). Conventionally, a line pattern of approximately 10 to 100 nm is formed by applying a solution of such a resist material to a substrate to prepare a thin resist film, and then irradiating the thin resist film with ultraviolet light, far ultraviolet light, an electron beam, extreme ultraviolet light, or the like.

[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 many film defects, insufficient sensitivity, insufficient etching resistance, and poor resist patterning. In particular, there is a demand for resist compositions that achieve both high resolution and high sensitivity.

[0008] In view of the above circumstances, an object of the present invention is to provide an iodine-containing compound, an iodine-containing hydroxy compound, an iodine-containing (co)polymer, a composition, a pattern forming method, and a method for producing an iodine-containing compound, which are capable of forming a film having high resolution and high sensitivity.

[0009] As a result of intensive research to solve the above-mentioned problems, the present inventors have found that iodine-containing compounds and iodine-containing (co)polymers having specific structures have high solubility in alkaline solutions, and that when these compounds are used in compositions for forming lithography films or resist films, films having high resolution and high sensitivity can be formed, thereby completing the present invention.

[0010] [1] An iodine-containing compound represented by formula (1):

[0011]

[0012] (In formula (1), R１ represents a hydrogen atom, a methyl group, or a halogen atom; ２ each independently represents 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; R Ａ each independently represents 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; A represents an organic group having 5 to 30 carbon atoms including an alicyclic ring; L represents an ester bond (—COO—), a single bond, or an oxygen atom; n １ represents 0 or 1; ２ represents an integer of 1 to 20, ３ represents an integer from 1 to 20.

[0013] [1-1] n １ is 0, and A is an alicyclic ring having 5 to 30 carbon atoms which may have a substituent.

[0014] [1-2] The iodine-containing compound according to [1-1], wherein the alicyclic ring having 5 to 30 carbon atoms, which may have a substituent, is an adamantane ring, which may have a substituent.

[0015] [2] The iodine-containing compound according to [1], wherein the compound represented by formula (1) is a compound represented by formula (2):

[0016]

[0017] (In formula (2), R １ , R ２ , R Ａ , A, n １ , n ２ , n ３ is as defined in the above formula (1).

[0018] [2-1] n １ [3] The iodine-containing compound according to [2], wherein R is 0 and A is an alicyclic ring having 5 to 30 carbon atoms which may have a substituent.

[0019] [2-2] The iodine-containing compound according to [2-1], wherein the alicyclic ring having 5 to 30 carbon atoms, which may have a substituent, is an adamantane ring, which may have a substituent.

[0020] [3] The iodine-containing compound according to [2], wherein the compound represented by formula (2) is a compound represented by formula (3):

[0021]

[0022] (In formula (3), R １ , R Ａ , A, n ２ , n ３ is as defined in the above formula (1).

[0023] [3-1] The iodine-containing compound according to [3], wherein A is an alicyclic ring having 5 to 30 carbon atoms which may have a substituent.

[0024] [3-2] The iodine-containing compound according to [3-1], wherein the alicyclic ring having 5 to 30 carbon atoms, which may have a substituent, is an adamantane ring, which may have a substituent.

[0025] [4] The iodine-containing compound according to [2], wherein the compound represented by formula (2) is a compound represented by formula (4):

[0026]

[0027] (In formula (4), R ２’ each independently represents 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; R １ , R Ａ , A, n １ , n ２ , n ３ is as defined in the above formula (1).

[0028] [4-1] The iodine-containing compound according to [4], wherein A is an alicyclic ring having 5 to 30 carbon atoms which may have a substituent.

[0029] [4-2] The iodine-containing compound according to [4-1], wherein the alicyclic ring having 5 to 30 carbon atoms, which may have a substituent, is an adamantane ring, which may have a substituent.

[0030] [5] The iodine-containing compound according to [1], wherein the compound represented by formula (1) is a compound represented by formula (5):

[0031]

[0032] (In formula (5), R １ , R ２ , R Ａ , A, n １ , n ２ , n ３ is as defined in the above formula (1).

[0033] [5-1] n １ [6] The iodine-containing compound according to [5], wherein R is 0 and A is an alicyclic ring having 5 to 30 carbon atoms which may have a substituent.

[0034] [5-2] The iodine-containing compound according to [5-1], wherein the alicyclic ring having 5 to 30 carbon atoms, which may have a substituent, is an adamantane ring, which may have a substituent.

[0035] [6] The iodine-containing compound according to [1], wherein the compound represented by formula (1) is a compound represented by formula (6):

[0036]

[0037] (In formula (6), R １ , R ２ , R Ａ , A, n １ , n ２ , n ３ is as defined in the above formula (1).

[0038] [7] n ２ [6] The iodine-containing compound according to any one of [1] to [6], wherein represents an integer of 1 to 15.

[0039] [8] R Ａeach independently represent 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.

[0022] The iodine-containing compound according to any one of [1] to [7].

[0040] [9] The iodine-containing compound according to any one of [1] to [8], wherein the alicyclic ring in A is an adamantane ring.

[0041]

[10] An iodine-containing (co)polymer having a repeating unit represented by formula (7):

[0042]

[0043] (In formula (7), R １ represents a hydrogen atom, a methyl group, or a halogen atom; ２ each independently represents 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; R Ａ each independently represents 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; A represents an organic group having 5 to 30 carbon atoms including an alicyclic ring; L represents an ester bond (—COO—), a single bond, or an oxygen atom; n １ represents 0 or 1; ２ represents an integer of 1 to 20, ３ represents an integer of 1 to 20, and the symbol * represents the bonding point to the adjacent repeating unit.

[0044] [10-1] n １

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

[10] , wherein R is 0 and A is an alicyclic ring having 5 to 30 carbon atoms which may have a substituent.

[0045] [10-2] The iodine-containing (co)polymer according to [10-1], wherein the alicyclic ring having 5 to 30 carbon atoms which may have a substituent is an adamantane ring which may have a substituent.

[0046]

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

[10] , wherein the repeating unit represented by the formula (7) is a repeating unit represented by the formula (8):

[0047]

[0048] (In formula (8), R １ , R ２ , R Ａ , A, n １ , n ２ , n ３ , the symbol * is as defined in the above formula (7).

[0049] [11-1] n １

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

[11] , wherein R is 0 and A is an alicyclic ring having 5 to 30 carbon atoms which may have a substituent.

[0050] [11-2] The iodine-containing (co)polymer according to [11-1], wherein the alicyclic ring having 5 to 30 carbon atoms which may have a substituent is an adamantane ring which may have a substituent.

[0051]

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

[10] , wherein the repeating unit represented by the formula (7) is a repeating unit represented by the formula (9):

[0052]

[0053] (In formula (9), R １ , R Ａ , A, n ２ , n ３ , the symbol * is as defined in the above formula (7).

[0054] [12-1] The iodine-containing (co)polymer according to

[12] , wherein A is an alicyclic ring having 5 to 30 carbon atoms which may have a substituent.

[0055] [12-2] The iodine-containing (co)polymer according to [12-1], wherein the alicyclic ring having 5 to 30 carbon atoms which may have a substituent is an adamantane ring which may have a substituent.

[0056]

[13] The iodine-containing (co)polymer according to

[10] , wherein the repeating unit represented by the formula (7) is a repeating unit represented by the formula (10):

[0057]

[0058] (In formula (10), R２’ each independently represents 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; R １ , R Ａ , A, n １ , n ２ , n ３ , the symbol * is as defined in the above formula (7).

[0059]

[14] The iodine-containing (co)polymer according to

[10] , wherein the repeating unit represented by the formula (7) is a repeating unit represented by the formula (11):

[0060]

[0061] (In formula (11), R １ , R ２ , R Ａ , A, n １ , n ２ , n ３ , the symbol * is as defined in the above formula (7).

[0062]

[15] The iodine-containing (co)polymer according to

[10] , wherein the repeating unit represented by the formula (7) is a repeating unit represented by the formula (12):

[0063]

[0064] (In formula (12), R １ , R ２ , R Ａ , A, n １ , n ２ , n ３ , the symbol * is as defined in the above formula (7).

[0065]

[16] n ２

[10] to

[15] , wherein represents an integer of 1 to 15. The iodine-containing (co)polymer according to any one of

[10] to

[15] .

[0066]

[17] R Ａ each independently represent 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.

[10] The iodine-containing (co)polymer according to any one of items

[16] to

[17] .

[0067]

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

[10] to

[17] , wherein the alicyclic ring in A is an adamantane ring.

[0068]

[19] A composition comprising the iodine-containing (co)polymer according to any one of

[10] to

[18] .

[0069]

[20] The composition according to

[19] , further comprising a solvent.

[0070]

[21] The composition according to

[19] or

[20] , further comprising an acid generator.

[0071]

[22] The composition according to any one of

[19] to

[21] , further comprising an acid diffusion controller.

[0072]

[23] A pattern forming method, comprising: a step of forming a film using the composition according to any one of

[19] to

[22] ; a step of exposing the film; and a step of removing the exposed portion of the exposed film using a developer to form a pattern.

[0073]

[24] The method for producing the iodine-containing compound according to any one of [1] to [9], comprising a step of reacting an iodine-containing hydroxy compound represented by formula (a) with a (meth)acrylic acid compound represented by formula (b).

[0074]

[0075] (In formula (a), R ２ each independently represents 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; R Ａ each independently represents 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; A represents an organic group having 5 to 30 carbon atoms including an alicyclic ring; n １ represents 0 or 1; ２ represents an integer of 1 to 20, ３ represents an integer from 1 to 20.

[0076]

[0077] (In formula (b), R １ is as defined in the formula (1), Ｂ is selected from the group consisting of a hydroxy group, a halogen atom, and a (meth)acryloyloxy group.

[0078] [24-1] n １

[25] The method for producing an iodine-containing compound according to

[24] , wherein R is 0 and A is an alicyclic ring having 5 to 30 carbon atoms which may have a substituent.

[0079] [24-2] The method for producing an iodine-containing compound according to [24-1], wherein the alicyclic ring having 5 to 30 carbon atoms which may have a substituent is an adamantane ring which may have a substituent.

[0080]

[25] The method for producing an iodine-containing compound according to

[24] , wherein the compound represented by formula (a) is a compound represented by formula (a1):

[0081]

[0082] (In formula (a1), R Ａ , A, n ２ , n ３ is as defined in formula (a) above.

[0083] [25-1] The method for producing an iodine-containing compound according to

[25] , wherein A is an alicyclic ring having 5 to 30 carbon atoms which may have a substituent.

[0084] [25-2] The method for producing an iodine-containing compound according to [25-1], wherein the alicyclic ring having 5 to 30 carbon atoms which may have a substituent is an adamantane ring which may have a substituent.

[0085]

[26] n ２ represents an integer of 1 to 15.

[24] The method for producing an iodine-containing compound according to

[25] or

[26] .

[0086]

[27] R Ａ each independently represent 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.

[24] The method for producing an iodine-containing compound according to any one of

[26] to

[27] .

[0087]

[28] The method for producing an iodine-containing compound according to any one of

[24] to

[27] , wherein the alicyclic ring in A is an adamantane ring.

[0088]

[29] An iodine-containing hydroxy compound represented by formula (a):

[0089]

[0090] (In formula (a), R ２ each independently represents 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; R Ａ each independently represents 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; A represents an organic group having 5 to 30 carbon atoms including an alicyclic ring; n １ represents 0 or 1; ２ represents an integer of 1 to 20, ３ represents an integer from 1 to 20.

[0091] [29-1] n １

[29] The iodine-containing hydroxy compound according to

[29] , wherein R is 0 and A is an alicyclic ring having 5 to 30 carbon atoms which may have a substituent.

[0092] [29-2] The iodine-containing hydroxy compound according to [29-1], wherein the alicyclic ring having 5 to 30 carbon atoms, which may have a substituent, is an adamantane ring, which may have a substituent.

[0093]

[30] The iodine-containing hydroxy compound according to

[29] , wherein the compound represented by formula (a) is a compound represented by formula (a1):

[0094]

[0095] (In formula (a1), R Ａ , A, n ２ , n ３ is as defined in the formula (a) above.

[0096] [30-1] The iodine-containing hydroxy compound according to

[30] , wherein A is an alicyclic ring having 5 to 30 carbon atoms which may have a substituent.

[0097] [30-2] The iodine-containing hydroxy compound according to [30-1], wherein the alicyclic ring having 5 to 30 carbon atoms, which may have a substituent, is an adamantane ring, which may have a substituent.

[0098]

[31] n ２ represents an integer of 1 to 15. The iodine-containing hydroxy compound according to

[29] or

[30] .

[0099]

[32] R Ａ each independently represent 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. The iodine-containing hydroxy compound according to any one of

[29] to

[31] .

[0100]

[33] The iodine-containing hydroxy compound according to any one of

[29] to

[32] , wherein the alicyclic ring in A is an adamantane ring.

[0101]

[34] The method for producing an iodine-containing compound according to any one of

[24] to

[28] , further comprising a step of introducing iodine into a compound represented by the following formula (Sa1) or formula (Sa2):

[0102]

[0103] (In formula (Sa1), R ２ , R Ａ , A, n １ , n ３ is as defined in the above formula (1).

[0104]

[0105] (In formula (Sa2), A, R Ａ , n ３ is as defined in the formula (1) above, and E is a hydrocarbon group having 1 to 30 carbon atoms and having at least one group selected from the group consisting of a hydroxy group, an aldehyde group, an ether group, a thiol group, and an amino group.

[0106]

[35] The method for producing an iodine-containing compound according to

[34] , wherein the alicyclic ring in A is an adamantane ring.

[0107] According to the present invention, it is possible to provide an iodine-containing compound, an iodine-containing hydroxy compound, an iodine-containing (co)polymer, a composition, a pattern forming method, and a method for producing an iodine-containing compound, which are capable of forming a film having high resolution and high sensitivity.

[0108] Hereinafter, an embodiment of the present invention will be described (hereinafter, may be 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.

[0109] In this specification, the substituent is not particularly limited, but examples thereof include halogen atoms, hydroxy groups, cyano groups, nitro groups, thiol groups, heterocyclic groups, linear aliphatic hydrocarbon groups, branched aliphatic hydrocarbon groups, cyclic aliphatic hydrocarbon groups, aryl groups, aralkyl groups, alkoxy groups, alkenyl groups, acyl groups, alkoxycarbonyl groups, alkyloyloxy groups, aryloyloxy groups, and alkylsilyl groups. These groups may also contain ether bonds, ketone bonds, and ester bonds. Specific examples of these substituents may refer to the examples of groups described in this specification.

[0110] In this specification, the organic group refers to a functional group composed of atoms selected from the group consisting of carbon, hydrogen, nitrogen, oxygen, silicon, sulfur, and halogen atoms, such as fluorine, chlorine, bromine, and iodine atoms.

[0111] In this specification, (meth)acrylate means acrylate and methacrylate. Other terms containing the expression (meth) are also interpreted in the same way as (meth)acrylate.

[0112] In this specification, (co)polymer means a homopolymer and a copolymer.

[0113] [Iodine-Containing Compound] The iodine-containing compound of this embodiment is a compound represented by the following formula (1). The compound represented by formula (1) contains an iodine atom and a carboxy group and / or an ester group, and therefore, when used in a composition for forming a lithography film or a resist film, it can form a film having high resolution and high sensitivity. The iodine-containing compound contains an iodine atom, which improves the EUV sensitivity and temporal stability of the resulting film, thereby improving etching defects and temporal stability.

[0114]

[0115] (In formula (1), R １ represents a hydrogen atom, a methyl group, or a halogen atom; ２ each independently represents 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; R Ａ each independently represents 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; A represents an organic group having 5 to 30 carbon atoms including an alicyclic ring; L represents an ester bond (—COO—), a single bond, or an oxygen atom; n １ represents 0 or 1; ２ represents an integer of 1 to 20, ３ represents an integer from 1 to 20.

[0116] R １ R can be a hydrogen atom, a methyl group, or a halogen atom. As the halogen atom, known atoms can be used, such as F (fluorine atom), Cl (chlorine atom), Br (bromine atom), and I (iodine atom). １ is preferably a hydrogen atom, a methyl group, or a halogen atom from the viewpoints of exposure sensitivity when the iodine-containing compound of the present embodiment is used as a structural unit of a resin (resist resin) for a resist material, and stability of the iodine-containing compound, the iodine-containing (co)polymer, or the composition, which will be described in detail later; and is more preferably a hydrogen atom, a methyl group, or an iodine atom, and even more preferably a methyl group, particularly from the viewpoint of exposure sensitivity.

[0117] R ２ may be a combination of two or more selected from the group consisting of linear organic groups having 1 to 20 carbon atoms, branched organic groups having 3 to 20 carbon atoms, and cyclic organic groups having 3 to 20 carbon atoms.

[0118] R ２ is preferably a hydrogen atom for the purpose of suppressing an increase in the Tg of the resin and improving the effect of introducing the iodine element. It is also preferably an organic group having one or more carbon atoms for the purpose of controlling solubility in a developer or improving acid decomposition property. It is also preferably a hydrogen atom for the purpose of suppressing acid decomposition property, ensuring solubility in an alkaline developer in particular, and suppressing residues.

[0119] R ２ may have a substituent. ２ Examples of the alkyl group 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.

[0120] R ２Specific examples of the alkyl group include, for example, optionally substituted 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 groups, which may contain an ether bond, a ketone bond, or an ester bond.

[0121] In this specification, the exemplified groups include isomers, 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.

[0122] R ２ The substituent is not particularly limited, but examples thereof include a halogen atom, a hydroxy 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.

[0123] 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. Examples of the crosslinkable group include, but are not limited to, 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 hydroxy 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.

[0124] 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 hydroxy group, a carboxy group, a sulfonic acid group, a hexafluoroisopropanol group), or the like. 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 acid-dissociable groups include those described in WO 2016 / 158168.

[0125] n １ represents 0 or 1. Since the solubility in a developer can be more suitably controlled and the acid decomposition property can be further improved, n １ is preferably 0. In addition, n is preferably 0 because it is possible to more suitably control the solubility in a developer and to further improve the acid decomposition property. １ It is also preferred that is 1.

[0126] R Ａ In the above, the linear organic group having 1 to 20 carbon atoms, the branched organic group having 3 to 20 carbon atoms, and the cyclic organic group having 3 to 20 carbon atoms are represented by R ２ Please refer to the following.

[0127] Since it has better heat resistance, Ａ is preferably 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.

[0128] R ＡExamples of the alkyl group 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.

[0129] R Ａ The substituents in ２ Please refer to the following.

[0130] R Ａ is preferably a hydrogen atom for the purpose of suppressing an increase in the Tg of the resin and improving the effect of introducing the iodine element. Furthermore, for the purpose of controlling solubility in a developer or improving acid decomposition property, it is also preferably an organic group having 1 or more carbon atoms, more preferably a linear organic group having 1 to 20 carbon atoms or a branched organic group having 3 to 20 carbon atoms, even more preferably a linear organic group having 1 to 20 carbon atoms, even more preferably a methyl group, ethyl group, or propyl group, and even more preferably a methyl group. Furthermore, it is also preferably a hydrogen atom for the purpose of suppressing acid decomposition property and, in particular, ensuring solubility in an alkaline developer and suppressing residues.

[0131] The iodine-containing compound preferably contains at least one selected from the group consisting of a carboxy group and an ester group, and more preferably contains at least one selected from the group consisting of a carboxy group and an ester group as a substituent on A, and R Ａis more preferably at least one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, an alkynyl group having 2 to 20 carbon atoms which may have a substituent, a cycloalkyl group having 3 to 20 carbon atoms which may have a substituent, a cycloalkenyl group having 3 to 20 carbon atoms which may have a substituent, a cycloalkynyl group having 3 to 20 carbon atoms which may have a substituent, and an aryl group having 5 to 20 carbon atoms which may have a substituent, Ａ is even more preferably an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, an alkynyl group having 2 to 20 carbon atoms which may have a substituent, a cycloalkyl group having 3 to 20 carbon atoms which may have a substituent, a cycloalkenyl group having 3 to 20 carbon atoms which may have a substituent, a cycloalkynyl group having 3 to 20 carbon atoms which may have a substituent, or an aryl group having 5 to 20 carbon atoms which may have a substituent. When the iodine-containing compound contains such a group, the etching stability of the resulting film tends to be further improved.

[0132] The iodine-containing compound preferably contains an ester group. When the iodine-containing compound contains an ester group, hydrogen bonds are less likely to be formed, which tends to further improve the solubility of the resin in a resist solvent such as PGMEA.

[0133] The iodine-containing compound has a polymerizable moiety (i.e., R １ -C(=CH ２ )-L-) is an acryloyloxy group (R １ is a hydrogen atom and L is an ester bond) or a methacryloyloxy group (R １ is a methyl group and L is an ester bond), and more preferably a methacryloyloxy group. When the iodine-containing compound contains such a group, the solubility of the resin is further improved, and the etching stability of the resulting film tends to be further improved.

[0134] The iodine-containing compound has a polymerizable moiety (i.e., R １ -C(=CH ２)-L-) is a vinyl group (R １ is a hydrogen atom, and L is a single bond. When the iodine-containing compound contains a vinyl group, stability is further improved, and the sensitivity over time and EB patternability tend to be further improved.

[0135] Since the solubility in a developer can be more suitably controlled and the acid decomposition property can be further improved, R Ａ In the formula (I), the organic group having 1 or more carbon atoms is preferably an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a cycloalkenyl group having 3 to 20 carbon atoms, or a cycloalkynyl group having 3 to 20 carbon atoms. These groups may have a substituent. These groups may contain an ether bond, a ketone bond, or an ester bond. As the substituent, a group containing an iodine atom is preferred.

[0136] Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, an icosyl group, an eicosyl group, a heneicosyl group, and a heneicosyl group. As the alkyl group, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, or an octyl group is preferred, and a methyl group, an ethyl group, a propyl group, or a butyl group is more preferred, since this allows for more suitable control of solubility in a developer and more improved acid decomposition property.

[0137] Examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group. As the cycloalkyl group, a cyclobutyl group, a cyclopentyl group, or a cyclohexyl group is preferred, as these can more suitably control the solubility in a developer and can further improve acid decomposition properties, and a 1-methyl-cyclobutyl group, a 1-ethyl-cyclobutyl group, a 1-propyl-cyclobutyl group, a 1-methyl-cyclopentyl group, a 1-ethyl-cyclopentyl group, a 1-propyl-cyclopentyl group, a 1-methyl-cyclohexyl group, a 1-ethyl-cyclohexyl group, or a 1-propyl-cyclohexyl group is more preferred.

[0138] Examples of the aryl group include a phenyl group, a benzyl group, a 1,1-dimethylbenzyl group, a 1-methyl-1-ethylbenzyl group, a 1,1-diethylbenzyl group, a 1-methyl-1-isopropylbenzyl group, a 1-ethyl-1-isopropylbenzyl group, a cyclohexylphenylene group, a hydroxyphenylene group, a cyanophenylene group, a nitrophenylene group, a naphthylene group, a biphenylene group, an anthryl group, a pyrenyl group, and a fluorenyl group. The aryl group is preferably a benzyl group or a 1,1-dimethylbenzyl group, and more preferably a 1,1-dimethylbenzyl group, because these groups can more suitably control the solubility in a developer and can further improve acid decomposition properties.

[0139] Examples of the cycloalkenyl group include a cycloprotenyl group, a cyclobutenyl group, a cyclopentenyl group, a cyclohexenyl group, a cyclohexadienyl group, a cyclooctatrienyl group, and a norbornylenyl group. The cycloalkenyl group is preferably a cyclopentenyl group or a cyclohexenyl group, since this can more suitably control the solubility in a developer and can further improve the acid decomposition property.

[0140] Examples of cycloalkynyl groups include cyclooctynyl groups.

[0141] The organic group having 5 to 30 carbon atoms and containing an alicyclic ring in A is preferably an alicyclic ring having 5 to 30 carbon atoms which may have a substituent, more preferably an alicyclic hydrocarbon having 5 to 30 carbon atoms which may have a substituent, even more preferably an adamantane which may have a substituent, and even more preferably an adamantane which contains a halogen atom. When A is such an alicyclic ring, higher resolution and higher sensitivity tend to be more favorably achieved at the same time. Since solubility in a developer can be more favorably controlled and acid decomposition can be further improved, the substituent preferably contains at least one selected from the group consisting of a halogen atom and a hydroxy group, and more preferably contains a halogen atom. The halogen atom is preferably an iodine atom.

[0142] Examples of the alicyclic ring in A include a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, a cycloheptane ring, a cyclooctane ring, a cyclononane ring, a cyclodecane ring, a cycloicosane ring, a cyclotriacontane ring, an adamantane ring, a norbornene ring, a decalin ring, and combinations thereof.Adamantane ring is preferred as the alicyclic ring in A because it tends to more suitably achieve both higher resolution and higher sensitivity.These rings may contain an ether bond, a ketone bond, and an ester bond.

[0143] Alicyclic hydrocarbons include, for example, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, cycloicosane, cyclotriacontane, adamantane, norbornene, and decalin.

[0144] The substituent in A is not particularly limited, and examples thereof include halogen atoms (fluorine, chlorine, bromine), hydroxy groups, cyano groups, nitro groups, amino groups, thiol groups, heterocyclic groups, linear aliphatic hydrocarbon groups, branched aliphatic hydrocarbon groups, cyclic aliphatic hydrocarbon groups, aryl groups, aralkyl groups, alkoxy groups, alkenyl groups, acyl groups, alkoxycarbonyl groups, alkyloyloxy groups, aryloyloxy groups, alkylsilyl groups, various crosslinkable groups, and acid-dissociable groups. The substituent may also contain an ether bond, a ketone bond, and an ester bond. Since this can more suitably control the solubility in a developer and further improve the acid decomposition property, the substituent in A is preferably COOR. Ａ It is preferred that the hydroxy group is included in addition to the hydroxy group.

[0145] 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 first embodiment can be used.

[0146] A is at least one COOR Ａ Since there is a tendency that higher resolution and higher sensitivity can be more suitably achieved at the same time, Ａ The group is preferably contained as a substituent in the iodine-containing compound that forms the skeleton of A. The substituent may contain an ether bond, a ketone bond, or an ester bond.

[0147] A is at least one COOR Ａ By including the group, when the composition is used in a film-forming application for lithography or a resist, the etching resistance of the resin and the stability of the composition tend to be more excellent. Also, it is preferable from the viewpoint of increasing the productivity of the iodine-containing compound and the iodine-containing (co)polymer.

[0148] n ３ represents an integer of 1 to 20. ３ is preferably an integer of 1 to 10, more preferably an integer of 1 to 5, even more preferably an integer of 1 to 3, and even more preferably 1. ３is in the above range, the stability of the iodine-containing compound and / or the iodine-containing (co)polymer becomes higher, the resin containing the iodine-containing compound and / or the iodine-containing (co)polymer dissolves better in an alkaline solution, and the storage stability of the composition containing the iodine-containing compound and / or the iodine-containing (co)polymer tends to be more excellent.

[0149] L represents an ester bond (—COO—), a single bond, or an oxygen atom. L is preferably an ester bond (—COO—) because this tends to more suitably achieve both higher resolution and higher sensitivity.

[0150] Furthermore, L is preferably a single bond, since this tends to more suitably achieve both higher resolution and higher sensitivity.

[0151] By including iodine atoms, the iodine-containing compound further improves the etching stability of the lithography film, and further improves the EUV sensitivity, its sensitivity over time, and the stability of the EB pattern.

[0152] n ２ is an integer of 1 to 20, preferably an integer of 1 to 15, more preferably an integer of 1 to 10, even more preferably an integer of 1 to 5, and even more preferably 1 or 2. ２ When the content is in the above range, the sensitivity and heat resistance tend to be excellent.

[0153] The compound represented by the formula (1) is １ is 0, and A is preferably an alicyclic ring having 5 to 30 carbon atoms which may have a substituent, more preferably an alicyclic hydrocarbon having 5 to 30 carbon atoms which may have a substituent, and even more preferably an adamantane which may have a substituent. １ When A is 0 and A is such an alicyclic ring, higher resolution and higher sensitivity tend to be more favorably achieved at the same time.

[0154] The compound represented by the formula (1) is preferably a compound represented by the following formula (2), since it has a tendency to have higher reactivity and to be able to further reduce roughness during pattern formation.

[0155]

[0156] In formula (2), R １ , R ２ , R Ａ , A, n １ , n ２ , n ３ is as defined in the above formula (1), including its preferred range.

[0157] The compound represented by the formula (2) is １ is 0, and A is preferably an alicyclic ring having 5 to 30 carbon atoms which may have a substituent, more preferably an alicyclic hydrocarbon having 5 to 30 carbon atoms which may have a substituent, and even more preferably an adamantane which may have a substituent. １ When A is 0 and A is such an alicyclic ring, higher resolution and higher sensitivity tend to be more favorably achieved at the same time.

[0158] The compound represented by the formula (2) is more preferably a compound represented by the following formula (3), since the compound has better etching resistance of the resin and tends to be able to further reduce roughness during pattern formation.

[0159]

[0160] In formula (3), R １ , R Ａ , A, n ２ , n ３ is as defined in the above formula (1), including its preferred range.

[0161] In the compound represented by formula (3), A is preferably an alicyclic ring having 5 to 30 carbon atoms which may have a substituent, more preferably an alicyclic hydrocarbon having 5 to 30 carbon atoms which may have a substituent, and even more preferably an adamantane which may have a substituent. When A is such an alicyclic ring, there is a tendency that higher resolution and higher sensitivity can be more suitably achieved at the same time.

[0162] The compound represented by the formula (2) is more preferably a compound represented by the following formula (4), since it tends to provide better contrast and thereby reduce roughness.

[0163]

[0164] In formula (4), R ２’ each independently represents 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; R １ , R Ａ , A, n １ , n ２ , n ３ is as defined in the above formula (1), including its preferred range.

[0165] R ２’ In the above, the linear organic group having 1 to 20 carbon atoms, the branched organic group having 3 to 20 carbon atoms, and the cyclic organic group having 3 to 20 carbon atoms are represented by R ２ Please refer to the following.

[0166] R ２’ is preferably an organic group having one or more carbon atoms for the purpose of controlling solubility in a developer or for the purpose of improving acid decomposition property.

[0167] In the compound represented by formula (4), A is preferably an alicyclic ring having 5 to 30 carbon atoms which may have a substituent, more preferably an alicyclic hydrocarbon having 5 to 30 carbon atoms which may have a substituent, and even more preferably an adamantane which may have a substituent. When A is such an alicyclic ring, there is a tendency that higher resolution and higher sensitivity can be more suitably achieved at the same time.

[0168] The compound represented by the formula (1) is more preferably a compound represented by the following formula (5) because better sensitivity can be obtained.

[0169]

[0170] In formula (5), R １ , R ２ , R Ａ , A, n １ , n ２, n ３ is as defined in the above formula (1), including its preferred range.

[0171] The compound represented by the formula (5) is １ is 0, and A is preferably an alicyclic ring having 5 to 30 carbon atoms which may have a substituent, more preferably an alicyclic hydrocarbon having 5 to 30 carbon atoms which may have a substituent, and even more preferably an adamantane which may have a substituent. １ When A is 0 and A is such an alicyclic ring, higher resolution and higher sensitivity tend to be more favorably achieved at the same time.

[0172] The compound represented by the formula (1) is more preferably a compound represented by the following formula (6) because it provides higher stability.

[0173]

[0174] In formula (6), R １ , R ２ , R Ａ , A, n １ , n ２ , n ３ is as defined in the above formula (1), including its preferred range.

[0175] The compound represented by the formula (6) is １ is 0, and A is preferably an alicyclic ring having 5 to 30 carbon atoms which may have a substituent, more preferably an alicyclic hydrocarbon having 5 to 30 carbon atoms which may have a substituent, and even more preferably an adamantane which may have a substituent. １ When A is 0 and A is such an alicyclic ring, higher resolution and higher sensitivity tend to be more favorably achieved at the same time.

[0176] Specific examples of the iodine-containing compound of the present embodiment are listed below, but are not limited thereto. １ represents a hydrogen atom or a methyl group. Ａ R each independently represents 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.Ｂ represents an alkyl group having 1 to 10 carbon atoms. Examples of the alkyl group having 1 to 10 carbon atoms include R ２ Please refer to the following.

[0177]

[0178]

[0179]

[0180]

[0181]

[0182]

[0183]

[0184]

[0185]

[0186] Specific examples of the iodine-containing compound of the present embodiment are listed below, but are not limited thereto.

[0187]

[0188]

[0189]

[0190] [Iodine-Containing Hydroxy Compound] The iodine-containing hydroxy compound of the present embodiment is represented by the following formula (a).

[0191]

[0192] In formula (a), R ２ each independently represents 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; R Ａ each independently represents 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; A represents an organic group having 5 to 30 carbon atoms including an alicyclic ring; n １ represents 0 or 1;２ represents an integer of 1 to 20, ３ represents an integer of 1 to 20. ２ , R Ａ , A, L, n １ , n ２ , and n ３ is as defined in the above formula (1), including its preferred range.

[0193] In formula (a), n １ is 0, and A is preferably an alicyclic ring having 5 to 30 carbon atoms which may have a substituent, more preferably an alicyclic hydrocarbon having 5 to 30 carbon atoms which may have a substituent, and even more preferably an adamantane which may have a substituent. １ When A is 0 and A is such an alicyclic ring, higher resolution and higher sensitivity tend to be more favorably achieved at the same time.

[0194] The compound represented by formula (a) is preferably a compound represented by formula (a1) below, since it has better solubility in a developer.

[0195]

[0196] In formula (a1), R Ａ , A, n ２ , n ３ is as defined in the formula (1) or the formula (a) above, including its preferred range.

[0197] In formula (a1), the organic group having 5 to 30 carbon atoms and containing an alicyclic ring for A is preferably an alicyclic ring having 5 to 30 carbon atoms which may have a substituent, more preferably an alicyclic hydrocarbon having 5 to 30 carbon atoms which may have a substituent, and even more preferably an adamantane which may have a substituent. When A is such an alicyclic ring, there is a tendency that higher resolution and higher sensitivity can be more suitably achieved at the same time.

[0198] In formula (a) or formula (a1), n ２ is preferably an integer of 1 to 15, more preferably an integer of 1 to 10, even more preferably an integer of 1 to 5, and even more preferably 1 or 2. ２When the value is in the above range, roughness during pattern formation tends to be further reduced.

[0199] In order to obtain better heat resistance, R Ａ are preferably 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.

[0200] In formula (a) or formula (a1), the alicyclic ring in A is preferably an adamantane ring, since this tends to more suitably achieve both higher resolution and higher sensitivity. These may contain an ether bond, a ketone bond, or an ester bond.

[0201] [Method for Producing Iodine-Containing Compound] The iodine-containing compound of the present embodiment can be synthesized by a known method.

[0202] First, the iodination reaction can be carried out by introducing iodine into the mother nucleus by a known method, such as a method using an iodine source and an oxidizing agent, or a method in which an iodine source and an inorganic salt are combined to form an iodide cation species, thereby causing the iodination reaction to proceed.

[0203] As the iodination reaction, a method of introducing iodine into an aliphatic alcohol group by a substitution reaction can also be used as appropriate. For example, a method of substituting the alcohol moiety with iodine using an aqueous hydrogen iodide solution can be mentioned.

[0204] The iodine-containing compound is preferably obtained by a method using a compound having a carboxy group as a starting material, for example, a method including a step of synthesizing an acid chloride from a compound having a carboxy group by a known method, and then reacting the acid chloride with various tertiary alcohols to synthesize a tertiary ester compound.

[0205] Another example is a method including a step of synthesizing a primary alcohol, which is a reduced form, from a compound having a carboxy group by a known method, and synthesizing a vinyl compound by oxidation to a formyl group or reduction of the formyl group.

[0206] The method may include a step of synthesizing a primary (meth)acrylate compound through a step of further reacting the primary alcohol obtained above with a (meth)acrylic acid compound.

[0207] Examples of methods for producing iodine-containing compounds include methods in which the above methods are appropriately combined with an iodination step.

[0208] As a method for producing an iodine-containing compound, for example, the schemes of the following formulas (I) to (III) may be referred to.

[0209]

[0210]

[0211]

[0212] Further, a method including a step of reacting the iodine-containing hydroxy compound represented by formula (a) of the present embodiment with a (meth)acrylic acid compound represented by formula (b) is also included, but is not limited thereto.

[0213]

[0214] In formula (a), R ２ , R Ａ , A, n １ , n ２ , n ３ is as defined in the above formula (1), including its preferred range.

[0215]

[0216] In formula (b), R １ is as defined in the formula (1) above, including its preferred range, and R Ｂ is selected from the group consisting of a hydroxy group, a halogen atom, and a (meth)acryloyloxy group.

[0217] In formula (a), n １is 0, and A is preferably an alicyclic ring having 5 to 30 carbon atoms which may have a substituent, more preferably an alicyclic hydrocarbon having 5 to 30 carbon atoms which may have a substituent, and even more preferably an adamantane which may have a substituent. １ When A is 0 and A is such an alicyclic ring, higher resolution and higher sensitivity tend to be more favorably achieved at the same time.

[0218] The compound represented by formula (a) is preferably a compound represented by formula (a1).

[0219]

[0220] In formula (a1), R Ａ , A, n ２ , n ３ is as defined in the formula (1) or the formula (a) above, including its preferred range.

[0221] In formula (a1), A is preferably an alicyclic ring having 5 to 30 carbon atoms which may have a substituent, more preferably an alicyclic hydrocarbon having 5 to 30 carbon atoms which may have a substituent, and even more preferably an adamantane which may have a substituent. When A is such an alicyclic ring, there is a tendency that higher resolution and higher sensitivity can be more suitably achieved at the same time.

[0222] Examples of the (meth)acrylic acid compound represented by formula (b) according to this embodiment are shown below.

[0223]

[0224] Of these (meth)acrylic acid compounds, (meth)acrylic acid chloride is preferred because it has superior reactivity.

[0225] In formula (a) or formula (a1), n ２ is preferably an integer of 1 to 15, more preferably an integer of 1 to 10, even more preferably an integer of 1 to 5, and even more preferably 1 or 2. ２ When the value is in the above range, roughness during pattern formation tends to be further reduced.

[0226] In order to obtain better heat resistance, R Ａ Preferably, each independently represents 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.

[0227] In formula (a) or formula (a1), the alicyclic ring in A is preferably an adamantane ring, since this tends to more suitably achieve both higher resolution and higher sensitivity. These may contain an ether bond, a ketone bond, or an ester bond.

[0228] Next, a method for synthesizing an iodine-containing hydroxy compound represented by formula (a) will be described. Examples of methods for synthesizing an iodine-containing hydroxy compound represented by formula (a) are not particularly limited, but for example, the compound can be synthesized by including a step of carrying out an iodine introduction reaction on a compound represented by formula (Sa1) or formula (Sa2). When carrying out an iodine introduction reaction on a compound of formula (Sa2), the method may further include a step of converting the resulting iodine introduction product into a compound of formula (a).

[0229]

[0230] In formula (Sa1), R ２ , R Ａ , A, n １ , n ３ is as defined in the above formula (1), including its preferred range.

[0231]

[0232] In formula (Sa2), A, R Ａ , n ３ is as defined in the formula (1) above, including its preferred range, and E is a hydrocarbon group having 1 to 30 carbon atoms and having at least one group selected from the group consisting of a hydroxy group, an aldehyde group, an ether group, a thiol group, and an amino group.

[0233] Examples of iodine introduction reactions that can be used 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 of an iodizing agent or a compound that serves as an iodine source is improved by using a zeolite or the like, and a method in which iodination is performed by a substitution reaction of a functional group such as a hydroxy group or a halogen group. Examples of iodine introduction agents that can be used include iodine, potassium iodide, HI (hydrogen iodide), 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.

[0234] In formula (Sa1) or formula (Sa2), the alicyclic ring for A is preferably an adamantane ring, since this tends to more suitably achieve both higher resolution and higher sensitivity. These may contain an ether bond, a ketone bond, or an ester bond.

[0235] Next, the method for producing an iodine-containing compound of this embodiment will be described using as an example the case where L in formula (1) is an ester bond (iodine compound represented by formula (2)). As described above, the iodine-containing compound represented by formula (1) (preferably the iodine-containing compound represented by formula (2)) can be produced by a method including a step of reacting an iodine-containing hydroxy compound represented by formula (a) with a (meth)acrylic acid compound represented by formula (b). The (meth)acrylic acid compound represented by formula (b) is used in an amount of, for example, 0.5 to 100 molar equivalents, preferably 1 to 20 molar equivalents, and more preferably 1.2 to 5 molar equivalents relative to the iodine-containing hydroxy compound represented by formula (a). This range is preferred because the reaction proceeds sufficiently and the yield of the target iodine-containing compound represented by formula (1) is high. Furthermore, when the amount of the (meth)acrylic acid compound represented by formula (b) is 0.5 molar equivalents or more, the iodine-containing hydroxy compound represented by formula (a) tends to be converted more effectively. When the amount of the (meth)acrylic acid compound represented by formula (b) is 100 molar equivalents or less, the amount of remaining impurities in the (meth)acrylic acid compound represented by formula (b) can be further suppressed, so that the purity tends to be less likely to decrease. A solvent can also be used in the step of reacting the iodine-containing hydroxy compound represented by formula (a) with the (meth)acrylic acid compound represented by formula (b). Commonly available solvents can be used as the solvent. For example, alcohols, ethers, hydrocarbons, aromatic solvents, halogenated solvents, etc. can be used appropriately as long as they do not inhibit the reaction. A mixture of multiple solvents can also be used as long as they do not inhibit the reaction. Since water inhibits the reaction, it is preferable to use a dehydrated solvent.

[0236] The solvent used in producing the iodine-containing compound of this embodiment preferably has good solubility in order to improve the stability of the material and the efficiency of the processes from reaction to obtaining the final compound. The 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 for the preferred solvent, 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 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.

[0237] The reaction temperature and reaction time in the production of the iodine-containing compound of this embodiment depend on the substrate concentration (e.g., the concentration of the iodine-containing hydroxy compound represented by Formula (a)) and the catalyst used, but generally the reaction temperature is −20° C. to 100° C., the reaction time is 1 hour to 10 hours, and the pressure is normal, reduced, or increased. The reaction can be carried out by an appropriately selected known method such as a batch system, a semi-batch system, or a continuous system.

[0238] A polymerization inhibitor may be added in the reaction, and a commercially available product that is generally available can be used. For example, nitroso compounds such as 2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxyl, N-nitrosophenylhydroxyamine ammonium salt, N-nitrosophenylhydroxyamine aluminum salt, N-nitroso-N-(1-naphthyl)hydroxyamine 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; N-phenyl-N Examples of the compound include amines such as '-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).

[0239] The iodine-containing compound represented by formula (1) (preferably the iodine-containing compound represented by formula (2)) 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.

[0240] [Iodine-Containing (Co)Polymer and Production Method Thereof] By forming a polymer containing the iodine-containing compound of this embodiment as a structural unit (polymerization unit), it is possible to form a polymer containing one or more iodine atoms, one or more hydrophilic groups, or one or more decomposable groups. As a result, a resist composition containing, as a resin component, a (co)polymer containing the iodine-containing compound of this embodiment as a structural unit can achieve high sensitivity in a lithography process and high resolution due to an increased solubility contrast of the resin during development.

[0241] The iodine-containing (co)polymer of this embodiment has a repeating unit represented by the following formula (7).

[0242]

[0243] In formula (7), R １ represents a hydrogen atom, a methyl group, or a halogen atom; ２ each independently represents 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; R Ａ each independently represents 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; A represents an organic group having 5 to 30 carbon atoms including an alicyclic ring; L represents an ester bond (—COO—), a single bond, or an oxygen atom; n １ represents 0 or 1; ２ represents an integer of 1 to 20, ３ represents an integer of 1 to 20, and the symbol * represents the bonding point to the adjacent repeating unit.

[0244] In the above formula (7), R １ , R ２ , R Ａ , A, L, n １ , n ２ , and n ３ is the same as defined in the iodine-containing compound represented by formula (1) above, including its preferred range.

[0245] An iodine-containing (co)polymer having a repeating unit represented by the above formula (7) can be obtained by polymerizing one or more iodine-containing compounds represented by the formula (1) of this embodiment or by copolymerizing one or more iodine-containing compounds represented by the formula (1) of this embodiment with other monomers. The iodine-containing (co)polymer can be suitably used as a film-forming material for lithography.

[0246] In the iodine-containing (co)polymer having a repeating unit represented by the above formula (7), the repeating units other than the above formula (7), and the compound that provides the repeating unit are not particularly limited, but for example, International Publication WO2016 / 125782 (particularly, compounds that provide the repeating units described in paragraphs 0017 to 0018, 0034 to 0039), International Publication WO2015 / 115613, JP2015 / 117305, International Publication WO2014 / 175275, International Publication WO2024 / 005049 (particularly, compounds described in paragraphs 0088 to 0097), those described in JP2012 / 162498, or the following formula (C1) Compounds represented by, and compounds represented by formula (C2) can be used.

[0247]

[0248] 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 Ｃ１３together with the carbon atom to which it is bonded, represent a cycloalkyl group or heterocycloalkyl group having 4 to 20 carbon atoms, and the dot * represents the point of attachment to the adjacent repeating unit. Specific examples of these groups can be found in the groups described in this specification. Examples of heterocycloalkyl groups having 4 to 20 carbon atoms include aziridinyl, oxiranyl, thiiranyl, azetidinyl, oxetanyl, thietanyl, tetrahydrothienyl, tetrahydrofuranyl, pyrrolidinyl, imidazolidinyl, oxazolidinyl, pyrazolidinyl, thiazolidinyl, tetrahydroisothiazolyl, tetrahydrooxazolyl, tetrahydroisoxazolyl, piperidinyl, piperazinyl, tetrahydropyranyl, tetrahydrothiopyranyl, morpholinyl, thiomorpholinyl, azepanyl, diazepanyl, oxepanyl, azocanyl, and diazocanyl.

[0249] Preferably, R Ｃ１２ represents hydrogen or an alkyl group having 1 to 3 carbon atoms; R Ｃ１３ is R Ｃ１３ R is, together with the carbon atom to which it is attached, a cycloalkyl group or heterocycloalkyl group having 4 to 10 carbon atoms. １３ may have a substituent (for example, an oxo group).

[0250]

[0251] In formula (C2), R Ｃ２１ 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, which may have a hydroxyl group, a carboxyl group, or an ester group; R Ｃ２２ ~R Ｃ２４ Two or three of these may form, together with the carbon atoms to which they are attached, an alicyclic structure having 3 to 20 carbon atoms, and the dot * indicates the bonding point to the adjacent repeating unit. Specific examples of these groups can be found in the groups described in this specification.

[0252] 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 hydroxy group or an alkyl group).

[0253] The monomer raw material that provides 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- Examples thereof include methyl-1-(meth)acryloyloxycyclohexane, 1-ethyl-1-(meth)acryloyloxycyclohexane, 1-methyl-1-(meth)acryloyloxycycloheptane, 1-ethyl-1-(meth)acryloyloxycycloheptane, 1-methyl-1-(meth)acryloyloxycyclooctane, 1-ethyl-1-(meth)acryloyloxycyclooctane, 2-ethyl-2-(meth)acryloyloxydecahydro-1,4:5,8-dimethanonaphthalene, and 2-ethyl-2-(meth)acryloyloxynorbornane. Commercially available products of these monomers can be used.

[0254] The iodine-containing (co)polymer having a repeating unit represented by the formula (7) is preferably an iodine-containing (co)polymer having a repeating unit represented by any one of the formulae (8) to (12), since it further improves the performance of the film-forming material for lithography.

[0255] An iodine-containing (co)polymer having a repeating unit represented by formula (8) obtained from an iodine-containing compound represented by formula (2), an iodine-containing (co)polymer having a repeating unit represented by formula (9) obtained from an iodine-containing compound represented by formula (3), an iodine-containing (co)polymer having a repeating unit represented by formula (10) obtained from an iodine-containing compound represented by formula (4), an iodine-containing (co)polymer having a repeating unit represented by formula (11) obtained from an iodine-containing compound represented by formula (5), and an iodine-containing (co)polymer having a repeating unit represented by formula (12) obtained from an iodine-containing compound represented by formula (6) can also be obtained in the same manner as the iodine-containing (co)polymer having a repeating unit represented by formula (7) obtained from an iodine-containing compound represented by formula (1).

[0256]

[0257] In formula (8), R １ , R ２ , R Ａ , A, n １ , n ２ , n ３ , the symbol * is as defined in the formula (1) or the formula (7).

[0258] In the iodine-containing (co)polymer having a repeating unit represented by formula (8), n １ is 0, and A is preferably an alicyclic ring having 5 to 30 carbon atoms which may have a substituent, more preferably an alicyclic hydrocarbon having 5 to 30 carbon atoms which may have a substituent, and even more preferably an adamantane which may have a substituent. １ When A is 0 and A is such an alicyclic ring, higher resolution and higher sensitivity tend to be more favorably achieved at the same time.

[0259]

[0260] In formula (9), R １ , R Ａ , A, n ２ , n ３ The symbol * is as defined in the formula (1) or (7) above, including its preferred range.

[0261] In the iodine-containing (co)polymer having a repeating unit represented by formula (9), A is preferably an alicyclic ring having 5 to 30 carbon atoms which may have a substituent, more preferably an alicyclic hydrocarbon having 5 to 30 carbon atoms which may have a substituent, and even more preferably an adamantane which may have a substituent. When A is such an alicyclic ring, there is a tendency that higher resolution and higher sensitivity can be more suitably achieved at the same time.

[0262]

[0263] In formula (10), R ２’ each independently represents 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; R １ , R Ａ , A, n １ , n ２ , n ３ , the symbol * is as defined in the formula (1) or (7), including its preferred range. ２’ For specific examples of the groups, see the groups described in this specification.

[0264] In the iodine-containing (co)polymer having a repeating unit represented by formula (10), n １ is 0, and A is preferably an alicyclic ring having 5 to 30 carbon atoms which may have a substituent, more preferably an alicyclic hydrocarbon having 5 to 30 carbon atoms which may have a substituent, and even more preferably an adamantane which may have a substituent. １ When A is 0 and A is such an alicyclic ring, higher resolution and higher sensitivity tend to be more favorably achieved at the same time.

[0265]

[0266] In formula (11), R １ , R ２ , R Ａ , A, n １ , n ２ , n ３ The symbol * is as defined in the formula (1) or (7) above, including its preferred range.

[0267] In the iodine-containing (co)polymer having a repeating unit represented by formula (11), n １ is 0, and A is preferably an alicyclic ring having 5 to 30 carbon atoms which may have a substituent, more preferably an alicyclic hydrocarbon having 5 to 30 carbon atoms which may have a substituent, and even more preferably an adamantane which may have a substituent. １ When A is 0 and A is such an alicyclic ring, higher resolution and higher sensitivity tend to be more favorably achieved at the same time.

[0268]

[0269] In formula (12), R １ , R ２ , R Ａ , A, n １ , n ２ , n ３ The symbol * is as defined in the formula (1) or (7) above, including its preferred range.

[0270] In the iodine-containing (co)polymer having a repeating unit represented by formula (12), n １ is 0, and A is preferably an alicyclic ring having 5 to 30 carbon atoms which may have a substituent, more preferably an alicyclic hydrocarbon having 5 to 30 carbon atoms which may have a substituent, and even more preferably an adamantane which may have a substituent. １ When A is 0 and A is such an alicyclic ring, higher resolution and higher sensitivity tend to be more favorably achieved at the same time.

[0271] In formulas (7) to (12), n ２ is preferably an integer of 1 to 15, more preferably an integer of 1 to 10, even more preferably an integer of 1 to 5, and even more preferably 1 or 2. ２ When the value is in the above range, roughness during pattern formation tends to be further reduced.

[0272] In formulas (7) to (12), R Ａare preferably 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.

[0273] In formulas (7) to (12), the alicyclic ring in A is preferably an adamantane ring, since this tends to more suitably achieve both higher resolution and higher sensitivity. These may contain an ether bond, a ketone bond, and an ester bond.

[0274] Next, a method for producing an iodine-containing (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 arbitrarily depending on the type of initiator, the initiation method (e.g., heat or light), temperature, pressure, concentration, solvent, additives, etc. The iodine-containing (co)polymer of this embodiment can be produced by known methods, such as radical polymerization using a radical generator (e.g., azoisobutyronitrile or peroxide), or ionic polymerization using a catalyst (e.g., alkyllithium or Grignard reagent).

[0275] As the solvent used in the polymerization reaction, commercially available products that are generally available can be used. For example, various solvents such as alcohols, ethers, hydrocarbons, and halogenated solvents can be used as appropriate within the range that does not inhibit the reaction. A mixture of multiple solvents can also be used within the range that does not inhibit the reaction.

[0276] The iodine-containing (co)polymer obtained by the polymerization reaction can be purified by a known method, 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.

[0277] [Composition Comprising Iodine-Containing Compound and / or Iodine-Containing (Co)Polymer] The composition of this embodiment comprises the iodine-containing compound and / or the iodine-containing (co)polymer of this embodiment. The composition of this embodiment is particularly suitable for lithography techniques. Although not particularly limited, the composition of this embodiment can be used for forming a film for lithography, for example, for forming a resist film (i.e., a "resist composition"). Furthermore, the composition of this embodiment 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.

[0278] 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.

[0279] The composition of the present embodiment contains an iodine-containing compound and / or an iodine-containing (co)polymer, 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.

[0280] In this embodiment, when the iodine-containing compound and / or the iodine-containing (co)polymer contains an ester group, the ester groups in the resist resin are less likely to form hydrogen bonds with each other, which tends to suppress crystallization of the resin. Therefore, a composition containing such an iodine-containing compound and / or an iodine-containing (co)polymer tends to have improved solubility in a resist solvent.

[0281] (Substrate (A)) In this embodiment, the term "substrate (A)" refers to a compound (including a resin) other than an iodine-containing compound and / or an iodine-containing (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.

[0282] 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. The derivative 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.

[0283] 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 hydroxy group, a carboxy group, a sulfonic acid group, and a hexafluoroisopropanol group. The phenolic hydroxy group and the carboxy group are preferred, and the phenolic hydroxy group is particularly preferred.

[0284] 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 hydroxy group, a group having a urethane(meth)acryloyl group, a group having a glycidyl group, and a group having a vinyl-containing phenylmethyl group.

[0285] (Solvent (S)) The composition of the present embodiment preferably further contains a solvent (S). As the 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 compound and / or the iodine-containing (co)polymer described above.Specific examples of the solvent (S) 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; lactates such as methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, and n-amyl lactate. Acid 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-methyl-2-methylpropionate, methyl 3-methoxybutyl acetate, methyl 3-methoxybutyl 3-methylpropionate ... Examples of the ester include, but are not particularly limited to, other esters such as butyl 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 (S) 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. The solvent (S) can be used alone or in combination of two or more.

[0286] In this embodiment, the amounts of the solid components and the solvent (S) in the composition are not particularly limited, but are preferably 1 to 80% by mass of the solid components and 20 to 99% by mass of the solvent (S), more preferably 1 to 50% by mass of the solid components and 50 to 99% by mass of the solvent (S), even more preferably 2 to 40% by mass of the solid components and 60 to 98% by mass of the solvent (S), and particularly preferably 2 to 10% by mass of the solid components and 90 to 98% by mass of the solvent (S). In this specification, the term "solid components" refers to components other than the solvent contained in the composition of this embodiment.

[0287] (Acid Generator (C)) The composition of the present embodiment preferably further contains an acid generator (C). The composition of the present 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 for example, those described in International Publication WO2013 / 024778 can be used. The acid generators (C) can be used alone or in combination of two or more.

[0288] The content of the acid generator (C) 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, based on the total mass of the solid components in the composition. When the content of the acid generator (C) is within the above range, a pattern profile with high sensitivity and low edge roughness tends to be obtained. In this embodiment, the method for generating the 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.

[0289] (Base Generator (G)) The composition of the present embodiment may contain a base generator (G). A 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 irradiation with electromagnetic waves and heating as external stimuli.

[0290] The photobase generator that can be used in the present embodiment is not particularly limited and may be a known one, such as a carbamate derivative, an amide derivative, an imide derivative, an α-cobalt complex, an imidazole derivative, a cinnamic acid amide derivative, or an oxime derivative.

[0291] 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. As the basic substance to be generated, compounds having an amino group with a higher basicity (higher pKa value of the conjugate acid) are preferred because they provide better sensitivity and resolution. 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.

[0292] The photobase generator may be used alone or in combination of two or more. The content of the photobase generator is preferably 0.001 to 49 mass%, more preferably 1 to 40 mass%, still more preferably 3 to 30 mass%, and particularly preferably 10 to 25 mass%, based on the total mass of the solid components in the composition. When the content of the photobase generator is within the above range, there is a tendency that the sensitivity is better and a pattern with lower edge roughness can be formed.

[0293] (Acid Diffusion Controller (E)) The composition of the present embodiment preferably further contains an acid diffusion controller (E). In the present 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 (C) in the resist film upon irradiation with radiation, thereby preventing undesirable chemical reactions in unexposed regions. The use of the acid diffusion controller (E) tends to improve the storage stability of the composition of the present embodiment. Furthermore, the use of the acid diffusion controller (E) tends to improve the resolution of the film formed using the composition of the present embodiment, and also tends to suppress changes in the line width of the resist pattern due to fluctuations in the waiting 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.

[0294] 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.

[0295] The content 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 in the composition. When the content of the acid diffusion controller (E) is within the above range, it tends to be possible to prevent a decrease in resolution and deterioration of the pattern shape, dimensional fidelity, and the like. Furthermore, even if the exposure time between electron beam irradiation and post-exposure heating is long, it is possible to suppress deterioration in the shape of the upper layer of the pattern. Furthermore, when the content is 10% by mass or less, it tends to be possible to prevent a decrease in sensitivity, developability of unexposed areas, and the like. Furthermore, the use of such an acid diffusion controller (E) 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 the exposure time before and after radiation exposure, tending to result in excellent process stability.

[0296] (Other Components (F)] If necessary, one or more of various additives such as a crosslinking agent, a dissolution promoter, a dissolution controller, a sensitizer, a surfactant, and an organic carboxylic acid, a phosphorus oxoacid, or a derivative thereof may be added to the composition of the present embodiment as other components (F).

[0297] 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 an iodine-containing compound and / or an iodine-containing (co)polymer. 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).

[0298] 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 and carboxy (alkyl group having 1 to 6 carbon atoms), or groups derived therefrom; (iii) dimethylaminomethyl group, diethylaminomethyl group, dimethylolaminomethyl group, diethylolaminomethyl group, and methylaminomethyl group. (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.

[0299] 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.

[0300] In this embodiment, the content 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, based on the total mass of the solid components in the composition. The lower limit is not particularly limited, but is, for example, 0.001% by mass or more, based on the total mass of the solid components in the composition.

[0301] The 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 solid component is too low, thereby appropriately increasing the dissolution rate of the compound during development. The dissolution accelerator is preferably a low-molecular-weight component, 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.

[0302] The content of the dissolution promoter is adjusted appropriately depending on the type of the solid component used, but is preferably 0 to 49 mass%, more preferably 0 to 5 mass%, even more preferably 0 to 1 mass%, and particularly preferably 0 mass%, relative to the total mass of the solid components in the composition.

[0303] The dissolution controller is a component that has the effect of controlling the solubility of a solid component in a developer when the solubility of the solid component is too high, thereby appropriately reducing the dissolution rate during development. Such a dissolution controller is preferably one that does not undergo chemical changes during processes such as baking, irradiation, and development of the resist film.

[0304] 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.

[0305] The content 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, based on the total mass of the solid components in the composition.

[0306] 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 of two or more.

[0307] The content of the sensitizer is adjusted appropriately depending on the type of the compound used, but is preferably 0 to 49 mass %, more preferably 0 to 5 mass %, still more preferably 0 to 1 mass %, and particularly preferably 0 mass %, relative to the total mass of the solid components in the composition.

[0308] The surfactant is a component that acts to improve the coatability, striations, resist developability, and the like of the composition of this embodiment. 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. Commercially available surfactants include, under the trade names listed below, Eftop (manufactured by Gemco), Megafac (manufactured by Dainippon Ink and Chemicals, Inc.), Fluorad (manufactured by Sumitomo 3M Limited), Asahi Guard, and Surflon (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.).

[0309] The content of the surfactant is adjusted appropriately depending on the type of the solid component used, but is preferably 0 to 49 mass%, more preferably 0 to 5 mass%, even more preferably 0 to 1 mass%, and particularly preferably 0 mass%, relative to the total mass of the solid components in the composition.

[0310] 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 contained 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; and phosphinic acid, phenylphosphinic acid, and other ester derivatives thereof. Of these, phosphonic acid is particularly preferred.

[0311] The organic carboxylic acid, phosphorus oxo acid, or derivative thereof may be used alone or in combination of two or more. The content 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, based on the total mass of the solid components in the composition.

[0312] 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. Further examples of other additives include antihalation agents, storage stabilizers, antifoaming agents, and shape modifiers, specifically 4-hydroxy-4'-methylchalcone.

[0313] In the composition of the present embodiment, the total content of the additives can be 0 to 99 mass%, 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%, relative to the total mass of the solid components in the composition.

[0314] [Pattern Forming Method] The pattern forming method of this embodiment includes the steps of forming a film using the composition of this embodiment, exposing the film to light, and removing the exposed portion of the film using a developer to form a pattern. Such a specific pattern forming method can form a film with higher resolution and higher sensitivity.

[0315] 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 optionally 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 (wavelength 13n) such as an F2 excimer laser (wavelength 157 nm), an ArF excimer laser (wavelength 193 nm), or a KrF excimer laser (wavelength 248 nm), extreme ultraviolet light (wavelength 13n), X-rays, or electron beams can be appropriately selected and used. Furthermore, exposure conditions such as the exposure dose are appropriately selected depending on the blending composition of the compound or (co)polymer of this embodiment described above, the type of additives, and the like.

[0316] 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, it is preferable to use an alkaline developer as the developer. A predetermined resist pattern is formed by developing with the alkaline developer under conditions of typically 10 to 50°C for 10 to 200 seconds, preferably 20 to 25°C for 15 to 90 seconds.

[0317] 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.

[0318] 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.

[0319] Examples of ester solvents include methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, propyl acetate, isopropyl acetate, amyl acetate (pentyl acetate), isoamyl acetate (isopentyl acetate, 3-methylbutyl acetate), 2-methylbutyl acetate, 1-methylbutyl acetate, hexyl acetate, isohexyl acetate, heptyl acetate, octyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, propylene glycol monomethyl ether acetate (PGMEA; also known as 1-methoxy-2-acetoxypropane), ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, and 2-methoxybutyl acetate. , 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3 -methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, butyl propionate,Examples of the alkyl esters include isobutyl propionate, pentyl propionate, hexyl propionate, heptyl propionate, butyl butanoate, isobutyl butanoate, pentyl butanoate, hexyl butanoate, isobutyl isobutanoate, propyl pentanoate, isopropyl pentanoate, butyl pentanoate, pentyl pentanoate, ethyl hexanoate, propyl hexanoate, butyl hexanoate, isobutyl hexanoate, methyl heptanoate, ethyl heptanoate, propyl heptanoate, cyclohexyl acetate, cycloheptyl acetate, 2-ethylhexyl acetate, cyclopentyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl-3-methoxypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, and propyl-3-methoxypropionate. Among these, butyl acetate, amyl acetate, isoamyl acetate, 2-methylbutyl acetate, 1-methylbutyl acetate, hexyl acetate, pentyl propionate, hexyl propionate, heptyl propionate, methyl hydroxyisobutyrate, or butyl butanoate are preferably used, and butyl acetate, isoamyl acetate, or methyl hydroxyisobutyrate are particularly preferably used.

[0320] Examples of ketone solvents include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 2-heptanone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methyl naphthyl ketone, isophorone, propylene carbonate, and γ-butyrolactone, and among these, 2-heptanone is preferred.

[0321] Examples of alcohol-based solvents include methanol, ethanol, 1-propanol, isopropanol, 1-butanol, 2-butanol, 3-methyl-1-butanol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 1-decanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, and 3-methyl-1-butanol. methyl-3-pentanol, cyclopentanol, 2,3-dimethyl-2-butanol, 3,3-dimethyl-2-butanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-2-pentanol, 4-methyl-3-pentanol, cyclohexanol, 5-methyl-2-hexanol, 4-methyl-2-hexanol, 4,5-dimethyl-2-hexal, 6-methyl-2-heptanol Examples of suitable solvents include alcohols (monohydric alcohols) such as ethanol, 7-methyl-2-octanol, 8-methyl-2-nonal, 9-methyl-2-decanol, and 3-methoxy-1-butanol; glycol-based solvents such as ethylene glycol, diethylene glycol, and triethylene glycol; and glycol ether-based solvents containing a hydroxy group such as ethylene glycol monomethyl ether, propylene glycol monomethyl ether (PGME; also known as 1-methoxy-2-propanol), diethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methoxymethylbutanol, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, and propylene glycol monophenyl ether. Of these, glycol ether-based solvents are preferably used.

[0322] Examples of ether solvents include, in addition to the above-mentioned glycol ether solvents containing a hydroxy group, glycol ether solvents not containing a hydroxy group, such as propylene glycol dimethyl ether, propylene glycol diethyl ether, diethylene glycol dimethyl ether, and diethylene glycol diethyl ether; aromatic ether solvents such as anisole and phenetole; dioxane, tetrahydrofuran, tetrahydropyran, perfluoro-2-butyltetrahydrofuran, perfluorotetrahydrofuran, 1,4-dioxane, and isopropyl ether. Of these, glycol ether solvents and aromatic ether solvents such as anisole are preferred.

[0323] Examples of amide solvents include N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, hexamethylphosphoric triamide, and 1,3-dimethyl-2-imidazolidinone.

[0324] Examples of hydrocarbon solvents include aliphatic hydrocarbon solvents such as pentane, hexane, octane, nonane, decane, dodecane, undecane, hexadecane, 2,2,4-trimethylpentane, 2,2,3-trimethylhexane, perfluorohexane, and perfluoroheptane; and aromatic hydrocarbon solvents such as toluene, xylene, ethylbenzene, propylbenzene, 1-methylpropylbenzene, 2-methylpropylbenzene, dimethylbenzene, diethylbenzene, ethylmethylbenzene, trimethylbenzene, ethyldimethylbenzene, and dipropylbenzene. Unsaturated hydrocarbon solvents can also be used, including unsaturated hydrocarbon solvents such as octene, nonene, decene, undecene, dodecene, and hexadecene. The number of double or triple bonds possessed by the unsaturated hydrocarbon solvent is not particularly limited, and the double or triple bond may be located at any position in the hydrocarbon chain. Furthermore, when the unsaturated hydrocarbon solvent has a double bond, the cis- and trans-isomers may be present together.

[0325] The aliphatic hydrocarbon solvent may be a mixture of compounds having the same number of carbon atoms but different structures. For example, when decane is used as the aliphatic hydrocarbon solvent, the aliphatic hydrocarbon solvent may contain compounds having the same number of carbon atoms but different structures, such as 2-methylnonane, 2,2-dimethyloctane, 4-ethyloctane, and isooctane.

[0326] The compound having the same carbon number but different structures may contain only one type, or may contain multiple types as described above.

[0327] A basic compound, a water-soluble organic solvent, or a surfactant may be added to the developer comprising the organic solvent as described above.

[0328] The present invention will be explained in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples in any way.

[0329] [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 d6-DMSO Internal standard: TMS Measurement temperature: 23°C

[0330] Synthesis Example 1 Synthesis of Compound (MAC-ADI-COOM) 32 g (0.1 mol) of 5-hydroxy-3-iodo-1-adamantanecarboxylic acid was dissolved in 150 mL of methanol, and 21.3 g (0.15 mol) of methyl iodide and 22.8 g (0.15 mol) of diazabicycloundecene were added at 10°C or below. The mixture was then heated to 60°C and stirred for 3 hours to react. After completion of the reaction, the mixture was quenched by adding 150 g of a saturated aqueous solution of ammonium chloride under ice cooling, and the methanol was evaporated under reduced pressure to concentrate the mixture. Water and ethyl acetate were added to the concentrate to extract the organic layer. Sodium sulfate was added to the organic layer to dry it, and the solvent was evaporated under reduced pressure to obtain a crude product of methyl 5-hydroxy-3-iodo-1-adamantanecarboxylate. The resulting crude product was purified by column chromatography to obtain 28 g (yield 83%) of methyl 5-hydroxy-3-iodo-1-adamantanecarboxylate shown below.

[0331]

[0332] 16.8 g (50 mmol) of methyl 5-hydroxy-3-iodo-1-adamantanecarboxylate obtained above was dissolved in chloroform, and 7.6 g (75 mmol) of triethylamine and 7.8 g (75 mmol) of methacrylic acid chloride were added dropwise under ice-cooling. Subsequently, the mixture was stirred for 1 hour under ice-cooling and then for 3 hours at room temperature (20°C) to allow the reaction to proceed. After completion of the reaction, water was added to the reaction solution, which was then washed with a saturated aqueous solution of sodium bicarbonate. The organic phase was then dried over sodium sulfate, concentrated, and purified by column chromatography to obtain 17 g (yield 84%) of the target product (MAC-ADI-COOM) shown below.

[0333] The obtained compound (MAC-ADI-COOM) was subjected to NMR measurement under the above measurement conditions, and the following peaks were observed, confirming that the compound had the chemical structure of the following formula (MAC-ADI-COOM): δ (ppm) (CDCl ３ ):6.4(1H,=CH ２ ), 6.0 (1H, =CH ２ ), 3.6 (3H, COOCH ３ ), 3.1 (1H), 2.9 (1H), 2.4 (2H), 2.3-2.1 (4H), 2.0 (3H, -CH３ ), 1.9 (1H), 1.6-1.3 (4H)

[0334]

[0335] Synthesis Example 2 Synthesis of Compound (MAC-ADI2-COOM) The target compound (MAC-ADI2-COOM) shown below was obtained by the same procedure as in Synthesis Example 1, except that 7-hydroxy-3,5-diiodo-1-adamantanecarboxylic acid was used instead of 5-hydroxy-3-iodo-1-adamantanecarboxylic acid as the substrate.

[0336] When the obtained compound (MAC-ADI2-COOM) was subjected to NMR measurement under the above-mentioned measurement conditions, the following peaks were found, and it was confirmed that the compound had the chemical structure of the following formula (MAC-ADI2-COOM).

[0337] δ (ppm) (CDCl ３ ):6.4(1H,=CH ２ ), 6.0 (1H, =CH ２ ), 4.3 (1H), 4.0 (1H) 3.6 (3H, COOCH ３ ), 3.2 (1H), 2.9 (1H), 2.6 (2H), 2.3-2.1 (4H), 2.0 (3H, -CH ３ ), 1.6 (1H), 1.4 (1H)

[0338]

[0339] Synthesis Example 3 Compound (MAC-ADI-COOH) 32 g (0.1 mol) of 5-hydroxy-3-iodo-1-adamantanecarboxylic acid was dissolved in 150 mL of tetrahydrofuran, and 86 g (1.0 mol) of methacrylic acid and 22.7 g (0.11 mol) of N,N'-dicyclohexylcarbodiimide were added under ice-cooling. The mixture was then stirred at room temperature (20°C) for 24 hours to allow the reaction to proceed. After completion of the reaction, water was added to the reaction solution, and then an aqueous sodium sulfite solution was added and the mixture was ice-cooled to form a precipitate. The precipitate was recovered by filtration, and then 300 g of ethyl acetate was added to dissolve the precipitate. The mixture was then washed five times with 100 g of water and concentrated. After concentration, 200 g of hexane was added under ice-cooling to precipitate crystals. The precipitated crystals were filtered off and dried under reduced pressure at 50°C to obtain 28 g of white crystals (MAC-ADI-COOH) (yield 72%).

[0340] The resulting compound (MAC-ADI-COOH) was subjected to NMR measurement under the above-mentioned measurement conditions. The following peaks were observed, confirming that the compound had the chemical structure of the following formula (MAC-ADI-COOH): δ (ppm) (d6-DMSO): 12.1 (1H, COOH), 6.5 (1H, ═CH ２ ), 6.4 (1H, =CH ２ ), 3.1 (1H), 3.0 (1H), 2.3 (2H), 2.2-2.1 (4H), 2.0 (3H, -CH ３ ), 1.6-1.3 (5H)

[0341]

[0342] Synthesis Example 4 Compound (MAC-ADI2-COOH) The target compound (MAC-ADI2-COOH) shown below was obtained by the same procedure as in Synthesis Example 3, except that 7-hydroxy-3,5-diiodo-1-adamantanecarboxylic acid was used instead of 5-hydroxy-3-iodo-1-adamantanecarboxylic acid as the substrate.

[0343] The resulting compound (MAC-ADI2-COOH) was subjected to NMR measurement under the above-mentioned measurement conditions. The following peaks were observed, confirming that the compound had the chemical structure of the following formula (MAC-ADI2-COOH): δ (ppm) (d6-DMSO): 12.2 (1H, COOH), 6.5 (1H, ═CH ２ ), 6.4 (1H, =CH ２ ), 4.3 (1H), 4.0 (1H), 3.1 (1H), 2.8 (1H), 2.6 (2H), 2.3-2.1 (4H), 2.0 (3H, -CH ３ ), 1.7 (1H), 1.5 (1H)

[0344]

[0345] Synthesis Example 5 Synthesis of Compound (AA1) 32 g (0.1 mol) of 5-hydroxy-3-iodo-1-adamantanecarboxylic acid was dissolved in 150 mL of dichloromethane, and 74.1 g (1.0 mol) of tert-butanol, 9.8 g (0.1 mol) of concentrated sulfuric acid, and 12.0 g (0.1 mol) of magnesium sulfate were added at 10°C or below. The mixture was then warmed to room temperature and stirred for 24 hours to react. After the reaction, the mixture was quenched by adding 100 mL of saturated aqueous sodium bicarbonate solution under ice cooling, and extracted with ethyl acetate. The organic layer was washed twice with ion-exchanged water and concentrated by distillation under reduced pressure. The concentrate was purified by column chromatography to obtain 31.0 g (yield 82%) of t-butyl 5-hydroxy-3-iodo-1-adamantanecarboxylate shown below.

[0346]

[0347] 18.9 g (50 mmol) of the t-butyl 5-hydroxy-3-iodo-1-adamantanecarboxylate obtained above was dissolved in chloroform, and 7.6 g (75 mmol) of triethylamine and 7.8 g (75 mmol) of methacrylic acid chloride were added dropwise under ice-cooling. Subsequently, the mixture was stirred for 1 hour under ice-cooling and then for 3 hours at room temperature (20°C) to allow the reaction to proceed. After completion of the reaction, water was added to the reaction solution, which was then washed with a saturated aqueous solution of sodium bicarbonate. The organic phase was then dried over sodium sulfate, concentrated, and purified by column chromatography to obtain 18.7 g (yield 84%) of the target product (MAC-ADI-COOtBu, compound (AA1)) shown below.

[0348] When the obtained compound (AA1) was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the compound had the chemical structure of the following formula (AA1): δ (ppm) (CDCl3): 6.4 (1H, ═CH2), 6.0 (1H, ═CH2), 3.1 (1H), 2.9 (1H), 2.4 (2H), 2.3-2.1 (4H), 2.0 (3H, —CH3), 1.9 (1H), 1.4 (9H, COOtBu), 1.6-1.3 (4H).

[0349]

[0350] Synthesis Example 6 Synthesis of Compound (AA2) 32 g (0.1 mol) of 5-hydroxy-3-iodo-1-adamantanecarboxylic acid was dissolved in 150 mL of dichloromethane, and 14.3 g (0.12 mol) of thionyl chloride was added at 10°C or below. The reaction was allowed to proceed for 2 hours while maintaining the temperature at 10°C or below. Subsequently, 15.0 g (0.15 mol) of 1-methylcyclopentanol and 30.4 g (0.4 mol) of triethylamine were added at 10°C or below. The temperature was then raised to room temperature, and the reaction was allowed to proceed with stirring for 3 hours. After completion of the reaction, water was added to the reaction solution, and extraction was performed with ethyl acetate. The organic layer was washed twice with ion-exchanged water, and then concentrated by distillation under reduced pressure. The concentrate was purified by column chromatography to obtain 33.5 g (yield 83%) of 5-hydroxy-3-iodo-1-adamantanecarboxylate-1-methyl-cyclopentyl shown below.

[0351]

[0352] The same operation as in Synthesis example 5 was carried out except that 20.2 g (50 mmol) of 1-methyl-cyclopentyl 5-hydroxy-3-iodo-1-adamantanecarboxylate was used instead of t-butyl 5-hydroxy-3-iodo-1-adamantanecarboxylate as the substrate, to obtain 19.3 g (yield 82%) of the target product (MAC-ADI-COOMcP, compound (AA2)) shown below.

[0353] When the obtained compound (AA2) was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the compound had the chemical structure of the following formula (AA2): δ (ppm) (CDCl3): 6.5 (1H, ═CH2), 6.4 (1H, ═CH2), 2.9 (2H), 2.4 (2H), 2.3-2.1 (4H), 2.0 (3H, —CH3), 1.9-1.6 (13H), 1.4 (3H, —CH3).

[0354]

[0355] (Synthesis Example 7) The same procedure as in Synthesis Example 6 was carried out, except that 1-ethylcyclopentanol was used instead of 1-methylcyclopentanol as the synthetic raw material for compound (AA3), to obtain 19.4 g (yield 82%) of the target product (MAC-ADI-COOEcP, compound AA3) shown below.

[0356] When the obtained compound (AA3) was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the compound had the chemical structure of the following formula (AA3): δ (ppm) (CDCl3): 6.5 (1H, ═CH2), 6.4 (1H, ═CH2), 2.9 (2H), 2.4 (2H), 2.3-2.1 (4H), 2.0 (3H, —CH3), 1.9-1.6 (13H), 0.9 (3H, —CH3).

[0357]

[0358] (Synthesis Example 8) The same procedure as in Synthesis Example 6 was carried out, except that 1-isopropylcyclopentanol was used instead of 1-methylcyclopentanol as the synthetic raw material for compound (AA4), to obtain 19.5 g (yield 82%) of the target product (MAC-ADI-COOPcP, compound AA4) shown below.

[0359] When the obtained compound (AA4) was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the compound had the chemical structure of the following formula (AA4): δ (ppm) (CDCl3): 6.5 (1H, ═CH2), 6.4 (1H, ═CH2), 2.9 (2H), 2.4 (2H), 2.3-2.1 (4H), 2.0 (3H, —CH3), 1.9-1.6 (14H), 0.9 (6H, —CH3).

[0360]

[0361] (Synthesis Example 9) The same procedure as in Synthesis Example 6 was carried out except that 1-methylcyclohexanol was used instead of 1-methylcyclopentanol as the synthetic raw material for compound (AA5), to obtain 19.4 g (yield 82%) of the target product (MAC-ADI-COOMcH, compound AA5) shown below.

[0362] When the obtained compound (AA5) was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the compound had the chemical structure of the following formula (AA5): δ (ppm) (CDCl3): 6.5 (1H, ═CH2), 6.4 (1H, ═CH2), 2.9 (2H), 2.4 (2H), 2.3-2.1 (4H), 2.0 (3H, —CH3), 1.9-1.6 (15H), 1.4 (3H, —CH3).

[0363]

[0364] Synthesis Example 10 Synthesis of Compound (AA6) A 200 mL three-necked flask was prepared, and 38 mL of dehydrated THF and 5.0 g (19.1 mmol) of methyl 4-iodobenzoate were added. The mixture was stirred for 30 minutes under a nitrogen flow while ice-cooling so that the internal temperature was 10°C or less. 57 mL (57 mmol, 1.0 M THF solution) of methylmagnesium bromide (nucleophile: Grignard reagent) was added to the 200 mL three-necked flask over 5 minutes, and the internal temperature was then returned to 25°C over 15 minutes, and then increased to 50°C over 20 minutes, and stirring was continued for 40 minutes. After the reaction, the mixture was cooled to 0°C and quenched by adding 20 mL of saturated aqueous ammonium chloride and 20 mL of ion-exchanged water under ice-cooling, followed by extraction with ethyl acetate. The organic layer was concentrated and then separated and purified by column chromatography to obtain 2-(4-iodophenyl)propan-2-ol (4.05 g, 15.5 mmol) represented by the following formula (13).

[0365]

[0366] 3.2 g (10 mmol) of 5-hydroxy-3-iodo-1-adamantanecarboxylic acid was dissolved in 150 mL of dichloromethane, and 1.43 g (12 mmol) of thionyl chloride was added at 10°C or below. The reaction was allowed to proceed for 2 hours while maintaining the temperature at 10°C or below. Subsequently, 2.61 g (10 mmol) of 2-(4-iodophenyl)propan-2-ol obtained above and 3.04 g (40 mmol) of triethylamine were added at 10°C or below. The temperature was then raised to room temperature, and the reaction was allowed to proceed with stirring for 3 hours. After completion of the reaction, water was added to the reaction solution, and extraction was performed with ethyl acetate. The organic layer was washed twice with ion-exchanged water, and the organic layer was concentrated by distillation under reduced pressure. The concentrate was purified by column chromatography to obtain 4.36 g (77% yield) of a compound represented by the following formula (14).

[0367]

[0368] The same operation as in Synthesis example 5 was performed except that 4.0 g (6 mmol) of the compound represented by formula (14) obtained was used instead of t-butyl 5-hydroxy-3-iodo-1-adamantanecarboxylate as the substrate, to obtain 3.1 g (yield 81%) of the target product (compound AA6) shown below.

[0369] When the obtained compound (AA6) was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the compound had the chemical structure of the following formula (AA6): δ (ppm) (CDCl3): 7.6 (2H), 7.1 (2H), 6.4 (1H, ═CH2), 6.1 (1H, ═CH2), 2.8 (2H), 2.4 (2H), 2.3-2.1 (3H), 2.0 (3H, —CH3), 1.9-1.6 (6H), 1.5 (6H, —CH3).

[0370]

[0371] Synthesis Example 11 Synthesis of Compound (AA7) A 200 mL three-necked flask was prepared, and 38 mL of dehydrated THF and 4.9 g (20 mmol) of 4-iodoacetophenone were added. The mixture was stirred for 30 minutes under a nitrogen flow while ice-cooling so that the internal temperature was 10°C or less. 10 mL (30 mmol, 3.0 M ethyl ether solution) of ethyl magnesium bromide (nucleophile: Grignard reagent) was added to the 200 mL three-necked flask over 5 minutes, and the internal temperature was then returned to 25°C over 15 minutes, and then increased to 50°C over 20 minutes, and stirring was continued for 40 minutes. After the reaction, the mixture was cooled to 0°C and quenched by adding 20 mL of saturated aqueous ammonium chloride and 20 mL of ion-exchanged water under ice-cooling, followed by extraction with ethyl acetate. The organic layer was concentrated and then separated and purified by column chromatography to obtain 2-(4-iodophenyl)butan-2-ol (4.30 g, 15.6 mmol) represented by the following formula (15).

[0372]

[0373] The same operations as in Synthesis example 10 were carried out except that 2-(4-iodophenyl)butan-2-ol was used instead of 2-(4-iodophenyl)propan-2-ol represented by formula (13) as a starting material, to obtain 3.1 g (yield 80%) of the target product (compound AA7) shown below.

[0374] When the obtained compound (AA7) was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the compound had the chemical structure of the following formula (AA7): δ (ppm) (CDCl3): 7.6 (2H), 7.1 (2H), 6.4 (1H, ═CH2), 6.1 (1H, ═CH2), 2.8 (2H), 2.4 (2H), 2.3-2.1 (3H), 2.0 (3H, —CH3), 1.9-1.6 (8H), 1.5 (3H, —CH3), 0.9 (3H, —CH3).

[0375]

[0376] Synthesis Example 12 Synthesis of Compound (AA8) A 300 mL three-neck flask was prepared, and 70 mL of toluene and 7.8 g (40 mmol) of 3-hydroxy-1-adamantanecarboxylic acid were added thereto. Under a nitrogen flow, 89 mL of 57% hydroiodic acid was added thereto over 5 minutes, and the temperature was then raised to 85°C and the mixture was stirred for 2 hours. After the reaction, the mixture was cooled to room temperature and quenched by adding 50 mL of a saturated aqueous solution of sodium hydrogen sulfite, followed by extraction with ethyl acetate. The organic layer was concentrated, and then hexane was added to cause crystallization. The mixture was then filtered under reduced pressure to obtain 3-iodo-1-adamantanecarboxylic acid (10.8 g, 35.2 mmol) represented by the following formula (16):

[0377]

[0378] 10.0 g (33 mmol) of 3-iodo-1-adamantanecarboxylic acid was dissolved in 100 mL of dichloromethane, and 4.75 g (40 mmol) of thionyl chloride was added at 10°C or below. The reaction was allowed to proceed for 2 hours while maintaining the temperature at 10°C or below. Subsequently, 50 mL of methanol was added at 10°C or below. The temperature was then raised to 60°C, and the reaction was allowed to proceed with stirring for 3 hours. After completion of the reaction, water was added to the reaction solution, and extraction was performed with ethyl acetate. The organic layer was washed twice with ion-exchanged water, and the organic layer was concentrated by distillation under reduced pressure. The concentrate was purified by column chromatography to obtain 9.4 g (yield 89%) of methyl 3-iodo-1-adamantanecarboxylate represented by the following formula (17):

[0379]

[0380] A 300 mL three-necked flask was prepared, and 90 mL of dehydrated THF and 9.0 g (28 mmol) of methyl 3-iodo-1-adamantanecarboxylate obtained above were added. The mixture was stirred for 30 minutes under a nitrogen flow while ice-cooling so that the internal temperature was 10°C or less. 84 mL (84 mmol, 1.0 M THF solution) of methylmagnesium bromide (nucleophile: Grignard reagent) was added to the 300 mL three-necked flask over 10 minutes, and the internal temperature was then returned to 25°C over 15 minutes, then raised to 50°C over 20 minutes, and stirring was continued for 40 minutes. After the reaction, the mixture was cooled to 0°C and quenched by adding 90 mL of saturated aqueous ammonium chloride and 30 mL of ion-exchanged water under ice-cooling, followed by extraction with ethyl acetate. The organic layer was concentrated and then separated and purified by column chromatography to obtain 2-((1r,3s,5R,7S)-3-iodoadamantan-1-yl)propan-2-ol (6.90 g, 21.56 mmol) represented by the following formula (18).

[0381]

[0382] The same operations as in Synthesis example 10 were carried out except that 2-((1r,3s,5R,7S)-3-iodoadamantan-1-yl)propan-2-ol was used instead of 2-(4-iodophenyl)propan-2-ol represented by formula (13) as a starting material, to obtain 3.1 g (yield 80%) of the target product (compound AA8) shown below.

[0383] When the obtained compound (AA8) was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the compound had the chemical structure of the following formula (AA8): δ (ppm) (CDCl): 6.4 (1H, ═CH), 6.1 (1H, ═CH), 3.0 (2H), 2.8 (2H), 2.6-2.1 (8H), 2.0 (3H, —CH), 1.9-1.6 (8H), 1.4 (6H, —CH), 1.4-1.1 (7H).

[0384]

[0385] Synthesis Example 13 Synthesis of Compound (AA9) A 300 mL three-neck flask was prepared, and 80 mL of a mixed solvent (a mixed solvent of acetonitrile and water in a volume ratio of 1:1) and 6.7 g (30 mmol) of 1,3-adamantanedicarboxylic acid were added thereto. The mixture was stirred at room temperature for 30 minutes under a nitrogen flow. Subsequently, 0.11 g (0.5 mmol) of ruthenium chloride, 9.6 g (45 mmol) of sodium periodate, and 0.12 g (1.5 mmol) of pyridine were added thereto, and the mixture was heated to 70°C and reacted for 3 hours. After completion of the reaction, the mixture was cooled to room temperature, and 150 mL of 2-propanol was added thereto, followed by filtration under reduced pressure. The filtrate was concentrated, and 120 mL of acetonitrile was added thereto, followed by re-concentration. After concentration, the mixture was filtered under reduced pressure to obtain 5.5 g (23 mmol) of 5-hydroxy-1,3-adamantanedicarboxylic acid represented by the following formula (19).

[0386]

[0387] A 300 mL three-neck flask was prepared, and 4.8 g (20 mmol) of the 5-hydroxy-1,3-adamantanedicarboxylic acid obtained above, 100 mL of toluene, and 22.2 g (100 mmol) of 57% hydroiodic acid were charged thereto. The reaction was carried out at 90°C for 6 hours under a nitrogen flow. After completion of the reaction, the mixture was cooled to room temperature, and 5 mL of a 35% aqueous solution of sodium hydrogen sulfite was added to quench the reaction. 100 mL of ion-exchanged water was then added, and the mixture was filtered under reduced pressure. The resulting filtrate was dissolved in methanol, and crystallized by adding ion-exchanged water while cooling. This was followed by filtration under reduced pressure to obtain 6.2 g (18 mmol) of 5-iodo-1,3-adamantanedicarboxylic acid represented by the following formula (20).

[0388]

[0389] A 300 mL three-neck flask was prepared, and 5.0 g (14 mmol) of the 5-iodo-1,3-adamantanedicarboxylic acid obtained above was dissolved in 50 mL of tetrahydrofuran. 1.5 g (14 mmol) of ethyl chloroformate and 1.4 g (14 mmol) of triethylamine were added under ice cooling conditions. After the dropwise addition, the mixture was stirred for 30 minutes under a nitrogen flow so that the internal temperature did not exceed 10°C. Then, an aqueous solution prepared by dissolving 1.1 g (28 mmol) of sodium borohydride in 5 g of ion-exchanged water was added dropwise over 30 minutes so that the internal temperature did not exceed 10°C. After the dropwise addition, the mixture was allowed to react for 30 minutes. After completion of the reaction, the mixture was quenched by adding 50 mL of 1 M hydrochloric acid. Then, extraction was performed with 150 mL of diethyl ether. The organic layer was washed with saturated aqueous sodium bicarbonate and saturated saline, and then concentrated. Thereafter, separation and purification was carried out by column chromatography to obtain 2.9 g (8.7 mmol) of 3-hydroxymethyl-5-iodo-1-adamantanecarboxylic acid represented by the following formula (21).

[0390]

[0391] A 300 mL three-neck flask was prepared, and 2.0 g (6 mmol) of the 3-hydroxymethyl-5-iodo-1-adamantanecarboxylic acid obtained above, 20 mL of dichloromethane, 1.9 g (6 mmol) of diacetoxyiodobenzene, and 0.05 g (0.3 mmol) of 2,2,6,6-tetramethylpiperidine 1-oxyl free radical were added thereto, followed by stirring at room temperature for 60 minutes under a nitrogen flow. After completion of the reaction, 20 mL of ion-exchanged water was added to quench the reaction, followed by extraction with ethyl acetate. The organic layer was concentrated and then separated and purified by column chromatography to obtain 1.8 g (5.5 mmol) of 3-formyl-5-iodo-1-adamantanecarboxylic acid represented by the following formula (22):

[0392]

[0393] A 300 mL three-neck flask was prepared, and 2.5 g (7 mmol) of methyltriphenylphosphonium bromide and 20 mL of dehydrated tetrahydrofuran were charged under a nitrogen flow. 0.8 g (7 mmol) of potassium t-butoxide was added so that the internal temperature did not exceed 10°C, and the mixture was stirred for 30 minutes. Subsequently, 1.6 g (5 mmol) of 3-formyl-5-iodo-1-adamantanecarboxylic acid obtained above was added over 20 minutes so that the internal temperature did not exceed 10°C. After the addition, the mixture was allowed to react for 30 minutes under ice cooling. After completion of the reaction, the mixture was quenched by adding 30 mL of 1 M hydrochloric acid. Then, extraction was performed with 50 mL of ethyl acetate. The organic layer was washed with ion-exchanged water and then concentrated. Subsequently, separation and purification was performed by column chromatography to obtain 1.4 g (4.2 mmol) of 3-vinyl-5-iodo-1-adamantanecarboxylic acid (compound AA9).

[0394] When the obtained compound (AA9) was subjected to NMR measurement under the above-mentioned measurement conditions, the following peaks were found, and it was confirmed that the compound had the chemical structure of the following formula (AA9).

[0395] δ (ppm) (CDCl3): 5.9 (1H, -CH=CH2), 4.8 (1H, =CH2), 4.7 (1H, =CH2), 2.7 (2H), 2.3 (2H), 2.1 (2H), 1.8-1.3 (7H)

[0396]

[0397] Synthesis Example 14 Synthesis of Compound (AA10) A 300 mL three-neck flask was prepared, and 80 mL of a mixed solvent (a mixed solvent of acetonitrile and water in a volume ratio of 1:1) and 6.7 g (30 mmol) of 1,3-adamantanedicarboxylic acid were added thereto. The mixture was stirred at room temperature for 30 minutes under a nitrogen flow. Subsequently, 0.11 g (0.5 mmol) of ruthenium chloride, 38.5 g (180 mmol) of sodium periodate, and 0.39 g (5 mmol) of pyridine were added thereto. The mixture was heated to 70°C and reacted for 6 hours. After completion of the reaction, the mixture was cooled to room temperature, and 150 mL of 2-propanol was added thereto, followed by filtration under reduced pressure. The filtrate was concentrated, and 120 mL of acetonitrile was added thereto, followed by re-concentration. After concentration, filtration under reduced pressure was performed to obtain 4.2 g (16 mmol) of 5,7-dihydroxy-1,3-adamantanedicarboxylic acid represented by the following formula (23).

[0398]

[0399] The same operation as in Synthesis example 13 was carried out except that 5,7-dihydroxy-1,3-adamantanedicarboxylic acid was used instead of 5-hydroxy-1,3-adamantanedicarboxylic acid represented by formula (19) as a starting material, to obtain 1.7 g (4.9 mmol) of 3-vinyl-5-iodo-7-hydroxy-1-adamantanecarboxylic acid, which is the target product (compound AA10) shown below.

[0400] When the obtained compound (AA10) was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the compound had the chemical structure of the following formula (AA10): δ (ppm) (CDCl): 5.9 (1H, -CH=CH), 4.8 (1H, =CH), 4.7 (1H, =CH), 4.5 (1H, -OH), 2.7 (2H), 2.3 (2H), 2.1 (2H), 1.8-1.3 (6H).

[0401]

[0402] Synthesis Example 15 Synthesis of Compound (AA11) A 300 mL three-neck flask was prepared, and 3.8 g (15 mmol) of 5,7-dihydroxy-1,3-adamantanedicarboxylic acid represented by formula (23) obtained in Synthesis Example (14), 100 mL of toluene, and 28.6 g (225 mmol) of 57% hydroiodic acid were added thereto, and the mixture was reacted at 100°C for 24 hours under a nitrogen flow. After completion of the reaction, the mixture was cooled to room temperature, and 15 mL of a 35% aqueous sodium hydrogen sulfite solution was added to quench the reaction. 150 mL of ion-exchanged water was then added, and the mixture was filtered under reduced pressure. The resulting filtrate was dissolved in methanol, and crystallized by adding ion-exchanged water while cooling. Filtration under reduced pressure then gave 5.8 g (12 mmol) of 5,7-diiodo-1,3-adamantanedicarboxylic acid represented by the following formula (24).

[0403]

[0404] The same operation as in Synthesis example 13 was performed, except that 5,7-diiodo-1,3-adamantanedicarboxylic acid obtained above was used instead of 5-iodo-1,3-adamantanedicarboxylic acid represented by formula (20), to obtain 8.5 g (18 mmol) of 3-vinyl-5,7-diiodo-1-adamantanecarboxylic acid, which is the target product (compound AA11) shown below.

[0405] When the obtained compound (AA11) was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the compound had the chemical structure of the following formula (AA11): δ (ppm) (CDCl): 5.9 (1H, -CH=CH), 4.8 (1H, ═CH), 4.7 (1H, ═CH), 3.5 (2H), 3.2 (2H), 2.9 (2H), 2.7 (2H), 2.2 (2H), 1.6 (1H), 1.4 (1H).

[0406]

[0407] Synthesis Example 16 Synthesis of Compound (AA12) A 300 mL three-neck flask was prepared, and 1.6 g (5 mmol) of 3-formyl-5-iodo-1-adamantanecarboxylic acid represented by formula (22) obtained according to the method of Synthesis Example (9), 3.7 g (50 mmol) of t-butanol, 3.0 g (5 mmol) of magnesium sulfate, and 0.4 g (5 mmol) of concentrated sulfuric acid were added to dichloromethane under a nitrogen flow, and the mixture was allowed to react at room temperature for 24 hours. After completion of the reaction, the mixture was quenched with saturated aqueous sodium bicarbonate and extracted with 50 mL of ethyl acetate. The organic layer was washed with ion-exchanged water and then concentrated. Thereafter, separation and purification was carried out by column chromatography to obtain 1.8 g (5.5 mmol) of 3-formyl-5-iodo-1-adamantanecarboxylic acid t-butyl ester represented by the following formula (25).

[0408]

[0409] The same operation as in the final step of Synthesis example 13 was performed, except that 3-formyl-5-iodo-1-adamantanecarboxylic acid t-butyl ester was used instead of 3-formyl-5-iodo-1-adamantanecarboxylic acid represented by formula (22), to obtain 1.5 g (3.8 mmol) of 3-vinyl-5-iodo-1-adamantanecarboxylic acid t-butyl ester, which is the target product (Compound AA12) shown below.

[0410] When the obtained compound (AA12) was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the compound had the chemical structure of the following formula (AA12): δ (ppm) (CDCl): 5.8 (1H, -CH=CH), 4.8 (1H, =CH), 4.7 (1H, =CH), 2.8 (2H), 2.4 (2H), 2.1 (2H), 1.7-1.5 (7H), 1.4 (9H).

[0411]

[0412] (Synthesis Example 17) The same procedure as in Synthesis Example 16 was carried out, except that 1-methylcyclopentanol was used instead of t-butanol as the synthetic raw material for compound (AA13), to obtain 1.6 g (3.8 mmol) of the target product (compound AA13) shown below, 3-vinyl-5-iodo-1-adamantanecarboxylic acid-1-methylcyclopentyl ester.

[0413] When the obtained compound (AA13) was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the compound had the chemical structure of the following formula (AA13): δ (ppm) (CDCl): 5.8 (1H, -CH=CH), 4.8 (1H, =CH), 4.7 (1H, =CH), 2.8 (2H), 2.4 (2H), 2.1 (2H), 1.8-1.3 (18H).

[0414]

[0415] Synthesis Example 18 Synthesis of Compound (AA14) A 300 mL three-neck flask was prepared, and 2.0 g (6 mmol) of 3-hydroxymethyl-5-iodo-1-adamantanecarboxylic acid represented by formula (21) obtained in Synthesis Example 13, 20 mL of dichloromethane, 5.1 g (60 mmol) of methacrylic acid, and 1.2 g (6 mmol) of N,N'-dicyclohexylcarbodiimide were added thereto. The mixture was stirred at room temperature for 24 hours under a nitrogen flow. After completion of the reaction, the remaining methacrylic acid was quenched by adding a saturated aqueous sodium sulfite solution. Then, extraction with ethyl acetate was performed. The organic layer was washed successively with 1 M hydrochloric acid and ion-exchanged water. After concentration, separation and purification by column chromatography were performed to obtain 2.0 g (4.9 mmol) of 3-iodo-5-((methacryloyloxy)methyl)-1-adamantanecarboxylic acid (compound AA14).

[0416] When the obtained compound (AA14) was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the compound had the chemical structure of the following formula (AA14): δ (ppm) (CDCl3): 6.5 (1H, ═CH2), 6.4 (1H, ═CH2), 4.1 (2H), 2.7 (2H), 2.1 (2H), 2.0 (-CH ３ ), 1.9-1.4 (9H)

[0417]

[0418] (Synthesis Example 19) 3-hydroxymethyl-5,7-diiodo-1-adamantanecarboxylic acid was obtained by the same procedure as in Synthesis Example 13, except that 5,7-dihydroxy-1,3-adamantanedicarboxylic acid represented by formula (23) obtained in Synthesis Example 14 was used instead of 5-hydroxy-1,3-adamantanedicarboxylic acid represented by formula (19) as the synthetic raw material for compound (AA15). Thereafter, 1.7 g (4.0 mmol) of 3-iodo-5-hydroxy-7-((methacryloyloxy)methyl)-1-adamantanecarboxylic acid, the target product (compound AA15) shown below, was obtained by the same procedure as in Synthesis Example 18, except that 3-hydroxymethyl-5,7-diiodo-1-adamantanecarboxylic acid was used instead of 3-hydroxymethyl-5-iodo-1-adamantanecarboxylic acid represented by formula (21) as the raw material.

[0419] When the obtained compound (AA15) was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the compound had the chemical structure of the following formula (AA15): δ (ppm) (CDCl3): 6.5 (1H, ═CH2), 6.4 (1H, ═CH2), 4.5 (1H, —OH), 4.1 (2H), 2.7 (2H), 2.1 (2H), 2.0 (—CH ３ ), 1.9-1.2 (8H)

[0420]

[0421] (Synthesis Example 20) 3-hydroxymethyl-5,7-diiodo-1-adamantanecarboxylic acid was obtained by the same procedure as in Synthesis Example 13, except that 5,7-dihydroxy-1,3-adamantanedicarboxylic acid represented by formula (23) obtained in Synthesis Example 14 was used instead of 5-hydroxy-1,3-adamantanedicarboxylic acid represented by formula (18) as the synthetic raw material for compound (AA16). Thereafter, 2.2 g (4.0 mmol) of 3,5-diiodo-7-((methacryloyloxy)methyl)-1-adamantanecarboxylic acid, the target product (compound AA16) shown below, was obtained by the same procedure as in Synthesis Example 18, except that 3-hydroxymethyl-5-iodo-1-adamantanecarboxylic acid represented by formula (21) was used as the raw material.

[0422] When the obtained compound (AA16) was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the compound had the chemical structure of the following formula (AA16): δ (ppm) (CDCl3): 6.5 (1H, ═CH2), 6.4 (1H, ═CH2), 4.1 (2H), 4.0 (2H), 2.7 (2H), 2.5 (2H), 2.2 (2H), 2.0 (-CH ３ )1.9-1.6 (4H)

[0423]

[0424] (Synthesis Example A1) Synthesis of Polymer A1 Represented by Formula (A1) 2.0 g of the compound (MAC-ADI-COOM) obtained in Synthesis Example 1, 4.0 g of 2-methyl-2-adamantyl methacrylate, 0.9 g of γ-butyrolactone methacrylic acid ester, and 2.7 g of p-hydroxystyrene were dissolved in 45 mL of tetrahydrofuran, and 0.20 g of azobisisobutyronitrile was added. After refluxing for 12 hours, the reaction solution was added dropwise to 2 L of n-heptane. The precipitated polymer was separated by filtration and dried under reduced pressure to obtain Polymer A1 represented by the following Formula (A1) in the form of white powder. The weight average molecular weight (Mw) of this polymer was 12,000, and the dispersity (Mw / Mn) was 1.90. １３As a result of C-NMR measurement, the composition ratio (molar ratio) in the following formula (A1) was found to be a:b:c:d = 50:10:20:20. Note that, although the following formula (A1) is written in a simplified form to indicate the ratio of each structural unit, the arrangement order of the structural units is random, and it is not a block copolymer in which each structural unit forms an independent block. For the polymers represented by formulas (A1) to (A20) and the polymers represented by formulas (B1) to (B3), the molar ratio was determined based on the integral ratio of the root carbon of the benzene ring for the styrene-based monomer, and the integral ratio of the carbonyl carbon of the ester bond for the methacrylate-based monomers (2-methyl-2-adamantyl methacrylate, γ-butyrolactone methacrylate, and adamantyl methacrylate). The type and ratio of each monomer in the polymer obtained in Synthesis Example A1, as well as the composition ratio, are shown in Table 1. The types and ratios of the monomers in the polymers obtained in the examples described below, as well as the composition ratios, are also shown in Table 1.

[0425]

[0426] (Synthesis Examples A2 to A4 and Synthesis Comparative Examples B1 to B3) Synthesis of polymers A2 to A4 represented by formulas (A2) to (A4) and polymers B1 to B3 represented by formulas (B1) to (B3) Polymers A2 to A4 represented by formulas (A2) to (A4) and polymers B1 to B3 represented by formulas (B1) to (B3) were obtained by the method described in Synthesis Example A1, except that the types and amounts of the compound (MAC-ADI2-COOM) obtained in Synthesis Example 2, the compound (MAC-ADI2-COOH) obtained in Synthesis Example 3, the compound (MAC-ADI2-COOH) obtained in Synthesis Example 4, the following compound (AR1), the following compound (AR2), or the following compound (AR3) were used instead of 2.0 g of the compound (MAC-ADI-COOM) obtained in Synthesis Example 1, as shown in Table 1.

[0427] The following formulas (A2) to (A4) and formulas (B1) to (B3) are each written in a simplified form to indicate the ratio of each structural unit, but the arrangement order of the structural units is random, and they are not block copolymers in which the structural units each form an independent block.

[0428]

[0429]

[0430]

[0431]

[0432]

[0433]

[0434]

[0435]

[0436]

[0437] (Synthesis Examples A5 to A20) Synthesis of Polymers A5 to A20 Represented by Formulae (A5) to (A20) Polymers A5 to A20 represented by the following formulae (A5) to (A20) were obtained by the method described in Synthesis Example A1, except that instead of 2.0 g of the compound (MAC-ADI-COOM) obtained in Synthesis Example 1, the types and amounts of compounds AA1 to AA16 obtained in Synthesis Examples 5 to 20 were changed as shown in Table 1.

[0438] It should be noted that the following formulas (A5) to (A20) are each written in a simplified form to indicate the ratio of each structural unit, but the arrangement order of the structural units is random, and they are not block copolymers in which the structural units each form an independent block.

[0439]

[0440]

[0441]

[0442]

[0443]

[0444]

[0445]

[0446]

[0447]

[0448]

[0449]

[0450]

[0451]

[0452]

[0453]

[0454]

[0455]

[0456] The meanings of the abbreviations in Table 1 are as follows: MAMA: 2-methyl-2-adamantyl methacrylate BLMA: γ-butyrolactone methacrylate pHS: p-hydroxystyrene

[0457] [Evaluation] The polymers obtained in the above-mentioned Synthesis Examples A1 to A4 and A5 to A20 and Comparative Synthesis Examples B1 to B3 were evaluated as follows. The results are shown in Tables 2 and 3.

[0458] (Evaluation of EUV sensitivity by TMAH aqueous solution development) 5 parts by mass of the polymer obtained in the synthesis example or synthesis comparative example, 1 part by mass of triphenylsulfonium nonafluorobutanesulfonate, 0.2 parts by mass of tributylamine, 80 parts by mass of PGMEA (propylene glycol monomethyl ether acetate), and 12 parts by mass of PGME (propylene glycol monomethyl ether) were blended to prepare a solution. The solution was applied to a silicon wafer and baked at 110°C for 60 seconds to form a photoresist layer (resist film) with a film thickness of 100 nm. Next, the photoresist 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 ２After 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 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.

[0459] (Evaluation of sensitivity over time by development in aqueous TMAH solution) The solution prepared in the above-mentioned EUV sensitivity evaluation was subjected to forced aging treatment under conditions of 40°C / 240 hours under light-shielded conditions, and the EUV sensitivity of the solution after the aging treatment was similarly evaluated, and an evaluation was carried out according to the amount of change in sensitivity. As a specific evaluation method, in the EUV sensitivity evaluation, the sensitivity value at which the slope value was maximum in the film thickness-sensitivity curve after development, with the horizontal axis representing sensitivity and the vertical axis representing film thickness, was measured as the standard sensitivity. The standard sensitivity of the solution before and after the forced aging treatment was determined, and the sensitivity deviation due to the aging treatment was evaluated using the value obtained from the following calculation formula.

[0460] The evaluation criteria for each of the polymers obtained in Synthesis Examples A1 to A4 and Synthesis Comparative Examples B1 to B3 are as follows: [Sensitivity deviation] = 1 - ([Standard sensitivity of solution after aging] / [Standard sensitivity of solution before aging]) (Evaluation criteria) A: [Sensitivity deviation] ≦ 0.005 B: 0.005 < [Sensitivity deviation] ≦ 0.02 C: 0.02 < [Sensitivity deviation] ≦ 0.05 D: 0.05 < [Sensitivity deviation]

[0461] The evaluation criteria for each of the polymers obtained in Synthesis Examples A5 to A20 are as follows: [Sensitivity deviation] = 1 - ([Standard sensitivity of solution after aging] / [Standard sensitivity of solution before aging]) (Evaluation criteria) S: [Sensitivity deviation] ≦ 0.002 A: 0.002 < [Sensitivity deviation] ≦ 0.005 B: 0.005 < [Sensitivity deviation] ≦ 0.02 C: 0.02 < [Sensitivity deviation] ≦ 0.05 D: 0.05 < [Sensitivity deviation]

[0462] (EB Pattern Evaluation by TMAH Aqueous Solution Development) A solution was prepared by blending 5 parts by mass of the polymer obtained in the Synthesis Example or Synthesis Comparative Example, 1 part by mass of triphenylsulfonium nonafluorobutanesulfonate, 0.1 parts by mass of tributylamine, and 92 parts by mass of PGMEA. The solution was applied to a silicon wafer and baked at 110 to 130°C for 60 seconds to form a photoresist layer (resist film) with a thickness of 100 nm. The wafer was then exposed using an electron beam lithography system "ELS-7500" (product name, manufactured by Elionix Co., Ltd., 50 keV), baked at 115°C for 90 seconds (PEB), and developed for 60 seconds with a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (TMAH) to obtain a positive pattern. The exposure dose was adjusted to obtain a line-and-space pattern with a half pitch of 50 nm. Eighty pattern images of the obtained resist pattern were taken at a magnification of 100,000 times using a scanning electron microscope "S-4800" (product name, manufactured by Hitachi, Ltd.), and the number of residues in the spaces between the resist patterns was counted, and the total amount of residues was used for evaluation.

[0463] The evaluation criteria for each of the polymers obtained in Synthesis Examples A1 to A4 and Synthesis Comparative Examples B1 to B3 are as follows: (Evaluation Criteria) A: Number of residues≦10 B: 10<Number of residues≦80 C: 80<Number of residues≦400 D: 400<Number of residues

[0464] The evaluation criteria for each of the polymers obtained in Synthesis Examples A5 to A20 are as follows: (Evaluation Criteria) S: Number of residues≦5 A: 5 residues<Number of residues≦10 B: 10 residues<Number of residues≦80 C: 80 residues<Number of residues≦400 D: 400 residues<Number of residues

[0465] (Evaluation of Etching Defects by Development with TMAH Aqueous Solution) 5 parts by mass of the polymer obtained in the Synthesis Example or the Synthesis Comparative Example, 1 part by mass of triphenylsulfonium nonafluorobutanesulfonate, 0.2 parts by mass of tributylamine, 80 parts by mass of PGMEA, and 12 parts by mass of PGME were blended to prepare a solution. The solution was applied to an 8-inch silicon wafer having a 100 nm-thick oxide film formed on its outermost surface, and baked at 110°C for 60 seconds to form a 100 nm-thick photoresist layer (resist film). Next, using an extreme ultraviolet (EUV) exposure device "EUVES-7000" (product name, manufactured by Litho Tech Japan Co., Ltd.), shot exposure was performed on the entire surface of the wafer at an exposure dose 10% less than the EUV sensitivity value obtained in the above EUV sensitivity evaluation, followed by baking (PEB) at 110°C for 90 seconds and developing with a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution for 60 seconds, thereby obtaining a wafer that had been shot-exposed for 80 shots on the entire surface of the wafer. The exposed wafer thus produced was then subjected to CF ４ The oxide film was etched by 50 nm using Ar / Ar gas. The wafers produced by etching were subjected to defect evaluation using a defect inspection system "Surfscan SP5" (product name, manufactured by KLA Corporation), and the number of cone defects of 19 nm or more was calculated as an index of etching defects.

[0466] The evaluation criteria for each of the polymers obtained in Synthesis Examples A1 to A4 and Synthesis Comparative Examples B1 to B3 are as follows: (Evaluation Criteria) A: Number of cone defects ≦ 10 B: 10 < Number of cone defects ≦ 80 C: 80 < Number of cone defects ≦ 400 D: 400 < Number of cone defects

[0467] The evaluation criteria for each of the polymers obtained in Synthesis Examples A5 to A20 are as follows: (Evaluation Criteria) S: Number of residues≦5 A: 5 residues<Number of residues≦10 B: 10 residues<Number of residues≦80 C: 80 residues<Number of residues≦400 D: 400 residues<Number of residues

[0468] (Evaluation of changes over time in etching defects by TMAH aqueous solution development) The solutions prepared in the above-mentioned etching defect evaluation were left for 7 days under light-shielded conditions at room temperature (20°C), and the solutions after leaving were similarly evaluated for etching defects, and an evaluation was carried out according to the amount of change in the number of defects. Specific evaluation methods were as follows: a change in EUV sensitivity before and after leaving was evaluated as "G" if it was less than 6%, and an change of 6% or more was evaluated as "N." The same method was used to evaluate each of the polymers obtained in Synthesis Examples A1 to A4 and A5 to A20, and Synthesis Comparative Examples B1 to B3.

[0469]

[0470] From the evaluation results of etching defects and changes in etching defects over time in Table 2, it was found that the iodine-containing compound of this embodiment, which contains a carboxy group and / or an ester group, further improves the etching stability of a film for lithography. Furthermore, from other evaluation results, it was found that the iodine-containing compound of this embodiment, which contains an iodine atom, further improves the etching stability of a film for lithography, and further improves the EUV sensitivity, its sensitivity over time, and the stability of the EB pattern.

[0471] When the iodine-containing compound of this embodiment contains an ester group, the etching stability of the lithography film is further improved.

[0472] Comparing Synthesis Examples A5 to A12 and A18 to A20 with Synthesis Examples A13 to A17, it can be seen that the iodine-containing compound of this embodiment has a (meth)acryloyloxy group (R １is a hydrogen atom or a methyl group, and L is an ester bond), the solubility is further improved, and the etching stability of the lithography film is further improved. On the other hand, the iodine-containing compound of this embodiment has a vinyl group (R １ is a hydrogen atom and L is a single bond), the stability of the lithography film is further improved, and the sensitivity over time and the EB pattern are further improved.

[0473] (Solubility in Organic Solvent) PGMEA (propylene glycol monomethyl ether acetate) was added to 1 g of each of Polymers A1 to A20 obtained in Synthesis Examples A1 to A20, and the amount of PGMEA at which the solid matter was completely dissolved visually was defined as the minimum amount of solvent (g). The amount of polymer (1 g) relative to that minimum amount of solvent was calculated and defined as the solubility. These results are shown in Table 3.

[0474]

[0475] As shown in Table 3, when the iodine-containing compound of this embodiment contains a carboxy group, the carboxy groups in the resist resin form hydrogen bonds with each other, promoting crystallization of the resin and making the compound less soluble in PGMEA, a resist solvent. In contrast, when the iodine-containing compound contains an ester group, hydrogen bonds are less likely to be formed, and the compound's solubility in PGMEA tends to improve.

[0476] This application is based on a Japanese patent application (Patent Application No. 2024-155121) filed on September 9, 2024, the contents of which are incorporated herein by reference.

[0477] According to the present invention, it is possible to provide an iodine-containing compound, an iodine-containing hydroxy compound, an iodine-containing (co)polymer, a composition, a pattern forming method, and a method for producing an iodine-containing compound, which are capable of forming a lithography film having high resolution and high sensitivity. For this reason, the present invention is particularly suitable for use in lithography techniques.

Claims

1. An iodine-containing compound represented by formula (1). (In formula (1), R １ represents a hydrogen atom, a methyl group, or a halogen atom; ２ each independently represents 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; R Ａ each independently represents 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; A represents an organic group having 5 to 30 carbon atoms including an alicyclic ring; L represents an ester bond (—COO—), a single bond, or an oxygen atom; n １ represents 0 or 1; ２ represents an integer of 1 to 20, ３ represents an integer from 1 to 20.

2. The iodine-containing compound according to claim 1, wherein the compound represented by formula (1) is a compound represented by formula (2). (In formula (2), R １ , R ２ , R Ａ , A, n １ , n ２ , n ３ is as defined in the above formula (1).

3. The iodine-containing compound according to claim 2, wherein the compound represented by formula (2) is a compound represented by formula (3). (In formula (3), R １ , R Ａ , A, n ２ , n ３ is as defined in the above formula (1).

4. The iodine-containing compound according to claim 2, wherein the compound represented by formula (2) is a compound represented by formula (4). (In formula (4), R ２’ each independently represents 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; R １ , R Ａ , A, n １ , n ２ , n ３ is as defined in the above formula (1).

5. The iodine-containing compound according to claim 1, wherein the compound represented by formula (1) is a compound represented by formula (5). (In formula (5), R １ , R ２ , R Ａ , A, n １ , n ２ , n ３ is as defined in the above formula (1).

6. The iodine-containing compound according to claim 1, wherein the compound represented by formula (1) is a compound represented by formula (6). (In formula (6), R １ , R ２ , R Ａ , A, n １ , n ２ , n ３ is as defined in the above formula (1).

7. n ２ The iodine-containing compound according to any one of claims 1 to 6, wherein represents an integer of 1 to 15.

8. R Ａ each independently represent 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.

9. The iodine-containing compound according to any one of claims 1 to 6, wherein the alicyclic ring in A is an adamantane ring.

10. An iodine-containing (co)polymer having a repeating unit represented by formula (7). (In formula (7), R １ represents a hydrogen atom, a methyl group, or a halogen atom; ２ each independently represents 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; R Ａ each independently represents 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; A represents an organic group having 5 to 30 carbon atoms including an alicyclic ring; L represents an ester bond (—COO—), a single bond, or an oxygen atom; n １ represents 0 or 1; ２ represents an integer of 1 to 20, ３ represents an integer of 1 to 20, and the symbol * represents the bonding point to the adjacent repeating unit.

11. The iodine-containing (co)polymer according to claim 10, wherein the repeating unit represented by formula (7) is a repeating unit represented by formula (8). (In formula (8), R １ , R ２ , R Ａ , A, n １ , n ２ , n ３ , the symbol * is as defined in the above formula (7).

12. The iodine-containing (co)polymer according to claim 10, wherein the repeating unit represented by formula (7) is a repeating unit represented by formula (9). (In formula (9), R １ , R Ａ , A, n ２ , n ３ , the symbol * is as defined in the above formula (7).

13. The iodine-containing (co)polymer according to claim 10, wherein the repeating unit represented by formula (7) is a repeating unit represented by formula (10). (In formula (10), R ２’ each independently represents 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; R １ , R Ａ , A, n １ , n ２ , n ３ , the symbol * is as defined in the above formula (7).

14. The iodine-containing (co)polymer according to claim 10, wherein the repeating unit represented by formula (7) is a repeating unit represented by formula (11). (In formula (11), R １ , R ２ , R Ａ , A, n １ , n ２ , n ３ , the symbol * is as defined in the above formula (7).

15. The iodine-containing (co)polymer according to claim 10, wherein the repeating unit represented by formula (7) is a repeating unit represented by formula (12). (In formula (12), R １ , R ２ , R Ａ , A, n １ , n ２ , n ３ , the symbol * is as defined in the above formula (7).

16. n ２ The iodine-containing (co)polymer according to any one of claims 10 to 15, wherein represents an integer of 1 to 15.

17. R Ａ each independently represent 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. The iodine-containing (co)polymer according to any one of claims 10 to 15.

18. The iodine-containing (co)polymer according to any one of claims 10 to 15, wherein the alicyclic ring in A is an adamantane ring.

19. A composition comprising the iodine-containing (co)polymer according to any one of claims 10 to 15.

20. The composition of claim 19, further comprising a solvent.

21. The composition of claim 19, further comprising an acid generator.

22. The composition of claim 19, further comprising an acid diffusion control agent.

23. A pattern forming method comprising the steps of: forming a film using the composition according to claim 19; exposing the film to light; and removing the exposed portion of the film using a developer to form a pattern.

24. A method for producing the iodine-containing compound according to claim 1, comprising the 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 each independently represents 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; R Ａ each independently represents 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; A represents an organic group having 5 to 30 carbon atoms including an alicyclic ring; n １ represents 0 or 1; ２ represents an integer of 1 to 20, ３ represents an integer from 1 to 20. (In formula (b), R １ is as defined in the formula (1), Ｂ is selected from the group consisting of a hydroxy group, a halogen atom, and a (meth)acryloyloxy group.

25. The method for producing an iodine-containing compound according to claim 24, wherein the compound represented by formula (a) is a compound represented by formula (a1). (In formula (a1), R Ａ , A, n ２ , n ３ is as defined in formula (a) above.

26. n ２ The method for producing an iodine-containing compound according to claim 24 or 25, wherein represents an integer of 1 to 15.

27. R Ａ each independently represent 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.

28. The method for producing an iodine-containing compound according to claim 24 or 25, wherein the alicyclic ring in A is an adamantane ring.

29. An iodine-containing hydroxy compound represented by formula (a): (In formula (a), R ２ each independently represents 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; R Ａ each independently represents 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; A represents an organic group having 5 to 30 carbon atoms including an alicyclic ring; n １ represents 0 or 1; ２ represents an integer of 1 to 20, ３ represents an integer from 1 to 20.

30. The iodine-containing hydroxy compound according to claim 29, wherein the compound represented by formula (a) is a compound represented by formula (a1). (In formula (a1), R Ａ , A, n ２ , n ３ is as defined in the formula (a) above.

31. n ２ The iodine-containing hydroxy compound according to claim 29 or 30, wherein represents an integer of 1 to 15.

32. R Ａ each independently represent 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.

33. The iodine-containing hydroxy compound according to claim 29 or 30, wherein the alicyclic ring in A is an adamantane ring.

34. The method for producing an iodine-containing compound according to claim 24, further comprising a step of carrying out an iodine introduction reaction on a compound represented by the following formula (Sa1) or formula (Sa2): (In formula (Sa1), R ２ , R Ａ , A, n １ , n ３ is as defined in the above formula (1). (In formula (Sa2), A, R Ａ , n ３ is as defined in the formula (1) above, and E is a hydrocarbon group having 1 to 30 carbon atoms and having at least one group selected from the group consisting of a hydroxy group, an aldehyde group, an ether group, a thiol group, and an amino group.

35. The method for producing an iodine-containing compound according to claim 34, wherein the alicyclic ring in A is an adamantane ring.

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