Compound, composition, (CO) polymer, composition for film formation, and method for producing compound

Abstract

Provided is a compound represented by formula (0). (In the formula, A is a C6-C30 aromatic group, X1 is a single bond or an ester bond, O is an oxygen atom, I is an iodine atom, R1 is a hydrogen atom or a methyl group, R2 moieties are each independently a hydrogen atom or an acid-decomposable group and at least one of the R2 moieties is the acid-decomposable group, n is an integer of 1 or larger, m is an integer of 2 or larger, and m>n.)

Description

Compounds, compositions, (co)polymers, film-forming compositions, and methods for producing compounds

[0001] The present invention relates to compounds, compositions, (co)polymers, film-forming compositions, and methods for producing compounds.

[0002] In recent years, advances in lithography technology have led to rapid miniaturization of semiconductors (patterns) and pixels in the manufacturing of semiconductor devices and liquid crystal display elements. To achieve pixel miniaturization, the wavelength of the exposure light source is generally shortened. Specifically, while ultraviolet light, represented by g-line and i-line ultraviolet light, was conventionally used, methods using far-ultraviolet light such as KrF excimer lasers (248 nm) and ArF excimer lasers (193 nm) are now becoming the main method for mass production, and the introduction of extreme ultraviolet (EUV) lithography (13.5 nm) is also progressing. In addition, electron beams (EB) are used to form fine patterns.

[0003] Conventional resist materials are polymer-based resist materials capable of forming amorphous films. Examples include polymer-based resist compositions such as polymethyl methacrylate and polyhydroxystyrene or polyalkyl methacrylate having acid-dissociable groups (see, for example, Non-Patent Document 1). Conventionally, line patterns of about 10 to 100 nm are formed on resist thin films made by coating a substrate with a solution of these resist compositions and then irradiating them with ultraviolet light, far ultraviolet light, electron beams, extreme ultraviolet light, etc.

[0004] Furthermore, electron beam or extreme ultraviolet lithography has a reaction mechanism different from that of conventional photolithography (Non-Patent Documents 2 and 3). Moreover, electron beam or extreme ultraviolet lithography aims to form fine patterns of several nanometers to tens of nanometers. As the dimensions of the resist pattern become smaller in this way, a resist composition that is even more sensitive to the exposure light source is required. In particular, in extreme ultraviolet lithography, there is a need to further increase sensitivity in terms of throughput. As a resist material that improves the above-mentioned problems, resist compositions containing metal complexes such as titanium, tin, hafnium, and zirconium have been proposed (see, for example, Patent Document 1).

[0005] Furthermore, as the dimensions of the resist pattern become smaller, there is a need for a resist composition that is even more sensitive to the exposure light source, and a resist composition using iodine-containing 4-hydroxystyrene as a raw material monomer has been proposed (see, for example, Patent Documents 2-3). In addition, the present inventors have proposed a resist composition with excellent exposure sensitivity using an iodine-containing hydroxystyrene compound (see, for example, Patent Documents 4 and 5).

[0006] Japanese Patent Publication No. 2015-108781, US Publication No. 2019 / 0187342, WO2019 / 187881, WO2021 / 029395, WO2024 / 005049

[0007] Shinji Okazaki and 8 others “40 years of lithography technology” S&T Publishing, December 9, 2016 H. Yamamoto, et al. , Jpn. J. Appl. Phys. 46, L142 (2007) H. Yamamoto, et al. , J. Vac. Sci. Technol. b 23, 2728 (2005)

[0008] Resist compositions are typically polymerized from, for example, hydroxystyrene compounds containing iodine, then dissolved in a solvent and subsequently used to form a film. However, if a certain proportion or more of the iodine-containing compound is used, the polymer may become less soluble in the solvent, or uniform film formation may not occur on the substrate (resulting in cloudiness, etc.). Therefore, there is a limit to the amount of iodine that can be introduced into the resist, and the development of a technology that can maximize the sensitizing effect of iodine has been highly desired.

[0009] Furthermore, when polymerizing hydroxystyrene compounds containing iodine, chain transfer can occur during the polymerization reaction, inhibiting the desired polymerization reaction. Therefore, there is a need for a technology that can efficiently introduce iodine-containing structural units during polymerization.

[0010] To address these challenges, the present invention aims to provide a compound capable of providing a (co)polymer with a high iodine introduction rate, as well as a composition, a (co)polymer with a high iodine introduction rate, a film-forming composition, and a method for producing the compound.

[0011] As a result of diligent research to solve the above-mentioned problems, the present inventors have discovered that by using a compound having a specific structure, (co)polymers with a high iodine introduction rate can be efficiently synthesized, and have completed the present invention. That is, the present invention is as follows.

[0012] <1> A compound represented by the following formula (0). (In the formula, A is an aromatic group having 6 to 30 carbon atoms, and X １ is a single bond or an ester bond, O is an oxygen atom, I is an iodine atom, R １ R is a hydrogen atom or a methyl group. ２ Each is independently a hydrogen atom or an acid-degradable group, and R ２ At least one of them is an acid-degradable group, n is an integer of 1 or more, m is an integer of 2 or more, and m > n.) <2> The compound described in <1> above, represented by the following formula (0A) or (0B). (In the formula, A, R １ O, I, R ２, n, and m are the same as in formula (0), and m > n.) <3> The compound according to <1>, represented by the following formula (0C). (In the formula, A, R １ , O, I, R ２ , n, and m are the same as in formula (0), and m > n.) <4> The compound according to <1>, represented by the following formula (1). (In the formula, R １ , X １ , O, I, and R ２ are the same as in formula (0), n is an integer from 1 to 2, m is an integer from 2 to 3, n + m is 3 or more and 5 or less, and m > n.) <5> The compound according to <4>, represented by the following formula (A). (In the formula, R １ , O, I, n, and m are the same as in formula (1), and RA is, independently of each other, an alkyl group having 1 to 4 carbon atoms.) <6> In the formula (A), n = 1 and m = 2, the compound according to any one of <1> to <5>. <7> The compound according to <5>, represented by the following formula (A1) or the following formula (A2). (In the formula, R １ , O, I, and RA are the same as in formula (A).) <8> The compound according to <4>, represented by the following formula (B). (In the formula, R １ , O, I, n, and m are the same as in formula (1), RB is, independently of each other, an alkyl group having 1 to 6 carbon atoms, and RC is, independently of each other, a hydrogen atom or a group that combines with the alkyl group of RB to form a ring structure.) <9> In the formula (B), n = 1 and m = 2, the compound according to <8>. <10> The compound according to <8>, represented by the following formula (B1) or the following formula (B2). (In the formula, R １ , O, I, RB, and RC are the same as in formula (B).) <11> The compound according to <4>, in which the group represented by -OR ２ in the formula (1) is, independently of each other, an acetal group. <12> R ２The compound according to <4>, wherein the compound is a group selected from a tetrahydropyranyl group, a methoxymethyl group, an ethoxymethyl group, and an ethoxyethyl group. <13> A composition comprising the compound according to any one of <1> to <12> and a solvent. <14> A composition comprising the compound according to any one of <1> to <12> and a compound represented by the following formula (2). (In the formula, R １ , X １ O and I are the same as in equation (0), and R ４ Each of these is independently a hydrogen atom, an acid-degradable group, or a group to which two acid-degradable groups are bonded, R ４ At least one of the groups is a group to which the two acid-degradable groups are bonded, n is an integer from 1 to 2, m is an integer from 2 to 3, n + m is 3 or more and 5 or less, and m > n.) <15> The composition according to <14>, wherein the total amount of the compound represented by formula (2) relative to the total amount of the compounds described in any of <1> to <12> is 1 ppm by mass or more and 10% by mass or less. <16> The composition according to <14> or <15>, wherein in formula (2), n = 1 and m = 2. <17> A composition comprising at least one of the compounds described in any of <1> to <12> and at least one of the compounds represented by the following formula (2A) and the following formula (2B). (In the formula, R １ O and I are the same as in formula (0), RA is independently an alkylene group having 1 to 4 carbon atoms, RA1 is independently an alkyl group having 2 to 4 carbon atoms which may have a hydrogen atom or an ether group, at least one of RA1 is an alkyl group having 2 to 4 carbon atoms which may have an ether group, n is an integer from 1 to 2, m is an integer from 2 to 3, n + m is between 3 and 5, and m > n. (In the formula, R １, O and I are the same as in formula (0), RB is independently an alkylene group having 1 to 6 carbon atoms, RC is independently a hydrogen atom or a group that forms a ring structure by bonding with the alkyl group of RB, RB1 is independently a hydrogen atom or an alkyl group having 2 to 6 carbon atoms which may have an ether group, at least one of RB1 is an alkyl group having 2 to 6 carbon atoms which may have the ether group, n is an integer from 1 to 2, m is an integer from 2 to 3, n + m is 3 or more and 5 or less, m > n.) <18> The composition according to <17>, wherein the compound represented by formula (2A) is the compound represented by the following formula (2A1) or formula (2A2), and the compound represented by formula (2B) is the compound represented by the following formula (2B1) or formula (2B2). <19> The composition according to <17>, wherein in formulas (2A) and (2B), n = 1 and m = 2. <20> The composition according to any one of <17> to <19>, wherein the total amount of the compound represented by formulas (2A) and (2B) relative to the total amount of the compound according to any one of <1> to <12> is 1 ppm by mass or more and 10% by mass or less. <21> A (co)polymer comprising a structural unit corresponding to the compound according to any one of <1> to <12>, and / or a structural unit in which at least a portion of the group containing an acid-degradable group in the compound according to any one of <1> to <12> is converted to a hydroxyl group. <22> The (co)polymer according to <21>, further comprising a structural unit corresponding to a compound having an adamantane skeleton, and / or a structural unit corresponding to a compound having a lactone skeleton. <23> A film-forming composition comprising the (co)polymer according to <21> or <22> and a solvent. <24> The film-forming composition according to <23>, further comprising at least one selected from an acid generator, a base generator, and a base compound. <25> A method for producing a compound represented by the following formula (1), comprising: an iodine introduction step of introducing iodine into a compound represented by the following formula (X1) to obtain a compound represented by the following formula (X2); a protecting group introduction step of introducing a protecting group to at least one hydroxyl group in the compound represented by the following formula (X2) obtained in the iodine introduction step; and a methyleneization step of methyleneizing the compound obtained in the protecting group introduction step. (In the formula, X １ is a single bond or an ester bond, O is an oxygen atom, I is an iodine atom, R １ R is a hydrogen atom or a methyl group. ２ Each is independently a hydrogen atom or an acid-degradable group, and R ２) At least one of is an acid-degradable group, n is an integer from 1 to 2, m is an integer from 2 to 3, n + m is 3 or more and 5 or less, and m > n.) <26> A method for producing the compound according to <25>, wherein in the protecting group introduction step, a protecting group is introduced to all the hydroxyl groups in the compound represented by formula (X2) obtained in the iodine introduction step. <27> A method for producing the compound according to <25>, wherein the protecting group introduction step includes introducing a protecting group to some of the hydroxyl groups in the compound represented by formula (X2) obtained in the iodine introduction step, the methyleneization step includes methyleneizing the compound obtained in the protecting group introduction step, and further introducing a protecting group to all the hydroxyl groups in the compound obtained in the methyleneization step. <28> A method for producing the compound according to <25> or <26>, wherein in the formula, n = 1 and m = 2. <29> In formula (1), I is in the meta position and there are two ORs ２ ortho and para positions respectively, or I is in the para position and two ORs ２ A method for producing the compound according to any one of <25> to <28>, wherein each of the is bonded to the meta position. <30> -OR in formula (1) ２ A method for producing the compound according to any one of <25> to <28>, wherein each of the groups represented by is independently an acetal group. <31> R in formula (1) ２ A method for producing the compound according to any one of <25> to <28>, wherein the group is selected from a tetrahydropyranyl group, a methoxymethyl group, an ethoxymethyl group, and an ethoxyethyl group.

[0013] According to the present invention, it is possible to provide compounds capable of providing polymers with a high iodine introduction rate, as well as compositions, polymers with a high iodine introduction rate, film-forming compositions, and methods for producing compounds.

[0014] The embodiments of the present invention will be described below (hereinafter sometimes referred to as "this embodiment"). This embodiment is an example for illustrating the present invention, and the present invention is not limited to this embodiment.

[0015] In this specification, the meanings of each term are as follows: "(meth)acrylate" means at least one selected from acrylates, haloacrylates, and methacrylates. Haloacrylate means an acrylate in which a halogen is substituted at the position of the methyl group of methacrylate. Other terms containing the expression (meth) are interpreted in the same way as (meth)acrylate. "(co)polymer" means at least one selected from homopolymers and copolymers.

[0016] 《Compound》 The compound of this embodiment is represented by the following formula (0). The uses of the compound of this embodiment are not particularly limited, but the compound of this embodiment can be polymerized and then the acid-degradable group can be decomposed with acid or acid and water to be used as an OH group (hydroxyl group). Hereinafter, the (co)polymer obtained by polymerizing the compound of this embodiment will be referred to as "polymer (A)", the (co)polymer obtained by removing the acid-degradable group in the constituent unit corresponding to the compound of this embodiment in polymer (A) and converting it to an OH group will be referred to as "polymer (B)", and polymers (A) and (B) may be collectively referred to as "the (co)polymer of this embodiment". Hereinafter, the compound of this embodiment may be referred to as "the first compound".

[0017] The compound of this embodiment is a compound having an iodine atom, -OR ２ (R ２ It also has an acid-degradable group, and after polymerization, it can be hydrolyzed with an acid, for example, to remove the protecting group and function as a hydroxyl group. Furthermore, the compound of this embodiment has more -OR than the number of iodine atoms ２ The number of such values ​​is large (i.e., "m > n" in equation (0)).

[0018] If only hydroxyl groups are positioned on the aromatic group represented by A, the hydroxyl groups will cause chain transfer during the polymerization reaction in polymerization (resist formation), inhibiting the desired polymerization reaction and potentially reducing the rate of introduction of the constituent units corresponding to the compound of this embodiment in the (co)polymer. In contrast, the compound of this embodiment has at least some of the hydroxyl groups protected by a protecting group (acid-degradable group) -OR ２ (That is, R２ Because it has an acid-degradable group, the influence of hydroxyl groups is suppressed during polymerization, and the introduction rate of the constituent units corresponding to the compound of this embodiment in the (co)polymer (polymer (A) and polymer (B)) can be increased, and as a result, a (co)polymer with a high iodine introduction rate can be provided. Furthermore, by using this (co)polymer in a film-forming composition, a resist with excellent sensitivity, sensitivity change over time, exposure stability, and etching defect change over time can be obtained, even with exposure light sources such as EUV and EB. In terms of the introduction rate of the constituent units containing iodine, in the compound represented by formula (0), R ２ -OR is an acid-degradable group ２ Compounds having two or more of the R are advantageous, and all R ２ -OR is an acid-degradable group ２ Compounds having the above-mentioned polymerizability are even more preferred.

[0019] Furthermore, when a (co)polymer having iodine atoms and hydroxyl groups is dissolved in a solvent to form a film, if the number of iodine atoms is greater than the number of hydroxyl groups, the solubility of the (co)polymer in the solvent may decrease, or when a film is formed on a substrate, it may not form uniformly, resulting in cloudiness. In contrast, the compound of this embodiment has a number of -ORs greater than the number of iodine atoms. ２ Due to the large number of iodine atoms, the (co)polymers using the compounds of this embodiment as monomers tend to have excellent solubility in solvents. Furthermore, by increasing the proportion of iodine atoms introduced into the resist ((co)polymer), the EUV sensitization effect by iodine atoms can be maximized.

[0020] (Compound represented by formula (0)) Formula (0) will be explained below. (In the formula, A is an aromatic group having 6 to 30 carbon atoms, and X １ is a single bond or an ester bond, O is an oxygen atom, I is an iodine atom, R １ R is a hydrogen atom or a methyl group. ２ Each is independently a hydrogen atom or an acid-degradable group, and R ２At least one of the groups is an acid-degradable group, n is an integer greater than or equal to 1, m is an integer greater than or equal to 2, and m > n.

[0021] In formula (0), A is an aromatic group having 6 to 30 carbon atoms. The number of carbon atoms in A is preferably 6 to 14, and more preferably 6 to 10.

[0022] A can be an aromatic group represented by any of the following, more preferably a benzene ring or a naphthalene ring, and even more preferably a benzene ring.

[0023]

[0024] X １ X represents a single bond or an ester bond. １ The following are examples of compounds represented by formula (0) in which X is shown by a single bond or an ester bond: １ In one preferred embodiment, a single bond is used. (In the formula, A, R １ O, I, R ２ n and m are the same as in equation (0), and m > n.

[0025] Also, X １ If it is an ester bond, X １ C = C(R １ The compound may also contain a group that connects a (meth)acryloyloxy group, such as a methacryloyloxy group or acryloyloxy, to ring A, which is formed together with the -" portion. Examples of such groups include a methylene group, and for example, compounds represented by the following formula (0C) can be found. (In the formula, A, R １ O, I, R ２ n and m are the same as in equation (0), and m > n.

[0026] In equation (0), "O" represents an oxygen atom and "I" represents an iodine atom. Also, R １ R represents a hydrogen atom or a methyl group, and is preferably a hydrogen atom. １If the group exhibits a methyl group, it may have halogen atoms (for example, iodine, fluorine, chlorine, or bromine atoms) as substituents.

[0027] In formula (0), R ２ Each of these independently represents a hydrogen atom or an acid-degradable group. However, R ２ At least one of the groups is an acid-degradable group. Here, "acid-degradable group" means a group that is removed upon contact with an acid, or with both acid and water, to form a hydrophilic group (for example, a hydroxyl group). Specifically, R ２ If it is an acid-degradable group, then "-OR ２ The acid-degradable group of " is removed by contact with an acid or an acid and water and converted to an -OH group (hydroxyl group). In this embodiment, the types of acids that can remove the acid-degradable group will be described later. Note that in the compound represented by formula (0), R ２ -OR is an acid-degradable group ２ Compounds having two or more R are preferred, and all R ２ -OR is an acid-degradable group ２ Compounds having the characteristic are even more preferred.

[0028] R ２ Examples of acid-degradable groups shown are not limited to R ２ In terms of achieving both stability as a protecting group and deprotection performance during use, an acetal group is preferred. Examples of the acetal group include a group selected from a tetrahydropyranyl group, a methoxymethyl group, an ethoxymethyl group, and an ethoxyethyl group, with a group selected from a tetrahydropyranyl group and an ethoxyethyl group being even more preferred.

[0029] In equation (0), n is an integer greater than or equal to 1, m is an integer greater than or equal to 2, and m > n. The upper limits of n and m are determined by the ring structure of the aromatic group represented by A.

[0030] (Compound represented by formula (1)) A compound represented by formula (1) can be given as a preferred example of the compound of this embodiment. The compound represented by formula (1) is a compound in which A in formula (0) is a benzene ring.

[0031] In formula (1), R １ , X １ , O, I and R ２ The same as in equation (0), where n is an integer from 1 to 2, m is an integer from 2 to 4, n+m is between 3 and 5, and m>n. Note that in the compound shown in equation (1), R ２ -OR is an acid-degradable group ２ Compounds having two or more R are preferred, and all R ２ -OR is an acid-degradable group ２ Compounds having the characteristic are even more preferred.

[0032] (Compound represented by formula (A) or formula (B)) As described above, R ２ As an example of an acid-degradable group represented by, an acetal group can be given. In the compound represented by formula (1), R ２ Examples of compounds in which the acid-degradable group shown is an acetal group include the compounds represented by the following formulas (A'), (A), (B'), or (B), and in particular, the compound represented by formula (A) or the compound represented by formula (B) is preferred from the viewpoint of polymerizability. As described above, R in formula (1) ２ When X is an acetal group, it is superior in terms of achieving both stability as a protecting group and deprotection performance during use. Note that the compounds represented by the following formulas are those in formula (1) where X １ This is a "single bond".

[0033] (In the formula, R １ O, I, and n are the same as in formula (1), m1 is 1 to 3, l is 1 to 3, m1 + l is 2 or more and 4 or less, and RA are each independently alkyl groups having 1 to 4 carbon atoms.

[0034] (In the formula, R １ O, I, n, and m are the same as in formula (1), and RA are each independently alkyl groups having 1 to 4 carbon atoms.

[0035] (In the formula, R １O, I, and n are the same as in formula (1), m1 is 1 to 3, l is 1 to 3, m1 + l is 2 or more and 4 or less, RB are each independently alkyl groups having 1 to 6 carbon atoms, and RC are each independently hydrogen atoms or groups that bond with the alkyl group of RB to form a ring structure.

[0036] (In the formula, R １ O, I, n, and m are the same as in formula (1), RB is independently an alkyl group having 1 to 6 carbon atoms, and RC is independently a hydrogen atom or a group that forms a ring structure by bonding with the alkyl group of RB.

[0037] In formula (A'), R １ , O, I and n, and in formula (A), R １ ,O,I,n and m are the same as in formula (1). In formula (A'), m1 is 1 to 3, l is 1 to 3, and m1 + l is 2 or more and 4 or less. In formula (A') and formula (A), RA is independently an alkyl group having 1 to 4 carbon atoms. Examples of alkyl groups having 1 to 4 carbon atoms are, but are not limited to, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, and a t-butyl group, with the ethyl group being preferred. Compounds in which RA is an ethyl group can be synthesized, for example, using ethyl vinyl ether as a raw material.

[0038] In formula (B'), R １ , O, I and n, and in formula (B), R １, O, I, n and m are the same as in formula (1). In formula (B'), m1 is 1 to 3, l is 1 to 3, and m1 + l is 2 or more and 4 or less. In formulas (B') and (B), RB is independently an alkyl group having 1 to 6 carbon atoms, and RC is independently a hydrogen atom or a group that forms a ring structure by bonding with the alkyl group of RB. Examples of alkyl groups having 1 to 6 carbon atoms include, but are not limited to, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, t-butyl group, n-pentyl group, and n-hexyl group, and may be branched or cyclic alkyl groups. As for RB, for example, a ring structure bonded with an ethyl group or RC is preferred, and a ring structure bonded with RC is more preferred.

[0039] With respect to RC in formula (B') and formula (B), "a group that forms a ring structure by bonding with the alkyl group of RB" means that when RB forms a ring structure in formula (B), etc., RC becomes a single bond, and the end opposite to the side to which the oxygen atom of the alkyl group of RB is bonded directly bonds to the carbon atom bonded to RC. Furthermore, when a ring structure is formed by the bonding of the alkyl group of RB and RC, the ring structure composed of "-CH-O-RB-RC- (RC is also bonded to -CH-)" is preferably a tetrahydropyranyl group, and more preferably a 2-tetrahydropyranyl group.

[0040] The compound represented by formula (A) or the compound represented by formula (B) preferably has n=1 and m=2, respectively, in terms of the solubility of the resulting (co)polymer in the solvent.

[0041] (Compounds represented by formula (A1), formula (A2), formula (B1), or formula (B2)) Compounds represented by formula (0), formula (1), formula (A'), formula (A), formula (B'), or formula (B) have a hydroxyl group or -OR adjacent to the iodine atom on the aromatic group. ２ A structure in which the groups enclosed in parentheses denoted by m or m1 in each of the formulas (hereinafter collectively referred to as "acid-dissociable sites") are arranged is preferred, and a structure in which an iodine atom is sandwiched between two acid-dissociable sites is even more preferred.

[0042] First, when a polymer having an iodine atom and a hydroxyl group is exposed to EUV light, the iodine atom absorbs the EUV light and is excited, and then reacts with the hydroxyl group in the vicinity of the iodine atom to generate H ＋ . The generated H ＋ decomposes an acid dissociable unit in the polymer (a unit that is converted into a structure having a hydroxyl group by reaction with H ＋ ; for example, a unit having an ester group, an acetal group, a carbonate group, an ether group, an amide group, etc.), and the solubility of the polymer in the developer changes, enabling development. That is, the higher the conversion efficiency from "excitation of iodine atoms by EUV" to "generation of H ＋ (for example, generation of coumarin), the higher the exposure sensitivity of the resist (polymer). Therefore, in the polymer of the present embodiment, by having a hydroxyl group that can be a source of H ＋ adjacent to (preferably both adjacent positions of) the iodine atom, the efficiency from "excitation of iodine atoms by EUV" to "generation of H ＋ by the hydroxyl group" can be increased to the maximum, and as a result, excellent high-sensitivity performance can be imparted.

[0043] Further, as H ＋ generated in the vicinity of the iodine atom propagates / diffuses in the polymer, a large number of acid dissociation units can be catalytically decomposed, and the resolution during development can be increased. For the propagation of this H ＋ , a highly polar protic functional group having a high affinity for H ＋ is useful. Since the polymer in the present embodiment contains a large number of hydroxyl groups, which are representative examples of highly polar protic functional groups, the propagation ability of H ＋ is high, and excellent high-resolution performance can be exhibited.

[0044] Furthermore, when the compounds represented by formula (1), formula (A'), formula (A), or formula (B') have two acid-dissociable sites adjacent to one iodine atom, it is preferable that each group is arranged (bonded) on the benzene ring as shown in (i) or (ii) below, in order to obtain a resist with excellent sensitivity, sensitivity change over time, exposure stability, and etching defect change over time. (i) The two acid-dissociable sites are each in the meta position, and the iodine atom is in the p position. (ii) One acid-dissociable site is in the ortho position, the iodine atom is in the meta position, and the other acid-dissociable site is in the para position.

[0045] When each group is arranged (bonded) to a benzene ring as in (i) or (ii) above, the oxidation of the hydroxyl group can be suppressed when introducing an iodine atom before protecting the hydroxyl group with an acid-degradable group, and as a result, the compound of this embodiment can be synthesized with high purity.

[0046] Compounds represented by formula (1), formula (A), or formula (B) are compounds in which two acid-dissociable sites are adjacent to one iodine atom and each group is arranged (bonded) on a benzene ring as in (i) or (ii) above. Examples of such compounds include the following, and compounds represented by formula (A1), formula (A2), formula (B1), or formula (B2) are particularly preferred.

[0047] (In the formula, R １ O, I, and RA are the same as in formula (A).

[0048] (In the formula, R 1 O, I, RB, and RC are the same as in formula (B).

[0049] Specific examples of the compounds of this embodiment are not limited to the following compounds. Among the following compounds, compounds corresponding to the above formulas (A1), (A2), (B1), or (B2) are preferred.

[0050]

[0051] (Compound represented by formula (0C)) Another preferred example of the compound in this embodiment is the compound represented by formula (0C).

[0052]

[0053] In formula (0C), A, R １ O, I, R ２ n and m are the same as in formula (0), but A is more preferably a benzene ring or a naphthalene ring, and even more preferably a benzene ring. Also, R ２ For example, R ２ In terms of achieving both stability as a protecting group and deprotection performance during use, an acetal group is preferred. Examples of the acetal group include a group selected from tetrahydropyranyl, methoxymethyl, ethoxymethyl, and ethoxyethyl groups, with a group selected from tetrahydropyranyl and ethoxyethyl groups being more preferred. １ R represents a hydrogen atom or a methyl group, and is preferably a hydrogen atom. １ If the group exhibits a methyl group, it may have halogen atoms (for example, iodine, fluorine, chlorine, or bromine atoms) as substituents.

[0054] In equation (0), n is an integer greater than or equal to 1, m is an integer greater than or equal to 2, and m > n. The upper limits of n and m are determined by the ring structure of the aromatic group represented by A.

[0055] In formula (0C), A and R ２ A preferred combination is when A is either a benzene ring or a naphthalene ring and R ２ A combination in which is a group selected from a tetrahydropyranyl group, a methoxymethyl group, an ethoxymethyl group, and an ethoxyethyl group is mentioned, and a more preferred combination is in which A is a benzene ring and R ２ Examples include combinations in which the group is selected from a tetrahydropyranyl group and an ethoxyethyl group.

[0056] Examples of compounds represented by formula (0C) include the following:

[0057] 《Method for Producing the Compound of Formula (1)》 The method for producing the compound of this embodiment will be explained using the method for producing the compound represented by formula (1) as an example. The compound represented by formula (1) described above can be produced by various methods, but from the viewpoint of raw material availability and yield, it is preferable to produce it by a method that includes the following steps. The compound represented by formula (1) can be synthesized by a method that includes: an iodine introduction step in which iodine is introduced into the compound represented by the following formula (X1) to obtain the compound represented by the following formula (X2); a protecting group introduction step in which a protecting group is introduced into at least one hydroxyl group in the compound represented by formula (X2) obtained in the iodine introduction step; and a methyleneization step in which the compound obtained in the protecting group introduction step is methyleneated. The explanation of the substituents in each formula is the same as described above and will therefore be omitted. (In the formula, X １ is a single bond or an ester bond, O is an oxygen atom, I is an iodine atom, R １ R is a hydrogen atom or a methyl group. ２ Each is independently a hydrogen atom or an acid-degradable group, and R ２ At least one of the groups is an acid-degradable group, n is an integer between 1 and 2, m is an integer between 2 and 4, n + m is between 3 and 5, and m > n.

[0058] (Iodine introduction step) The iodine introduction step is a step in which iodine is introduced into the compound represented by formula (X1) to obtain the compound represented by formula (X2). In the iodine introduction step, the compound represented by formula (X1) and an iodizing agent can be reacted in a solvent as needed to introduce an iodine atom into the benzene ring of the compound represented by formula (X2).

[0059] —Compounds represented by formulas (X1), (X2), and (1)— The compound represented by formula (X1) can be synthesized by known methods. Examples of compounds represented by formula (X1) are listed below. However, the compounds represented by formula (X1) are not limited to the examples below.

[0060]

[0061] In formulas (X1) to (1), it is preferable that n = 1 and m = 2. Also, in formulas (X2) to (1), I is at the meta position and has two hydroxyl groups or OR ２ These are in the ortho and para positions, respectively, or I is in the para position and has two hydroxyl groups or OR ２ From the viewpoint of obtaining a highly sensitive compound, it is preferable that each of these compounds is bonded at the meta position.

[0062] Furthermore, in equation (1) - OR ２ Preferably, each of the groups represented is an acetal group, and further, R ２ However, it is preferable that the group is selected from a tetrahydropyranyl group, a methoxymethyl group, an ethoxymethyl group, and an ethoxyethyl group.

[0063] - Iodizing Agent - The iodine introduction step can be carried out using any known method as appropriate. The iodizing agent is not particularly limited, but examples include iodine chloride, iodine, N-iodosuccinimide, iodic acid, and hydrogen iodide (including hydroiodic acid and aqueous hydrogen iodide solutions), and it is preferable to use iodine and / or iodic acid. In the iodine introduction step, the ratio of the iodizing agent used to introduce one iodine atom to the substrate (for example, the compound represented by formula (X1)) is preferably 0.2 molar times or more and 10 molar times or less, more preferably 0.5 molar times or more and 5.0 molar times or less, and even more preferably 0.8 molar times or more and 2.0 molar times or less. Furthermore, the ratio of iodizing agent used to introduce two iodine atoms is preferably 0.4 molars or more and 20 molars or less, more preferably 1.0 molars or more and 10 molars or less, and even more preferably 1.5 molars or more and 4.0 molars or less.

[0064] -Solvent- A wide variety of solvents can be used in the iodine introduction step, including polar aprotic solvents and protic polar solvents. A single protic polar solvent or a single polar aprotic solvent can be used. Furthermore, mixtures of polar aprotic solvents, mixtures of protic polar solvents, mixtures of polar aprotic solvents and protic polar solvents, and mixtures of aprotic or protic solvents and nonpolar solvents can be used. Polar protic solvents or mixtures thereof are preferred, and a mixture of polar protic solvent and water is preferred from the viewpoint of suppressing side reactions. Note that the solvent is an active ingredient but not an essential ingredient.

[0065] Examples of polar aprotic solvents, though not limited to them, include ether-based solvents such as diethyl ether, tetrahydrofuran, dimethoxyethane, diglyme, and trigrime; ester-based solvents such as ethyl acetate and γ-butyrolactone; nitrile-based solvents such as acetonitrile; hydrocarbon-based solvents such as toluene and hexane; amide-based solvents such as N,N-dimethylformamide, 1-methyl-2-pyrrolidinone, N,N-dimethylacetamide, hexamethylphosphoramide, and hexamethylphosphite triamide; ketone-based solvents such as acetone and ethyl methyl ketone; chlorine-based solvents such as dichloromethane and chloroform; and dimethyl sulfoxide.

[0066] Examples of protic polar solvents, though not limited to them, include water, methanol, ethanol, propanol, butanol, and other alcoholic solvents, as well as di(propylene glycol) methyl ether, di(ethylene glycol) methyl ether, 2-butoxyethanol, ethylene glycol, 2-methoxyethanol, propylene glycol methyl ether, n-hexanol, and n-butanol.

[0067] The amount of solvent used can be appropriately set depending on the substrate used (for example, the compound represented by formula (X1)), the iodinating agent, the catalyst used if necessary, and the reaction conditions, and is not particularly limited, but generally, 0 to 10,000 parts by mass is suitable per 100 parts by mass of the reaction raw materials (total of substrate and iodinating agent), and from the viewpoint of yield, 100 to 2,000 parts by mass is preferred.

[0068] - Reaction Conditions, etc. - The reaction mixture is formed by adding the reaction raw materials (e.g., a compound represented by formula (X1), an iodizing agent), a catalyst and solvent as needed, to a reactor. The reaction can be carried out by selecting any known method such as batch, semi-batch, or continuous. The reaction temperature is not particularly limited, and its preferred range depends on the concentration of the reaction raw materials, the stability of the reaction product, the choice of catalyst, and the desired yield and purity. Generally, a reaction temperature of 0°C to 200°C is suitable, and from the viewpoint of yield, a reaction temperature of 0°C to 100°C is preferred, a reaction temperature of 0°C to 70°C is more preferred, and a reaction temperature of 0°C to 50°C is even more preferred.

[0069] The reaction pressure is not particularly limited, but its preferred range depends on the concentration of the reactants, the stability of the reaction products, the choice of catalyst, and the desired yield and purity. The pressure can be adjusted using an inert gas such as nitrogen, or by using an intake pump. Conventional pressure reactors, including shaking vessels, rocker vessels, and stirred autoclaves, can be used for high-pressure reactions, but are not limited to these. In this embodiment, the preferred reaction pressure is reduced pressure to atmospheric pressure, with reduced pressure being more preferable. The reaction time is not particularly limited, and its preferred range depends on the concentration of the reactants, the stability of the reaction products, the choice of catalyst, and the desired yield and purity. Typically, most reactions are carried out in less than 6 hours, with a reaction time of 15 to 600 minutes being common. In this embodiment, the reaction time is preferably 15 to 600 minutes, and more preferably 15 to 360 minutes.

[0070] The isolation and purification of the reaction products can be carried out after the completion of the reaction using conventionally known appropriate methods. For example, the reaction mixture is poured into ice water and extracted into a solvent such as ethyl acetate or diethyl ether. The product is then recovered by removing the solvent using evaporation under reduced pressure. The desired high-purity compound can then be isolated and purified using separation and purification methods well known in the art, such as filtration, concentration, distillation, extraction, crystallization, recrystallization, column chromatography, activated carbon, or combinations thereof.

[0071] (Protecting group introduction step) The protecting group introduction step is a step of introducing a protecting group to at least one hydroxyl group in the compound obtained in the iodine introduction step. In the protecting group introduction step, the compound represented by formula (X2) and the protecting group introduction agent are reacted in a solvent to convert the hydroxyl group of the compound represented by formula (X2), and a group in which an acid-degradable group is introduced to the oxygen atom of the hydroxyl group can be formed.

[0072] The protecting group introduction step may include: (Step 1) introducing a protecting group to all hydroxyl groups of the compound obtained in the iodine introduction step (for example, the compound represented by formula (X2)) before the methyleneization step; or (Step 2) introducing a protecting group to some of the hydroxyl groups of the compound represented by compound formula (X2) obtained in the iodine introduction step (first protecting group introduction step), and then, in the methyleneization step described later, after methyleneizing the compound obtained in the first protecting group introduction step, further introducing a protecting group to all of the hydroxyl groups of the compound obtained in the methyleneization step (second protecting group introduction step). Note that in Steps 1 and 2, "introducing a protecting group to all of the hydroxyl groups" or "introducing a protecting group to some of the hydroxyl groups" of the compound means introducing a protecting group to all or some of the hydroxyl groups in formula (X2). For this reason, in Step 1, it is not necessary to introduce a protecting group to all of the hydroxyl groups of "all of the compounds" obtained in the iodine introduction step. Furthermore, in the first protecting group introduction step of step 2, protecting groups may be introduced to all hydroxyl groups in "some of the compounds" obtained in the iodine introduction step, or protecting groups may not be introduced to all hydroxyl groups in "all of the compounds" in the second protecting group introduction step.

[0073] - Protecting Group Introducers - A wide variety of protecting group introducers that function under the reaction conditions of this embodiment can be used as protecting group introducers. Examples of protecting group introducers include compounds that can impart acid-degradable groups, preferably compounds that can impart acetal groups, such as acetal group introducers like 3,4-dihydro-2H-pyran, ethyl vinyl ether, and chloromethyl ethyl ether.

[0074] In the protecting group introduction step, the ratio of the protecting group introduction agent to the substrate (for example, the compound represented by formula (X2)) is not particularly limited, but is preferably 0.2 molar times or more and 50 molar times or less, more preferably 0.5 molar times or more and 20 molar times or less, and even more preferably 1.0 molar time or more and 10 molar times or less.

[0075] -Solvent- A wide variety of solvents can be used in the protecting group introduction step, including polar aprotic solvents and protic polar solvents. The solvent can be a single protic polar solvent or a single polar aprotic solvent. Furthermore, mixtures of polar aprotic solvents, mixtures of protic polar solvents, mixtures of polar aprotic solvents and protic polar solvents, and mixtures of aprotic or protic solvents and nonpolar solvents can be used, with polar aprotic solvents or mixtures thereof being preferred. Note that the solvent is an active ingredient but not an essential ingredient.

[0076] Examples of polar aprotic solvents, though not limited to them, include ether-based solvents such as diethyl ether, tetrahydrofuran, dimethoxyethane, diglyme, and trigrime; ester-based solvents such as ethyl acetate and γ-butyrolactone; nitrile-based solvents such as acetonitrile; hydrocarbon-based solvents such as toluene and hexane; amide-based solvents such as N,N-dimethylformamide, 1-methyl-2-pyrrolidinone, N,N-dimethylacetamide, hexamethylphosphoramide, and hexamethylphosphite triamide; ketone-based solvents such as acetone and ethyl methyl ketone; chlorine-based solvents such as dichloromethane and chloroform; and dimethyl sulfoxide.

[0077] Examples of protic polar solvents, though not limited to them, include water, methanol, ethanol, propanol, butanol, and other alcoholic solvents, as well as di(propylene glycol) methyl ether, di(ethylene glycol) methyl ether, 2-butoxyethanol, ethylene glycol, 2-methoxyethanol, propylene glycol methyl ether, n-hexanol, and n-butanol.

[0078] The amount of solvent used can be appropriately set depending on the substrate used (for example, the compound represented by formula (X2)), the protecting agent, the catalyst used if necessary, and the reaction conditions, and is not particularly limited, but generally, 0 to 10,000 parts by mass per 100 parts by mass of the total amount of substrate is suitable, and from the viewpoint of yield, 0 to 2,000 parts by mass is preferred.

[0079] - Reaction conditions, etc. - In the protecting group introduction step, when introducing a protecting group to a hydroxyl group, from the viewpoint of improving yield and scaling up, an inorganic base can be used to introduce the protecting group to the hydroxyl group. For example, an amide solvent and an inorganic base can be combined.

[0080] Furthermore, a protective compound (e.g., the compound represented by formula (X2)), a catalyst and solvent used as needed are added to the reactor to form a reaction mixture. The reaction can be carried out by selecting any known method, such as batch, semi-batch, or continuous. The reaction temperature is not particularly limited, and its preferred range depends on the concentration of the reaction raw materials (e.g., the compound represented by formula (X2), the protecting agent), the stability of the reaction product, the choice of catalyst, and the desired yield and purity. Generally, a temperature of 0°C to 200°C is suitable, and from the viewpoint of yield, a temperature of 10°C to 190°C is preferred, more preferably 25°C to 150°C, and even more preferably 50°C to 100°C.

[0081] The reaction pressure is not particularly limited, but its preferred range depends on the concentration of the reactants, the stability of the reaction products, the choice of catalyst, and the desired yield and purity. The pressure can be adjusted using an inert gas such as nitrogen, or by using an intake pump. Conventional pressure reactors, including shaking vessels, rocker vessels, and stirred autoclaves, can be used for high-pressure reactions, although they are not limited to high-pressure reactions. In this embodiment, the preferred reaction pressure is reduced pressure to atmospheric pressure, with reduced pressure being more preferable. The reaction time is not particularly limited, and its preferred range depends on the concentration of the reactants, the stability of the reaction products, the choice of catalyst, and the desired yield and purity. Typically, the reaction time is 15 minutes to 600 minutes.

[0082] The reaction product can be isolated and purified after the reaction is complete using conventionally known appropriate methods. For example, the reaction mixture is poured onto ice water and extracted into a solvent such as ethyl acetate or diethyl ether. The product is then recovered by removing the solvent using evaporation under reduced pressure. The desired high-purity monomer can then be isolated and purified using separation and purification methods well known in the art, such as filtration, concentration, distillation, extraction, crystallization, recrystallization, column chromatography, activated carbon, or combinations thereof.

[0083] (Methyleneization step) The methyleneization step is a step in which the compound obtained in the protecting group introduction step is methyleneized. Specifically, the methyleneization step is the methyleneization of the aldehyde moiety (for example, the -C(=O)R of formula (X2)). ２ ) to methylene (-C (=CH ２ ) R ２ This is a step to convert to a vinyl group. In the reaction of this step, a method can be used to convert the aldehyde moiety of a known aldehyde derivative to a vinyl group. Known methods include, for example, the Wittig reaction (e.g., the method described in Synthetic Communications; Vol. 22; nb4; 1992 p513, Synthesis; Vol. 49; nb. 23; 2017; p5217), which can be used as appropriate.

[0084] When forming an alkene by the Witting reaction, there are no limitations, but a phosphorus ylide is used to form the alkene from the carbonyl moiety containing an aldehyde or ketone. Phosphorus ylides that can be used in the methyleneization step include triphenylalkylphosphine bromides such as triphenylmethylphosphine bromide, which are capable of forming a stable phosphorus ylide. Alternatively, a phosphonium salt can be reacted with a base to form a phosphorus ylide in the reaction system and used in the above-mentioned reaction. Conventional known bases can be used, such as alkali metal salts of alkoxides, as appropriate.

[0085] The ratio of the phosphorus ylide to the substrate (for example, a compound represented by formula (X2) in which a protecting group is introduced to at least one hydroxyl group) is preferably, for example, 0.1 molar times or more and 10 molar times or less, more preferably 0.1 molar times or more and 5 molar times or less, and even more preferably 0.5 molar times or more and 2 molar times or less.

[0086] - Solvents - A wide variety of solvents can be used in the methyleneization step, including polar aprotic solvents and protic polar solvents. A single protic polar solvent or a single polar aprotic solvent can be used. Furthermore, mixtures of polar aprotic solvents, mixtures of protic polar solvents, mixtures of polar aprotic solvents and protic polar solvents, and mixtures of aprotic or protic solvents and nonpolar solvents can be used, with polar aprotic solvents or mixtures thereof being preferred. Examples of these solvents include those that can be used in the iodine introduction step and protecting group introduction step described above, such as THF (tetrahydrofuran).

[0087] The amount of solvent used can be appropriately set depending on the substrate used (for example, a compound represented by formula (X2) in which a protecting group is introduced to at least one hydroxyl group), the catalyst used if necessary, and the reaction conditions, and is not particularly limited, but generally, 0 to 10,000 parts by mass is suitable per 100 parts by mass of the total amount of substrate, and 100 to 2,000 parts by mass is preferred from the viewpoint of yield.

[0088] - Reaction Conditions, etc. - In the methyleneization process, there are no particular restrictions on reaction temperature and other conditions, and they vary depending on the concentration of the reaction raw materials, the stability of the reaction product, the choice of catalyst, and the desired yield and purity. Generally, a reaction temperature of 0°C to 200°C is suitable, and from the viewpoint of yield, a temperature of 10°C to 190°C is preferred, a temperature of 25°C to 150°C is more preferred, and a temperature of 50°C to 100°C is even more preferred. In this embodiment, the preferred reaction pressure is reduced pressure to atmospheric pressure, and reduced pressure is more preferred. The reaction time is not particularly limited, and its preferred range varies depending on the concentration of the reaction raw materials, the stability of the reaction product, the choice of catalyst, and the desired yield and purity.

[0089] 《Method for Producing the Compound of Formula (0C)》 An alternative method for producing the compound in this embodiment will be explained using the method for producing the compound represented by formula (0C) as an example. The compound represented by formula (0C) described above can be produced by various methods, but from the viewpoint of raw material availability and yield, it is preferable to produce it by a method that includes the following steps. The compound represented by formula (0C) can be synthesized by a method that includes: an iodine introduction step of introducing iodine into the compound represented by the following formula (X1) to obtain the compound represented by the following formula (X2); a protecting group introduction step of introducing a protecting group to at least one hydroxyl group in the compound represented by formula (X2) obtained in the iodine introduction step to obtain the compound represented by the following formula (Y3); a reduction step of reducing the compound (Y3) obtained in the protecting group introduction step to obtain the compound represented by the following formula (Y4); and a (meth)acrylate formation step of introducing a (meth)acryloyl group into the compound of formula (Y4) obtained in the reduction step. The explanation of substituents in each formula, and the iodine introduction step and protecting group introduction step are the same as described above and will be omitted. (In the formula, O is an oxygen atom, I is an iodine atom, and R １ R is a hydrogen atom or a methyl group. ２ Each is independently a hydrogen atom or an acid-degradable group, and R ２ At least one of the groups is an acid-degradable group, n is an integer between 1 and 2, m is an integer between 2 and 4, n + m is between 3 and 5, and m > n.

[0090] (Reduction step) The reduction step is a step in which the compound (Y3) obtained in the protecting group introduction step is reduced to obtain the compound represented by the following formula (Y4). Known methods can be appropriately employed in the reduction step, and reducing agents can be used.

[0091] -Reducing agent- The reducing agent is not particularly limited, but it is preferable to use, for example, sodium borohydride, sodium hydride, lithium triethylborohydride, lithium borohydride, sodium cyanoborohydride, etc. In the reduction step, the ratio of the reducing agent to the substrate (for example, the compound represented by formula (Y3)) is preferably 0.25 molar times or more and 4.0 molar times or less, more preferably 0.3 molar times or more and 2.0 molar times or less, and even more preferably 0.5 molar times or more and 1.0 molar time or less.

[0092] -Solvent- Protic polar solvents can be used as solvents in the reduction step. In addition to a single protic polar solvent, a mixture of protic polar solvents can be used. From the viewpoint of the solubility of the secondary reducing agent, a mixture of a polar protic solvent and water is preferred. Note that the solvent is an active ingredient but not an essential ingredient.

[0093] Examples of protic polar solvents, though not limited to them, include water, methanol, ethanol, propanol, butanol, and other alcoholic solvents, as well as di(propylene glycol) methyl ether, di(ethylene glycol) methyl ether, 2-butoxyethanol, ethylene glycol, 2-methoxyethanol, propylene glycol methyl ether, n-hexanol, and n-butanol.

[0094] The amount of solvent used can be appropriately set depending on the substrate used (for example, the compound represented by formula (Y3)), the reducing agent, the catalyst used if necessary, and the reaction conditions, and is not particularly limited, but generally, 0 to 10,000 parts by mass of solvent per 100 parts by mass of reaction raw materials (total of substrate and reducing agent) is suitable, and from the viewpoint of yield, 100 to 2,000 parts by mass is preferred.

[0095] - Reaction Conditions, etc. - The reaction mixture is formed by adding the reaction raw materials (e.g., a compound represented by formula (Y3), a reducing agent), a catalyst and solvent as needed, to a reactor. The reaction can be carried out by selecting any known method such as batch, semi-batch, or continuous reactions as appropriate. The reaction temperature is not particularly limited, and its preferred range depends on the concentration of the reaction raw materials, the stability of the reaction product, the choice of catalyst, and the desired yield and purity. Generally, a reaction temperature of 30°C to -20°C is suitable, and from the viewpoint of yield, a reaction temperature of 20°C to -10°C is preferred, and a reaction temperature of 10°C to 0°C is more preferred.

[0096] The reaction pressure is not particularly limited, but its preferred range depends on the concentration of the reactants, the stability of the reaction products, the choice of catalyst, and the desired yield and purity. The pressure can be adjusted using an inert gas such as nitrogen, or by using an intake pump. Conventional pressure reactors, including shaking vessels, rocker vessels, and stirred autoclaves, can be used for high-pressure reactions, but are not limited to these. In this embodiment, the preferred reaction pressure is reduced pressure to atmospheric pressure, with reduced pressure being more preferable. The reaction time is not particularly limited, and its preferred range depends on the concentration of the reactants, the stability of the reaction products, the choice of catalyst, and the desired yield and purity. Typically, most reactions are carried out in less than two hours, with a reaction time of 10 to 120 minutes being common. In this embodiment, a reaction time of 10 to 60 minutes is preferred.

[0097] The isolation and purification of the reaction products can be carried out after the completion of the reaction using conventionally known appropriate methods. For example, the reaction mixture is poured into ice water and extracted into a solvent such as ethyl acetate or diethyl ether. The product is then recovered by removing the solvent using evaporation under reduced pressure. The desired high-purity compound can then be isolated and purified using separation and purification methods well known in the art, such as filtration, concentration, distillation, extraction, crystallization, recrystallization, column chromatography, activated carbon, or combinations thereof.

[0098] The (meth)acrylate step is a step in which a (meth)acryloyl group is introduced into the compound (Y4) obtained in the reduction step to obtain a compound represented by the following formula (Y4). The (meth)acrylate step can be carried out using any known method, and a (meth)acryloyl group introducing agent can be used.

[0099] - (meth)acryloyl group introducing agent - The (meth)acryloyl group introducing agent is not particularly limited, but it is preferable to use, for example, methacrylic anhydride, methacrylate chloride, etc. In the (meth)acrylate step, the ratio of the (meth)acryloyl group introducing agent to the substrate (for example, the compound represented by formula (Y4)) is preferably 0.25 molar times or more and 8 molar times or less, more preferably 0.5 molar times or more and 4 molar times or less, and even more preferably 1 molar time or more and 2 molar times or less.

[0100] -Solvent- Suitable solvents for use in the (meth)acrylate step include polar aprotic solvents. In addition to a single polar aprotic solvent, a mixture of polar aprotic solvents can be used. A mixture of polar aprotic solvents is preferred from the viewpoint of suppressing side reactions. Note that while the solvent is an active ingredient, it is not an essential component.

[0101] Examples of polar aprotic solvents, though not limited to them, include ether-based solvents such as diethyl ether, tetrahydrofuran, dimethoxyethane, diglyme, and trigrime; ester-based solvents such as ethyl acetate and γ-butyrolactone; nitrile-based solvents such as acetonitrile; hydrocarbon-based solvents such as toluene and hexane; amide-based solvents such as N,N-dimethylformamide, 1-methyl-2-pyrrolidinone, N,N-dimethylacetamide, hexamethylphosphoramide, and hexamethylphosphite triamide; ketone-based solvents such as acetone and ethyl methyl ketone; chlorine-based solvents such as dichloromethane and chloroform; and dimethyl sulfoxide.

[0102] The amount of solvent used can be appropriately set depending on the substrate used (e.g., the compound represented by formula (Y4)), the (meth)acryloyl group introducer, the catalyst used as needed (e.g., DMAP (N,N-dimethyl-4-aminopyridine), etc.), and the reaction conditions, and is not particularly limited, but generally, 0 to 10,000 parts by mass of solvent per 100 parts by mass of reaction raw materials (total of substrate and (meth)acryloyl group introducer) is suitable, and from the viewpoint of yield, 100 to 2,000 parts by mass is preferred.

[0103] - Reaction Conditions, etc. - The reaction mixture is formed by adding the reaction raw materials (e.g., a compound represented by formula (Y4), a (meth)acryloyl group introducer), a catalyst and solvent as needed, to a reactor. The reaction can be carried out by selecting any known method such as batch, semi-batch, or continuous. The reaction temperature is not particularly limited, and its preferred range depends on the concentration of the reaction raw materials, the stability of the reaction product, the choice of catalyst, and the desired yield and purity. Generally, a reaction temperature of -20°C to 30°C is suitable, and from the viewpoint of yield, a reaction temperature of -10°C to 20°C is preferred, and a reaction temperature of 0°C to 10°C is more preferred.

[0104] The reaction pressure is not particularly limited, but its preferred range depends on the concentration of the reactants, the stability of the reaction products, the choice of catalyst, and the desired yield and purity. The pressure can be adjusted using an inert gas such as nitrogen, or by using an intake pump. Conventional pressure reactors, including shaking vessels, rocker vessels, and stirred autoclaves, can be used for high-pressure reactions, but are not limited to these. In this embodiment, the preferred reaction pressure is reduced pressure to atmospheric pressure, with reduced pressure being more preferable. The reaction time is not particularly limited, and its preferred range depends on the concentration of the reactants, the stability of the reaction products, the choice of catalyst, and the desired yield and purity. Typically, most reactions are carried out in less than 3 hours, with a reaction time of 10 to 120 minutes being common. In this embodiment, a reaction time of 10 to 60 minutes is preferred.

[0105] The isolation and purification of the reaction products can be carried out after the completion of the reaction using conventionally known appropriate methods. For example, the reaction mixture is poured into ice water and extracted into a solvent such as ethyl acetate or diethyl ether. The product is then recovered by removing the solvent using evaporation under reduced pressure. The desired high-purity compound can then be isolated and purified using separation and purification methods well known in the art, such as filtration, concentration, distillation, extraction, crystallization, recrystallization, column chromatography, activated carbon, or combinations thereof.

[0106] <Uses of the Compounds of This Embodiment> The compounds of this embodiment can be added to film-forming compositions, either as is or as polymers as described later, to increase sensitivity to exposure light sources. For example, they are preferably used in photoresists.

[0107] [Composition] The composition of this embodiment comprises at least one of the compounds of this embodiment described above (the first compound) and a solvent. The composition of this embodiment may also contain the compound of this embodiment, a compound represented by the following formula (2) (hereinafter sometimes referred to as the "second compound"), and a solvent. As the solvent in the composition of this embodiment, in addition to the solvent used in the method for producing the compound of formula (1) described above, a solvent used in the method for producing polymer (A) described later may be used.

[0108] When the first compound and the second compound are used in combination, the combination of the first compound and the second compound is R ２ The corresponding group (acid-degradable group) and R ４ The group corresponding to this (a group to which two acid-degradable groups are bonded) is a combination of compounds in which the other groups are different. When the second compound is used in combination with the compound of this embodiment, the storage stability of the compound of this embodiment can be improved. The improvement in "storage stability" can be evaluated, for example, by comparing the purity of the compound of this embodiment (e.g., LC purity) before and after the passage of time.

[0109] In this respect, the second compound is R ２ For a compound represented by formula (0) (the first compound) in which the number of oxygen atoms is "N (where N is an integer greater than or equal to 1)", the compound represented by formula (2) and R４ Compounds having "(N+1) or more" oxygen atoms are preferred. An example of a combination of the first compound and the second compound is, for example, R ２ A compound represented by formula (0) where the number of oxygen atoms inside is "N (for example, N=1)" (the first compound), and R ４ One example is a combination of second compounds in which the number of oxygen atoms is "N+1 or greater (for example, N=2)".

[0110] (In the formula, R １ , X １ O and I are the same as in equation (0), and R ４ Each of these is independently a hydrogen atom, an acid-degradable group, or a group to which two acid-degradable groups are bonded, R ４ At least one of the groups is a group to which the two acid-degradable groups are bonded, n is an integer between 1 and 2, m is an integer between 2 and 3, n + m is between 3 and 5, and m > n.

[0111] In formula (2), the explanation of the same group as in formula (1) is omitted. In formula (2), it is preferable that n=1 and m=2, and that I is in the meta position and has two ORs. ４ ortho and para positions respectively, or I is in the para position and two ORs ４ It is even more preferable that each of these is bonded to the meta position.

[0112] In equation (2), R ４ Each of these is independently a hydrogen atom, an acid-degradable group, or a group to which two acid-degradable groups are bonded, R ４ At least one of them is a group to which two acid-degradable groups are bonded. For example, R ４ When there are two (i.e., m=2), all R ４ This could be a "group in which two acid-degradable groups are bonded"; or one of the R ４ is a "group in which two acid-degradable groups are bonded" and the other R ４ It may also be an "acid-degradable group". Also, for example, R ４ When there are three (i.e., m=3), all R ４ This may also be a "group to which two acid-degradable groups are bonded"; two R４ It is a "group in which two acid-degradable groups are bonded" and has one R ４ It may be an "acid-degradable group"; or one R ４ It is a "group in which two acid-degradable groups are bonded" and also has two R ４ It may also be an "acid-degradable group".

[0113] Here, "a group with two acid-degradable groups bonded together" means a group in which at least a portion of an acid-degradable group is bonded to an acid-degradable group. Examples of such groups include a group in which at least a portion of a "compound that can confer an acetal group by reacting with a hydroxyl group" is bonded to an acetal group. Examples of acetal groups in such groups include the tetrahydropyranyl group, methoxymethyl group, ethoxymethyl group, and ethoxyethyl group mentioned above, and examples of "compounds that can confer an acetal group by reacting with a hydroxyl group" include the acetal group introducing agents such as 3,4-dihydro-2H-pyran, ethyl vinyl ether, and chloromethyl ethyl ether mentioned above. Specifically, "*-O-R ４ The following are specific examples of "(where * indicates a bond with the benzene ring)".

[0114]

[0115] Furthermore, examples of the second compound include compounds represented by the following formulas (2A'), (2B'), (2A), or (2B), with the compound represented by formula (2A) or (2B) being preferred. For this reason, the composition of this embodiment may contain at least one of the compounds of this embodiment (the first compound) and at least one of the compounds represented by the following formulas (2A'), (2B'), (2A), and (2B), and it is preferable to contain at least one of the first compound and at least one of the compound represented by formula (2A) and the compound represented by formula (2B). (In the formula, R １O and I are the same as in formula (0), RA is independently an alkylene group having 1 to 4 carbon atoms, l is 0 to 3, m+l is 2 or more and 4 or less, RA1 is independently an alkyl group having 2 to 4 carbon atoms which may have a hydrogen atom or an ether group, at least one of RA1 is an alkyl group having 2 to 4 carbon atoms which may have the ether group, n is an integer from 1 to 2, m is an integer from 2 to 3, n+m is 3 or more and 5 or less, and m > n. (In the formula, R １ O and I are the same as in formula (0), RA is independently an alkylene group having 1 to 4 carbon atoms, RA1 is independently an alkyl group having 2 to 4 carbon atoms which may have a hydrogen atom or an ether group, at least one of RA1 is an alkyl group having 2 to 4 carbon atoms which may have an ether group, n is an integer from 1 to 2, m is an integer from 2 to 3, n + m is between 3 and 5, and m > n. (In the formula, R １ O and I are the same as in formula (0), l is 0 to 3, m+l is 2 to 4, RB is each independently an alkylene group having 1 to 6 carbon atoms, RC is each independently a hydrogen atom or a group that forms a ring structure by bonding with the alkyl group of RB, RB1 is each independently a hydrogen atom or an alkyl group having 2 to 6 carbon atoms which may have an ether group, at least one of RB1 is an alkyl group having 2 to 6 carbon atoms which may have the ether group, n is an integer from 1 to 2, m is an integer from 2 to 3, n+m is 3 to 5, and m > n. (In the formula, R １, O and I are the same as in formula (0), RB is independently an alkylene group having 1 to 6 carbon atoms, RC is independently a hydrogen atom or a group that forms a ring structure by bonding with the alkyl group of RB, RB1 is independently a hydrogen atom or an alkyl group having 2 to 6 carbon atoms which may have an ether group, at least one of RB1 is an alkyl group having 2 to 6 carbon atoms which may have the ether group, n is an integer from 1 to 2, m is an integer from 2 to 3, n + m is 3 or more and 5 or less, and m > n.

[0116] In formulas (2A'), (2B'), (2A), or (2B), the description of groups similar to those in formula (1) is omitted. In formula (2A) or (2B), it is preferable that n = 1 and m = 2, and it is even more preferable that I is in the meta position and a group having a hydroxyl group or two RA or RB groups is bonded to the ortho and para positions, respectively, or that I is in the para position and a group having a hydroxyl group or two RA or RB groups is bonded to the meta position, respectively.

[0117] In formula (2A), RA is an alkylene group having 1 to 4 carbon atoms. In formula (2A), the alkylene group represented by RA is obtained by converting an alkyl group exemplified by the C1 to C4 alkyl groups shown in formula (A) to a divalent alkylene group. In formula (2A), RA1 is each independently a C2 to C4 alkyl group which may have a hydrogen atom or an ether group, and at least one of RA1 is the C2 to C4 alkyl group which may have an ether group. Examples of RA1 include alkyl groups such as ethyl groups and alkoxy groups such as ethoxy groups. The group represented by "-RA-RA1" can also be expressed as "an alkyl group having 3 to 8 carbon atoms which may have an ether bond". Examples of C3 to C8 alkyl groups which may have an ether bond include ethoxymethyl group, ethoxyethyl group, ethoxypropyl group, and ethoxybutyl group.

[0118] In formula (2A') and formula (2A), “*-O-CH(-CH ２Specific examples of the group represented by "-RA1)-O-RA-RA1 (where * indicates a bond with a benzene ring)" are listed below.

[0119] In formula (2B), RB is an alkylene group having 1 to 6 carbon atoms. The alkylene group represented by RB in formula (2B) is obtained by converting the alkyl group exemplified by the C1 to C6 alkyl group shown in formula (B) to a divalent alkylene group. In the formula, RC is a group that independently bonds with a hydrogen atom or the alkyl group of RB to form a ring structure, and the ring structure formed by the bonding of the alkyl group of RB and RC is the same as that of formula (B) described above.

[0120] In formulas (2B') and (2B), RB1 is independently a C2-C6 alkyl group which may have a hydrogen atom or an ether group, and at least one of RB1 is a C2-C6 alkyl group which may have an ether group. Examples of RB1 include alkoxy groups such as ethoxy groups and tetrahydropyranyl groups. The group represented by "-RB-RB1" can also be expressed as a C3-C12 alkyl group which may have an ether bond.

[0121] Specific examples of the group represented by “*-O-CH(-RC)-O-RB-RB1 (where * indicates a bond with a benzene ring)” in formulas (2B') and (2B) are as follows:

[0122] In formulas (2A'), (2B'), (2A), and (2B), for example, when m=2, all RA1 (or RB1) may be "alkyl groups which may have an ether group"; or one RA1 (or RB1) may be "alkyl groups which may have an ether group" and the other RA1 (or RB1) may be a hydrogen atom. Also, for example, when m=3, all RA1 (or RB1) may be "alkyl groups which may have an ether group"; two RA1 (or RB1) may be "alkyl groups which may have an ether group" and one RA1 (or RB) may be a hydrogen atom; or one RA1 (or RB1) may be "alkyl groups which may have an ether group" and two RA1 (or RB1) may be hydrogen atoms.

[0123] The compound represented by formula (2A) is preferably, for example, the compound represented by formula (2A1) or formula (2A2) below. Furthermore, the compound represented by formula (2B) is preferably the compound represented by formula (2B1) or formula (2B2) below.

[0124] Other compounds that can be represented by formula (2A') or formula (2B') include the following: (In the formulas, R1, O, I, RB, RC, and RB1 are the same as in formula (A') or formula (B').

[0125] In the composition of this embodiment, the content of the first compound is preferably 90% by mass or more, more preferably 95% by mass or more, and even more preferably 99% by mass or more.

[0126] In other preferred forms of the composition of this embodiment, the second compound (the compound represented by formula (2), or the compounds represented by formulas (2A) and (2B)) is preferably included in an amount of 1 ppm to 10% by mass, more preferably 1 ppm to 5% by mass, even more preferably 20 ppm to 2% by mass, and particularly preferably 50 ppm to 1% by mass, relative to the total amount of the first compound (the compound of this embodiment).

[0127] In the composition of this embodiment, the content of impurities containing K (potassium) is preferably 1 ppm by mass or less, more preferably 0.5 ppm by mass or less, even more preferably 0.1 ppm by mass or less, and even more preferably 0.005 ppm by mass or less, relative to the total amount of the first compound and the second compound, in terms of elemental basis.

[0128] In the composition of this embodiment, the content of one or more elemental impurities selected from the group consisting of Fe (iron), Ni (nickel), Mn (manganese), W (tagsten), Al (aluminum), Li (lithium), Na (sodium), K (silicon), Si (silicon), Sn (tin), Sb (antimony), Zn (zinc), Co (cobalt), Cr (chromium), Zr (zirconium), Mo (molybdenum), and Pb (lead) (preferably one or more elemental impurities selected from the group consisting of Mn and Al) is, in terms of elemental equivalent, preferably 1 ppm by mass or less, more preferably 0.5 ppm by mass or less, and even more preferably 0.1 ppm by mass or less, relative to the total amount of the first compound (or the total amount of the first and second compounds), from the viewpoint of suppressing pattern defects.

[0129] The content of K, Mn, Al, etc., can be measured by inorganic element analysis (IPC-AES / IPC-MS). An example of an inorganic element analyzer is the "AG8900" manufactured by Agilent Technologies, Inc.

[0130] In the composition of this embodiment, the content of the phosphorus-containing compound is preferably 10 ppm by mass or less, more preferably 8 ppm by mass or less, and even more preferably 5 ppm by mass or less, relative to the total amount of the first compound (or the total amount of the first and second compounds), from the viewpoint of pattern shape.

[0131] In the composition of this embodiment, the maleic acid content is preferably 10 ppm by mass or less, more preferably 8 ppm by mass or less, and even more preferably 5 ppm by mass or less, relative to the total amount of the first compound (or the total amount of the first and second compounds), from the viewpoint of pattern shape. The phosphorus-containing compound and maleic acid content can be calculated from the area fraction of the GC chart and the peak intensity ratio of the target peak to the reference peak by gas chromatography-mass spectrometry (GC-MS).

[0132] In the composition of this embodiment, the peroxide content is preferably 10 ppm by mass or less, more preferably 1 ppm by mass or less, and even more preferably 0.1 ppm by mass or less, relative to the total amount of the first compound (or the total amount of the first and second compounds), from the viewpoint of reactivity.

[0133] The peroxide content can be quantified by the ammonium ferrothiocyanate method (AFTA method), in which trichloroacetic acid is added to the sample, followed by the addition of ammonium iron(II) sulfate and potassium thiocyanate. A calibration curve for known peroxides is then determined using standard substances, and the absorbance at a wavelength of 480 μm is measured.

[0134] The water content in the composition of this embodiment is preferably 100,000 ppm by mass or less, more preferably 20,000 ppm by mass or less, even more preferably 1,000 ppm by mass or less, even more preferably 500 ppm by mass or less, and even more preferably 100 ppm by mass or less, relative to the total amount of the first compound and the second compound. The water content can be measured by the Karl Fischer method (Karl Fischer moisture analyzer).

[0135] [(Co)polymer] The polymer (A) of this embodiment contains constituent units derived from the first compound (compound of this embodiment) described above. When a polymer is synthesized using the compound of this embodiment, the content of constituent units derived from the first compound in polymer (A) can be increased.

[0136] Furthermore, as described above, polymer (A) of this embodiment can be used as polymer (B) obtained by further decomposing the acid-degradable groups with acid and converting them to hydroxyl groups. Polymer (B), for example, when used in resist applications, contains "iodine that absorbs EUV light during exposure" in the polymer, and more preferably H, which is essential in chemically amplified resists. ＋ Because the hydroxyl groups that serve as the source of hydrogen are located adjacent to iodine atoms, where they have high EUV absorption capacity, the two hydrophilic hydroxyl groups can compensate for the decrease in solubility of the resist polymer caused by iodine content, thus enabling high functionality in EUV patterning. Specifically, H generated near the iodine atom ＋ As H propagates / diffuses through polymer (B), it catalytically decomposes a large number of acid dissociation units, thereby increasing the resolution during development. ＋ H ＋ Highly polar protic functional groups with high affinity are useful, and a typical example of this is polymer (B) containing many hydroxyl groups, H ＋ It has high propagation ability and can achieve high resolution.

[0137] Therefore, polymer (B) of this embodiment can increase sensitivity to exposure light sources when incorporated into a film-forming composition. In particular, even when extreme ultraviolet light is used as the exposure light source, it exhibits sufficient sensitivity and can successfully form fine line patterns with narrow line widths.

[0138] The (co)polymer of this embodiment can be rephrased as comprising a constituent unit corresponding to the compound of this embodiment (the first compound) (hereinafter sometimes referred to as "constituent unit (A)"), and / or a constituent unit in which at least a portion of the groups containing acid-degradable groups in the constituent unit corresponding to the compound of this embodiment are converted to hydroxyl groups (hereinafter sometimes referred to as "constituent unit (B)").

[0139] The constituent unit (A) is the methylene group (vinyl group) portion in formula (0) and each formula representing its sub-concept, where "-C=CH" is the methylene group (vinyl group) portion in the formula. ２ (R １ This refers to a constituent unit formed when the double bond of the group represented by ") is cleaved. An example of the constituent unit (A) is given by the following formula (MA).

[0140] (In the formula, A, １ O, I, R １ , R ２ n and m are the same as in equation (0), and * indicates a connection site with an adjacent constituent unit.

[0141] Furthermore, in constituent unit (B), in constituent unit (A), -OR in formula (0) ２ (R ２ : Acid-degradable group) (In each formula showing a sub-concept of formula (0), -OR ２ (R ２ This refers to a constituent unit in which a group equivalent to an acid-degradable group is converted to a hydroxyl group. An example of constituent unit (B) is given by the following formula (MB).

[0142] (In the formula, A, １ O, I, R １ n is the same as in equation (0), and R ２Ａ Each of these is an independently acid-degradable group, o is an integer of 1 or more, m1 is 0 or an integer of 1 or more, m1 + o > n, and * is a bonding site with an adjacent constituent unit.

[0143] The amount of constituent unit (A) in polymer (A) (molar ratio d in the specific examples described below) is preferably 5 mol% or more, more preferably 8 mol% or more, even more preferably 10 mol% or more, and particularly preferably 17 mol% or more, relative to the total amount of monomer components of polymer (A). Similarly, the amount of constituent unit (B) in polymer (B) (molar ratio d in the specific examples described below) is preferably 5 mol% or more, more preferably 8 mol% or more, even more preferably 10 mol% or more, and particularly preferably 17 mol% or more, relative to the total amount of monomer components of polymer (B). Furthermore, the amount of constituent unit (A) in polymer (A) is preferably 100 mol% or less, more preferably 80 mol% or less, even more preferably 70 mol% or less, and particularly preferably 30 mol% or less, relative to the total amount of monomer components of polymer (A). Furthermore, the amount of constituent units (B) in polymer (B) is preferably 100 mol% or less, more preferably 80 mol% or less, even more preferably 70 mol% or less, and particularly preferably 30 mol% or less, relative to the total amount of monomer components of polymer (B).

[0144] Specific examples of constituent units (A) and (B) include constituent units corresponding to the specific examples of compounds of this embodiment described above.

[0145] (Other monomers) Other monomers copolymerized with the first compound preferably include polymerization units that have an aromatic compound having an unsaturated double bond as a substituent and a functional group whose solubility in an alkaline developer is improved by the action of an acid or a base.

[0146] Other monomers include, but are not limited to, those described in International Publication WO2016 / 125782, International Publication WO2015 / 115613, Japanese Patent Publication No. 2015 / 117305, International Publication WO2014 / 175275, Japanese Patent Publication No. 2012 / 162498, those described in paragraphs 0015 to 0131 of Japanese Patent Publication No. 2015-161823, those described in paragraphs 0050 to 0059 of Japanese Patent No. 7044011, those described in paragraphs 0096 to 0125 of Japanese Patent Publication No. 2022-123839, or compounds represented by the following formula (C1) or formula (C2). Among these, compounds represented by the following formula (C1) or formula (C2) are preferred.

[0147] In the lithography process, the quality of the pattern shape after exposure and development, particularly in terms of suppressing roughness and pattern collapse, is considered to be the dissolution rate R of the resin in the alkaline developer, which forms the pattern protrusions during alkaline development in the unexposed areas during exposure. ｍｉｎ The dissolution rate R of the resin in the alkaline developer at the exposure point during exposure, which forms a pattern recess during alkaline development. ｍａｘ It is preferable that the difference is three orders of magnitude or larger, that the difference in dissolution rate with and without the protecting group is large, and that the rate of removal of the protecting group during baking (PEB) and development after exposure is large. From these viewpoints, the other monomer copolymerized with the first compound in polymer (A) may have a structural unit represented by the following formula (C1).

[0148] In formula (C1), R Ｃ１１ R is a hydrogen atom or a methyl group. Ｃ１２ R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Ｃ１３ R Ｃ１３ Together with the carbon atom to which it is bonded, it forms a cycloalkyl group or heterocycloalkyl group having 4 to 20 carbon atoms, and * indicates a bonding site with an adjacent structural unit.

[0149] R Ｃ１２ R is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Ｃ１３ Preferably, R Ｃ１３Together with the carbon atom to which it is bonded, it forms a cycloalkyl group or heterocycloalkyl group having 4 to 10 carbon atoms. Ｃ１３ The cycloalkyl group or heterocycloalkyl group may have substituents (e.g., an oxo group).

[0150] As a constituent unit represented by formula (C1), preferred examples include constituent units corresponding to compounds having a lactone skeleton. Examples of constituent units corresponding to compounds having a lactone skeleton are as follows: (In the formula, R Ｃ１１ R is a hydrogen atom or a methyl group. Ｃ１２１ (where C1 is an alkyl group having 1 to 4 carbon atoms, C1 is an integer from 0 to 2, and * indicates a bonding site with an adjacent structural unit.)

[0151] The amount of the constituent unit represented by formula (C1) (molar ratio b in the specific examples described below) is preferably 5 mol% or more, and more preferably 10 mol% or more, relative to the total amount of monomer components of polymer (A) or polymer (B). Furthermore, the amount of the constituent unit represented by formula (C1) is preferably 50 mol% or less, and more preferably 20 mol% or less, relative to the total amount of monomer components of polymer (A) or polymer (B).

[0152] In polymer (A), other monomers copolymerized with the first compound may have constituent units represented by the following formula (C2) from the viewpoint of the quality of the pattern shape after exposure and development in the lithography process, particularly roughness and suppression of pattern collapse.

[0153]

[0154] In formula (C2), R Ｃ２１ R is a hydrogen atom or a methyl group. Ｃ２２ and R Ｃ２３ Each of these is an alkyl group having 1 to 4 carbon atoms, and R Ｃ２４ R is an alkyl group having 1 to 4 carbon atoms or a cycloalkyl group having 5 to 20 carbon atoms. Ｃ２２ , R Ｃ２３ , and R Ｃ２４Two or three of these may, together with the carbon atoms to which they are bonded, form an alicyclic structure with 3 to 20 carbon atoms, and * indicates a bonding site with an adjacent structural unit.

[0155] R Ｃ２２ Preferably, R is an alkyl group having 1 to 3 carbon atoms. Ｃ２４ R is a cycloalkyl group having 5 to 10 carbon atoms. Ｃ２２ , R Ｃ２３ , and R Ｃ２４ The alicyclic structure formed by may include multiple rings, such as adamantyl groups. Furthermore, the alicyclic structure may have substituents (e.g., hydroxyl groups, alkyl groups).

[0156] As a constituent unit represented by formula (C2), preferred examples include constituent units corresponding to compounds having an adamantane skeleton. Examples of constituent units corresponding to compounds having an adamantane skeleton are as follows: (In the formula, R Ｃ２１ R is a hydrogen atom or a methyl group. Ｃ２１１ (where c2 is a hydroxyl group, an alkyl group having 1 to 4 carbon atoms, or a cycloalkyl group having 5 to 20 carbon atoms, c2 is an integer from 0 to 9, and * indicates a bonding site with an adjacent structural unit.)

[0157] The total amount of the constituent units represented by formula (C2) is preferably 5 mol% or more, more preferably 10 mol% or more, and even more preferably 20 mol% or more, relative to the total amount of monomer components of polymer (A) or polymer (B). Furthermore, the amount of the constituent units represented by formula (C2) is preferably 80 mol% or less, more preferably 70 mol% or less, and even more preferably 65 mol% or less, relative to the total amount of monomer components of polymer (A).

[0158] Specifically, when the constituent unit represented by formula (C22) does not have a hydroxyl group, its amount (molar ratio a in the specific example described below) is preferably 5 mol% or more, more preferably 20 mol% or more, and even more preferably 45 mol% or more, relative to the total amount of monomer components of polymer (A) or polymer (B). Furthermore, the amount of the constituent unit represented by formula (C2) that does not have a hydroxyl group is preferably 80 mol% or less, more preferably 60 mol% or less, and even more preferably 55 mol% or less, relative to the total amount of monomer components of polymer (A).

[0159] When the constituent unit represented by formula (C22) has a hydroxyl group, its amount (molar ratio c in the specific examples described below) is preferably 5 mol% or more, more preferably 10 mol% or more, relative to the total amount of monomer components of polymer (A) or polymer (B). Furthermore, the amount of the constituent unit represented by formula (C2) having a hydroxyl group is preferably 70 mol% or less, more preferably 30 mol% or less, and even more preferably 20 mol% or less, relative to the total amount of monomer components of polymer (A).

[0160] The monomer raw materials for the constituent unit represented by formula (C2) are not limited to, but include, for example, 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, 2-hydroxy-2-(meth)acryloyloxyadamantane, 1-hydroxy-1-(meth)acryloyloxycyclopentane, and 1-methyl-1-(meth)acryloyloxy Examples include cyclohexane, 1-ethyl-1-(meth)acryloyloxycyclohexane, 1-hydroxy-1-(meth)acryloyloxycyclohexane, 1-methyl-1-(meth)acryloyloxycycloheptane, 1-ethyl-1-(meth)acryloyloxycycloheptane, 1-hydroxy-1-(meth)acryloyloxycycloheptane, 1-methyl-1-(meth)acryloyloxycyclooctane, 1-ethyl-1-(meth)acryloyloxycyclooctane, 1-hydroxy-1-(meth)acryloyloxycyclooctane, 2-ethyl-2-(meth)acryloyloxydecahydro-1,4:5,8-dimethanonaphthalene, and 2-ethyl-2-(meth)acryloyloxynorbornane. Commercially available monomers can be used for these.

[0161] For example, a (co)polymer of this embodiment that includes other monomers is a (co)polymer that further includes a structural unit corresponding to a compound having an adamantane skeleton and / or a structural unit corresponding to a compound having a lactone skeleton. Examples of such (co)polymers include the following:

[0162] (In the formula, a, b, c, and d represent the molar ratios of their respective constituent units, and the rest is as described above.)

[0163] (Method for producing polymer (A)) Next, a method for producing polymer (A) will be described. The polymerization reaction is carried out by dissolving the monomers that will be the constituent units in a solvent, adding a polymerization initiator, and heating or cooling. The reaction conditions can be arbitrarily set by the type of polymerization initiator, the method of initiation such as heat or light, temperature, pressure, concentration, solvent, additives, etc. Examples of polymerization initiators include radical polymerization initiators such as azoisobutyronitrile and peroxides, and anionic polymerization initiators such as alkyllithium and Grignard reagents.

[0164] As the solvent used in the polymerization reaction, commercially available products that are generally available can be used. For example, various solvents such as alcohol-based solvents, ether-based solvents, hydrocarbon-based solvents, and halogen-based solvents can be used as appropriate, as long as they do not inhibit the reaction. Specific examples of these solvents are those described in the method for producing the compound of formula (1) above. Multiple solvents can also be used in mixture form, as long as they do not inhibit the reaction.

[0165] The polymer (A) obtained by the polymerization reaction can be purified by known methods. Specifically, this can be done by a combination of ultrafiltration, crystallization, microfiltration, acid washing, water washing with an electrical conductivity of 10 mS / m or less, and extraction.

[0166] (Method for producing polymer (B)) Polymer (B) is obtained by reacting polymer (A) with an acid or an acid and water to remove some or substantially all (preferably substantially all) of the protecting groups (acid-degradable groups) in the constituent units of polymer (A) corresponding to the compound of this embodiment, converting them to hydroxyl groups. The acid is not particularly limited, but examples include toluenesulfonic acid (TsOH).

[0167] The conditions for the elimination reaction of the protecting group are not particularly limited, and any known method can be appropriately selected and applied. Examples of such known methods include the hydrolysis reaction of an acetal group.

[0168] Specific examples of polymer (B) in this embodiment include the following:

[0169] [Resin Composition] The resin composition in this embodiment may, for example, include polymer (A) or polymer (B) and, optionally, a second compound. The content of the second compound in the resin composition is preferably 1% by mass or less, more preferably 0.1% by mass or less, and even more preferably 0.05% by mass or less, relative to the total amount of polymer (A) and polymer (B) in the resin composition.

[0170] [Film-forming composition] The film-forming composition of this embodiment may contain a first compound or polymer (A) or polymer (B), and optionally a second compound, and is particularly suitable for lithography technology. Furthermore, the film-forming composition of this embodiment can be manufactured from the composition of this embodiment described above, but may also contain the composition of this embodiment or the resin composition of this embodiment. Although not particularly limited, the film-forming composition of this embodiment can be used for lithography film formation applications, for example, for resist film formation applications (i.e., "resist composition"). Moreover, the film-forming composition of this embodiment can be used for upper layer film formation applications (i.e., "upper layer film-forming composition"), intermediate layer formation applications (i.e., "intermediate layer-forming composition"), lower layer film formation applications (i.e., "lower layer film-forming composition"), etc. According to the film-forming composition of this embodiment, it is possible to form a film with high sensitivity and to impart a good resist pattern shape.

[0171] The film-forming composition of this embodiment can also be used as an optical component forming composition applying lithography technology. The optical components are useful not only in film and sheet form, but also as plastic lenses (prism lenses, lenticular lenses, microlenses, Fresnel lenses, field-of-view control lenses, contrast-enhancing lenses, etc.), phase difference films, electromagnetic 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 electroluminescent (EL) displays, optical semiconductor (LED) elements, solid-state image sensors, organic thin-film solar cells, dye-sensitized solar cells, and organic thin-film transistors (TFTs). The composition is particularly suitable for use as a filling film and planarization film on a photodiode, a planarization film before and after a color filter, a microlens, a planarization film on a microlens, and a conformal film, which are components of solid-state image sensors requiring a high refractive index.

[0172] In other preferred forms of the film-forming composition of this embodiment, the second compound is preferably contained in an amount of 1 ppm by mass or more and 10% by mass or less, more preferably in an amount of 20 ppm by mass or more and 2% by mass or less, and preferably in an amount of 50 ppm by mass or more and 1% by mass or less, relative to the first compound or polymer (A) or polymer (B).

[0173] By setting the content of the second compound within the specified range, although the mechanism is not clear, the second compound effectively and actively captures radicals generated by heat, etc., thereby suppressing the alteration of the first compound or polymer (A) or polymer (B) in the composition, suppressing the generation of trace amounts of particle foreign matter, and suppressing defects in the film obtained over time and in the pattern after development.

[0174] The film-forming composition of this embodiment comprises a first compound or polymer (A) or polymer (B), and may optionally contain other components such as a second compound, a substrate (D), a solvent (S), an acid generator (C), a base generator (G), a base compound (H), or an acid diffusion control agent (E). Each component will be described below.

[0175] [Substrate (D)] In this embodiment, "substrate (D)" means a compound (including resin) other than the first compound, polymer (A), or polymer (B), which is applied as a resist for g-ray, i-ray, KrF excimer laser (248 nm), ArF excimer laser (193 nm), extreme ultraviolet (EUV) lithography (13.5 nm), or electron beam (EB) (for example, a substrate for lithography or a substrate for resist). Any of these substrates is not particularly limited and can be used as substrate (D) in this embodiment. Examples of substrate (D) 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 having metallic elements such as titanium, tin, hafnium, and zirconium, as well as derivatives thereof. Among these, phenol novolac resins, cresol novolac resins, hydroxystyrene resins, (meth)acrylic resins, hydroxystyrene-(meth)acrylic copolymers, and inorganic resist materials having metallic elements such as titanium, tin, hafnium, and zirconium, as well as derivatives thereof, are preferred from the viewpoint of the shape of the resist pattern obtained.

[0176] The aforementioned derivatives are not particularly limited, but examples include those into which a dissociable group or a crosslinking group has been introduced. The derivatives into which the dissociable group or crosslinking group has been introduced can undergo dissociation reactions or crosslinking reactions by the action of light, acid, etc.

[0177] A "dissociable group" refers to a characteristic group that cleaves to produce functional groups such as alkali-soluble groups that change solubility. While not particularly limited, alkali-soluble groups include phenolic hydroxyl groups, carboxyl groups, sulfonic acid groups, and hexafluoroisopropanol groups, with phenolic hydroxyl groups and carboxyl groups being preferred, and phenolic hydroxyl groups being particularly preferred.

[0178] A "crosslinkable group" refers to a group that crosslinks in the presence or absence of a catalyst. Crosslinkable groups are not particularly limited, but examples include alkoxy groups having 1 to 20 carbon atoms, groups having an allyl group, groups having a (meth)acryloyl group, groups having an epoxy (meth)acryloyl group, groups having a hydroxyl group, groups having a urethane (meth)acryloyl group, groups having a glycidyl group, and groups having a vinylphenylmethyl group.

[0179] [Solvent (S)] In this embodiment, any known solvent (S) can be used as long as it is capable of dissolving at least the first compound described above, or polymer (A) or polymer (B).The solvent (S) is not particularly limited, but examples include: 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; methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, n- Lactic acid esters such as amyl; aliphatic carboxylic acid esters such as methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, n-amyl acetate, n-hexyl acetate, methyl propionate, 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, 3-methoxy-3-methylpropionate Other esters such as butyl pionate, butyl 3-methoxy-3-methylbutyrate, methyl acetoacetate, methyl pyruvate, and ethyl pyruvate; aromatic hydrocarbons such as toluene and xylene; ketones such as acetone, 2-butanone, 2-heptanone, 3-heptanone, 4-heptanone, cyclopentanone (CPN), and cyclohexanone (CHN); amides such as N,N-dimethylformamide, N-methylacetamide, N,N-dimethylacetamide, and N-methylpyrrolidone; and lactones such as γ-lactones.The solvent (S) used in this embodiment is preferably a safe solvent, more preferably at least one selected from PGMEA, PGME, CHN, CPN, 2-heptanone, anisole, butyl acetate, and ethyl lactate, and even more preferably at least one selected from PGMEA, PGME, CHN, CPN, and ethyl lactate.

[0180] In the film-forming composition of this embodiment, the concentration of the solid component is not particularly limited, but is preferably 1 to 80% by mass, more preferably 1 to 50% by mass, even more preferably 2 to 40% by mass, and even more preferably 2 to 10% by mass, based on the total mass of the film-forming composition.

[0181] [Acid Generator (C)] In the film-forming composition of this embodiment, it is preferable to include one or more acid generators (C) that generate acid directly or indirectly by irradiation with radiation. The radiation is at least one selected from the group consisting of visible light, ultraviolet light, excimer laser, electron beam, extreme ultraviolet (EUV), X-rays, and ion beam. The acid generator (C) is not particularly limited, but for example, one described in International Publication WO2013 / 024778 can be used. The acid generator (C) can be used alone or in combination of two or more.

[0182] The amount of acid generator (C) blended is preferably 0.001 to 49% by mass, more preferably 1 to 40% by mass, even more preferably 3 to 30% by mass, and even more preferably 10 to 25% by mass, based on the total mass of the solid components (total amount of components excluding the solvent (S) (the same applies hereinafter)). By using the acid generator (C) within the above range, a pattern profile with high sensitivity and low edge roughness tends to be obtained. In this embodiment, the method of generating the acid is not particularly limited as long as acid is generated in the system. If an excimer laser is used instead of ultraviolet rays such as g-rays and i-rays, finer processing is possible, and if an electron beam, extreme ultraviolet rays, X-rays, or ion beam is used as a high-energy beam, even finer processing is possible.

[0183] [Acid Diffusion Control Agent (E)] The film-forming composition of this embodiment may contain an acid diffusion control agent (E). The acid diffusion control agent (E) controls the diffusion of the acid generated from the acid generator (C) by radiation irradiation within the resist film, preventing undesirable chemical reactions from occurring in unexposed areas. Using the acid diffusion control agent (E) tends to improve the storage stability of the composition of this embodiment. Furthermore, using the acid diffusion control agent (E) can improve the resolution of the film formed using the composition of this embodiment, and can suppress changes in the line width of the resist pattern due to variations in the pre-irradiation and post-irradiation storage times, resulting in a process with excellent stability. The acid diffusion control agent (E) is not particularly limited, but examples include radiodegradable basic compounds such as nitrogen atom-containing basic compounds, basic sulfonium compounds, and basic iodium compounds.

[0184] The acid diffusion control agent (E) is not particularly limited, but for example, those described in International Publication WO2013 / 024778 can be used. The acid diffusion control agent (E) can be used alone or in combination of two or more types.

[0185] The amount of acid diffusion control agent (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 even more preferably 0.01 to 3% by mass, relative to the total mass of the solid components. When the amount of acid diffusion control agent (E) is within the above range, it tends to prevent deterioration of resolution, pattern shape, dimensional fidelity, etc. Furthermore, even if the settling time from electron beam irradiation to post-irradiation heating is long, deterioration of the shape of the upper layer of the pattern can be suppressed. Also, when the amount of acid diffusion control agent (E) is 10% by mass or less, it tends to prevent deterioration of sensitivity, developability of unexposed areas, etc. Furthermore, by using such an acid diffusion control agent (E), the storage stability of the film-forming composition is improved, the resolution is improved, and changes in the line width of the resist pattern due to variations in the settling time before and after irradiation can be suppressed, resulting in a process with excellent stability.

[0186] [Base Generator (G)] The case where the base generator (G) is a photobase generator will be explained. A photobase generator is a substance that generates a base upon exposure, and does not show activity under normal conditions at room temperature and pressure, but generates a base (basic substance) when exposed to electromagnetic waves and heated as external stimuli.

[0187] The photobase generator that can be used in this embodiment is not particularly limited and any known one can be used, for example, carbamate derivatives, amide derivatives, imide derivatives, α-cobalt complexes, imidazole derivatives, cinnamic acid amide derivatives, oxime derivatives, and the like.

[0188] The basic substances generated from the photobase generator are not particularly limited, but include compounds having an amino group, especially monoamines, polyamines such as diamines, and amidines. From the viewpoint of sensitivity and resolution, compounds having an amino group with a higher degree of basicity (higher pKa value of the conjugate acid) are preferred as the generated basic substances.

[0189] Examples of photobase generators include base generators having a cinnamic acid amide structure as disclosed in Japanese Patent Publication No. 2009-80452 and International Publication No. 2009 / 123122, base generators having a carbamate structure as disclosed in Japanese Patent Publication No. 2006-189591 and Japanese Patent Publication No. 2008-247747, base generators having an oxime structure or carbamoyl oxime structure as disclosed in Japanese Patent Publication No. 2007-249013 and Japanese Patent Publication No. 2008-003581, and compounds described in Japanese Patent Publication No. 2010-243773, but are not limited to these, and other known base generator structures can be used.

[0190] The photobase generator can be used alone or in combination of two or more types. The preferred content of the photobase generator in the film-forming composition is the same as the preferred content of the acid generator (C) in the film-forming composition described above.

[0191] [Basic compound (H)] The basic compound (H) is not particularly limited, but those described in International Publication WO2013 / 024778 may be used. One or more basic compounds (H) may be used.

[0192] The amount of the basic compound (H) is preferably 0.001 to 49% by mass, more preferably 0.01 to 5% by mass, and even more preferably 0.01 to 3% by mass, relative to the total mass of the solid components.

[0193] [Other components (F)] The film-forming composition of this embodiment may optionally contain one or more additives as other components (F), such as crosslinking agents, dissolution accelerators, dissolution control agents, sensitizers, surfactants, and organic carboxylic acids or phosphorus oxoacids or derivatives thereof.

[0194] (Crosslinking agent) The film-forming composition of this embodiment may contain a crosslinking agent. The crosslinking agent can crosslink at least one of the first compound, polymer (A) or polymer (B), and substrate (D). The crosslinking agent is preferably an acid crosslinking agent that can intramolecularly or intermolecularly crosslink the substrate (D) in the presence of 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") that can crosslink the substrate (D).

[0195] Examples of crosslinkable groups include (i) hydroxyl groups, hydroxyalkyl groups (alkyl groups having 1 to 6 carbon atoms), alkoxy groups having 1 to 6 carbon atoms, acetoxy groups (alkyl groups having 1 to 6 carbon atoms), and other hydroxyalkyl groups or groups derived therefrom; (ii) carbonyl groups such as formyl groups and carboxyl groups (alkyl groups having 1 to 6 carbon atoms), or groups derived therefrom; (iii) dimethylaminomethyl groups, diethylaminomethyl groups, dimethylolaminomethyl groups, and diethylol Examples of crosslinking agents include nitrogen-containing groups such as aminomethyl groups and morpholinomethyl groups; (iv) glycidyl group-containing groups such as glycidyl ether groups, glycidyl ester groups, and glycidylamino groups; (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), such as benzyloxymethyl groups and benzoyloxymethyl groups; and (vi) polymerizable multiple bond-containing groups such as vinyl groups and isopropenyl groups. In this embodiment, hydroxyalkyl groups and alkoxyalkyl groups are preferred as crosslinkable groups of the crosslinking agent, with alkoxymethyl groups being particularly preferred.

[0196] The crosslinking agent having a crosslinking group is not particularly limited, but for example, the acid crosslinking agent described in International Publication WO2013 / 024778 can be used. The crosslinking agent can be used alone or in combination of two or more.

[0197] In this embodiment, the amount of 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 even more preferably 20% by mass or less, based on the total mass of the solid components.

[0198] (Dissolution accelerator) A dissolution accelerator is a component that increases the solubility of a solid component in a developer when its solubility is too low, thereby moderately increasing the dissolution rate of the compound during development. Low molecular weight dissolution accelerators are preferred, and examples 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 individually or in combination of two or more.

[0199] The amount of dissolution accelerator added is adjusted as appropriate depending on the type of solid component used, but is preferably 0 to 49% by mass of the total mass of the solid component, more preferably 0 to 5% by mass, even more preferably 0 to 1% by mass, and particularly preferably 0% by mass.

[0200] (Dissolution Control Agent) A dissolution control agent is a component that controls the solubility of solid components in the developer when their solubility is too high, thereby appropriately reducing the dissolution rate during development. Preferably, such a dissolution control agent does not undergo chemical changes during processes such as firing, radiation irradiation, and development of the resist film.

[0201] The dissolution control agents are not particularly limited, but examples include aromatic hydrocarbons such as phenanthrene, anthracene, and acenaphthene; ketones such as acetophenone, benzophenone, and phenylnaphthylketone; and sulfones such as methylphenylsulfone, diphenylsulfone, and dinaphthylsulfone. These dissolution control agents can be used individually or in combination of two or more.

[0202] The amount of dissolution control agent is adjusted as appropriate depending on the type of compound used, but is preferably 0 to 49% by mass of the total mass of solid components, more preferably 0 to 5% by mass, even more preferably 0 to 1% by mass, and particularly preferably 0% by mass.

[0203] (Sensitizer) A sensitizer is a component that absorbs the energy of the irradiated radiation and transfers that energy to an acid generator (C), thereby increasing the amount of acid produced and improving the apparent sensitivity of the resist. Examples of such sensitizers include benzophenones, biacetyls, pyrenes, phenothiazines, fluorenes, etc., but are not particularly limited. These sensitizers can be used alone or in combination of two or more.

[0204] The amount of sensitizer is adjusted as appropriate depending on the type of compound used, but is preferably 0 to 49% by mass of the total mass of the solid components, more preferably 0 to 5% by mass, even more preferably 0 to 1% by mass, and particularly preferably 0% by mass.

[0205] (Surfactants) Surfactants are components that improve the applicability, striation, and developability of the resist of the composition of this embodiment. The surfactant may be anionic surfactant, cationic surfactant, nonionic surfactant, or amphoteric surfactant. Nonionic surfactants are preferred surfactants. Nonionic surfactants have good affinity with the solvent used in the manufacture of 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 alkylphenyl ethers, and higher fatty acid diesters of polyethylene glycol. Commercially available surfactants include the following product names: F-Top (manufactured by Gemco), Megafac (manufactured by Dainippon Ink and Chemicals), Florard (manufactured by Sumitomo 3M), Asahi Guard, Surflon (both manufactured by Asahi Glass Co.), Pepol (manufactured by Toho Chemical Industries), KP (manufactured by Shin-Etsu Chemical Co.), Polyflow (manufactured by Kyoeisha Oil & Fat Chemical Industry Co., Ltd.), and others.

[0206] The amount of surfactant is adjusted as appropriate depending on the type of solid component used, but is preferably 0 to 49% by mass of the total mass of the solid component, more preferably 0 to 5% by mass, even more preferably 0 to 1% by mass, and particularly preferably 0% by mass.

[0207] (Organic carboxylic acids or phosphorus oxoacids or derivatives thereof) For the purpose of preventing sensitivity degradation or improving resist pattern shape, settling stability, etc., organic carboxylic acids or phosphorus oxoacids or derivatives thereof may be included as additional optional components. Organic carboxylic acids or phosphorus oxoacids or derivatives thereof may be used in combination with an acid diffusion control agent or used alone. Suitable organic carboxylic acids include, for example, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, and salicylic acid. Suitable phosphorus oxoacids or derivatives thereof include phosphoric acid, di-n-butyl phosphate, diphenyl phosphate, and other phosphoric acid derivatives or their esters; phosphonic acid, dimethyl phosphonate, di-n-butyl phosphonate, phenylphosphonic acid, diphenyl phosphonate, dibenzyl phosphonate, and other phosphonic acid derivatives or their esters; and phosphinic acid, phenylphosphinic acid, and other phosphinic acid derivatives and their esters. Among these, phosphonic acid is particularly preferred.

[0208] Organic carboxylic acids or phosphorus oxoacids or derivatives thereof can be used alone or in combination of two or more. The amount of organic carboxylic acids or phosphorus oxoacids or derivatives thereof is adjusted as appropriate depending on the type of compound used, but is preferably 0 to 49% by mass of the total mass of solid components, more preferably 0 to 5% by mass, even more preferably 0 to 1% by mass, and particularly preferably 0% by mass.

[0209] [Other Additives] Furthermore, the composition of this embodiment may contain one or more additives other than those described above, as needed. Examples of such additives include dyes, pigments, and adhesive aids. For example, the inclusion of dyes or pigments is preferable because it makes the latent image of the exposed area visible and mitigates the effects of halation during exposure. The inclusion of adhesive aids is also preferable because it improves adhesion to the substrate. Other additives include anti-halation agents, preservative stabilizers, defoamers, shape modifiers, and specifically, 4-hydroxy-4'-methyl chalcone.

[0210] In the composition of this embodiment, the total amount of optional component (F) can be 0 to 99% by mass of the total mass of the solid components, preferably 0 to 49% by mass, more preferably 0 to 10% by mass, even more preferably 0 to 5% by mass, even more preferably 0 to 1% by mass, and particularly preferably 0% by mass.

[0211] [Method for forming a resist pattern] The method for forming a resist pattern according to this embodiment includes the steps of: forming a resist film on a substrate using the film-forming composition of this embodiment; exposing the resist film to a pattern; and developing the resist film after exposure.

[0212] As described above, the film-forming composition of this embodiment comprises, for example, a first compound, polymer (A), or polymer (B), and optionally a second compound or solvent.

[0213] The coating method used in the process of forming the resist film is not particularly limited, but examples include a spin coater, a dip coater, and a roller coater. The substrate is not particularly limited, but examples include a silicon wafer, metal, plastic, glass, and ceramic. After forming the resist film, a heat treatment may be performed at a temperature of about 50°C to 200°C. The thickness of the resist film is not particularly limited, but for example, it is 50 nm to 1 μm.

[0214] In the exposure process, exposure may be performed through a predetermined mask pattern, or maskless shot exposure may be performed. The thickness of the coating film is, for example, 0.1 to 20 μm, preferably about 0.3 to 2 μm. Various wavelengths of light rays, such as ultraviolet rays and X-rays, can be used for exposure. For example, as a light source, far ultraviolet rays such as F2 excimer lasers (wavelength 157 nm), ArF excimer lasers (wavelength 193 nm), and KrF excimer lasers (wavelength 248 nm), extreme ultraviolet rays (wavelength 13 nm), X-rays, and electron beams may be appropriately selected and used. Among these, extreme ultraviolet rays are preferred. Furthermore, exposure conditions such as the exposure amount are appropriately selected according to the formulation composition of the (co)polymer and / or compound, the type of each additive, etc.

[0215] In this embodiment, in order to stably form a high-precision 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 below 50°C, there is a risk that the sensitivity variation depending on the type of substrate will widen. Subsequently, a predetermined resist pattern is formed by developing with an alkaline developer under conditions of 10 to 50°C for 10 to 200 seconds, preferably 20 to 25°C for 15 to 90 seconds.

[0216] As the alkaline developer, for example, an alkaline aqueous solution is used, in which an alkaline compound such as 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 in an alkaline aqueous solution, usually at a concentration of 1 to 10% by mass, preferably 1 to 3% by mass. In addition, water-soluble organic solvents and surfactants may be added to the developer consisting of the alkaline aqueous solution as appropriate.

[0217] The composition of this embodiment can also be used as an optical component forming composition applying lithography technology. The optical components are useful in film and sheet form, as well as in plastic lenses (prism lenses, lenticular lenses, microlenses, Fresnel lenses, field-of-view control lenses, contrast-enhancing lenses, etc.), phase difference films, electromagnetic 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 electroluminescent (EL) displays, optical semiconductor (LED) elements, solid-state image sensors, organic thin-film solar cells, dye-sensitized solar cells, and organic thin-film transistors (TFTs). The composition is particularly suitable for use as a filling film and planarization film on a photodiode, a planarization film before and after a color filter, a microlens, a planarization film on a microlens, and a conformal film, which are components of solid-state image sensors requiring a high refractive index.

[0218] Furthermore, the composition of this embodiment can be used as a patterning material for lithography applications. It can be used in various applications in lithography processes, including semiconductors, liquid crystal display panels and OLED display panels, power devices, CCDs, and other sensors. In particular, for integrated circuits of semiconductors and devices, the composition of this embodiment can be suitably used in the process of forming device elements on a silicon wafer. This involves forming a pattern on the insulating film on the substrate side by etching based on a pattern formed using the composition of this embodiment on the upper surface of an insulating layer such as a silicon oxide film or other oxide film, and then further laminating a metal film or semiconductor material based on the formed insulating film pattern to form a circuit pattern, thereby constructing semiconductor elements and other devices.

[0219] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited in any way by these examples.

[0220] [Measurement Method] [Nuclear Magnetic Resonance (NMR)] The structure of the compound was confirmed by NMR measurement using the nuclear magnetic resonance spectrometer "Advance600II spectrummeter" (product name, manufactured by Bruker) under the following conditions. １ [H-NMR measurement] Frequency: 400 MHz Solvent: CDCl ３ , or d ６ -DMSO Internal standard: TMS Measurement temperature: 23℃ [ １３ [C-NMR measurement] Frequency: 500 MHz Solvent: CDCl ３ , or d ６ -DMSO Internal standard: TMS Measurement temperature: 23℃

[0221] [LC (Liquid Chromatography) Measurement Conditions] LC in each example was measured according to the following: Instrument name: Shimadzu Corporation (Nexera-i LC-2020C 3D) Column: Waters XBridge BEH C18 (2.5 μm 3.0 × 75 mm) Detector: PDA; Flow rate: 0.7 mL / min, Column oven temperature: 40°C, Autosampler temperature: 15°C, Input volume: 1.0 μL (2 mg / mL THF solution) Eluent (%), Ultrapure water: MeCN: Measured in the range of (0:98:2) to (93:5:2) of 1% phosphoric acid aqueous solution

[0222] [Synthesis Example 1] Synthesis of 3,5-di(2-tetrahydropyranyloxy)-4-iodostyrene (compound MA1) (1-1) Synthesis of 3,5-dihydroxy-4-iodobenzaldehyde 35.0 g (0.253 mol) of 3,5-dihydroxybenzaldehyde, 315 mL of methanol, and 10.5 g of activated carbon were placed in a 1000 mL glass flask, and stirring was started at room temperature of 20°C. The activated carbon was removed using a filter equipped with a filter aid, and the resulting solution was placed in a 2000 mL glass flask. Methanol was added until the total mass of the solution was 700 g. Subsequently, nitrogen was blown in at a flow rate of 10 mL / min. After adding 24.4 g (0.0963 mol) of iodine, 84.7 g (0.0481 mol) of a 10% by mass aqueous solution of iodate was added dropwise while adjusting the temperature to remain below 30°C. After stirring for 3 hours, 5 g of a 5% by mass sodium bisulfite aqueous solution was added. The container was reduced to 35 hPa (3500 Pa), and the solution was concentrated by immersion in a 30°C water bath to obtain 135 g of slurry. The obtained slurry was suspended and stirred in 676 g of deionized water, and the crude material was recovered by suction filtration. It was vacuum dried at 60°C to obtain 59.4 g of a white solid. The yield was 89%.

[0223] Analysis by liquid chromatography-mass spectrometry (LC-MS) revealed a molecular weight of 264. Furthermore, under the measurement conditions described above... １¹H-NMR measurements revealed the following peaks, confirming the presence of the chemical structure 3,5-dihydroxy-4-iodobenzaldehyde: δ(ppm)(d6-DMSO): 10.7 (2H, OH), 9.2 (1H, CHO), 6.8 (2H, ArH)

[0224]

[0225] (1-2) Synthesis of 3,5-di(2-tetrahydropyranyloxy)-4-iodobenzaldehyde In a 1000 mL glass reaction vessel, 52.0 g (0.197 mol) of 3,5-dihydroxy-4-iodobenzaldehyde obtained in (1-1) above, 689 g of dichloromethane, 133 g (1.58 mol) of 3,4-dihydro-2H-pyran, and 9.90 g (0.0394 mol) of pyridinium p-toluenesulfonate were charged, and stirring was started at room temperature of 20°C. Subsequently, nitrogen was blown in at a flow rate of 10 mL / min. After stirring for 3 hours, 5.0 g of triethylamine and 343 g of deionized water were added in sequence and separated. The organic layer was washed with deionized water. After dehydrating the organic layer with magnesium sulfate, the container was reduced in pressure and concentrated to dryness by immersion in a 30°C water bath to recover the crude product. The obtained crude material was purified by recrystallization in a toluene / methanol mixed solvent at -20°C to obtain 52.3 g of a white solid. The yield was 62%. Analysis by liquid chromatography-mass spectrometry (LC-MS) revealed a molecular weight of 432.

[0226] Furthermore, under the above measurement conditions １ ¹H-NMR measurements revealed the following peaks, confirming the presence of the chemical structure 3,5-di(2-tetrahydropyranyloxy)-4-iodobenzaldehyde. δ(ppm)(d6-DMSO): 9.9 (1H, CHO), 7.3 (2H, ArH), 5.8 (2H, -CH<), 3.7 (2H, -CH2-), 3.6 (2H, -CH2-), 2.0 (2H, -CH2-), 1.8 (4H, -CH2-), 1.6 (6H, -CH2-)

[0227]

[0228] (1-3) Synthesis of Compound MA1 34.7 g (0.0971 mol) of methyltriphenylphosphonium bromide and 196 g of THF were charged into a 1000 mL glass reaction vessel, and nitrogen was blown into the reaction vessel at a flow rate of 10 mL / min, and stirring was started. After cooling the reaction vessel to 0°C by immersing it in ice water, 10.9 g (0.0971 mol) of potassium tert-butoxide was added in stages, and stirring was continued for 30 minutes. 28.0 g (0.0648 mol) of 3,5-di(2-tetrahydropyranyloxy)-4-iodobenzaldehyde obtained in (1-2) above was added in stages, and after stirring for 30 minutes, 318 g of toluene and 247 g of deionized water were added in sequence. The reaction vessel was returned to room temperature and stirred. The organic layer was transferred to a separatory funnel and washed multiple times with deionized water to obtain a Wittig reaction solution containing the compound MA1 and triphenylphosphine oxide. The obtained Wittig reaction solution was purified by column chromatography, and the resulting compound MA1 solid was vacuum-dried at 25°C to obtain 14.8 g of a white solid. The yield was 53%.

[0229] Analysis by liquid chromatography-mass spectrometry (LC-MS) revealed a molecular weight of 430. Furthermore, under the aforementioned measurement conditions... １ ¹H-NMR measurements revealed the following peaks, confirming the presence of the chemical structure of compound MA1: δ(ppm)(d6-DMSO): 6.9 (2H, ArH), 6.7 (1H, -CH=), 5.9 (1H, =CH2), 5.7 (2H, -CH<), 5.3 (1H, =CH2), 3.7 (2H, -CH2-), 3.5 (2H, -CH2-), 2.0 (2H, -CH2-), 1.8 (4H, -CH2-), 1.6 (6H, -CH2-) [Synthesis Example 2] Synthesis of 3,5-di(1-ethoxyethoxy)-4-iodostyrene (compound MA2) (2-1) Synthesis of 3,5-dihydroxy-4-iodobenzaldehyde 3,5-dihydroxy-4-iodobenzaldehyde was obtained by the same method as in (1-1) of Synthesis Example 1.

[0230] (2-2) Synthesis of 3,5-di(1-ethoxyethoxy)-4-iodobenzaldehyde In a 200 mL glass reaction vessel, 5.00 g (0.0189 mol) of 3,5-dihydroxy-4-iodobenzaldehyde obtained in (2-1) above, 76 g of dichloromethane, 4.1 g (0.057 mol) of ethyl vinyl ether, and 0.024 g (0.096 mmol) of pyridinium p-toluenesulfonate were charged, and stirring was started at room temperature of 20°C. Subsequently, nitrogen was blown in at a flow rate of 10 mL / min. After stirring for 3 hours, 0.13 g of triethylamine and 38 g of deionized water were added in sequence and separated. The organic layer was washed multiple times with deionized water. After dehydrating the organic layer with magnesium sulfate, the crude product was recovered by concentrating the container under reduced pressure in a 30°C water bath. The obtained crude product was purified by column chromatography to obtain 3.00 g of yellow liquid. The yield was 39%.

[0231] Analysis by liquid chromatography-mass spectrometry (LC-MS) revealed a molecular weight of 408. Furthermore, under the measurement conditions described above... １ ¹H-NMR measurements revealed the following peaks, confirming the presence of the chemical structure 3,5-di(1-ethoxyethoxy)-4-iodobenzaldehyde: δ(ppm)(d6-DMSO): 9.9 (1H, CHO), 6.8 (2H, ArH), 5.6 (2H, -CH<), 3.9 (4H, -CH2-), 1.6 (6H, -CH3), 1.2 (6H, -CH3)

[0232] (2-3) Synthesis of Compound MA-2 4.0 g (0.011 mol) of methyltriphenylphosphonium bromide and 18 g of THF were charged into a 100 mL glass reaction vessel, and nitrogen was blown into the reaction vessel at a flow rate of 10 mL / min, and stirring was started. After cooling the reaction vessel to 0°C by immersing it in ice water, 1.2 g (0.011 mol) of potassium tert-butoxide was added in installments, and stirring was continued for 30 minutes. 3.0 g (0.0074 mol) of 3,5-di(1-ethoxyethoxy)-4-iodobenzaldehyde obtained from (2-2) above was added in installments, and after stirring for 1 hour, 34 g of toluene and 28 g of deionized water were added in sequence. The reaction vessel was returned to room temperature and stirred. The organic layer was transferred to a separatory funnel and washed multiple times with deionized water to obtain a Wittig reaction solution containing compound MA2 and triphenylphosphine oxide. The obtained Wittig reaction solution was purified by column chromatography to obtain 2.0 g of yellow liquid. The yield was 65%.

[0233] Analysis by liquid chromatography-mass spectrometry (LC-MS) revealed a molecular weight of 406. Furthermore, under the aforementioned measurement conditions... １ ¹H-NMR measurements revealed the following peaks, confirming the presence of the chemical structure of compound MA2: δ(ppm)(d6-DMSO): 6.8 (2H, ArH), 6.7 (1H, -CH=), 5.9 (1H, =CH2), 5.6 (2H, -CH<), 5.3 (1H, =CH2), 3.7 (2H, -CH2-), 3.5 (2H, -CH2-), 1.4 (6H, -CH3), 1.1 (6H, -CH3)

[0234]

[0235] [Synthesis Example 3] Synthesis of 3,5-di(ethoxymethoxy)-4-iodostyrene (compound MA3) (3-1) Synthesis of 3,5-dihydroxy-4-iodobenzaldehyde 3,5-dihydroxy-4-iodobenzaldehyde was obtained by the same method as in (1-1) of Synthesis Example 1.

[0236] (3-2) Synthesis of 3,5-di(ethoxymethoxy)-4-iodobenzaldehyde In a 200 mL glass reaction vessel, 5.00 g (0.0189 mol) of 3,5-dihydroxy-4-iodobenzaldehyde obtained in (3-1) above, 76 g of dichloromethane, 5.3 g (0.057 mol) of chloromethyl ethyl ether, and 5.7 g (0.057 mmol) of triethylamine were charged and stirred at room temperature of 20°C for 1 hour. Subsequently, 38 g of deionized water was added in sequence and the mixture was separated. The organic layer was washed multiple times with deionized water. After dehydrating the organic layer with magnesium sulfate, the container was reduced in pressure and concentrated in a 30°C water bath to recover the crude product. The obtained crude product was purified by column chromatography to obtain 6.62 g of yellow liquid. The yield was 92%.

[0237] Analysis by liquid chromatography-mass spectrometry (LC-MS) revealed a molecular weight of 380. Furthermore, under the measurement conditions described above... １ ¹H-NMR measurements revealed the following peaks, confirming the presence of the chemical structure 3,5-di(ethoxymethoxy)-4-iodobenzaldehyde: δ(ppm)(d6-DMSO): 9.9 (1H, CHO), 6.8 (2H, ArH), 5.2 (4H, O-CH2-O), 3.8 (4H, -CH2-), 1.2 (6H, -CH3)

[0238]

[0239] (3-3) Synthesis of Compound MA-3 In a 100 mL glass reaction vessel, 4.0 g (0.011 mol) of methyltriphenylphosphonium bromide and 18 g of THF were charged, and nitrogen was blown into the reaction vessel at a flow rate of 10 mL / min, and stirring was started. After cooling the reaction vessel to 0°C by immersing it in ice water, 1.2 g (0.011 mol) of potassium tert-butoxide was added in installments, and stirring was continued for 30 minutes. 3.0 g (0.0079 mol) of 3,5-di(ethoxymethoxy)-4-iodobenzaldehyde obtained from (3-2) above was added in installments, and after stirring for 1 hour, 34 g of toluene and 28 g of deionized water were added in sequence. The reaction vessel was returned to room temperature and stirred. The organic layer was transferred to a separatory funnel and washed several times with deionized water to obtain a Wittig reaction solution containing compound MA3 and triphenylphosphine oxide. The resulting Wittig reaction solution was purified by column chromatography to obtain 2.1 g of a yellow liquid. The yield was 70%.

[0240] Analysis by liquid chromatography-mass spectrometry (LC-MS) revealed a molecular weight of 378. Furthermore, under the measurement conditions described above... １ ¹H-NMR measurements revealed the following peaks, confirming the presence of the chemical structure of compound MA3: δ(ppm)(d6-DMSO): 6.8 (2H, ArH), 6.7 (1H, -CH=), 5.9 (1H, =CH2), 5.4 (4H, O-CH2-O), 5.3 (1H, =CH2), 3.7 (2H, -CH2-), 3.5 (2H, -CH2-), 1.1 (6H, -CH3)

[0241]

[0242] [Synthesis Example 4] Synthesis of 3-iodo-2,4-di(2-tetrahydropyranyloxy)styrene (compound MA4) (4-1) Synthesis of 2,4-dihydroxy-3-iodobenzaldehyde 27.8 g (0.201 mol) of 2,4-dihydroxybenzaldehyde, 139 g of methanol, and 276 g of deionized water were charged into a 1000 mL glass reaction vessel, and stirring was started at room temperature of 20°C. After confirming the dissolution of the aldehyde, nitrogen was blown in at a flow rate of 10 mL / min. The reaction vessel was immersed in ice water and cooled to 0°C. 50.2 g (0.198 mol) of iodine was added, followed by the addition of 16.9 g (0.201 mol) of sodium bicarbonate. After stirring for 2 hours under ice cooling, 16 g of 5% by mass aqueous sodium bisulfite solution and 138 g of deionized water were added. The crude product was recovered by suction filtration and redissolved in a mixed solvent of 163 g of ethyl acetate and 163 g of toluene. After washing the solution multiple times with deionized water, the container was reduced in pressure and the solution was concentrated by immersion in a 50°C water bath to obtain 146 g of concentrate. After adding 76 g of toluene, recrystallization was performed by stirring at 0°C for 3 hours. The obtained solid was recovered by suction filtration. Vacuum drying at 60°C yielded 39.6 g of a white solid. The yield was 75%.

[0243] Analysis by liquid chromatography-mass spectrometry (LC-MS) revealed a molecular weight of 264. Furthermore, under the measurement conditions described above... １ ¹H-NMR measurements revealed the following peaks, confirming the presence of the chemical structure of 2,4-dihydroxy-3-iodobenzaldehyde: δ(ppm)(d6-DMSO): 12.2 (¹H, -OH), 11.7 (¹H, -OH), 9.6 (¹H, -CHO), 7.6 (¹H, ArH), 6.6 (²H, ArH)

[0244]

[0245] (4-2) Synthesis of 2-hydroxy-3-iodo-4-(2-tetrahydropyranyloxy)benzaldehyde In a 300 mL glass reaction vessel, 5.0 g (19 mmol) of 2,4-dihydroxy-3-iodobenzaldehyde from (4-1) above, 50 g of toluene, and 0.43 g (3.8 mmol) of trifluoroacetic acid were charged, and nitrogen was blown in at a flow rate of 10 mL / min. The reaction vessel was immersed in ice water and cooled to 0°C. After adding 13 g (0.15 mol) of 3,4-dihydro-2H-pyran, the ice bath was removed and the vessel was allowed to return to room temperature. After stirring for 6 hours, 0.42 g of triethylamine and 25 g of deionized water were added. The organic layer was washed several times with deionized water, and the vessel containing the organic layer was reduced to 45 hPa and the solution was concentrated by immersion in a 40°C water bath to obtain a concentrate of 26 g. Crystallization was performed by adding 66 g of heptane and stirring at room temperature (20°C) for 1 hour. The obtained solid was recovered by suction filtration. Vacuum drying at 30°C yielded 4.3 g of a white solid. The yield was 65%. Analysis by liquid chromatography-mass spectrometry (LC-MS) revealed a molecular weight of 348. Furthermore, under the above measurement conditions... １ ¹H-NMR measurements revealed the following peaks, confirming the presence of the chemical structure of 2-hydroxy-3-iodo-4-(2-tetrahydropyranyloxy)benzaldehyde. δ(ppm)(d6-DMSO): 10.2 (1H, -CHO), 7.7 (1H, ArH), 6.5 (1H, ArH), 5.8 (1H, -CH<), 3.6 (2H, -CH2-), 2.0 (1H, -CH2-), 1.7 (5H, -CH2-)

[0246]

[0247] (4-3) Synthesis of 2-hydroxy-3-iodo-4-(2-tetrahydropyranyloxy)styrene In a 100 mL glass reaction vessel, 1.5 g (4.3 mmol) of methyltriphenylphosphonium bromide and 7.0 g of THF were charged, and nitrogen was blown into the reaction vessel at a flow rate of 10 mL / min, and stirring was started. After cooling the reaction vessel to 0°C by immersing it in ice water, 0.80 g (7.2 mmol) of potassium tert-butoxide was added in installments, and stirring was continued for 30 minutes. 1.0 g (2.9 mmol) of 2-hydroxy-3-iodo-4-(2-tetrahydropyranyloxy)benzaldehyde obtained from (4-2) above was added in installments, and after stirring for 1 hour, 11 g of toluene and 16 g of 0.5 M hydrochloric acid were added in sequence. The reaction vessel was returned to room temperature and stirred. The organic layer was transferred to a separatory funnel and washed multiple times with deionized water to obtain a Wittig reaction solution containing 2-hydroxy-3-iodo-4-(2-tetrahydropyranyloxy)styrene and triphenylphosphine oxide. The obtained Wittig reaction solution was purified by column chromatography to obtain 0.71 g of yellow liquid. The yield was 71%. Analysis by liquid chromatography-mass spectrometry (LC-MS) revealed a molecular weight of 346. Furthermore, under the above measurement conditions... １ ¹H-NMR measurements revealed the following peaks, confirming the presence of the chemical structure 2-hydroxy-3-iodo-4-(2-tetrahydropyranyloxy)styrene: δ(ppm)(d6-DMSO): 7.9 (1H, ArH), 7.4 (1H, -CH=), 6.2 (1H, ArH), 5.8 (1H, -CH<), 5.7 (1H, =CH2), 5.6 (1H, =CH2), 3.6 (2H, -CH2-), 2.0 (1H, -CH2-), 1.7 (5H, -CH2-)

[0248]

[0249] (4-4) Synthesis of Compound MA-4 In a 100 mL glass reaction vessel, 0.60 g (1.7 mmol) of 2,4-dihydroxy-3-iodobenzstyrene (as described in (4-3) above), 6.0 g of dichloromethane, and 1.2 g (14 mmol) of 3,4-dihydro-2H-pyran were charged, and nitrogen was blown in at a flow rate of 10 mL / min. 0.087 g (0.36 mmol) of pyridinium p-toluenesulfonate was added, and the mixture was stirred at room temperature of 20°C for 6 hours. 60 μL of triethylamine and 3 g of deionized water were added. After washing the organic layer multiple times with deionized water, the container containing the organic layer was reduced in pressure and the solution was concentrated by immersion in a 25°C water bath. The obtained concentrate was purified by column chromatography to obtain 0.40 g of yellow liquid. The yield was 53%.

[0250] Analysis by liquid chromatography-mass spectrometry (LC-MS) revealed a molecular weight of 430. Furthermore, under the measurement conditions described above... １ ¹H-NMR measurements revealed the following peaks, confirming the presence of the chemical structure of 3-iodo-2,4-di(2-tetrahydropyranyloxy)styrene (compound MA4): δ(ppm)(d6-DMSO): 8.0 (1H, ArH), 7.4 (1H, -CH=), 6.4 (1H, ArH), 5.8 (2H, -CH<), 5.7 (1H, =CH2), 5.6 (1H, =CH2), 3.6 (4H, -CH2-), 2.0 (2H, -CH2-), 1.6 (10H, -CH2-)

[0251]

[0252] [Synthesis Example 5] Synthesis of 2,4-di(1-ethoxyethoxy)-3-iodostyrene (compound MA5) (5-1) Synthesis of 2,4-dihydroxy-3-iodobenzaldehyde 2,4-dihydroxy-3-iodobenzaldehyde was obtained by the same method as in (4-1) of Synthesis Example 4.

[0253] (5-2) Synthesis of 4-(1-ethoxyethoxy)-2-hydroxy-3-iodobenzaldehyde In a 300 mL glass reaction vessel, 5.0 g (19 mmol) of 2,4-dihydroxy-3-iodobenzaldehyde from (5-1) above, 50 g of toluene, and 0.43 g (3.8 mmol) of trifluoroacetic acid were charged, and nitrogen was blown in at a flow rate of 10 mL / min. The reaction vessel was immersed in ice water and cooled to 0°C. After adding 11 g (0.15 mol) of ethyl vinyl ether, the ice bath was removed and the vessel was allowed to return to room temperature. After stirring for 6 hours, 0.42 g of triethylamine and 25 g of deionized water were added. The organic layer was washed several times with deionized water, and the vessel containing the organic layer was reduced to 45 hPa and the solution was concentrated by immersion in a 30°C water bath. The obtained concentrate was purified by column chromatography to obtain 4.7 g of yellow liquid. The yield was 74%.

[0254] Analysis by liquid chromatography-mass spectrometry (LC-MS) revealed a molecular weight of 336. Furthermore, under the measurement conditions described above... １ ¹H-NMR measurements revealed the following peaks, confirming the presence of the chemical structure 4-(1-ethoxyethoxy)-2-hydroxy-3-iodobenzaldehyde. δ(ppm)(d6-DMSO): 10.2 (1H, -CHO), 7.7 (1H, ArH), 6.5 (1H, ArH), 5.6 (1H, -CH<), 3.9 (2H, -CH2-), 1.6 (3H, -CH3), 1.2 (3H, -CH3)

[0255]

[0256] (5-3) Synthesis of 4-(1-ethoxyethoxy)-2-hydroxy-3-iodostyrene In a 100 mL glass reaction vessel, 1.5 g (4.3 mmol) of methyltriphenylphosphonium bromide and 7.0 g of THF were charged, and nitrogen was blown into the reaction vessel at a flow rate of 10 mL / min, and stirring was started. After cooling the reaction vessel to 0°C by immersing it in ice water, 0.80 g (7.2 mmol) of potassium tert-butoxide was added in installments, and stirring was continued for 30 minutes. 0.97 g (2.9 mmol) of 4-(1-ethoxyethoxy)-2-hydroxy-3-iodobenzaldehyde obtained from (5-2) above was added in installments, and after stirring for 1 hour, 11 g of toluene and 16 g of 0.1 M hydrochloric acid were added in sequence. The reaction vessel was returned to room temperature and stirred. The organic layer was transferred to a separatory funnel and washed multiple times with deionized water to obtain a Wittig reaction solution containing 4-(1-ethoxyethoxy)-2-hydroxy-3-iodostyrene and triphenylphosphine oxide. The obtained Wittig reaction solution was purified by column chromatography to obtain 0.67 g of yellow liquid. The yield was 67%. Analysis by liquid chromatography-mass spectrometry (LC-MS) revealed a molecular weight of 334. Furthermore, under the above measurement conditions... １ ¹H-NMR measurements revealed the following peaks, confirming the presence of the chemical structure 4-(2-ethoxyethoxy)-2-hydroxy-3-iodostyrene. δ(ppm)(d6-DMSO): 7.9(1H, ArH), 7.4(1H, -CH=), 6.2(1H, ArH), 5.7(1H, =CH2), 5.6(1H, =CH2), 5.6(1H, -CH<), 3.9(2H, -CH2-), 1.6(3H, -CH3), 1.2(3H, -CH3)

[0257]

[0258] (5-4) Synthesis of Compound MA5 In a 100 mL glass reaction vessel, 0.57 g (1.7 mmol) of 4-(2-ethoxyethoxy)-2-hydroxy-3-iodostyrene (as described in (5-3) above), 6.0 g of dichloromethane, and 1.0 g (14 mmol) of ethyl vinyl ether were charged, and nitrogen was blown in at a flow rate of 10 mL / min. 0.087 g (0.36 mmol) of pyridinium p-toluenesulfonate was added, and the mixture was stirred at room temperature of 20°C for 6 hours. 60 μL of triethylamine and 3 g of deionized water were added. After washing the organic layer multiple times with deionized water, the container containing the organic layer was reduced in pressure and the solution was concentrated by immersion in a 25°C water bath. The resulting concentrate was purified by column chromatography to obtain 0.46 g of yellow liquid. The yield was 66%.

[0259] Analysis by liquid chromatography-mass spectrometry (LC-MS) revealed a molecular weight of 406. Furthermore, under the measurement conditions described above... １ ¹H-NMR measurements revealed the following peaks, confirming the presence of the chemical structure 2,4-di(1-ethoxyethoxy)-3-iodostyrene (compound MA5). δ(ppm)(d6-DMSO): 8.0 (1H, ArH), 7.4 (1H, -CH=), 6.4 (1H, ArH), 5.7 (1H, =CH2), 5.6 (1H, =CH2), 5.6 (1H, -CH<), 5.4 (1H, -CH<), 3.9 (4H, -CH2-), 1.6 (6H, -CH3), 1.2 (6H, -CH3)

[0260]

[0261] [Synthesis Example 6] Synthesis of 2,4-di(ethoxymethoxy)-3-iodostyrene (compound MA6) (6-1) Synthesis of 2,4-dihydroxy-3-iodobenzaldehyde 2,4-dihydroxy-3-iodobenzaldehyde was obtained by the same method as in Synthesis Example (4-1).

[0262] (6-2) Synthesis of 2,4-di(ethoxymethoxy)-4-iodobenzaldehyde In a 200 mL glass reaction vessel, 5.00 g (0.0189 mol) of 2,4-dihydroxy-3-iodobenzaldehyde obtained in (6-1) above, 76 g of dichloromethane, 5.3 g (0.057 mol) of chloromethyl ethyl ether, and 5.7 g (0.057 mmol) of triethylamine were charged and stirred at room temperature of 20°C for 1 hour. Subsequently, 38 g of deionized water was added in sequence and the mixture was separated. The organic layer was washed multiple times with deionized water. After dehydrating the organic layer with magnesium sulfate, the container was reduced in pressure and concentrated in a 30°C water bath to recover the crude product. The obtained crude product was purified by column chromatography to obtain 6.40 g of yellow liquid. The yield was 89%.

[0263] Analysis by liquid chromatography-mass spectrometry (LC-MS) revealed a molecular weight of 380. Furthermore, under the measurement conditions described above... １ ¹H-NMR measurements revealed the following peaks, confirming the presence of the chemical structure 2,4-di(ethoxymethoxy)-4-iodobenzaldehyde: δ(ppm)(d6-DMSO): 10.0 (1H,CHO), 7.8 (1H,ArH), 7.2 (1H,ArH), 5.4 (2H,O-CH2-O), 5.2 (2H,O-CH2-O), 3.8 (2H,-CH2-), 3.7 (2H,-CH2-), 1.1 (6H,-CH3)

[0264]

[0265] (6-3): Synthesis of compound MA6 4.0 g (0.011 mol) of methyltriphenylphosphonium bromide and 18 g of THF were charged into a 100 mL glass reaction vessel, and nitrogen was blown into the reaction vessel at a flow rate of 10 mL / min, and stirring was started. After cooling the reaction vessel to 0°C by immersing it in ice water, 1.2 g (0.011 mol) of potassium tert-butoxide was added in installments, and stirring was continued for 30 minutes. 3.0 g (0.0079 mol) of 2,4-di(ethoxymethoxy)-3-iodobenzaldehyde obtained from (6-2) above was added in installments, and after stirring for 1 hour, 34 g of toluene and 28 g of deionized water were added in sequence. The reaction vessel was returned to room temperature and stirred. The organic layer was transferred to a separatory funnel and washed several times with deionized water to obtain a Wittig reaction solution containing compound MA6 and triphenylphosphine oxide. The resulting Wittig reaction solution was purified by column chromatography to obtain 2.3 g of a yellow liquid. The yield was 77%.

[0266] Analysis by liquid chromatography-mass spectrometry (LC-MS) revealed a molecular weight of 378. Furthermore, under the measurement conditions described above... １ ¹H-NMR measurements revealed the following peaks, confirming the presence of the chemical structure of compound MA6: δ(ppm)(d6-DMSO): 7.6 (1H, ArH), 6.9 (1H, ArH), 6.8 (1H, -CH=), 5.7 (1H, =CH2), 5.3 (2H, O-CH2-O), 5.2 (1H, =CH2), 5.0 (2H, O-CH2-O), 3.8 (2H, -CH2-), 3.7 (2H, -CH2-), 1.1 (6H, -CH3)

[0267]

[0268] [Polymer Synthesis Example 1] Synthesis of Polymer A1 1.5 g of compound MA1 obtained in Synthesis Example 1, 4.0 g of 2-methyl-2-adamantyl methacrylate, 0.9 g of γ-butyrolactone methacrylate, and 1.5 g of hydroxyadamantyl methacrylate were dissolved in 45 mL of tetrahydrofuran, and 0.20 g of azobisisobutyronitrile was added. The mixture was refluxed for 12 hours. After cooling to room temperature, 15 mL of 5% TsOH aqueous solution was added, and the mixture was stirred for 3 hours. Then, the reaction solution was added dropwise to 2 L of n-heptane. The precipitated polymer was filtered off and dried under reduced pressure to obtain polymer A1, represented by the following structural formula (A1), in the form of a white powder. The mass-average molecular weight (Mw) of this polymer was 12,000, and the degree of dispersion (Mw / Mn) was 1.90. １３ ¹³C-NMR measurements revealed that the composition ratio (molar ratio) in the following structural formula (A1) was a:b:c:d = 45:10:15:30. Note that the following structural formula (A1) is a simplified representation to show the ratio of each constituent unit; however, the arrangement order of each constituent unit is random, and it is not a block copolymer where each constituent unit forms an independent block. For styrene monomers, the molar ratio was determined based on the integral ratio of the carbon at the base of the benzene ring, and for methacrylate monomers (2-methyl-2-adamantyl methacrylate, γ-butyrolactone methacrylate, and adamantyl methacrylate), it was determined based on the integral ratio of the carbonyl carbon of the ester bond. The types of monomers, their ratios, and composition ratios in the polymer obtained in Polymer Synthesis Example 1 are shown in Table 1 below. Similarly, the types of monomers, their ratios, and composition ratios in the polymers obtained in the examples described below are also shown in Table 1.

[0269]

[0270] (Polymer Synthesis Examples 2-8) Synthesis of Polymers A2-A8 Polymers A2-A8 represented by structural formula (A1) or structural formula (A4) were obtained by the method described in Polymer Synthesis Example A1, except that 1.5 g of compound MA1 was changed to the type and amount of compound shown in Table 1.

[0271]

[0272] [Polymer Synthesis Comparative Examples 1-5] The monomers MB1-MB5 used in Comparative Examples 1-5 are as follows.

[0273]

[0274] Polymers B1 to B5, represented by the following structural formulas (B1) to (B5), were obtained according to the method described in Polymer Synthesis Example A1, except that the 1.5 g of compound MA1 in Polymer Synthesis Example 1 was changed to the type and amount of compound shown in Table 1 below.

[0275]

[0276]

[0277]

[0278] The meanings of the abbreviations in Table 1 are as follows: MAMA: 2-methyl-2-adamantyl methacrylate BLMA: γ-butyrolactone methacrylate HAMA: p-hydroxystyrene

[0279] From Table 1 above, it was confirmed that when polymerization was carried out using monomers that had been pre-protected with acetal, the ratio of iodine-containing units shown in d improved.

[0280] The polymers obtained in the above-mentioned synthesis examples and comparative examples were evaluated as follows: [EUV sensitivity evaluation by TMAH aqueous solution development] A solution (film-forming composition) was prepared by blending 5 parts by mass of the polymer obtained in the example or comparative example, 1 part by mass of triphenylsulfonium nonafluorobutanesulfonate, 0.2 parts by mass of tributylamine, 80 parts by mass of propylene glycol monomethyl ether acetate (PGMEA), and 12 parts by mass of propylene glycol monomethyl ether (PGME). 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 thickness of 100 nm. Then, it was exposed to 1 mJ / cm using an extreme ultraviolet (EUV) exposure apparatus "EUVES-7000" (product name, manufactured by Lithotech Japan Co., Ltd.). ２ From 1 mJ / cm ２ 80 mJ / cm ２After performing maskless shot exposure with increasing exposure, the wafer was baked (PEB) at 110°C for 90 seconds and developed with a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution for 60 seconds to obtain a wafer with 80 shot exposures. For each shot exposure area obtained, the film thickness was measured using an optical interferometer "VM3200" (product name, manufactured by SCREEN Semiconductor Solutions Co., Ltd.), and profile data of film thickness against exposure was obtained. The exposure value at which the slope of film thickness variation with respect to exposure was largest was set to the sensitivity value (mJ / cm²). ２ This was calculated as an indicator of the EUV sensitivity of the resist.

[0281] [Time-dependent sensitivity evaluation by TMAH aqueous solution development] For each example and comparative example, the solution prepared in the EUV sensitivity evaluation described above was subjected to forced aging treatment under light-shielding conditions at 40°C / 240 hours. The EUV sensitivity evaluation was then performed on the solution after aging treatment in the same manner, and an evaluation was conducted according to the amount of change in sensitivity. Specifically, in the EUV sensitivity evaluation, the sensitivity value at which the slope value is maximum on the film thickness-sensitivity curve after development, with sensitivity on the horizontal axis and film thickness on the vertical axis, was measured as the "standard sensitivity". The standard sensitivity of the solution before and after forced aging treatment was determined, and the "sensitivity shift" due to aging treatment was evaluated using the value obtained from the following formula. The evaluation criteria are as follows: [Sensitivity shift] = 1 - ([Standard sensitivity of solution after aging] ÷ [Standard sensitivity of solution before aging])

[0282] (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]

[0283] [EB Pattern Evaluation by TMAH Aqueous Solution Development] A solution (film-forming composition) was prepared by combining 5 parts by mass of the polymer obtained in the example or 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 110-130°C for 60 seconds to form a photoresist layer (resist film) with a thickness of 100 nm. Then, it was exposed with 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 with a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution for 60 seconds to obtain a positive type pattern. The exposure amount was adjusted so that the half-pitch was 50 nm line and space. For the obtained resist patterns, 80 pattern images were acquired at a magnification of 100,000x using a scanning electron microscope "S-4800" (product name, manufactured by Hitachi, Ltd.). The number of residues in the spaces between the resist patterns was counted, and the total amount of residue was used for evaluation. The evaluation criteria are as follows:

[0284] (Evaluation Criteria) A: Number of residues ≤ 10 B: 10 < Number of residues ≤ 80 C: 80 < Number of residues ≤ 400 D: 400 < Number of residues

[0285] [Etching defect evaluation by TMAH aqueous solution development] A solution (film-forming composition) was prepared by combining 5 parts by mass of the polymer obtained in the example or 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. This solution was applied to an 8-inch silicon wafer on which an oxide film with a thickness of 100 nm was formed as the outermost layer, and baked at 110°C for 60 seconds to form a photoresist layer (resist film) with a thickness of 100 nm. Next, using the extreme ultraviolet (EUV) lithography system "EUVES-7000" (product name, manufactured by Lithotech Japan Co., Ltd.), the entire wafer was shot-exposed with an exposure dose 10% less than the "sensitivity value" obtained in the aforementioned EUV sensitivity evaluation. Furthermore, it was baked (PEB) at 110°C for 90 seconds and developed with a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution for 60 seconds to obtain a wafer with 80 shots of lithography applied to the entire wafer. The fabricated exposed wafer was then subjected to CF etching using the etching system "Telius SCCM" (product name, manufactured by Tokyo Electron Limited). ４ An etching process was performed using Ar gas until the oxide film was etched to 50 nm. The wafers fabricated by etching were evaluated for defects using the "Surfscan SP5" defect inspection system (product name, manufactured by KLA), and the number of cone defects larger than 19 nm was used as an indicator of etching defects.

[0286] (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

[0287] [Evaluation of Etching Defect Changes Over Time by TMAH Aqueous Solution Development] For each example and comparative example, the solutions prepared in the etching defect evaluation described above were left at room temperature of 20°C under light-shielding conditions for 7 days. The etching defect evaluation was performed on the solutions after standing in the same manner, and ratings were given according to the change in the number of defects. Specifically, a change in EUV sensitivity of less than 6% before and after standing was evaluated as "G", and a change of 6% or more was evaluated as "N".

[0288]

[0289] From Table 2 above, it was confirmed that polymers A1 to A6 synthesized using compounds MA1 to MA6, which have a structure in which iodine is sandwiched between two acetal groups, showed improved EUV sensitivity and suppressed changes in sensitivity over time, as well as reduced residue (exposure stability) and improved etching defects. Furthermore, it was confirmed that polymers A1 and A4 showed improved stability over time due to changes in etching defects over time. In addition, it was confirmed that polymers A7 and A8 synthesized using compounds 4-3 and 5-3, which have a structure in which iodine is sandwiched between one acetal group and one hydroxyl group, also showed improved EUV sensitivity and suppressed changes in sensitivity over time.

[0290] [Synthesis Example 7] Synthesis of 3-(octahydro-2H,2'H-[2,3'-bipyran]-2'-yloxy)-5-(2-tetrahydropyranyloxy)-4-iodostyrene (compound MA7)

[0291] (7-1) Synthesis of 3-(octahydro-2H,2'H-[2,3'-bipyran]-2'-yloxy)-5-(2-tetrahydropyranyloxy)-4-iodobenzaldehyde In the same method as in (1-2) of Synthesis Example 1, except that the amount of "pyridinium p-toluenesulfonate" was 49.5 g (0.197 mol), 3-(octahydro-2H,2'H-[2,3'-bipyran]-2'-yloxy)-5-(2-tetrahydropyranyloxy)-4-iodobenzaldehyde was obtained.

[0292] (7-2)3-(octahydro-2H,2'H-[2.3'-bipyran]-2'-yloxy)-5-(2-tetrahydropyranyloxy)-4-iodostyrene Synthesis Example 1, except that in (1-3) of Example 1, 28.0 g (0.0648 mol) of “3,5-di(2-tetrahydropyranyloxy)-4-iodobenzaldehyde” was replaced with 33.4 g (0.0648 mol) of “3-(octahydro-2H,2'H-[2.3'-bipyran]-2'-yloxy)-5-(2-tetrahydropyranyloxy)-4-iodobenzaldehyde” was carried out in the same manner, to obtain 3-(octahydro-2H,2'H-[2.3'-bipyran]-2'-yloxy)-5-(2-tetrahydropyranyloxy)-4-iodostyrene (compound MA7). Furthermore, under the above measurement conditions １ ¹H-NMR measurements revealed the following peaks, confirming the presence of the chemical structure 3-(octahydro-2H,2'H-[2,3'-bipyran]-2'-yloxy)-5-(2-tetrahydropyranyloxy)-4-iodostyrene (compound MA7). δ(ppm)(d6-DMSO): 7.0(¹H,ArH), 6.9(¹H,ArH), 6.7(¹H,-CH=), 5.9(¹H,=CH²), 5.9(¹H,-CH<), 5.8(¹H,-CH<), 5.3(¹H,=CH²), 3.7(⁶H,-CH²-), 3.4(H,-CH<), 2.2(¹H,-CH<), 2.1(⁶H,-CH²-), 1.7-1.5(¹⁴H,-CH²-)

[0293] [Synthesis Example 8] Synthesis of 2-(1-ethoxyethoxy)-4-(1,3-diethoxybutoxy)-3-iodostyrene (compound MA8)

[0294] (8-1) Synthesis of Compound MA8 In the same method as in (5-2) of Synthesis Example 5, 2-(1-ethoxyethoxy)-4-(1,3-diethoxybutoxy)-3-iodostyrene (compound MA8) was obtained, except that 0.435 g (1.8 mmol) of "pyridinium p-toluenesulfonate" was used. Also, under the above measurement conditions １¹H-NMR measurements revealed the following peaks, confirming the presence of the chemical structure 2-(1-ethoxyethoxy)-4-(1,3-diethoxybutoxy)-3-iodostyrene (compound MA7). δ(ppm)(d6-DMSO): 8.0(1H,ArH), 7.4(1H,-CH=), 6.4(1H,ArH), 5.7(1H,=CH2), 5.6(1H,=CH2), 5.6(1H,-CH<), 5.4(1H,-CH<), 3.9(4H,-CH2-), 3.8(2H,-CH2-), 3.6(1H,-CH<), 1.8(2H,-CH2-), 1.6(3H,-CH3), 1.2(12H,-CH3)

[0295] [Storage Stability of Compound MA1] 0.1 g of 3,5-di(2-tetrahydropyranyloxy)-4-iodostyrene (compound MA1) was dissolved in 10 ml of PGMEA and stored for 60 days at 0°C under light-shielding conditions. After storage, the LC purity at 220 nm was measured and found to have decreased to 95.5%. In contrast, when 0.5% by mass of 3-(octahydro-2H,2'H-[2,3'-bipyran]-2'-yloxy)-5-(2-tetrahydropyranyloxy)-4-iodostyrene (compound MA7) was added to compound (MA1), the LC purity at 220 nm under the same storage conditions was 99.2%. This indicates that the composition containing compound MA1 and compound MA7 has superior storage stability compared to the composition containing compound MA1 alone.

[0296] [Storage Stability of Compound MA5] Under light-shielded conditions, 0.1 g of 2,4-di(1-ethoxyethoxy)-3-iodostyrene (Compound MA5) was dissolved in 10 ml of PGMEA and stored at 0°C for 60 days. After storage, the LC purity at 220 nm was measured and found to have decreased to 92.3%. In contrast, when 0.5% by mass of 2-(1-ethoxyethoxy)-4-(1,3-diethoxybutoxy)-3-iodostyrene (Compound MA8) was added to Compound (MA5), the LC purity at 220 nm was 99.2% under the same storage conditions. Thus, it was found that the composition in which Compound MA5 and Compound MA8 coexist is superior in storage stability to the composition of Compound MA5 alone.

[0297] [Synthesis Example 9] Synthesis of Methyl [4-iodo-3,5-di(1-ethoxyethoxy)phenyl]methacrylate (Compound MA9)

[0298] (9-1) Synthesis of Compound MA9-1 Into a 500 mL glass reaction vessel, 4.90 g (12 mmol) of 3,5-di(1-ethoxyethoxy)-4-iodobenzaldehyde obtained from (2-2) above was charged, 49 g of 2-ethanol was added, and nitrogen was blown in at a flow rate of 10 mL / min. The reaction vessel was immersed in ice water and cooled to 0°C. 0.15 g (4.0 mmol) of sodium borohydride was added portionwise over 10 minutes, then the ice bath was removed and the vessel was returned to room temperature of 20°C. After stirring for 1 hour, 10 g of a 5% aqueous ammonium chloride solution and 25 g of ion-exchanged water were added. The crude product was recovered by suction filtration and redissolved in a mixed solvent of 25 g of ethyl acetate and 25 g of toluene. The solution was washed several times with ion-exchanged water, then the vessel was depressurized and immersed in a water bath at 50°C to concentrate the solution, and 20 g of a concentrated solution was obtained. After adding 50 g of heptane, crystallization was carried out by stirring for 1 hour under ice cooling. The obtained solid was recovered by suction filtration. It was dried in vacuo at 30°C to obtain 4.63 g of a white solid (Compound MA9-1). The yield was 94 percent.

[0299] As a result of analysis by liquid chromatography-mass spectrometry (LC-MS), a molecular weight of 434 was observed. Also, under the said measurement conditions １When H-NMR measurement was carried out, the following peaks were found, confirming that it has the chemical structure of [4-iodo-3,5-di(1-ethoxyethoxy)-phenyl]methanol. δ (ppm) (d6-DMSO): 7.0 (2H, ArH), 5.8 (2H, -CH2-Ar), 5.6 (2H, -CH<), 4.5 (1H, -ОH), 3.9 (4H, -CH2-), 1.6 (6H, -CH3), 1.2 (6H, -CH3)

[0300]

[0301] (9-1) Synthesis of Compound MA9 4.10 g (10 mmol) of [4-iodo-3,5-di(1-ethoxyethoxy)-phenyl]methanol obtained from (9-1) above and 50 mL of tetrahydrofuran were charged into a 500 mL glass reaction vessel, and N ２ Under a flow, while ice-cooling to an internal temperature of 10 °C, 1.7 mL (12 mmol) of triethylamine, 127 mg (1.0 mmol) of DMAP, and 1.8 mL (12 mmol) of methacrylic anhydride were added, and then stirred for 40 minutes. While ice-cooling to keep the internal temperature at 10 °C or lower, 5 g of a saturated aqueous ammonium chloride solution was added. 50 g of ethyl acetate and 50 g of ion-exchanged water were further added, stirred for 15 minutes and allowed to stand, and then the aqueous layer was separated. The organic layer was washed with ion-exchanged water several times, and the recovered organic layer was concentrated by distillation under reduced pressure until the distillation of the solvent component disappeared to obtain a crude product. The obtained residue was purified by silica gel column chromatography to obtain 3.06 g of a white solid (Compound MA9). The yield was 64 percent.

[0302] As a result of analysis by liquid chromatography-mass spectrometry (LC-MS), a molecular weight of 502 was observed. Also under the said measurement conditions １¹H-NMR measurements revealed the following peaks, confirming the presence of the chemical structure of compound MA9 (methacrylic acid [4-iodo-3,5-di(1-ethoxyethoxy)-phenyl]methyl): δ(ppm)(d6-DMSO): 7.0 (2H, ArH), 6.1 (1H, C=CH2), 5.7 (1H, C=CH2), 5.6 (2H, -CH<), 5.0 (2H, ArCH2-), 3.9 (4H, -CH2-), 1.6 (6H, -CH3), 1.48 (3H, -CH3), 1.2 (6H, -CH3)

[0303] (Polymer Synthesis Example 9) Synthesis of Polymer A9 Polymer 9 represented by structural formula (A9) was obtained by the method described in Polymer Synthesis Example A1, except that 1.5 g of compound MA1 was changed to the type and amount of compound shown in Table 3.

[0304]

[0305] From Table 3 above, it was confirmed that polymer A9 synthesized using compound MA9, which has a structure in which iodine is sandwiched between two acetal groups, as a monomer, showed improved EUV sensitivity and suppressed changes in sensitivity over time, as well as reduced residue (exposure stability) and improved etching defects.

[0306] The disclosure of Japanese Patent Application No. 2024-164259, filed on September 20, 2024, is incorporated herein by reference in its entirety. Furthermore, all documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if the incorporation of each individual document, patent application, and technical standard were specifically and individually noted.

Claims

1. A compound represented by the following formula (0). (In the formula, A is an aromatic group having 6 to 30 carbon atoms, and X １ is a single bond or an ester bond, O is an oxygen atom, I is an iodine atom, R １ R is a hydrogen atom or a methyl group. ２ Each is independently a hydrogen atom or an acid-degradable group, and R ２ At least one of the groups is an acid-degradable group, n is an integer greater than or equal to 1, m is an integer greater than or equal to 2, and m > n.

2. The compound according to claim 1, represented by the following formula (0A) or (0B). (In the formula, R １ O, I, R ２ n and m are the same as in equation (0), and m > n.

3. The compound according to claim 1, represented by the following formula (0C). (In the formula, R １ O, I, R ２ n and m are the same as in equation (0).

4. The compound according to claim 1, represented by the following formula (1). (In the formula, R １ , X １ , O, I and R ２ are the same as in formula (0), n is an integer of 1 to 2, m is an integer of 2 to 3, n + m is 3 or more and 5 or less, and m > n.) 5. The compound according to claim 4, represented by the following formula (A). (In the formula, R １ O, I, n, and m are the same as in formula (1), and RA are each independently alkyl groups having 1 to 4 carbon atoms.

6. The compound according to claim 5, wherein in formula (A), n = 1 and m = 2.

7. The compound according to claim 5, represented by the following formula (A1) or the following formula (A2). (In the formula, R １ O, I, and RA are the same as in formula (A).

8. The compound according to claim 4, represented by the following formula (B). (In the formula, R １ O, I, n, and m are the same as in formula (1), RB is independently an alkyl group having 1 to 6 carbon atoms, and RC is independently a hydrogen atom or a group that forms a ring structure by bonding with the alkyl group of RB.

9. The compound according to claim 8, wherein in formula (B), n = 1 and m = 2.

10. The compound according to claim 8, represented by the following formula (B1) or the following formula (B2). (In the formula, R １ O, I, RB, and RC are the same as in formula (B).

11. -OR in formula (1) above ２ The compound according to claim 4, wherein each of the groups represented is independently an acetal group.

12. R in formula (1) above ２ The compound according to claim 4, wherein the group is selected from a tetrahydropyranyl group, a methoxymethyl group, an ethoxymethyl group, and an ethoxyethyl group.

13. A composition comprising a compound according to any one of claims 1 to 12 and a solvent.

14. A composition comprising a compound according to any one of claims 1 to 12 and a compound represented by the following formula (2). (In the formula, R １ , X １ O and I are the same as in equation (0), and R ４ Each of these is independently a hydrogen atom, an acid-degradable group, or a group to which two acid-degradable groups are bonded, R ４ At least one of the groups is a group to which the two acid-degradable groups are bonded, n is an integer between 1 and 2, m is an integer between 2 and 3, n + m is between 3 and 5, and m > n.

15. The composition according to claim 14, wherein the total amount of the compound represented by formula (2) relative to the total amount of the compounds described in any one of claims 1 to 12 is 1 ppm by mass or more and 10% by mass or less.

16. The composition according to claim 14, wherein in formula (2), n = 1 and m = 2.

17. A composition comprising at least one compound according to any one of claims 1 to 12, and at least one compound represented by the following formula (2A) and the following formula (2B). (In the formula, R １ O and I are the same as in formula (0), RA is independently an alkylene group having 1 to 4 carbon atoms, RA1 is independently an alkyl group having 2 to 4 carbon atoms which may have a hydrogen atom or an ether group, at least one of RA1 is an alkyl group having 2 to 4 carbon atoms which may have an ether group, n is an integer from 1 to 2, m is an integer from 2 to 3, n + m is between 3 and 5, and m > n. (In the formula, R １ , O and I are the same as in formula (0), RB is independently an alkylene group having 1 to 6 carbon atoms, RC is independently a hydrogen atom or a group that forms a ring structure by bonding with the alkyl group of RB, RB1 is independently a hydrogen atom or an alkyl group having 2 to 6 carbon atoms which may have an ether group, at least one of RB1 is an alkyl group having 2 to 6 carbon atoms which may have the ether group, n is an integer from 1 to 2, m is an integer from 2 to 3, n + m is 3 or more and 5 or less, and m > n.

18. The composition according to claim 17, wherein the compound represented by formula (2A) is the compound represented by the following formula (2A1) or formula (2A2), and the compound represented by formula (2B) is the compound represented by the following formula (2B1) or formula (2B2).

19. The composition according to claim 17, wherein in formulas (2A) and (2B), n = 1 and m = 2.

20. The composition according to claim 17, wherein the total amount of the compounds represented by formula (2A) and formula (2B) relative to the total amount of the compounds described in any one of claims 1 to 12 is 1 ppm by mass or more and 10% by mass or less.

21. A (co)polymer comprising a structural unit corresponding to a compound according to any one of claims 1 to 12, and / or a structural unit in which at least a portion of the groups containing an acid-degradable group in the compound according to any one of claims 1 to 12 is converted to a hydroxyl group.

22. The (co)polymer according to claim 21, further comprising a structural unit corresponding to a compound having an adamantane skeleton, and / or a structural unit corresponding to a compound having a lactone skeleton.

23. A film-forming composition comprising the (co)polymer according to claim 21 and a solvent.

24. The film-forming composition according to claim 23, further comprising at least one selected from an acid generator, a base generator, and a base compound.

25. A method for producing a compound represented by the following formula (1), comprising: an iodine introduction step of introducing iodine into a compound represented by the following formula (X1) to obtain a compound represented by the following formula (X2); a protecting group introduction step of introducing a protecting group to at least one hydroxyl group in the compound represented by the following formula (X2) obtained in the iodine introduction step; and a methyleneization step of methyleneizing the compound obtained in the protecting group introduction step. (In the formula, X １ is a single bond or an ester bond, O is an oxygen atom, I is an iodine atom, R １ R is a hydrogen atom or a methyl group. ２ Each is independently a hydrogen atom or an acid-degradable group, and R ２ At least one of the groups is an acid-degradable group, n is an integer between 1 and 2, m is an integer between 2 and 3, n + m is between 3 and 5 (inclusive), and m > n.

26. A method for producing the compound according to claim 25, wherein in the protecting group introduction step, a protecting group is introduced to all the hydroxyl groups in the compound represented by formula (X2) obtained in the iodine introduction step.

27. A method for producing the compound according to claim 25, wherein the protecting group introduction step includes introducing a protecting group to some of the hydroxyl groups in the compound represented by formula (X2) obtained in the iodine introduction step, the methyleneization step includes methyleneating the compound obtained in the protecting group introduction step, and further including introducing a protecting group to all of the hydroxyl groups in the compound obtained in the methyleneization step.

28. A method for producing the compound according to claim 25, wherein n = 1 and m = 2 in the above formula.

29. In equation (1) above, I is meta and two ORs ２ ortho and para positions respectively, or I is in the para position and two ORs ２ A method for producing the compound according to claim 28, wherein each of the compounds is bonded to the meta position.

30. -OR in formula (1) above ２ A method for producing the compound according to claim 25, wherein each of the groups represented is independently an acetal group.

31. R in formula (1) above ２ A method for producing the compound according to claim 25, wherein the group is selected from a tetrahydropyranyl group, a methoxymethyl group, an ethoxymethyl group, and an ethoxyethyl group.

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