Method for producing semiconductor substrate and resist underlayer film-forming composition

Abstract

The purpose of the present invention is to provide: a method for producing a semiconductor substrate, the method using a resist underlayer film-forming composition from which it is possible to form a resist underlayer film that has excellent solvent resistance and excellent resist pattern rectangularity; and a resist underlayer film-forming composition. The method for producing a semiconductor substrate comprises: a step for directly or indirectly applying a resist underlayer film-forming composition to a substrate; a step for applying a resist film-forming composition to a resist underlayer film that is formed in the step for applying the resist underlayer film-forming composition; a step for exposing, to radiation, a resist film that is formed in the step for applying the resist film-forming composition; and a step for developing at least the exposed resist film. The resist underlayer film-forming composition contains a polymer that has a partial structure represented by formula (i), and a solvent. (In formula (i), Y1 represents a divalent group selected from the group consisting of a sulfonyl group, a carbonyl group, and an alkanediyl group. Y2 represents a divalent group selected from the group consisting of a sulfonyl group, a carbonyl group, and a single bond. Note that in the case where Y1 represents an alkanediyl group, Y2 represents a sulfonyl group or a carbonyl group. In the case where Y2 represents a single bond, Y1 represents a sulfonyl group or a carbonyl group. R1 represents a monovalent organic group having 1-20 carbon atoms. X+ represents a monovalent onium cation.* represents a bond between the polymer and another structure.)

Description

Semiconductor substrate manufacturing method and composition for forming resist underlayer film

[0001] The present invention relates to a method for producing a semiconductor substrate and a composition for forming a resist underlayer film.

[0002] In the manufacture of semiconductor devices, for example, a multilayer resist process is used in which a resist pattern is formed by exposing and developing a resist film laminated on a substrate via a resist underlayer film such as an organic underlayer film or a silicon-containing film. In this process, the resist underlayer film is etched using the resist pattern as a mask, and the substrate is further etched using the resulting resist underlayer film pattern as a mask, thereby forming a desired pattern on the semiconductor substrate.

[0003] In recent years, semiconductor devices have become increasingly highly integrated, and the wavelength of the exposure light used has tended to be shortened from KrF excimer lasers (248 nm) and ArF excimer lasers (193 nm) to extreme ultraviolet light (13.5 nm, hereinafter also referred to as "EUV"). Various studies have been conducted on compositions for forming resist underlayer films (see International Publication No. 2013 / 141015).

[0004] International Publication No. 2013 / 141015

[0005] The resist underlayer film is required to have solvent resistance to the solvent in the resist composition, and to have a resist pattern rectangularity that prevents footing of the resist pattern and ensures rectangularity of the resist pattern.

[0006] The present invention has been made in light of the above circumstances, and an object of the present invention is to provide a method for producing a semiconductor substrate using a composition for forming a resist underlayer film, which is capable of forming a resist underlayer film that is excellent in solvent resistance and resist pattern rectangularity, and a composition for forming a resist underlayer film.

[0007] In one embodiment, the present invention relates to a method for producing a semiconductor substrate, comprising: a step of applying a composition for forming a resist underlayer film directly or indirectly to a substrate; a step of applying a composition for forming a resist film to the resist underlayer film formed in the step of applying the composition for forming a resist film; a step of exposing the resist film formed in the step of applying the composition for forming a resist film to radiation; and a step of developing at least the exposed resist film, wherein the composition for forming a resist underlayer film contains: a polymer having a partial structure represented by the following formula (i) (hereinafter also referred to as "polymer [A]"); and a solvent (hereinafter also referred to as "solvent [C]"). (In formula (i), Y １ Y is a divalent group selected from the group consisting of a sulfonyl group, a carbonyl group, and an alkanediyl group. ２ is a divalent group selected from the group consisting of a sulfonyl group, a carbonyl group, and a single bond. １ is an alkanediyl group, Y ２ is a sulfonyl group or a carbonyl group. ２ is a single bond, Y １ is a sulfonyl group or a carbonyl group. １ is a monovalent organic group having 1 to 20 carbon atoms. ＋ is a monovalent onium cation. * is a bond to another structure in the polymer.

[0008] In another embodiment, the present invention relates to a composition for forming a resist underlayer film, comprising: a polymer having a partial structure represented by the following formula (i); and a solvent. (In formula (i), Y １ Y is a divalent group selected from the group consisting of a sulfonyl group, a carbonyl group, and an alkanediyl group. ２ is a divalent group selected from the group consisting of a sulfonyl group, a carbonyl group, and a single bond. １ is an alkanediyl group, Y ２ is a sulfonyl group or a carbonyl group. ２ is a single bond, Y １ is a sulfonyl group or a carbonyl group.１ is a monovalent organic group having 1 to 20 carbon atoms. ＋ is a monovalent onium cation. * is a bond to another structure in the polymer.

[0009] According to the method for producing a semiconductor substrate, a composition for forming a resist underlayer film is used, which can form a resist underlayer film having excellent solvent resistance and rectangular resist pattern, and therefore, semiconductor substrates can be produced efficiently. The composition for forming a resist underlayer film can form a film having excellent solvent resistance and rectangular resist pattern. Therefore, these compositions can be suitably used in the production of semiconductor devices, etc.

[0010] Hereinafter, the method for producing a semiconductor substrate and the composition for forming a resist underlayer film according to each embodiment of the present invention will be described in detail.

[0011] <<Method for Manufacturing Semiconductor Substrate>> The method for manufacturing a semiconductor substrate includes a step of applying a composition for forming a resist underlayer film directly or indirectly to a substrate (hereinafter also referred to as a “coating step (I)”), a step of applying a composition for forming a resist film to the resist underlayer film formed in the above-mentioned coating step of the composition for forming a resist film (hereinafter also referred to as a “coating step (II)”), a step of exposing the resist film formed in the above-mentioned coating step of the composition for forming a resist film to radiation (hereinafter also referred to as an “exposure step”), and a step of developing at least the exposed resist film (hereinafter also referred to as a “development step”).

[0012] According to the method for producing a semiconductor substrate, by using a predetermined composition for forming a resist underlayer film in the coating step (I), a resist underlayer film having excellent solvent resistance and resist pattern rectangularity can be formed, and therefore a semiconductor substrate having a good pattern shape can be produced.

[0013] It is preferable that the method for producing a semiconductor substrate further includes, before the coating step (II), a step of heating the resist underlayer film formed in the resist underlayer film-forming composition coating step at 200°C or higher (hereinafter also referred to as a "heating step").

[0014] The method for producing a semiconductor substrate may further include, as necessary, a step of forming a silicon-containing film directly or indirectly on the substrate (hereinafter also referred to as a "silicon-containing film-forming step") prior to the coating step (I).

[0015] Hereinafter, a description will be given of the composition for forming a resist underlayer film used in the method for producing a semiconductor substrate, as well as each step in the case where the method includes a heating step, which is a preferred step, and a silicon-containing film-forming step, which is an optional step.

[0016] <Composition for forming a resist underlayer film> The composition for forming a resist underlayer film (hereinafter also referred to as the "composition") contains a polymer [A] and a solvent [C]. The composition may contain optional components within a range that does not impair the effects of the present invention. By containing the polymer [A] and the solvent [C], the composition for forming a resist underlayer film can form a resist underlayer film that has excellent solvent resistance and resist pattern rectangularity. The reason for this is unclear, but is presumed to be as follows. The composition for forming a resist underlayer film uses, as its main component, a polymer (i.e., polymer [A]) having a sulfonimide salt structure, sulfonamide salt structure, imide salt structure, or the like as a partial structure, thereby reducing solubility in organic solvents. Furthermore, acid generated from the partial structure in the resist underlayer film supplies acid to the bottom of the resist film in the exposed area during the exposure step, thereby increasing the solubility in the developer at the bottom of the resist film and achieving resist pattern rectangularity.

[0017] <Polymer [A]> The polymer [A] has a partial structure represented by the following formula (i): The composition can contain one or more types of polymer [A].

[0018] (In formula (i), Y １ Y is a divalent group selected from the group consisting of a sulfonyl group, a carbonyl group, and an alkanediyl group. ２ is a divalent group selected from the group consisting of a sulfonyl group, a carbonyl group, and a single bond. １ is an alkanediyl group, Y ２ is a sulfonyl group or a carbonyl group. ２is a single bond, Y １ is a sulfonyl group or a carbonyl group. １ is a monovalent organic group having 1 to 20 carbon atoms. ＋ is a monovalent onium cation. * is a bond to another structure in the polymer.

[0019] Y １ Examples of the alkanediyl group represented by the formula (I) include linear or branched alkanediyl groups having 1 to 10 carbon atoms, such as methanediyl, ethanediyl, propanediyl, and butanediyl groups. １ The alkanediyl group represented by the formula (I) is preferably a methanediyl group.

[0020] In the above formula (1), R １ Examples of the monovalent organic group having 1 to 20 carbon atoms represented by the formula (I) include a monovalent hydrocarbon group having 1 to 20 carbon atoms, a group having a divalent heteroatom-containing group between the carbon atoms of the hydrocarbon group, a group in which some or all of the hydrogen atoms of the hydrocarbon group have been substituted with a monovalent heteroatom-containing group, or a combination thereof. Note that an "organic group" is a group having at least one carbon atom.

[0021] Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms include a monovalent chain hydrocarbon group having 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, and combinations thereof.

[0022] In this specification, the term "hydrocarbon group" includes linear hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups. This "hydrocarbon group" includes saturated hydrocarbon groups and unsaturated hydrocarbon groups. The term "linear hydrocarbon group" refers to a hydrocarbon group that does not contain a ring structure and is composed only of a linear structure, and includes both linear hydrocarbon groups and branched hydrocarbon groups. The term "alicyclic hydrocarbon group" refers to a hydrocarbon group that contains only an alicyclic structure as a ring structure and does not contain an aromatic ring structure, and includes both monocyclic alicyclic hydrocarbon groups and polycyclic alicyclic hydrocarbon groups (however, it does not have to be composed only of an alicyclic structure and may contain a linear structure as part of it). The term "aromatic hydrocarbon group" refers to a hydrocarbon group that contains an aromatic ring structure as a ring structure (however, it does not have to be composed only of an aromatic ring structure and may contain an alicyclic structure or a linear structure as part of it).

[0023] Examples of the monovalent chain hydrocarbon group having 1 to 20 carbon atoms include alkyl groups such as methyl, ethyl, n-propyl, i-propyl, n-butyl, sec-butyl, and tert-butyl; alkenyl groups such as ethenyl, propenyl, and butenyl; and alkynyl groups such as ethynyl, propynyl, and butynyl.

[0024] Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group; cycloalkenyl groups such as a cyclopropenyl group, a cyclopentenyl group and a cyclohexenyl group; bridged ring saturated hydrocarbon groups such as a norbornyl group, an adamantyl group and a tricyclodecyl group; and bridged ring unsaturated hydrocarbon groups such as a norbornenyl group and a tricyclodecenyl group.

[0025] Examples of the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms include a phenyl group, a tolyl group, a naphthyl group, an anthracenyl group, a pyrenyl group, and a benzyl group.

[0026] Examples of heteroatoms constituting the divalent or monovalent heteroatom-containing group include oxygen atoms, nitrogen atoms, sulfur atoms, phosphorus atoms, silicon atoms, halogen atoms, etc. Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0027] Examples of the divalent heteroatom-containing group include -CO-, -CS-, -NH-, -O-, -S-, and combinations of these groups.

[0028] Examples of the monovalent heteroatom-containing group include a hydroxy group, a sulfanyl group, a cyano group, a nitro group, and a halogen atom.

[0029] R １ may have a substituent other than the monovalent heteroatom-containing group. Examples of the substituent include a monovalent chain hydrocarbon group having 1 to 10 carbon atoms, a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom, an alkoxy group such as a methoxy group, an ethoxy group, or a propoxy group, an aryloxy group such as a phenoxy group or a naphthyloxy group, an alkoxycarbonyl group such as a methoxycarbonyl group or an ethoxycarbonyl group, an alkoxycarbonyloxy group such as a methoxycarbonyloxy group or an ethoxycarbonyloxy group, an acyl group such as a formyl group, an acetyl group, a propionyl group, or a butyryl group, a cyano group, a nitro group, a hydroxy group, a carboxy group, and an oxo group (═O).

[0030] The above R １ is Y in the above formula (i). ２ Preferably, R is a monovalent organic group having 1 to 20 carbon atoms, in which a fluorine atom or a fluorinated hydrocarbon group is bonded to the carbon atom adjacent to R. This makes it possible to make the acid generated from the partial structure strongly acidic, thereby improving the rectangularity of the resist pattern. １ is Y in the above formula (i). ２ Preferably, Y is a monovalent fluorinated alkyl group having 1 to 20 carbon atoms, in which a fluorine atom or a fluorinated hydrocarbon group is bonded to the carbon atom adjacent to Y. ２ is a sulfonyl group or a carbonyl group, R １ is more preferably a perfluoroalkyl group having 1 to 5 carbon atoms, and particularly preferably a trifluoromethyl group. ２ is a single bond, R １is more preferably a fluoroalkyl group having 1 to 5 carbon atoms or a perfluoroalkyl group having 1 to 5 carbon atoms, and particularly preferably a 2,2,2-trifluoroethyl group or a perfluoroethyl group.

[0031] Above X ＋ Examples of the monovalent onium cation represented by the formula (c-a) below (hereinafter also referred to as "cation (c-a)"), the cation represented by the formula (c-b) below (hereinafter also referred to as "cation (c-b)"), and the cation represented by the formula (c-c) below (hereinafter also referred to as "cation (c-c)"), etc.

[0032]

[0033] In the above formula (ca), R Ｃ３ , R Ｃ４ and R Ｃ５ are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms, a halogen atom, or —OSO ２ -R ＣＣ１ or -SO ２ -R ＣＣ２ or a ring structure formed by combining two or more of these groups together. ＣＣ１ and R ＣＣ２ are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 5 to 25 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms. c1, c2, and c3 are each independently an integer of 0 to 5. R Ｃ３ ~R Ｃ５ and R ＣＣ１ and R ＣＣ２ If there are multiple R Ｃ３ ~R Ｃ５ and R ＣＣ１ and R ＣＣ２ may be the same or different.

[0034] In the above formula (c-b), R Ｃ６is a substituted or unsubstituted linear or branched alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 8 carbon atoms, or a halogen atom. c4 is an integer of 0 to 7. R Ｃ６ If there are multiple R Ｃ６ may be the same or different, and multiple R Ｃ６ may represent a ring structure formed by combining with each other. Ｃ７ is a substituted or unsubstituted linear or branched alkyl group having 1 to 7 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 or 7 carbon atoms, or a halogen atom. c5 is an integer of 0 to 6. Ｃ７ If there are multiple R Ｃ７ may be the same or different, and multiple R Ｃ７ may represent a ring structure formed by combining with each other. ｃ２ is an integer from 0 to 3. Ｃ８ is a single bond or a divalent organic group having 1 to 20 carbon atoms. ｃ１ is an integer from 0 to 2.

[0035] In the above formula (cc), R Ｃ９ and R Ｃ１０ are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms, a halogen atom, a cyano group, a nitro group, or —OSO ２ -R ＣＣ３ or -SO ２ -R ＣＣ４ or a ring structure formed by combining two or more of these groups together. ＣＣ３ and R ＣＣ４ are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 5 to 25 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms. c6 and c7 are each independently an integer of 0 to 5. R Ｃ９ , R Ｃ１０ , R ＣＣ３ and R ＣＣ４ If there are multiple R Ｃ９ , RＣ１０ , R ＣＣ３ and R ＣＣ４ may be the same or different.

[0036] R Ｃ３ , R Ｃ４ , R Ｃ５ , R Ｃ６ , R Ｃ７ , R Ｃ９ and R Ｃ１０ Examples of the unsubstituted linear alkyl group represented by the formula (I) include a methyl group, an ethyl group, an n-propyl group, and an n-butyl group.

[0037] R Ｃ３ , R Ｃ４ , R Ｃ５ , R Ｃ６ , R Ｃ７ , R Ｃ９ and R Ｃ１０ Examples of the unsubstituted branched alkyl group represented by the formula (I) include an isopropyl group, an isobutyl group, a sec-butyl group, and a t-butyl group.

[0038] R Ｃ３ , R Ｃ４ , R Ｃ５ , R Ｃ９ and R Ｃ１０ Examples of the unsubstituted aromatic hydrocarbon group represented by the formula include aryl groups such as phenyl, tolyl, xylyl, mesityl and naphthyl; and aralkyl groups such as benzyl and phenethyl.

[0039] R Ｃ６ and R Ｃ７ Examples of the unsubstituted aromatic hydrocarbon group represented by the formula (I) include a phenyl group, a tolyl group, and a benzyl group.

[0040] R Ｃ８ The divalent organic group represented by the above R １ Examples of the monovalent organic group include a group in which one hydrogen atom has been removed from the monovalent organic group represented by the following formula:

[0041] R Ｃ３ , R Ｃ４ , R Ｃ５ , R Ｃ６ , R Ｃ７ , R Ｃ９ and R Ｃ１０Examples of the substituent that may substitute a hydrogen atom on the alkyl group and aromatic hydrocarbon group represented by the formula (I) include a monovalent chain hydrocarbon group having 1 to 10 carbon atoms, a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom, an alkoxy group such as a methoxy group, an ethoxy group, or a propoxy group, an alkoxycarbonyl group such as a methoxycarbonyl group or an ethoxycarbonyl group, an alkoxycarbonyloxy group such as a methoxycarbonyloxy group or an ethoxycarbonyloxy group, an acyl group such as a formyl group, an acetyl group, a propionyl group, or a butyryl group, a cyano group, and a nitro group. Among these, a halogen atom is preferred, and a fluorine atom is more preferred.

[0042] R Ｃ３ , R Ｃ４ , R Ｃ５ , R Ｃ６ , R Ｃ７ , R Ｃ９ and R Ｃ１０ Examples of the alkyl group include an unsubstituted linear or branched alkyl group, a halogen atom, a fluorinated alkyl group, an unsubstituted monovalent aromatic hydrocarbon group, and —OSO ２ -R ＢＢ５ , and -SO ２ -R ＢＢ５ is preferred, a branched alkyl group, a halogen atom, a fluorinated alkyl group, and an unsubstituted monovalent aromatic hydrocarbon group are more preferred, and a t-butyl group and a fluorine atom are even more preferred. ＢＢ５ is an unsubstituted monovalent alicyclic hydrocarbon group or an unsubstituted monovalent aromatic hydrocarbon group.

[0043] In formula (ca), c1, c2, and c3 are preferably integers of 0 to 2, more preferably 0 or 1, and even more preferably 0. In formula (cb), c4 is preferably an integer of 0 to 2, more preferably 0 or 1, and even more preferably 1. In formula (cb), c5 is preferably an integer of 0 to 2, more preferably 0 or 1, and even more preferably 0. n ｃ２ is preferably 2 or 3, and more preferably 2. ｃ１ is preferably 0 or 1, and more preferably 0. c6 and c7 in formula (cc) are preferably integers of 0 to 2, and more preferably 0 or 1.

[0044] X＋ Among these, the cations (c-a) and (c-c) are preferred. As the cation (c-a), triphenylsulfonium cation and tris(4-fluorophenyl)sulfonium cation are more preferred. As the cation (c-c), diphenyliodonium cation, bis(4-t-butylphenyl)iodonium cation, bis(4-fluorophenyl)iodonium cation, bis(4-bromophenyl)iodonium cation, bis(4-cyanophenyl)iodonium cation and bis(4-nitrophenyl)iodonium cation are more preferred.

[0045] The polymer [A] preferably has a repeating unit represented by the following formula (1) (hereinafter also referred to as "repeating unit (1)"): When the polymer [A] has the repeating unit (1), a partial structure represented by the above formula (i) (i.e., an acid-generating structure such as a sulfonimide salt structure, a sulfonamide salt structure, or an imide salt structure) can be introduced into the polymer [A].

[0046] (In formula (1), R ａ is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms. １ represents a single bond or a divalent linking group other than an alkanediyl group. １ , Y ２ , R １ and X ＋ has the same meaning as in formula (i) above.

[0047] In the above formula (1), R ａ The monovalent hydrocarbon group having 1 to 20 carbon atoms represented by the formula (i) is １ A monovalent hydrocarbon group having 1 to 20 carbon atoms in the formula R ａ When R has a substituent, the substituent may be any of R Ｃ３ , R Ｃ４ , R Ｃ５ , R Ｃ６ , R Ｃ７ , R Ｃ９ and R Ｃ１０ The substituents that may be possessed by the alkyl group represented by the following formula can be suitably employed.ａ is preferably a hydrogen atom.

[0048] L １ The divalent linking group represented by the formula (i) is a divalent group other than an alkanediyl group. １ Examples of such a group include a group in which one hydrogen atom has been removed from a monovalent organic group having 1 to 20 carbon atoms, represented by the following formula: １ is preferably a divalent hydrocarbon group. １ The divalent hydrocarbon group in the formula (i) is R １ and groups in which one hydrogen atom has been removed from a monovalent hydrocarbon group having 1 to 20 carbon atoms in the formula: １ is preferably a divalent aromatic hydrocarbon group having 6 to 20 carbon atoms, more preferably a benzenediyl group.

[0049] Specific examples of the repeating unit (1) include repeating units represented by the following formulas (1-1) to (1-18).

[0050]

[0051]

[0052]

[0053] In the above formulas (1-1) to (1-18), R ａ has the same meaning as the above formula (1). Among these, the repeating units represented by the above formulae (1-1) to (1-3) and (1-10) to (1-18) are preferred.

[0054] The lower limit of the content of the repeating unit (1) in all repeating units constituting the polymer (A) (the total content when multiple types are included) is preferably 1 mol%, more preferably 5 mol%, even more preferably 10 mol%, and particularly preferably 20 mol%. The upper limit of the content is preferably 100 mol%, more preferably 70 mol%, even more preferably 60 mol%, and particularly preferably 50 mol%. By keeping the content of the repeating unit (1) within the above range, solvent resistance and resist pattern rectangularity can be exhibited at high levels.

[0055] The polymer (A) preferably further contains a repeating unit represented by the following formula (2) (excluding the case where it corresponds to the repeating unit (1) above) (hereinafter also referred to as "repeating unit (2)"). The polymer (A) may contain one or more types of repeating unit (2).

[0056] In the above formula (2), R ３ is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms. ３ is a single bond or a divalent linking group. ４ is a monovalent organic group having 1 to 20 carbon atoms.

[0057] R ３ The monovalent hydrocarbon group having 1 to 20 carbon atoms represented by the formula (1) is ａ The groups listed as examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms and represented by the above R ３ When R has a substituent, the substituent is R ａ Examples of the substituent include the groups listed above.

[0058] L ３ The divalent linking group represented by the formula (1) is １ Examples of the divalent linking group represented by the formula: ３ is preferably a single bond or —COO—.

[0059] R ４ The monovalent organic group having 1 to 20 carbon atoms represented by the formula (i) is R １ Among them, monovalent organic groups having 1 to 20 carbon atoms represented by R ４ As the R in the above formula (1), ａ and substituted or unsubstituted monovalent hydrocarbon groups represented by the following formula: ２ - or -NR'-, or a group containing a combination of two or more of these. R' is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. ４is preferably a substituted or unsubstituted monovalent aromatic hydrocarbon group, a substituted or unsubstituted monovalent chain hydrocarbon group, or a substituted or unsubstituted monovalent heterocyclic group.

[0060] The substituents that substitute a part or all of the hydrogen atoms of the organic group include R ａ Examples of the substituent include the groups listed as the substituents of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by the following formula:

[0061] Examples of the heterocyclic group include a group in which one hydrogen atom has been removed from an aromatic heterocyclic structure and a group in which one hydrogen atom has been removed from an alicyclic heterocyclic structure. Five-membered aromatic structures that have aromaticity due to the introduction of heteroatoms are also included in the heterocyclic structure. Examples of heteroatoms include oxygen atoms, nitrogen atoms, and sulfur atoms.

[0062] Examples of the aromatic heterocyclic structure include: oxygen atom-containing aromatic heterocyclic structures such as furan, pyran, benzofuran, and benzopyran; nitrogen atom-containing aromatic heterocyclic structures such as pyrrole, imidazole, pyridine, pyrimidine, pyrazine, indole, quinoline, isoquinoline, acridine, phenazine, and carbazole; sulfur atom-containing aromatic heterocyclic structures such as thiophene; and aromatic heterocyclic structures containing multiple heteroatoms such as thiazole, benzothiazole, thiazine, and oxazine.

[0063] Examples of the alicyclic heterocyclic structure include oxygen atom-containing alicyclic heterocyclic structures such as oxirane, oxetane, tetrahydrofuran, tetrahydropyran, dioxolane, and dioxane; nitrogen atom-containing alicyclic heterocyclic structures such as aziridine, pyrrolidine, pyrazolidine, piperidine, and piperazine; sulfur atom-containing alicyclic heterocyclic structures such as thietane, thiolane, and thiane; alicyclic heterocyclic structures containing multiple heteroatoms such as oxazoline, morpholine, oxathiolane, oxazine, and thiomorpholine; and structures in which an alicyclic heterocyclic structure and an aromatic ring structure are combined, such as benzoxazine.

[0064] The cyclic structure also includes a lactone structure, a cyclic carbonate structure, a sultone structure, and a structure containing a cyclic acetal.

[0065] Specific examples of the repeating unit (2) include repeating units represented by the following formulas (2-1) to (2-20).

[0066]

[0067]

[0068] In the above formulas (2-1) to (2-20), R ３ has the same meaning as the above formula (2). Among these, the repeating units represented by the above formulae (2-1) to (2-8) are preferred.

[0069] When the polymer [A] has a repeating unit (2), the lower limit of the content of the repeating unit (2) in all repeating units constituting the polymer [A] (the total content when multiple types are included) is preferably 5 mol%, more preferably 10 mol%, even more preferably 15 mol%, and particularly preferably 20 mol%. The upper limit of this content is preferably 95 mol%, more preferably 90 mol%, even more preferably 85 mol%, and particularly preferably 80 mol%. By setting the content of the repeating unit (2) within the above range, solvent resistance and resist pattern rectangularity can be exhibited at high levels.

[0070] The polymer [A] may further include a repeating unit (W) represented by the following formula (W-1) or (W-2): The polymer [A] may include one or more types of repeating units (W).

[0071] (In formula (W-1), R ｗ１ represents a ring structure having 6 to 20 ring members formed together with the two carbon atoms in the formula. ｗ２ represents a ring structure having 4 to 20 ring members formed together with one carbon atom in the formula.

[0072] R ｗ１ The ring structure having 6 to 20 ring members represented by the formula (1) is １ a structure corresponding to a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms in the above formula (1), １ a structure corresponding to a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms in the above formula (2), ４Examples of the ring structure include a structure corresponding to the monovalent heterocyclic group in the formula (I), a lactone structure, a cyclic carbonate structure, a sultone structure, a cyclic acetal, or a combination thereof. The ring structure may have a fused ring structure. A fused ring is a ring structure in which adjacent rings share one side (two adjacent atoms).

[0073] R ｗ２ As the ring structure having 4 to 20 ring members represented by the formula ｗ１ Examples include groups in which the ring structure having 6 to 20 ring members represented by the following formula (I) is extended to have 4 to 20 ring members.

[0074] R ｗ１ and R ｗ２ When has a substituent, the substituent is R in the above formula (i). １ Examples of the substituent include the groups listed above.

[0075] Specific examples of the repeating unit (W) include repeating units represented by the following formulae (W-1-1) to (W-1-2), (W-2-1) to (W-2-2).

[0076]

[0077] When the polymer [A] has a repeating unit (W), the content of the repeating unit (W) in all repeating units constituting the polymer [A] (the total content when multiple types are contained) is preferably 10 mol %, more preferably 20 mol %, and even more preferably 30 mol %. The upper limit of the content is preferably 80 mol %, more preferably 70 mol %, and even more preferably 60 mol %.

[0078] The lower limit of the weight-average molecular weight of the polymer (A) is preferably 1,000, more preferably 2,000, even more preferably 3,000, and particularly preferably 5,000. The upper limit of the molecular weight is preferably 22,000, more preferably 20,000, even more preferably 19,000, and particularly preferably 18,000. The method for measuring the weight-average molecular weight is as described in the Examples.

[0079] The lower limit of the content of the polymer (A) in the components other than the solvent (C) in the composition for forming a resist underlayer film is preferably 10% by mass, more preferably 20% by mass, and even more preferably 30% by mass, and the upper limit of the content is preferably 100% by mass, more preferably 90% by mass, and even more preferably 80% by mass.

[0080] [Method for Synthesizing Polymer [A]] The polymer [A] can be synthesized by radical polymerization, ionic polymerization, polycondensation, polyaddition, addition condensation, etc., depending on the type of monomer. For example, when the polymer [A] is synthesized by radical polymerization, the polymer can be synthesized by polymerizing monomers that provide each structural unit in an appropriate solvent using a radical polymerization initiator, etc.

[0081] Examples of the radical polymerization initiator include azo radical initiators such as azobisisobutyronitrile (AIBN), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2-cyclopropylpropionitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl 2,2'-azobisisobutyrate, and dimethyl-2,2'-azobis(2-methylpropionate); and peroxide radical initiators such as benzoyl peroxide, t-butyl hydroperoxide, and cumene hydroperoxide. These radical initiators can be used alone or in combination of two or more.

[0082] As the solvent used in the polymerization, the solvent [C] described below can be suitably used. These solvents used in the polymerization may be used alone or in combination of two or more kinds.

[0083] The reaction temperature in the polymerization is usually 40° C. to 150° C., preferably 50° C. to 120° C. The reaction time is usually 1 hour to 48 hours, preferably 1 hour to 24 hours.

[0084] [Other Polymers] The composition for forming a resist underlayer film may contain another polymer (hereinafter also referred to as "polymer [B]") in addition to polymer [A]. As polymer [B], for example, it may contain a polymer obtained by radical polymerization that does not contain repeating unit (1) (hereinafter also referred to as "polymer [B1]"). It may also contain a polymer obtained by addition condensation (hereinafter also referred to as "polymer [B2]"). The composition may contain one or more types of polymer [B1] and polymer [B2].

[0085] <Polymer [B1]> The polymer [B1] may have the following repeating unit in addition to the repeating unit (2) in the polymer [A] or in place of the repeating unit (2).

[0086] The polymer (B1) may have a repeating unit represented by the following formula (3) (hereinafter also referred to as "repeating unit (3)"). (In formula (3), R ４２ is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms. ４２ is a single bond or a divalent linking group.

[0087] In the above formula (3), R ４２ The substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ａ The groups shown as substituted or unsubstituted monovalent hydrocarbon groups having 1 to 20 carbon atoms, represented by the following formula, can be suitably used.

[0088] In the above formula (3), L ４２ The divalent linking group represented by the formula (1) is L １ The groups shown as divalent linking groups represented by the following formula can be preferably used. ４２is preferably a single bond, an alkanediyl group obtained by removing one hydrogen atom from an alkyl group having 1 to 10 carbon atoms, a cycloalkylene group obtained by removing one hydrogen atom from a cycloalkyl group having 5 to 10 carbon atoms, an arylene group obtained by removing one hydrogen atom from a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, a carbonyl group, an oxygen atom, or a combination thereof, and more preferably a single bond, an alkanediyl group having 1 to 5 carbon atoms, a cycloalkylene group having 5 to 7 carbon atoms, a phenylene group, a carbonyl group, an oxygen atom, or a combination thereof.

[0089] Specific examples of the repeating unit (3) include repeating units represented by the following formulas (3-1) to (3-8).

[0090]

[0091] In the above formulas (3-1) to (3-8), R ４２ is the same as the above formula (3).

[0092] When the polymer [B1] contains the repeating unit (3), the content of the repeating unit (3) in all repeating units constituting the polymer [B1] is preferably 30 mol %, more preferably 40 mol %, and even more preferably 50 mol %, and the upper limit of the content is preferably 99 mol %, more preferably 90 mol %, and even more preferably 85 mol %.

[0093] The polymer (B1) may have a repeating unit represented by the following formula (4) (excluding the case of the above formula (3)) (hereinafter also referred to as "repeating unit (4)"). (In formula (4), R ５３ is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms. ５３ is a single bond or a divalent linking group. ５４ is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms.

[0094] In the above formula (4), R ５３ and R ５４ The substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ａThe groups shown as substituted or unsubstituted monovalent hydrocarbon groups having 1 to 20 carbon atoms, represented by the following formula, can be preferably used. ５３ From the viewpoint of copolymerizability of the monomer that gives the repeating unit (4), R is preferably a hydrogen atom or a methyl group. ５４ R is preferably a monovalent chain hydrocarbon group having 1 to 15 carbon atoms or an aromatic hydrocarbon group having 6 to 20 carbon atoms, and more preferably a monovalent branched alkyl group having 1 to 10 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms. ５３ and R ５４ When R has a substituent, the substituent may be R ａ Suitable examples include the substituents that may be possessed by the following.

[0095] In the above formula (4), L ５３ The divalent linking group represented by the formula (1) is L １ The groups shown as divalent linking groups represented by the following formula can be preferably used. ５３ L is preferably a single bond, an alkanediyl group obtained by removing one hydrogen atom from an alkyl group having 1 to 10 carbon atoms, a cycloalkylene group obtained by removing one hydrogen atom from a cycloalkyl group having 5 to 10 carbon atoms, a carbonyl group, an oxygen atom, or a combination thereof, more preferably a single bond, an alkanediyl group having 1 to 5 carbon atoms, a cycloalkylene group having 5 to 7 carbon atoms, a carbonyl group, an oxygen atom, or a combination thereof, and even more preferably a single bond. ５３ When R has a substituent, the substituent may be R ａ Suitable examples include the substituents that may be possessed by the following.

[0096] Specific examples of the repeating unit (4) include repeating units represented by the following formulas (4-1) to (4-17).

[0097]

[0098]

[0099] In the above formulas (4-1) to (4-17), R ５３ is the same as the above formula (4).

[0100] When the polymer [B1] contains the repeating unit (4), the content of the repeating unit (4) in all repeating units constituting the polymer [B1] is preferably 1 mol %, more preferably 5 mol %, and even more preferably 10 mol %, and the upper limit of the content may be 100 mol %, preferably 50 mol %, more preferably 40 mol %, and even more preferably 30 mol %.

[0101] The polymer [B1] may have a repeating unit represented by the following formula (5) (excluding the cases of the above formula (3) and the above formula (4)) (hereinafter also referred to as “repeating unit (5)”): (In formula (5), R ６５ is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms. ６４ is a single bond or a divalent linking group. １ is a monovalent group having an aromatic ring with 6 to 20 ring members.

[0102] In this specification, the term "number of ring members" refers to the number of atoms constituting the ring. For example, a biphenyl ring has 12 members, a naphthalene ring has 10 members, and a fluorene ring has 13 members.

[0103] In the above formula (5), R ６５ The substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ａ The groups shown as substituted or unsubstituted monovalent hydrocarbon groups having 1 to 20 carbon atoms, represented by the following formula, can be preferably used. ６５ From the viewpoint of copolymerizability of the monomer that gives the repeating unit (5), R is preferably a hydrogen atom or a methyl group. ６５ When R has a substituent, the substituent may be R ａ Suitable examples include the substituents that may be possessed by the following.

[0104] In the above formula (5), L ６４ The divalent linking group represented by the formula (1) is L １ The groups shown as divalent linking groups represented by the following formula can be preferably used. ６４is preferably a single bond, an alkanediyl group obtained by removing one hydrogen atom from an alkyl group having 1 to 10 carbon atoms, a cycloalkylene group obtained by removing one hydrogen atom from a cycloalkyl group having 5 to 10 carbon atoms, a carbonyl group, an oxygen atom, or a combination thereof, more preferably a single bond, an alkanediyl group having 1 to 5 carbon atoms, a cycloalkylene group having 5 to 7 carbon atoms, a carbonyl group, an oxygen atom, or a combination thereof, and even more preferably a single bond.

[0105] In the above formula (5), Ar １ Examples of the aromatic ring having 6 to 20 ring members in Ar include aromatic hydrocarbon rings such as a benzene ring, a naphthalene ring, an anthracene ring, an indene ring, and a pyrene ring, aromatic heterocyclic rings such as a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, and a triazine ring, and combinations thereof. １ The aromatic ring is preferably at least one aromatic hydrocarbon ring selected from the group consisting of a benzene ring, a naphthalene ring, an anthracene ring, a phenalene ring, a phenanthrene ring, a pyrene ring, a fluorene ring, a perylene ring, and a coronene ring, and more preferably a benzene ring, a naphthalene ring, or a pyrene ring.

[0106] In the above formula (5), Ar １ As the monovalent group having an aromatic ring with 6 to 20 ring members represented by the formula １ Suitable examples include groups in which one hydrogen atom has been removed from an aromatic ring having 6 to 20 ring members in the formula: １ When R has a substituent, the substituent may be R ａ Suitable examples include the substituents that may be possessed by the following.

[0107] Specific examples of the repeating unit (5) include repeating units represented by the following formulas (5-1) to (5-10).

[0108]

[0109] In the above formulas (5-1) to (5-10), R ６５ has the same meaning as the above formula (5). Among them, the repeating unit represented by the above formula (5-1) is preferred.

[0110] When the polymer [B1] contains the repeating unit (5), the content of the repeating unit (5) in all repeating units constituting the polymer [B1] is preferably 5 mol %, more preferably 10 mol %, and even more preferably 20 mol %, and the upper limit of the content is preferably 70 mol %, more preferably 60 mol %, and even more preferably 40 mol %.

[0111] The lower limit of the weight-average molecular weight of the polymer [B1] is preferably 500, more preferably 1000, even more preferably 2000, and particularly preferably 3000. The upper limit of the molecular weight is preferably 10000, more preferably 9000, even more preferably 8000, and particularly preferably 7000.

[0112] When the composition for forming a resist underlayer film contains the polymer [B1], the lower limit of the content of the polymer [B1] is preferably 10 mass %, more preferably 20 mass %, and even more preferably 30 mass %, based on the total mass of the polymer [A] and the polymer [B1]. The upper limit of the content is preferably 80 mass %, more preferably 70 mass %, and even more preferably 60 mass %, based on the total mass of the polymer [A] and the polymer [B1].

[0113] [Method for Synthesizing Polymer [B1]] The polymer [B1] can be synthesized by radical polymerization, in which monomers that provide each structural unit are polymerized in an appropriate solvent using a radical polymerization initiator or the like.

[0114] <Polymer [B2]> The polymer [B2] has a repeating unit represented by the following formula (α). The polymer [B2] may have two or more types of repeating units represented by the following formula (α). The composition can contain one type or two or more types of polymer [B2]. (In formula (α), Ar ａ is a divalent group having an aromatic ring with 5 to 40 ring members. ｂ is a hydrogen atom or a divalent group having an aromatic ring with 5 to 40 ring members.

[0115] In the above formula (α), Ar ａ and Ar ｂExamples of the aromatic ring having 5 to 40 ring members in Ar include aromatic hydrocarbon rings such as a benzene ring, a naphthalene ring, an anthracene ring, a phenalene ring, a phenanthrene ring, a pyrene ring, a fluorene ring, a perylene ring, and a coronene ring, and heteroaromatic rings such as a furan ring, a pyrrole ring, a thiophene ring, a phosphole ring, a pyrazole ring, an oxazole ring, an isoxazole ring, a thiazole ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, and a triazine ring, and combinations thereof. ａ and Ar ｂ The aromatic ring in Ar is preferably at least one aromatic hydrocarbon ring selected from the group consisting of a benzene ring, a naphthalene ring, an anthracene ring, a phenalene ring, a phenanthrene ring, a pyrene ring, a fluorene ring, a perylene ring, and a coronene ring. ａ and Ar ｂ The aromatic ring is more preferably a benzene ring, a naphthalene ring or a pyrene ring.

[0116] In the above formula (α), Ar ａ and Ar ｂ As the divalent group having an aromatic ring with 5 to 40 ring members represented by the formula ａ Suitable examples include groups in which two hydrogen atoms have been removed from an aromatic ring having 5 to 40 ring members.

[0117] Ar ａ and Ar ｂ At least one of the above preferably has at least one group selected from the group consisting of a group represented by the following formula (β-1) and a group represented by the following formula (β-2): (In formulas (β-1) and (β-2), R ７ are each independently a divalent organic group having 1 to 20 carbon atoms or a single bond. * is a bond to a carbon atom in the aromatic ring.

[0118] In the above formulas (β-1) and (β-2), R ７Examples of the divalent organic group having 1 to 20 carbon atoms represented by the formula (I) include a divalent hydrocarbon group having 1 to 20 carbon atoms, a group having a divalent heteroatom-containing group between carbon atoms of the hydrocarbon group, a group in which some or all of the hydrogen atoms of the hydrocarbon group have been substituted with monovalent heteroatom-containing groups, and combinations thereof.

[0119] Examples of the divalent hydrocarbon group having 1 to 20 carbon atoms include a divalent chain hydrocarbon group having 1 to 20 carbon atoms, a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, a divalent aromatic hydrocarbon group having 6 to 20 carbon atoms, and combinations thereof.

[0120] Examples of divalent chain hydrocarbon groups having 1 to 20 carbon atoms include methanediyl, ethanediyl, propanediyl, butanediyl, hexanediyl, and octanediyl groups. Of these, alkanediyl groups having 1 to 8 carbon atoms are preferred.

[0121] Examples of the divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include cycloalkanediyl groups such as a cyclopentanediyl group and a cyclohexanediyl group; cycloalkenediyl groups such as a cyclopentenediyl group and a cyclohexenediyl group; bridged ring saturated hydrocarbon groups such as a norbornanediyl group, an adamantanediyl group and a tricyclodecanediyl group; and bridged ring unsaturated hydrocarbon groups such as a norbornenediyl group and a tricyclodecenediyl group.

[0122] Examples of the divalent aromatic hydrocarbon group having 6 to 20 carbon atoms include a phenylene group, a naphthalenediyl group, an anthracenediyl group, a pyrenediyl group, a toluenediyl group, and a xylenediyl group.

[0123] Examples of heteroatoms constituting the divalent or monovalent heteroatom-containing group include oxygen atoms, nitrogen atoms, sulfur atoms, phosphorus atoms, silicon atoms, halogen atoms, etc. Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0124] Examples of the divalent heteroatom-containing group include -CO-, -CS-, -NH-, -O-, -S-, and combinations of these groups.

[0125] Examples of the monovalent heteroatom-containing group include a hydroxy group, a sulfanyl group, a cyano group, a nitro group, and a halogen atom.

[0126] R ７ is preferably a divalent hydrocarbon group having 1 to 10 carbon atoms such as methanediyl, ethanediyl or phenylene, -O- or a combination thereof, more preferably a methanediyl group or a combination of a methanediyl group and -O-.

[0127] The above Ar ａ has a group represented by the above formula (β-1), and the group is preferably represented by the following formula (β-1-1).

[0128] Ar ａ and Ar ｂ may have a substituent other than the group represented by the above formula (β-1) and the group represented by the above formula (β-2). Examples of the substituent include a monovalent chain hydrocarbon group having 1 to 10 carbon atoms, a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom, an alkoxy group such as a methoxy group, an ethoxy group, or a propoxy group, an aryloxy group such as a phenoxy group or a naphthyloxy group, an alkoxycarbonyl group such as a methoxycarbonyl group or an ethoxycarbonyl group, an alkoxycarbonyloxy group such as a methoxycarbonyloxy group or an ethoxycarbonyloxy group, an acyl group such as a formyl group, an acetyl group, a propionyl group, or a butyryl group, a cyano group, a nitro group, and a hydroxy group.

[0129] Examples of the repeating unit represented by the above formula (α) include repeating units represented by the following formulas (α-1) to (α-7).

[0130]

[0131] (Other Polymers [B2]) In addition to the polymer having the repeating unit represented by the above formula (α), the polymer [B2] can also be a resol-based polymer, a polyarylene-based polymer, a triazine-based polymer, a calixarene-based polymer, etc. These polymers can be produced by known methods.

[0132] (Resol-Based Polymer) A resol-based polymer is a polymer obtained by reacting a phenolic compound with an aldehyde using an alkaline catalyst.

[0133] Examples of the phenolic compound include phenols such as phenol, cresol, xylenol, resorcinol, and bisphenol A; naphthols such as 1-naphthol, 2-naphthol, 1,5-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, and 9,9-bis(6-hydroxynaphthyl)fluorene; anthrols such as 9-anthrol; and hydroxypyrenes such as 1-hydroxypyrene and 2-hydroxypyrene.

[0134] Examples of aldehydes include aldehydes such as formaldehyde, acetaldehyde, benzaldehyde, and 1-pyrenecarboxaldehyde; and aldehyde sources such as paraformaldehyde, trioxane, and paraaldehyde.

[0135] (Polyarylene Polymer) The polyarylene polymer is a polymer having structural units derived from a compound containing an arylene skeleton. Examples of the arylene skeleton include a phenylene skeleton, a naphthylene skeleton, and a biphenylene skeleton.

[0136] Examples of polyarylene polymers include polyarylene ether, polyarylene sulfide, polyarylene ether sulfone, polyarylene ether ketone, and polymers having a structural unit containing a biphenylene skeleton and a structural unit derived from a compound containing an acenaphthylene skeleton.

[0137] (Triazine-Based Polymer) The triazine-based polymer is a polymer having a structural unit derived from a compound having a triazine skeleton. Examples of the compound having a triazine skeleton include a melamine compound and a cyanuric acid compound.

[0138] (Calixarene-based polymer) A calixarene-based polymer is a cyclic oligomer in which multiple aromatic rings to which hydroxy groups are bonded are cyclically bonded via hydrocarbon groups, or a compound in which some or all of the hydrogen atoms of the hydroxy groups, aromatic rings, and hydrocarbon groups have been substituted.

[0139] The lower limit of the weight-average molecular weight of the polymer [B2] is preferably 500, more preferably 1000, even more preferably 1500, and particularly preferably 2000. The upper limit of the molecular weight is preferably 8000, more preferably 7000, even more preferably 6000, and particularly preferably 5000.

[0140] When the composition for forming a resist underlayer film contains the polymer [B2], the lower limit of the content of the polymer [B2] is preferably 10 mass %, more preferably 20 mass %, and even more preferably 30 mass %, based on the total mass of the polymer [A] and the polymer [B2]. The upper limit of the content is preferably 80 mass %, more preferably 70 mass %, and even more preferably 60 mass %, based on the total mass of the polymer [A] and the polymer [B2].

[0141] [Method for synthesizing polymer [B2]] The polymer [B2] is typically a polymer obtained by synthesizing a polymer represented by the formula (α) ａ The compound can be synthesized by acid addition condensation of an aromatic ring compound as a precursor having a phenolic hydroxyl group with an aldehyde derivative as a precursor, followed by nucleophilic substitution reaction of the phenolic hydroxyl group with a halogenated hydrocarbon corresponding to the group represented by the above formula (β-1) or (β-2).

[0142] <Solvent (C)> The solvent (C) is not particularly limited as long as it can dissolve or disperse the polymer (A) and any optional components contained as needed.

[0143] Examples of the solvent (C) include hydrocarbon solvents, ester solvents, alcohol solvents, ketone solvents, ether solvents, nitrogen-containing solvents, etc. The solvent (C) can be used alone or in combination of two or more.

[0144] Examples of hydrocarbon solvents include aliphatic hydrocarbon solvents such as n-pentane, n-hexane, and cyclohexane, and aromatic hydrocarbon solvents such as benzene, toluene, and xylene.

[0145] Examples of ester-based solvents include carbonate-based solvents such as diethyl carbonate, acetate monoester-based solvents such as methyl acetate and ethyl acetate, lactone-based solvents such as γ-butyrolactone, polyhydric alcohol partial ether carboxylate-based solvents such as diethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate, and lactate-based solvents such as methyl lactate and ethyl lactate.

[0146] Examples of alcohol solvents include monoalcohol solvents such as methanol, ethanol, n-propanol, and 4-methyl-2-pentanol, and polyalcohol solvents such as ethylene glycol and 1,2-propylene glycol.

[0147] Examples of the ketone solvent include chain ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and 2-heptanone, and cyclic ketone solvents such as cyclohexanone.

[0148] Examples of the ether solvent include chain ether solvents such as n-butyl ether, polyhydric alcohol ether solvents such as cyclic ether solvents such as tetrahydrofuran, and polyhydric alcohol partial ether solvents such as diethylene glycol monomethyl ether and propylene glycol monomethyl ether.

[0149] Examples of the nitrogen-containing solvent include chain nitrogen-containing solvents such as N,N-dimethylacetamide, and cyclic nitrogen-containing solvents such as N-methylpyrrolidone.

[0150] The solvent (C) is preferably an alcohol solvent, an ether solvent, or an ester solvent, more preferably a monoalcohol solvent, a polyhydric alcohol partial ether solvent, a polyhydric alcohol partial ether carboxylate solvent, or a lactate ester solvent, and even more preferably 4-methyl-2-pentanol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, or ethyl lactate.

[0151] The lower limit of the content of the solvent (C) in the composition for forming a resist underlayer film is preferably 50% by mass, more preferably 60% by mass, and even more preferably 70% by mass, and the upper limit of the content is preferably 99.9% by mass, more preferably 99% by mass, and even more preferably 95% by mass.

[0152] [Optional Components] The composition for forming a resist underlayer film may contain optional components within a range that does not impair the effects of the present invention. Examples of optional components include the polymer (B) described above, as well as crosslinking agents, acid generators, dehydrating agents, acid diffusion controllers, surfactants, etc. The optional components may be used alone or in combination of two or more.

[0153] (Crosslinking Agent [D]) The type of crosslinking agent [D] is not particularly limited, and known crosslinking agents can be freely selected and used. Preferably, at least one selected from polyfunctional (meth)acrylates, cyclic ether-containing compounds, glycolurils, diisocyanates, melamines, benzoguanamines, polynuclear phenols, polyfunctional thiol compounds, polysulfide compounds, and sulfide compounds is used as the crosslinking agent. When the composition contains the crosslinking agent [D], crosslinking of the polymer [A] and, if necessary, the polymer [B] can be promoted, thereby improving the solvent resistance of the resist underlayer film.

[0154] The polyfunctional (meth)acrylates are not particularly limited as long as they are compounds having two or more (meth)acryloyl groups, and examples thereof include polyfunctional (meth)acrylates obtained by reacting an aliphatic polyhydroxy compound with (meth)acrylic acid, caprolactone-modified polyfunctional (meth)acrylates, alkylene oxide-modified polyfunctional (meth)acrylates, polyfunctional urethane (meth)acrylates obtained by reacting a (meth)acrylate having a hydroxyl group with a polyfunctional isocyanate, and polyfunctional (meth)acrylates having a carboxyl group obtained by reacting a (meth)acrylate having a hydroxyl group with an acid anhydride.

[0155] Specific examples include trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, glycerin tri(meth)acrylate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, ethylene glycol diisocyan ... Examples of the di(meth)acrylate include cholestyryl di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, and bis(2-hydroxyethyl)isocyanurate di(meth)acrylate.

[0156] Examples of cyclic ether-containing compounds include oxiranyl group-containing compounds such as 1,6-hexanediol diglycidyl ether, 3',4'-epoxycyclohexenylmethyl-3',4'-epoxycyclohexenecarboxylate, vinylcyclohexene monoxide, 1,2-epoxy-4-vinylcyclohexene, and 1,2:8,9 diepoxylimonene; and oxetanyl group-containing compounds such as 3-ethyl-3-hydroxymethyloxetane, 2-ethylhexyloxetane, xylylenebisoxetane, and 3-ethyl-3{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane. These cyclic ether-containing compounds can be used alone or in combination of two or more.

[0157] Examples of glycolurils include tetramethylol glycoluril, tetramethoxy glycoluril, tetramethoxymethyl glycoluril, a compound in which 1 to 4 methylol groups of tetramethylol glycoluril have been methoxymethylated, or a mixture thereof, a compound in which 1 to 4 methylol groups of tetramethylol glycoluril have been acyloxymethylated, and glycidyl glycolurils.

[0158] Examples of glycidyl glycolurils include 1-glycidyl glycoluril, 1,3-diglycidyl glycoluril, 1,4-diglycidyl glycoluril, 1,6-diglycidyl glycoluril, 1,3,4-triglycidyl glycoluril, 1,3,4,6-tetraglycidyl glycoluril, 1-glycidyl-3a-methyl glycoluril, 1-glycidyl-6a-methyl-glycoluril, 1,3-diglycidyl-3a-methyl glycoluril, 1,4-diglycidyl-3a-methyl glycoluril, 1,6-diglycidyl-3a-methyl glycoluril, 1,3,4-triglycidyl-3a-methyl glycoluril, 1,3,4-triglycidyl-6a-methyl glycoluril, 1,3,4,6-tetraglycidyl-3a-methyl glycoluril, 1-glycidyl-3a,6a-diglycidyl Examples of the glycol uril include methyl glycoluril, 1,3-diglycidyl-3a,6a-dimethyl glycoluril, 1,4-diglycidyl-3a,6a-dimethyl glycoluril, 1,6-diglycidyl-3a,6a-dimethyl glycoluril, 1,3,4-triglycidyl-3a,6a-dimethyl glycoluril, 1,3,4,6-tetraglycidyl-3a,6a-dimethyl glycoluril, 1-glycidyl-3a,6a-diphenyl glycoluril, 1,3-diglycidyl-3a,6a-diphenyl glycoluril, 1,4-diglycidyl-3a,6a-diphenyl glycoluril, 1,6-diglycidyl-3a,6a-diphenyl glycoluril, 1,3,4-triglycidyl-3a,6a-diphenyl glycoluril, and 1,3,4,6-tetraglycidyl-3a,6a-diphenyl glycoluril. These glycolurils can be used alone or in combination of two or more.

[0159] Examples of diisocyanates include 2,3-tolylene diisocyanate, 2,4-tolylene diisocyanate, 3,4-tolylene diisocyanate, 3,5-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, and 1,4-cyclohexane diisocyanate.

[0160] Examples of melamines include melamine, monomethylolmelamine, dimethylolmelamine, trimethylolmelamine, tetramethylolmelamine, pentamethylolmelamine, hexamethylolmelamine, monobutyrolmelamine, dibutylolmelamine, tributyrolmelamine, tetrabutylolmelamine, pentabutyrolmelamine, hexabutyrolmelamine, and alkylated derivatives of these methylolmelamines or butyrolmelamines. These melamines can be used alone or in combination of two or more.

[0161] Examples of benzoguanamines include benzoguanamines in which the amino group is modified with four alkoxymethyl groups (alkoxymethylol groups) (tetraalkoxymethylbenzoguanamines (tetraalkoxymethylolbenzoguanamines)), such as tetramethoxymethylbenzoguanamine; benzoguanamines in which the amino group is modified with a total of four alkoxymethyl groups (particularly methoxymethyl groups) and a hydroxymethyl group (methylol group); benzoguanamines in which the amino group is modified with three or less alkoxymethyl groups (particularly methoxymethyl groups); benzoguanamines in which the amino group is modified with a total of three or less alkoxymethyl groups (particularly methoxymethyl groups) and a hydroxymethyl group; and the like. These benzoguanamines can be used alone or in combination of two or more.

[0162] Examples of polynuclear phenols include dinuclear phenols such as 4,4'-biphenyldiol, 4,4'-methylenebisphenol, 4,4'-ethylidenebisphenol, and bisphenol A; trinuclear phenols such as 4,4',4"-methylidenetrisphenol, 4,4'-(1-(4-(1-(4-hydroxyphenyl)-1-methylethyl)phenyl)ethylidene)bisphenol, and 4,4'-(1-(4-(1-(4-hydroxy-3,5-bis(methoxymethyl)phenyl)-1-methylethyl)phenyl)ethylidene)bis(2,6-bis(methoxymethyl)phenol); and polyphenols such as novolak. These polynuclear phenols can be used alone or in combination of two or more.

[0163] The polyfunctional thiol compound is a compound having two or more mercapto groups in one molecule, and specific examples thereof include 1,2-ethanedithiol, 1,3-propanedithiol, 1,4-butanedithiol, 2,3-butanedithiol, 1,5-pentanedithiol, 1,6-hexanedithiol, 1,8-octanedithiol, 1,9-nonanedithiol, 2,3-dimercapto-1-propanol, dithioerythritol, 2,3-dimercaptosuccinic acid, 1,2-benzenedithiol, 1,2-benzenedimethanethiol, 1,3-benzenedithiol, 1,3-benzenedimethanethiol, 1,4-benzenedimethanethiol, 3,4-dimercaptotoluene, 4-chloro-1,3-benzenedithiol, 2,4,6-trimethyl-1,3-benzenedimethanethiol, 4,4'-thiodiphenol, 2-hexylamino-4,6-dimercapto-1,3,5-triazine, 2-diethylamino-4,6-dimercapto-1,3,5-triazine, 2-cyclohexylamino-4,6-dimercapto-1,3,5-triazine, 2-di-n-butylamino-4,6-dimercapto-1,3,5-triazine compounds having two mercapto groups such as ethylene glycol bis(3-mercaptopropionate), butanediol bisthioglycolate, ethylene glycol bisthioglycolate, 2,5-dimercapto-1,3,4-thiadiazole, 2,2'-(ethylenedithio)diethanethiol, 2,2-bis(2-hydroxy-3-mercaptopropoxyphenylpropane), 1,2,6-hexanetriol trithioglycolate, 1,3,5-trithiocyanuric acid, trimethylolpropane tris(3-mercaptopropionate), trimethylolpropane tris(3-mercaptopropionate), and compounds having four or more mercapto groups such as pentaerythritol tetrakis(2-mercaptoacetate), pentaerythritol tetrakis(2-mercaptopropionate), pentaerythritol tetrakis(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptobutyrate), and 1,3,5-tris(3-mercaptobutyryloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione.These polyfunctional thiol compounds can be used alone or in combination of two or more.

[0164] When the composition for forming a resist underlayer film contains the crosslinking agent [D], the lower limit of the content of the crosslinking agent [D] is preferably 10 parts by mass, more preferably 20 parts by mass, and even more preferably 30 parts by mass, relative to 100 parts by mass of the polymer [A] or 100 parts by mass of the polymer [A] and the polymer [B] combined. The upper limit of the content is preferably 100 parts by mass, more preferably 90 parts by mass, and even more preferably 80 parts by mass.

[0165] [Method for preparing a composition for forming a resist underlayer film] The composition for forming a resist underlayer film can be prepared by mixing the polymer [A], the solvent [C], and, if necessary, any optional components in a predetermined ratio, and preferably filtering the resulting mixture through a membrane filter or the like having a pore size of 0.5 μm or less.

[0166] [Silicon-containing film forming step] In this step, which is carried out before the coating step (I), a silicon-containing film is formed directly or indirectly on a substrate.

[0167] Examples of the substrate include metal or semimetal substrates such as silicon substrates, aluminum substrates, nickel substrates, chromium substrates, molybdenum substrates, tungsten substrates, copper substrates, tantalum substrates, and titanium substrates, among which silicon substrates are preferred.The substrate may also be a substrate on which a silicon nitride film, an alumina film, a silicon dioxide film, a tantalum nitride film, a titanium nitride film, or the like is formed.

[0168] The silicon-containing film can be formed by coating a silicon-containing film-forming composition, chemical vapor deposition (CVD), atomic layer deposition (ALD), or the like. Examples of methods for forming a silicon-containing film by coating a silicon-containing film-forming composition include a method in which the silicon-containing film-forming composition is directly or indirectly applied to a substrate, and the resulting coating film is then cured by exposure and / or heating. Examples of commercially available silicon-containing film-forming compositions include "NFC SOG01," "NFC SOG04," and "NFC SOG080" (all from JSR Corporation). Silicon oxide films, silicon nitride films, silicon oxynitride films, and amorphous silicon films can be formed by chemical vapor deposition (CVD) or atomic layer deposition (ALD).

[0169] Examples of radiation used for the exposure include electromagnetic waves such as visible light, ultraviolet light, far ultraviolet light, X-rays and gamma rays, and particle beams such as electron beams, molecular beams and ion beams.

[0170] The lower limit of the temperature when heating the coating film is preferably 90° C., more preferably 150° C., and still more preferably 200° C. The upper limit of the temperature is preferably 550° C., more preferably 450° C., and still more preferably 300° C.

[0171] The lower limit of the average thickness of the silicon-containing film is preferably 1 nm, more preferably 10 nm, and even more preferably 15 nm. The upper limit is preferably 20,000 nm, more preferably 1,000 nm, and even more preferably 100 nm. The average thickness of the silicon-containing film can be measured in the same manner as the average thickness of the resist underlayer film.

[0172] Examples of cases in which a silicon-containing film is formed indirectly on a substrate include cases in which a silicon-containing film is formed on a low dielectric insulating film or an organic underlayer film formed on a substrate.

[0173] [Coating step (I)] In this step, the resist underlayer film-forming composition is coated on the silicon-containing film formed on the substrate.The coating method of the resist underlayer film-forming composition is not particularly limited, and can be carried out by any suitable method such as spin coating, casting coating, roll coating, etc.This forms a coating film, and the resist underlayer film is formed by the evaporation of the solvent [C].

[0174] The lower limit of the average thickness of the resist underlayer film formed is preferably 0.5 nm, more preferably 1 nm, and even more preferably 2 nm. The upper limit of the average thickness is preferably 50 nm, more preferably 20 nm, even more preferably 10 nm, and particularly preferably 7 nm. The average thickness is measured according to the method described in the Examples.

[0175] When the composition for forming a resist underlayer film is applied directly to the substrate, the silicon-containing film forming step may be omitted.

[0176] [Heating Step] Next, the resist underlayer film formed in the coating step (I) is heated at 200°C or higher. Heating the resist underlayer film promotes decomposition of the sulfonimide salt structure in the polymer (A). This step is carried out before the coating step (II).

[0177] The coating film may be heated in an air atmosphere or a nitrogen atmosphere. The lower limit of the heating temperature is sufficient as long as it is 200°C, but is preferably 210°C, more preferably 220°C, and even more preferably 230°C. The upper limit of the heating temperature is preferably 400°C, more preferably 350°C, and even more preferably 280°C. The lower limit of the heating time is preferably 30 seconds, more preferably 40 seconds, and even more preferably 60 seconds. The upper limit of the time is preferably 800 seconds, more preferably 400 seconds, and even more preferably 200 seconds.

[0178] [Coating Step (II)] In this step, a resist film-forming composition is coated onto the resist underlayer film formed in the resist underlayer film-forming composition coating step. The method for coating the resist film-forming composition is not particularly limited, and examples thereof include a rotary coating method.

[0179] To explain this step in more detail, for example, a resist composition is applied so that the resist film to be formed has a predetermined thickness, and then the applied resist film is pre-baked (hereinafter also referred to as "PB") to volatilize the solvent in the applied film, thereby forming the resist film.

[0180] The PB temperature and PB time can be appropriately determined depending on the type of the resist film-forming composition used, etc. The lower limit of the PB temperature is preferably 30°C, more preferably 50°C. The upper limit of the PB temperature is preferably 200°C, more preferably 150°C. The lower limit of the PB time is preferably 10 seconds, more preferably 30 seconds. The upper limit of the PB time is preferably 600 seconds, more preferably 300 seconds.

[0181] Examples of the resist film-forming composition used in this step include positive or negative chemically amplified resist compositions containing a radiation-sensitive acid generator, positive resist compositions containing an alkali-soluble resin and a quinone diazide photosensitizer, negative resist compositions containing an alkali-soluble resin and a crosslinker, and metal-containing resist compositions containing a metal such as tin or zirconium. The resist film-forming composition used in this step is preferably a so-called positive resist film-forming composition for alkaline development. Such a resist film-forming composition is preferably, for example, a positive resist film-forming composition that contains a resin having an acid-dissociable group or a radiation-sensitive acid generator, and is intended for exposure with ArF excimer laser light (for ArF exposure) or extreme ultraviolet light (for EUV exposure).

[0182] [Exposure Step] In this step, the resist film formed in the resist film-forming composition application step is exposed to radiation. This step generates a difference in solubility in a basic liquid, which is a developer, between the exposed and unexposed areas of the resist film. More specifically, the solubility of the exposed areas of the resist film in a basic liquid is increased.

[0183] The radiation used for exposure can be appropriately selected depending on the type of the resist film-forming composition used, etc. Examples include visible light, ultraviolet light, far ultraviolet light, electromagnetic waves such as X-rays and gamma rays, and particle beams such as electron beams, molecular beams, and ion beams. Among these, far ultraviolet light is preferred, and KrF excimer laser light (wavelength 248 nm), ArF excimer laser light (wavelength 193 nm), F ２ Excimer laser light (wavelength 157 nm), Kr ２ Excimer laser light (wavelength 147 nm), ArKr excimer laser light (wavelength 134 nm), or extreme ultraviolet light (wavelength 13.5 nm, etc., also referred to as "EUV") is more preferred, and ArF excimer laser light or EUV is even more preferred. The exposure conditions can be appropriately determined depending on the type of resist film-forming composition used, etc.

[0184] Furthermore, in this process, after the exposure, post-exposure baking (hereinafter also referred to as "PEB") can be performed to improve the performance of the resist film, such as resolution, pattern profile, and developability. The PEB temperature and PEB time can be appropriately determined depending on the type of resist film-forming composition used, etc. The lower limit of the PEB temperature is preferably 50°C, more preferably 70°C. The upper limit of the PEB temperature is preferably 200°C, more preferably 150°C. The lower limit of the PEB time is preferably 10 seconds, more preferably 30 seconds. The upper limit of the PEB time is preferably 600 seconds, more preferably 300 seconds.

[0185] [Development Step] In this step, at least the exposed resist film is developed. In this step, it is preferable to use alkaline development in which the developer used is a basic liquid. Since the exposure step causes a difference in solubility in the basic liquid developer between the exposed and unexposed parts of the resist film, alkaline development removes the exposed parts, which have a relatively high solubility in the basic liquid, thereby forming a resist pattern.

[0186] In the step of developing the exposed resist film, it is preferable to further develop a portion of the resist underlayer film. The resist underlayer film contains a polymer containing sulfonic acid groups, which increases its solubility in a basic liquid developer, allowing it to be removed together with the resist film in the developing step of the resist film. It is sufficient for the resist underlayer film to be developed only partially in the thickness direction from the outermost surface of the resist underlayer film, but it is more preferable for the entire thickness direction to be developed (i.e., the entire resist underlayer film is removed in the exposed area). Although only a portion in the planar direction of the resist underlayer film may be developed, by continuously developing the resist underlayer film with a basic liquid following the resist film, it is possible to omit the etching step of the resist underlayer film, which has been conventionally required, thereby reducing the number of steps, suppressing the influence on other films, etc., and efficiently forming a good resist pattern.

[0187] The basic liquid for alkaline development is not particularly limited, and known basic liquids can be used. Examples of basic liquids for alkaline development include aqueous alkaline solutions containing at least one alkaline compound dissolved therein, such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide (TMAH), pyrrole, piperidine, choline, 1,8-diazabicyclo-[5.4.0]-7-undecene, and 1,5-diazabicyclo-[4.3.0]-5-nonene. Among these, aqueous TMAH solutions are preferred, and 2.38% by mass aqueous TMAH solutions are more preferred.

[0188] In addition, examples of the developer when organic solvent development is performed include the same as those exemplified above as the solvent (C).

[0189] In this step, washing and / or drying may be carried out after the development.

[0190] [Etching Step] In this step, etching is performed using the resist pattern (and resist underlayer film pattern) as a mask. The etching may be performed once or multiple times, i.e., etching may be performed sequentially using the pattern obtained by etching as a mask. From the viewpoint of obtaining a pattern with a better shape, multiple times is preferred. When etching is performed multiple times, for example, etching is performed sequentially in the order of the silicon-containing film and the substrate. Examples of etching methods include dry etching and wet etching. From the viewpoint of obtaining a better pattern shape on the substrate, dry etching is preferred. For this dry etching, for example, a gas plasma such as oxygen plasma is used. By the above etching, a semiconductor substrate having a predetermined pattern is obtained.

[0191] Dry etching can be performed using, for example, a known dry etching apparatus. The etching gas used for dry etching can be appropriately selected depending on the mask pattern, the elemental composition of the film to be etched, etc., and can be, for example, CHF ３ , C.F. ４ , C ２ F ６ , C ３ F ８ , SF ６ Fluorine-based gases such as Cl ２ , BCl ３ Chlorine gases such as O ２ , O ３ , H ２ Oxygen-based gases such as O, H ２ , N.H. ３ , CO, CO ２ , C.H. ４ , C ２ H ２ , C ２ H ４ , C ２ H ６ , C ３ H ４ , C ３ H ６ , C ３ H ８ , HF, HI, HBr, HCl, NO, NH ３ , BCl ３ reducing gases such as He, N２ and inert gases such as Ar. These gases may be used in combination. When etching a substrate using the pattern of the resist underlayer film as a mask, a fluorine-based gas is usually used.

[0192] The resist underlayer film-forming composition contains a polymer (A) and a solvent (C). As the resist underlayer film-forming composition, the resist underlayer film-forming composition used in the method for producing a semiconductor substrate can be suitably used.

[0193] The present invention will be specifically described below based on examples, but the present invention is not limited to these examples.

[0194] [Weight-average molecular weight (Mw)] The Mw of the polymer was measured by gel permeation chromatography (detector: differential refractometer) using GPC columns (two "G2000HXL" and one "G3000HXL" columns) manufactured by Tosoh Corporation under the following analytical conditions: flow rate: 1.0 mL / min, elution solvent: tetrahydrofuran, column temperature: 40°C, with monodisperse polystyrene as the standard.

[0195] [Average Film Thickness] The average film thickness was determined by measuring the film thickness at arbitrary nine positions at 5 cm intervals including the center of the resist underlayer film using a spectroscopic ellipsometer (J.A. WOOLLAM's "M2000D") and calculating the average of these film thicknesses.

[0196] <Synthesis of Monomers> The following compounds a-1 to a-23 were used in the synthesis of polymer [A].

[0197]

[0198]

[0199]

[0200]

[0201] [Synthesis of a-1] 166 mL of dimethylformamide, 50 g of sodium styrenesulfonate, and 0.5 g of di-tert-butylcatechol were added to a 3 L three-neck flask equipped with a Dimroth condenser, a dropping funnel, and a stirrer bar. 87 mL of thionyl chloride was slowly added dropwise from the dropping funnel into ice-cooled brine, and the mixture was stirred for 3 hours. After stirring, approximately 200 g of cold water was added in small increments. The generated hydrogen chloride was neutralized using a trapping device containing 2 N aqueous NaOH, and the excess thionyl chloride was decomposed. Then, 200 g of diisopropyl ether was added, and extraction was performed three times. The diisopropyl ether layer was dried over sodium sulfate, and the sodium sulfate was filtered off using a pleated filter paper. The diisopropyl ether solution was concentrated under reduced pressure and weighed to determine the yield, which was 40.2 g. Next, 29.8 g of trifluoromethanesulfonamide, 150 mL of methylene chloride, and 40.4 g of triethylamine were added to a 2 L three-neck flask equipped with a Dimroth condenser, a dropping funnel, and a stirrer bar. Under ice cooling, a mixture of 40.8 g of styrenesulfonyl chloride and 16 mL of methylene chloride was slowly added dropwise from the dropping funnel, and the mixture was stirred for 6 hours. 200 mL of ultrapure water was added to the reaction solution, and the mixture was washed with water three times. The organic layer was recovered, and water was removed with anhydrous sodium sulfate. The filtrate was then passed through a pleated filter paper to recover the filtrate, and the methylene chloride was distilled off using an evaporator. The target product obtained was １ The structure was identified by H-NMR spectrum, and 80.2 g was obtained (yield: 96.3%).

[0202] １ H-NMR (CDCl ３ ); 7.68 (m, 2H, Ph), 7.59 (m, 2H, Ph), 6.76 (q, 1H, CH), 5.76 (d, 1H, CH ２ ), 5.25 (d, 1H, CH ２ ), 3.28 (m, 6H, CH ２ ), 1.56 (t, 9H, CH ３ ).

[0203] [Synthesis of a-2] In a 300 mL recovery flask, 10.5 g of the synthesized a-1 was dissolved in 100 mL of methylene chloride and 100 mL of ultrapure water, and 9.1 g of diphenyliodonium chloride was added and stirred at room temperature for 8 hours. After the reaction was completed, the mixture was washed three times with ultrapure water to remove triethylamine hydrochloride produced by the salt exchange reaction. The organic layer was recovered and concentrated using an evaporator, purified by column chromatography using methylene chloride / methanol = 20 / 1 vol%, and concentrated using an evaporator to obtain a pale yellow solid. The target product was １ H. １３ C. １９ The structure was identified from the F NMR spectrum, and 10.5 g was obtained (yield: 73.5%).

[0204] １ H-NMR (DMSO-d ６ ); 8.27 (m, 4H, Ph), 7.83 (m, 2H, Ph), 7.75 (m, 2H, Ph), 7.67 (m, 4H, Ph), 7.59 (m, 2H, Ph), 6.72 (q, 1H, CH), 5.76 (d, 1H, CH ２ ), 5.25 (d, 1H, CH ２ ).

[0205] １３ C-NMR (DMSO-d ６ ); 155.7 (Ph), 140.1 (Ph), 136.2 (Ph), 135.4 (Ph), 129.4 (Ph), 127.0 (Ph), 126.5 (Ph), 117.1 (Ph), 113.4 (CF ３ ), 35.4 (CH), 31.2 (CH ２ ).

[0206] １９ F-NMR (DMSO-d ６ ); -77.4 (CF ３ )

[0207] [Synthesis of a-3] In a 300 mL recovery flask, 10.5 g of a-1 was dissolved in 100 mL of methylene chloride and 100 mL of ultrapure water, and 12.5 g of bis(4-t-butylphenyl)iodonium chloride was added and stirred at room temperature for 8 hours. After the reaction was completed, the mixture was washed three times with ultrapure water to remove triethylamine hydrochloride produced by the salt exchange reaction. The organic layer was recovered and concentrated using an evaporator, purified by column chromatography using methylene chloride / methanol = 20 / 1 vol%, and concentrated using an evaporator to obtain a pale yellow solid. The target product was １ H. １３ C. １９ The structure was identified from the F NMR spectrum, and 10.5 g was obtained (yield: 48.3%).

[0208] １ H-NMR (DMSO-d ６ ); 8.14 (m, 4H, Ph), 7.56 (m, 2H, Ph), 7.54 (m, 6H, Ph), 6.79 (m, 1H, CH), 5.97 (d, 1H, CH ２ ), 5.40 (d, 1H, CH ２ ), 1.26(s, 18H, CH ３ )

[0209] １３ C-NMR (DMSO-d ６ ); 155.6 (Ph), 136.2 (Ph), 135.4 (Ph), 129.3 (Ph), 127 (Ph), 126.5 (Ph), 117.2 (Ph), 113.9 (CH), 35.4 (C), 31.3 (CH ３ ).

[0210] １９ F-NMR (DMSO-d ６ ); -77.5 (CF ３ ).

[0211] [Synthesis of a-4] In a 300 mL recovery flask, 10.5 g of a-1 was dissolved in 100 mL of methylene chloride and 100 mL of ultrapure water, and 12.5 g of bis(4-fluorophenyl)iodonium chloride was added and stirred at room temperature for 8 hours. After the reaction was completed, the mixture was washed three times with ultrapure water to remove triethylamine hydrochloride produced by the salt exchange reaction. The organic layer was recovered and concentrated using an evaporator, purified by column chromatography using methylene chloride / methanol = 20 / 1 vol%, and concentrated using an evaporator to obtain a pale yellow solid. The target product was １ H. １３ C. １９ The structure was identified from the F NMR spectrum, and 10.5 g was obtained (yield: 72.6%).

[0212] １ H-NMR (DMSO-d ６ ); 8.34 (m, 4H, Ph), 7.72 (m, 2H, Ph), 7.59 (m, 2H, Ph), 7.42 (m, 2H, Ph), 6.78 (q, 1H, CH), 5.93 (d, 1H, CH ２ ), 5.37 (d, 1H, CH ２ ).

[0213] １３ C-NMR (DMSO-d ６ ); 165.7 (Ph), 163.2 (Ph), 144.8 (Ph), 140.2 (Ph), 138.5 (Ph), 136.1 (Ph) , 127.0 (Ph), 126.5 (Ph), 119.9 (Ph), 119.7 (Ph), 117.2 (CF3), 111.8 (CH),

[0214] １９ F-NMR (DMSO-d6); -77.5 (CF ３ ), -106.6 (F-Ph).

[0215] [Synthesis of a-6] 33 g of styrenesulfonamide, 150 mL of methylene chloride, and 36.5 g of triethylamine were added to a 2 L three-neck flask equipped with a Dimroth condenser, a dropping funnel, and a stirrer bar. Under ice cooling, a mixture of 45.2 g of (-)-10-camphorsulfonyl chloride and 16 mL of methylene chloride was slowly added dropwise from the dropping funnel, and the mixture was stirred for 6 hours. 200 mL of ultrapure water was added to the reaction solution, and the mixture was washed with water three times. The organic layer was recovered, and water was removed with anhydrous sodium sulfate. The filtrate was then passed through a pleated filter paper and recovered. The methylene chloride was removed using an evaporator, yielding 85.2 g of a white powder (yield: 90.0%).

[0216] [Synthesis of a-7] 10.5 g of a-6 was dissolved in 100 mL of methylene chloride and 100 mL of ultrapure water in a 300 mL recovery flask, and 7.4 g of triphenylsulfonium bromide was added directly underneath, followed by stirring at room temperature for 8 hours. After completion of the reaction, the mixture was washed three times with ultrapure water to remove triethylamine hydrobromide produced by the salt exchange reaction. The organic layer was recovered and concentrated using an evaporator, purified by column chromatography using methylene chloride / methanol = 20 / 1 vol%, and concentrated using an evaporator to obtain a pale yellow solid. The target product was １ The structure was identified by H-NMR spectrum, and 12.5 g of a white powder was obtained (yield: 80.0%).

[0217] [Synthesis of a-8] 30 g of vinylbenzylamine, 150 mL of methylene chloride, and 45.6 mL of triethylamine were added to a 2 L three-neck flask equipped with a Dimroth condenser, a dropping funnel, and a stirrer bar. Under ice cooling, a mixture of 38.0 g of trifluoromethylsulfonyl chloride and 16 mL of methylene chloride was slowly added dropwise from the dropping funnel, and the mixture was stirred for 6 hours. 200 mL of ultrapure water was added to the reaction solution, and the mixture was washed with water three times. The organic layer was recovered, and after removing water with anhydrous sodium sulfate, the filtrate was collected through a pleated filter paper, and the methylene chloride was distilled off using an evaporator. The target product obtained was １ The structure was identified by H-NMR spectrum, and 70.2 g of a white powder was obtained (yield: 85.5%).

[0218] [Synthesis of a-9] 10.5 g of a-8 was dissolved in 100 mL of methylene chloride and 100 mL of ultrapure water in a 300 mL recovery flask, and 9.1 g of diphenyliodonium chloride was added directly underneath and stirred at room temperature for 8 hours. After completion of the reaction, the mixture was washed three times with ultrapure water to remove triethylamine hydrochloride produced by the salt exchange reaction. The organic layer was recovered and concentrated using an evaporator, purified by column chromatography using methylene chloride / methanol = 20 / 1 vol%, and concentrated using an evaporator to obtain a pale yellow solid. The target product was １ The structure was identified by H-NMR spectrum, and 11.7 g of a white powder was obtained (yield: 75.0%).

[0219] [Synthesis of a-10] 10.5 g of a-8 was dissolved in 100 mL of methylene chloride and 100 mL of ultrapure water in a 300 mL recovery flask, and 11.1 g of triphenylsulfonium bromide was added directly underneath, followed by stirring at room temperature for 8 hours. After completion of the reaction, the mixture was washed three times with ultrapure water to remove triethylamine hydrobromide produced by the salt exchange reaction. The organic layer was recovered and concentrated using an evaporator, purified by column chromatography using methylene chloride / methanol = 20 / 1 vol%, and concentrated using an evaporator to obtain a pale yellow solid. The target product was １ The structure was identified by H-NMR spectrum, and 11.3 g of a white powder was obtained (yield: 75.0%).

[0220] [Synthesis of a-11] 30 g of a-5, 150 mL of methylene chloride, and 33.1 g of triethylamine were added to a 2 L three-neck flask equipped with a Dimroth condenser, a dropping funnel, and a stirrer bar. Under ice cooling, a mixture of 12.5 g of trifluoroacetic acid chloride and 16 mL of methylene chloride was slowly added dropwise from the dropping funnel, and the mixture was stirred for 6 hours. 200 mL of ultrapure water was added to the reaction solution, and the mixture was washed with water three times. The organic layer was recovered, and water was removed with anhydrous sodium sulfate. The filtrate was then passed through a pleated filter paper to recover the filtrate, and the methylene chloride was distilled off using an evaporator. The target product obtained was １ The structure was identified by H-NMR spectrum, and 45.3 g of a white powder was obtained (yield: 85.0%).

[0221] [Synthesis of a-12] 10.5 g of a-11 was dissolved in 100 mL of methylene chloride and 100 mL of ultrapure water in a 300 mL recovery flask, and 11.1 g of triphenylsulfonium bromide was added directly underneath, followed by stirring at room temperature for 8 hours. After completion of the reaction, the mixture was washed three times with ultrapure water to remove triethylamine hydrobromide produced by the salt exchange reaction. The organic layer was recovered and concentrated using an evaporator, purified by column chromatography using methylene chloride / methanol = 20 / 1 vol%, and concentrated using an evaporator to obtain a pale yellow solid. The target product was １ The structure was identified by H-NMR spectrum, and 11.3 g of a white powder was obtained (yield: 75.0%).

[0222] [Synthesis of a-13] 30 g of vinylbenzylamine, 150 mL of methylene chloride, and 45.6 mL of triethylamine were added to a 2 L three-necked flask equipped with a Dimroth condenser, a dropping funnel, and a stirrer bar. Under ice cooling, a mixture of 68.0 g of pentafluorobenzenesulfonic acid chloride and 50 mL of methylene chloride was slowly added dropwise from the dropping funnel, and the mixture was stirred for 6 hours. 200 mL of ultrapure water was added to the reaction solution, and the mixture was washed with water three times. The organic layer was recovered, and after removing water with anhydrous sodium sulfate, the filtrate was passed through a pleated filter paper and recovered, and the methylene chloride was distilled off using an evaporator. The target product obtained was １ The structure was identified by H-NMR spectrum, and 73.1 g of a white powder was obtained (yield: 70.5%).

[0223] [Synthesis of a-14] 10.5 g of a-13 was dissolved in 100 mL of methylene chloride and 100 mL of ultrapure water in a 300 mL recovery flask, and 11.1 g of triphenylsulfonium bromide was added directly underneath, followed by stirring at room temperature for 8 hours. After completion of the reaction, the mixture was washed three times with ultrapure water to remove triethylamine hydrobromide produced by the salt exchange reaction. The organic layer was recovered and concentrated using an evaporator, purified by column chromatography using methylene chloride / methanol = 20 / 1 vol%, and concentrated using an evaporator to obtain a pale yellow solid. The target product was １ The structure was identified by H-NMR spectrum, and 11.3 g of a white powder was obtained (yield: 75.0%).

[0224] [Synthesis of a-15] 14.7 g of trifluoroethylamine, 150 mL of methylene chloride, and 30.0 g of triethylamine were added to a 2 L three-neck flask equipped with a Dimroth condenser, a dropping funnel, and a stirrer bar. Under ice cooling, a mixture of 30.0 g of styrenesulfonyl chloride and 16 mL of methylene chloride was slowly added dropwise from the dropping funnel, and the mixture was stirred for 6 hours. 200 mL of ultrapure water was added to the reaction solution, and the mixture was washed with water three times. The organic layer was recovered, and water was removed with anhydrous sodium sulfate. The filtrate was then passed through a pleated filter paper to recover the filtrate, and the methylene chloride was distilled off using an evaporator. The target product obtained was １ The structure was identified by H-NMR spectrum, and 43.2 g of a white powder was obtained (yield: 80.0%).

[0225] [Synthesis of a-16] 10.5 g of a-15 was dissolved in 100 mL of methylene chloride and 100 mL of ultrapure water in a 300 mL recovery flask, and 9.9 g of triphenylsulfonium bromide was added directly underneath, followed by stirring at room temperature for 8 hours. After completion of the reaction, the mixture was washed three times with ultrapure water to remove triethylamine hydrobromide produced by the salt exchange reaction. The organic layer was recovered and concentrated using an evaporator, purified by column chromatography using methylene chloride / methanol = 20 / 1 vol%, and concentrated using an evaporator to obtain a pale yellow solid. The target product was １ The structure was identified by H-NMR spectrum, and 12.1 g of a white powder was obtained (yield: 80.0%).

[0226] [Synthesis of a-18] 4.47 g of trifluorosulfonamide, 15 mL of methylene chloride, and 6.07 g of triethylamine were added to a 2 L three-neck flask equipped with a Dimroth condenser, a dropping funnel, and a stirrer bar. Under ice cooling, a mixture of 5.00 g of a-17 and 5 mL of methylene chloride was slowly added dropwise from the dropping funnel, and the mixture was stirred for 6 hours. 50 mL of ultrapure water was added to the reaction solution, and the mixture was washed with water three times. The organic layer was collected, and after removing water with anhydrous sodium sulfate, the filtrate was collected through pleated filter paper, and the methylene chloride was distilled off using an evaporator. The target product obtained was １ The structure was identified by H-NMR spectrum, and 7.12 g of a white powder was obtained (yield: 85.0%).

[0227] [Synthesis of a-19] 10.0 g of a-18 was dissolved in 100 mL of methylene chloride and 100 mL of ultrapure water in a 300 mL recovery flask, and 9.02 g of triphenylsulfonium bromide was added directly underneath, followed by stirring at room temperature for 8 hours. After completion of the reaction, the mixture was washed three times with ultrapure water to remove triethylamine hydrobromide produced by the salt exchange reaction. The organic layer was recovered and concentrated using an evaporator, purified by column chromatography using methylene chloride / methanol = 20 / 1 vol%, and concentrated using an evaporator to obtain a pale yellow solid. The target product was １ The structure was identified by H-NMR spectrum, and 11.4 g was obtained (yield: 80.0%).

[0228] [Synthesis of a-20] 6.79 g of trifluoroacetamide, 12.1 g of triethylamine, and 50 mL of methylene chloride were added to a reaction vessel, and 10.0 g of a-17 and 10 mL of methylene chloride were added dropwise under ice cooling. The mixture was stirred at room temperature for 6 hours, and 50 mL of ultrapure water was added to the reaction solution, which was then washed with water three times. The organic layer was recovered, and the water was removed with anhydrous sodium sulfate. The filtrate was then passed through a pleated filter paper, and the filtrate was recovered, and the methylene chloride was distilled off using an evaporator. The target product obtained was １ The structure was identified by H-NMR spectrum, and 15.5 g of a white powder was obtained (yield: 75.0%).

[0229] [Synthesis of a-21] 10.0 g of a-20 was dissolved in 100 mL of methylene chloride and 100 mL of ultrapure water in a 300 mL recovery flask, and 9.02 g of triphenylsulfonium bromide was added directly underneath, followed by stirring at room temperature for 8 hours. After completion of the reaction, the mixture was washed three times with ultrapure water to remove triethylamine hydrobromide produced by the salt exchange reaction. The organic layer was recovered and concentrated using an evaporator, purified by column chromatography using methylene chloride / methanol = 20 / 1 vol%, and concentrated using an evaporator to obtain a pale yellow solid. The target product was １ The structure was identified by H-NMR spectrum, and 11.7 g was obtained (yield: 80.0%).

[0230] [Synthesis of a-22] 10.0 g of chloromethylstyrene, 30.9 g of triiodophenol, 6.6 g of triethylamine, and 300 mL of methylene chloride were added to a reaction vessel and stirred at room temperature for 4 hours. After the reaction was completed, the mixture was washed once with a 5% aqueous oxalic acid solution and three times with ultrapure water. The organic layer was concentrated, then purified by column chromatography using methylene chloride / methanol = 20 / 1 vol%, and concentrated using an evaporator to obtain a pale yellow solid. The target product was １ The structure was identified by H-NMR spectrum, and 31 g was obtained (yield: 80.0%).

[0231] <Synthesis of Polymer [A]> Each polymer [A] was synthesized according to the procedure shown below. In the formulas shown in the synthesis examples below, the number attached to each repeating unit indicates the content (mol %) of that repeating unit. When no number is attached to a repeating unit, the content of that repeating unit is 100 mol %. The same applies to the structural formula of polymer [B]. The composition ratio is １３ This was confirmed by C-NMR.

[0232] Synthesis Example 1-1 (Synthesis of Polymer (A-1)) 8 g of acetonitrile was placed in a three-neck flask equipped with a thermometer, a Dimroth condenser, and a stirrer bar and maintained at 80°C. A mixed solution of 4.0 g of a-2, 0.31 g of dimethyl-2,2-azobis(2-methylpropionate), and 4 g of acetonitrile was added dropwise from a feeder over 3 hours. After completion of the dropwise addition, the mixture was aged at 80°C for 3 hours. The resulting polymerization solution was concentrated using an evaporator and then purified by precipitation with a 10-fold amount of diisopropyl ether to obtain 3.6 g of a white solid (yield: 90%). The resulting polymer (A-1) represented by the following formula (A-1) had Mw of 16092, Mn of 10088, and a molecular weight dispersity of 1.60.

[0233]

[0234] Synthesis Example 1-2 (Synthesis of Polymer (A-2)) 14 g of acetonitrile was placed in a three-neck flask equipped with a thermometer, a Dimroth condenser, and a stirrer bar and maintained at 80°C. A mixed solution of 7.0 g of a-3, 0.68 g of dimethyl-2,2-azobis(2-methylpropionate), and 7 g of acetonitrile was added dropwise from a feeder over 3 hours. After completion of the dropwise addition, the mixture was aged at 80°C for 3 hours. The resulting polymerization solution was concentrated using an evaporator and then purified by precipitation with a 10-fold amount of diisopropyl ether to obtain 6.40 g of a white solid (yield: 91.4%). The resulting polymer (A-2) represented by the following formula (A-2) had Mw of 16,190, Mn of 10,014, and a molecular weight dispersity of 1.62.

[0235]

[0236] Synthesis Example 1-3 Synthesis of Polymer (A-3) A three-neck flask equipped with a thermometer, a Dimroth condenser, and a stirrer bar was charged with 14 g of diacetonitrile and maintained at 80°C. A mixed solution of 7.0 g of a-4, 0.77 g of dimethyl-2,2-azobis(2-methylpropionate), and 7 g of acetonitrile was added dropwise from a feeder over 3 hours. After completion of the dropwise addition, the mixture was aged at 80°C for 3 hours. The resulting polymerization solution was purified by precipitation with a 10-fold amount of methanol, yielding 8 g of a white solid (yield: 95%). The resulting polymer (A-3) represented by the following formula (A-3) had an Mw of 16332, an Mn of 10112, and a molecular weight dispersity of 1.62.

[0237]

[0238] Synthesis Example 1-4 Synthesis of Polymer (A-4) A three-neck flask equipped with a thermometer, a Dimroth condenser, and a stirrer bar was charged with 8 g of acetonitrile and maintained at 80°C. A mixed solution of 3.6 g of a-2, 0.42 g of styrene, 0.46 g of dimethyl-2,2-azobis(2-methylpropionate), and 4 g of acetonitrile was added dropwise from a feeder over 3 hours. After completion of the dropwise addition, the mixture was aged at 80°C for 3 hours. The resulting polymerization solution was concentrated using an evaporator and then purified by precipitation with a 10-fold amount of diisopropyl ether to obtain 1.8 g of a white solid (yield: 45%). The resulting polymer (A-4) represented by the following formula (A-4) had an Mw of 10092, an Mn of 6288, and a molecular weight dispersity of 1.60.

[0239]

[0240] Synthesis Example 1-5 Synthesis of Polymer (A-5) 8 g of acetonitrile was placed in a three-neck flask equipped with a thermometer, a Dimroth condenser, and a stirrer bar and maintained at 80°C. A mixed solution of 3.4 g of a-2, 0.66 g of 4-t-butoxystyrene, 0.43 g of dimethyl-2,2-azobis(2-methylpropionate), and 4 g of acetonitrile was added dropwise from a feeder over 3 hours. After completion of the dropwise addition, the mixture was aged at 80°C for 3 hours. The resulting polymerization solution was concentrated using an evaporator and then purified by precipitation with a 10-fold amount of diisopropyl ether to obtain 2.8 g of a white solid (yield: 70%). The resulting polymer (A-5) represented by the following formula (A-5) had an Mw of 17,340, an Mn of 10,632, and a molecular weight dispersity of 1.63.

[0241]

[0242] Synthesis Example 1-6 Synthesis of Polymer (A-6) 8 g of acetonitrile was placed in a three-neck flask equipped with a thermometer, a Dimroth condenser, and a stirrer bar and maintained at 80°C. A mixed solution of 2.0 g of a-2, 2.1 g of t-butyl methacrylate, 0.79 g of dimethyl-2,2-azobis(2-methylpropionate), and 4 g of acetonitrile was added dropwise from a feeder over 3 hours. After completion of the dropwise addition, the mixture was aged at 80°C for 3 hours. The resulting polymerization solution was concentrated using an evaporator and then purified by precipitation with a 10-fold amount of diisopropyl ether to obtain 2.9 g of a white solid (yield: 72%). The resulting polymer (A-6) represented by the following formula (A-6) had an Mw of 15,600, an Mn of 9,760, and a molecular weight dispersity of 1.60.

[0243]

[0244] Synthesis Example 1-7 Synthesis of Polymer (A-7) 8 g of acetonitrile was placed in a three-neck flask equipped with a thermometer, a Dimroth condenser, and a stirrer bar and maintained at 80°C. A mixed solution of 3.3 g of a-2, 0.70 g of 4-glycidyloxymethylstyrene, 0.43 g of dimethyl-2,2-azobis(2-methylpropionate), and 4 g of acetonitrile was added dropwise from a feeder over 3 hours. After completion of the dropwise addition, the mixture was aged at 80°C for 3 hours. The resulting polymerization solution was concentrated using an evaporator and then purified by precipitation with a 10-fold amount of diisopropyl ether to obtain 3.2 g of a white solid (yield: 80%). The resulting polymer (A-7) represented by the following formula (A-7) had an Mw of 17,320, an Mn of 10,654, and a molecular weight dispersity of 1.63.

[0245]

[0246] Synthesis Example 1-8 Synthesis of Polymer (A-8) 8 g of N,N-dimethylacetamide was placed in a three-neck flask equipped with a thermometer, a Dimroth condenser, and a stirrer bar and maintained at 80°C. A mixed solution of 3.3 g of a-23, 3.23 g of 2-vinylnaphthalene, 1.81 g of 4-propargyloxystyrene, 1.75 g of dimethyl-2,2-azobis(2-methylpropionate), and 4 g of N,N-dimethylacetamide was added dropwise from a feeder over 3 hours. After completion of the dropwise addition, the mixture was aged at 80°C for 3 hours. The resulting polymerization solution was concentrated using an evaporator and then purified by precipitation with a 10-fold amount of methyl isobutyl ketone to obtain 6.67 g of a white solid (yield: 80%). The resulting polymer (A-8) had an Mw of 12,200, an Mn of 6,777, and a molecular weight dispersity of 1.8.

[0247]

[0248] Synthesis Example 1-9 Synthesis of Polymer (A-9) 8 g of N,N-dimethylacetamide was placed in a three-neck flask equipped with a thermometer, a Dimroth condenser, and a stirrer bar and maintained at 80°C. A mixed solution of 3.3 g of a-7, 2.83 g of 2-vinylnaphthalene, 1.81 g of 4-propargyloxystyrene, 1.85 g of dimethyl-2,2-azobis(2-methylpropionate), and 4 g of N,N-dimethylacetamide was added dropwise from a feeder over 3 hours. After completion of the dropwise addition, the mixture was aged at 80°C for 3 hours. The resulting polymerization solution was concentrated using an evaporator and then purified by precipitation with a 10-fold amount of methyl isobutyl ketone to obtain 7.62 g of a white solid (yield: 80%). The resulting polymer (A-9) had an Mw of 12,200, an Mn of 6,777, and a molecular weight dispersity of 1.8.

[0249]

[0250] Synthesis Example 1-10 (Synthesis of Polymer (A-10)) 8 g of N,N-dimethylacetamide was placed in a three-neck flask equipped with a thermometer, a Dimroth condenser, and a stirrer bar and maintained at 80°C. A mixed solution of 3.00 g of a-9, 0.21 g of dimethyl-2,2-azobis(2-methylpropionate), and 4 g of N,N-dimethylacetamide was added dropwise from a feeder over 3 hours. After completion of the dropwise addition, the mixture was aged at 80°C for 3 hours. The resulting polymerization solution was concentrated using an evaporator and then purified by precipitation with a 10-fold amount of methyl isobutyl ketone to obtain 2.57 g of a white solid (yield: 80%). The resulting polymer (A-10) had Mw: 8400, Mn: 4670, and molecular weight dispersity: 1.8.

[0251]

[0252] Synthesis Example 1-11 (Synthesis of Polymer (A-11)) 8 g of N,N-dimethylacetamide was placed in a three-neck flask equipped with a thermometer, a Dimroth condenser, and a stirrer bar, and a mixed solution of 3.3 g of a-9, 4.67 g of N-vinylcarbazole, 5.93 g of 3,4-epoxycyclohexylmethyl methacrylate, 2.78 g of dimethyl-2,2-azobis(2-methylpropionate), and 4 g of N,N-dimethylacetamide was added dropwise from a feeder over 3 hours at 80°C. After completion of the dropwise addition, the mixture was aged at 80°C for 3 hours. The resulting polymerization solution was concentrated using an evaporator and then purified by precipitation with a 10-fold amount of methyl isobutyl ketone to obtain 9.76 g of a white solid (yield: 80%). The resulting polymer (A-11) had Mw: 9800, Mn: 5440, and molecular weight dispersity: 1.8.

[0253]

[0254] Synthesis Example 1-12 Synthesis of Polymer (A-12) A three-neck flask equipped with a thermometer, a Dimroth condenser, and a stirrer bar was charged with 8 g of N,N-dimethylacetamide, and a mixed solution of 3.3 g of a-9, 4.67 g of N-vinylcarbazole, 4.05 g of vinylbenzyl alcohol, 2.78 g of dimethyl-2,2-azobis(2-methylpropionate), and 4 g of N,N-dimethylacetamide was added dropwise from a feeder over 3 hours at 80°C. After completion of the dropwise addition, the mixture was aged at 80°C for 3 hours. The resulting polymerization solution was concentrated using an evaporator and then purified by precipitation with a 10-fold amount of methyl isobutyl ketone to obtain 11.84 g of a white solid (yield: 80%). The resulting polymer (A-12) had an Mw of 9,800, an Mn of 5,440, and a molecular weight dispersity of 1.8.

[0255]

[0256] Synthesis Example 1-13 Synthesis of Polymer (A-13) A three-neck flask equipped with a thermometer, a Dimroth condenser, and a stirrer bar was charged with 8 g of N,N-dimethylacetamide, and a mixed solution of 3.3 g of a-9, 4.68 g of N-vinylcarbazole, 4.79 g of 4-propargyloxystyrene, 2.79 g of dimethyl-2,2-azobis(2-methylpropionate), and 4 g of N,N-dimethylacetamide was added dropwise from a feeder over 3 hours at 80°C. After completion of the dropwise addition, the mixture was aged at 80°C for 3 hours. The resulting polymerization solution was concentrated using an evaporator and then purified by precipitation with a 10-fold amount of methyl isobutyl ketone to obtain 11.05 g of a white solid (yield: 80%). The resulting polymer (A-13) had an Mw of 9,800, an Mn of 5,440, and a molecular weight dispersity of 1.8.

[0257]

[0258] Synthesis Example 1-14 Synthesis of Polymer (A-14) A three-neck flask equipped with a thermometer, a Dimroth condenser, and a stirrer bar was charged with 8 g of N,N-dimethylacetamide, and a mixed solution of 3.3 g of a-9, 3.68 g of acenaphthylene, 4.06 g of vinylbenzyl alcohol, 2.79 g of dimethyl-2,2-azobis(2-methylpropionate), and 4 g of N,N-dimethylacetamide was added dropwise from a feeder over 3 hours at 80°C. After completion of the dropwise addition, the mixture was aged at 80°C for 3 hours. The resulting polymerization solution was concentrated using an evaporator and then purified by precipitation with a 10-fold amount of methyl isobutyl ketone to obtain 11.86 g of a white solid (yield: 80%). The resulting polymer (A-14) had an Mw of 9,800, an Mn of 5,440, and a molecular weight dispersity of 1.8.

[0259]

[0260] Synthesis Example 1-15 Synthesis of Polymer (A-15) A three-neck flask equipped with a thermometer, a Dimroth condenser, and a stirrer bar was charged with 8 g of N,N-dimethylacetamide, and a mixed solution of 3.3 g of a-10, 4.83 g of N-vinylcarbazole, 4.95 g of 4-propargyloxystyrene, 2.88 g of dimethyl-2,2-azobis(2-methylpropionate), and 4 g of N,N-dimethylacetamide was added dropwise from a feeder over 3 hours at 80°C. After completion of the dropwise addition, the mixture was aged at 80°C for 3 hours. The resulting polymerization solution was concentrated using an evaporator and then purified by precipitation with a 10-fold amount of methyl isobutyl ketone to obtain 12.77 g of a white solid (yield: 80%). The resulting polymer (A-15) had an Mw of 9,800, an Mn of 5,440, and a molecular weight dispersity of 1.8.

[0261]

[0262] Synthesis Example 1-16 Synthesis of Polymer (A-16) A three-neck flask equipped with a thermometer, a Dimroth condenser, and a stirrer bar was charged with 8 g of N,N-dimethylacetamide, and a mixed solution of 3.3 g of a-12, 4.83 g of vinylbenzylphthalimide, 1.98 g of 4-propargyloxystyrene, 1.92 g of dimethyl-2,2-azobis(2-methylpropionate), and 4 g of N,N-dimethylacetamide was added dropwise from a feeder over 3 hours at 80°C. After completion of the dropwise addition, the mixture was aged at 80°C for 3 hours. The resulting polymerization solution was concentrated using an evaporator and then purified by precipitation with a 10-fold amount of methyl isobutyl ketone to obtain 10.59 g of a white solid (yield: 80%). The resulting polymer (A-16) had an Mw of 9,800, an Mn of 5,440, and a molecular weight dispersity of 1.8.

[0263]

[0264] Synthesis Example 1-17 Synthesis of Polymer (A-17) A three-neck flask equipped with a thermometer, a Dimroth condenser, and a stirrer bar was charged with 8 g of N,N-dimethylacetamide, and a mixed solution of 3.3 g of a-12, 3.45 g of vinylnaphthalene, 1.93 g of 4-propargyloxystyrene, 1.87 g of dimethyl-2,2-azobis(2-methylpropionate), and 4 g of N,N-dimethylacetamide was added dropwise from a feeder over 3 hours at 80°C. After completion of the dropwise addition, the mixture was aged at 80°C for 3 hours. The resulting polymerization solution was concentrated using an evaporator and then purified by precipitation with a 10-fold amount of methyl isobutyl ketone to obtain 8.59 g of a white solid (yield: 80%). The resulting polymer (A-17) had an Mw of 9,800, an Mn of 5,440, and a molecular weight dispersity of 1.8.

[0265]

[0266] Synthesis Example 1-18 Synthesis of Polymer (A-18) A three-neck flask equipped with a thermometer, a Dimroth condenser, and a stirrer bar was charged with 8 g of N,N-dimethylacetamide, and a mixed solution of 3.3 g of a-12, 2.19 g of α-methylene-γ-butyrolactone, 1.93 g of 4-propargyloxystyrene, 1.87 g of dimethyl-2,2-azobis(2-methylpropionate), and 4 g of N,N-dimethylacetamide was added dropwise from a feeder over 3 hours at 80°C. After completion of the dropwise addition, the mixture was aged at 80°C for 3 hours. The resulting polymerization solution was concentrated using an evaporator and then purified by precipitation with a 10-fold amount of methyl isobutyl ketone to obtain 7.43 g of a white solid (yield: 80%). The resulting polymer (A-18) had an Mw of 9,800, an Mn of 5,440, and a molecular weight dispersity of 1.8.

[0267]

[0268] Synthesis Example 1-19 (Synthesis of Polymer (A-19)) 8 g of N,N-dimethylacetamide was placed in a three-neck flask equipped with a thermometer, a Dimroth condenser, and a stirrer bar, and a mixed solution of 3.3 g of a-10, 3.80 g of vinylnaphthalene, 2.12 g of 4-propargyloxystyrene, 2.06 g of dimethyl-2,2-azobis(2-methylpropionate), and 4 g of N,N-dimethylacetamide was added dropwise from a feeder over 3 hours at 80°C. After completion of the dropwise addition, the mixture was aged at 80°C for 3 hours. The resulting polymerization solution was concentrated using an evaporator and then purified by precipitation with a 10-fold amount of methyl isobutyl ketone to obtain 9.02 g of a white solid (yield: 80%). The resulting polymer (A-19) had an Mw of 9,800, an Mn of 5,440, and a molecular weight dispersity of 1.8.

[0269]

[0270] Synthesis Example 1-20 Synthesis of Polymer (A-20) A three-neck flask equipped with a thermometer, a Dimroth condenser, and a stirrer bar was charged with 8 g of N,N-dimethylacetamide, and a mixed solution of 3.3 g of a-14, 4.08 g of N-vinylcarbazole, 4.17 g of 4-propargyloxystyrene, 2.43 g of dimethyl-2,2-azobis(2-methylpropionate), and 4 g of N,N-dimethylacetamide was added dropwise from a feeder over 3 hours at 80°C. After completion of the dropwise addition, the mixture was aged at 80°C for 3 hours. The resulting polymerization solution was concentrated using an evaporator and then purified by precipitation with a 10-fold amount of methyl isobutyl ketone to obtain 11.18 g of a white solid (yield: 80%). The resulting polymer (A-20) had an Mw of 9,800, an Mn of 5,440, and a molecular weight dispersity of 1.8.

[0271]

[0272] Synthesis Example 1-21 Synthesis of Polymer (A-21) A three-neck flask equipped with a thermometer, a Dimroth condenser, and a stirrer bar was charged with 8 g of N,N-dimethylacetamide, and a mixed solution of 3.3 g of a-16, 4.83 g of N-vinylcarbazole, 4.95 g of 4-propargyloxystyrene, 2.88 g of dimethyl-2,2-azobis(2-methylpropionate), and 4 g of N,N-dimethylacetamide was added dropwise from a feeder over 3 hours at 80°C. After completion of the dropwise addition, the mixture was aged at 80°C for 3 hours. The resulting polymerization solution was concentrated using an evaporator and then purified by precipitation with a 10-fold amount of methyl isobutyl ketone to obtain 12.77 g of a white solid (yield: 80%). The resulting polymer (A-21) had an Mw of 9,800, an Mn of 5,440, and a molecular weight dispersity of 1.8.

[0273]

[0274] Synthesis Example 1-22 Synthesis of Polymer (A-22) A three-neck flask equipped with a thermometer, a Dimroth condenser, and a stirrer bar was charged with 8 g of N,N-dimethylacetamide, and a mixed solution of 3.3 g of a-19, 4.71 g of N-vinylcarbazole, 4.82 g of 4-propargyloxystyrene, 2.81 g of dimethyl-2,2-azobis(2-methylpropionate), and 4 g of N,N-dimethylacetamide was added dropwise from a feeder over 3 hours at 80°C. After completion of the dropwise addition, the mixture was aged at 80°C for 3 hours. The resulting polymerization solution was concentrated using an evaporator and then purified by precipitation with a 10-fold amount of methyl isobutyl ketone to obtain 12.51 g of a white solid (yield: 80%). The resulting polymer (A-22) had an Mw of 9,800, an Mn of 5,440, and a molecular weight dispersity of 1.8.

[0275]

[0276] Synthesis Example 1-23 Synthesis of Polymer (A-23) A three-neck flask equipped with a thermometer, a Dimroth condenser, and a stirrer bar was charged with 8 g of N,N-dimethylacetamide, and a mixed solution of 3.3 g of a-12, 4.71 g of N-vinylcarbazole, 4.82 g of 4-propargyloxystyrene, 2.81 g of dimethyl-2,2-azobis(2-methylpropionate), and 4 g of N,N-dimethylacetamide was added dropwise from a feeder over 3 hours at 80°C. After completion of the dropwise addition, the mixture was aged at 80°C for 3 hours. The resulting polymerization solution was concentrated using an evaporator and then purified by precipitation with a 10-fold amount of methyl isobutyl ketone to obtain 12.51 g of a white solid (yield: 80%). The resulting polymer (A-23) had an Mw of 9,800, an Mn of 5,440, and a molecular weight dispersity of 1.8.

[0277]

[0278] Synthesis Example 1-24 Synthesis of Polymer (A-24) A three-neck flask equipped with a thermometer, a Dimroth condenser, and a stirrer bar was charged with 8 g of N,N-dimethylacetamide, and a mixed solution of 3.3 g of a-21, 5.05 g of N-vinylcarbazole, 5.16 g of 4-propargyloxystyrene, 3.01 g of dimethyl-2,2-azobis(2-methylpropionate), and 4 g of N,N-dimethylacetamide was added dropwise from a feeder over 3 hours at 80°C. After completion of the dropwise addition, the mixture was aged at 80°C for 3 hours. The resulting polymerization solution was concentrated using an evaporator and then purified by precipitation with a 10-fold amount of methyl isobutyl ketone to obtain 13.22 g of a white solid (yield: 80%). The resulting polymer (A-24) had an Mw of 9,800, an Mn of 5,440, and a molecular weight dispersity of 1.8.

[0279]

[0280] Synthesis Example 1-25 Synthesis of Polymer (A-25) 8 g of N,N-dimethylacetamide was placed in a three-neck flask equipped with a thermometer, a Dimroth condenser, and a stirrer bar and maintained at 80°C. A mixed solution of 3.3 g of a-23, 6.60 g of 4-iodostyrene, 3.60 g of 4-propargyloxystyrene, 2.60 g of dimethyl-2,2-azobis(2-methylpropionate), and 4 g of N,N-dimethylacetamide was added dropwise from a feeder over 3 hours. After completion of the dropwise addition, the mixture was aged at 80°C for 3 hours. The resulting polymerization solution was concentrated using an evaporator and then purified by precipitation with a 10-fold amount of methyl isobutyl ketone to obtain 12.9 g of a white solid (yield: 80%). The resulting polymer (A-25) had an Mw of 12,200, an Mn of 6,777, and a molecular weight dispersity of 1.8.

[0281]

[0282] Synthesis Example 1-26 Synthesis of Polymer (A-26) 8 g of N,N-dimethylacetamide was placed in a three-neck flask equipped with a thermometer, a Dimroth condenser, and a stirrer bar and maintained at 80°C. A mixed solution of 3.3 g of a-23, 17.0 g of triiodophenoxymethylstyrene, 3.60 g of 4-propargyloxystyrene, 2.60 g of dimethyl-2,2-azobis(2-methylpropionate), and 4 g of N,N-dimethylacetamide was added dropwise from a feeder over 3 hours. After completion of the dropwise addition, the mixture was aged at 80°C for 3 hours. The resulting polymerization solution was concentrated using an evaporator and then purified by precipitation with a 10-fold amount of methyl isobutyl ketone to obtain 12.9 g of a white solid (yield: 80%). The resulting polymer (A-26) had an Mw of 12,200, an Mn of 6,777, and a molecular weight dispersity of 1.8.

[0283]

[0284] <Synthesis of Polymer [B]> Polymers represented by the following formulae (B-1) to (B-11) (hereinafter also referred to as "polymer (B-1)") were synthesized according to the procedure described below.

[0285]

[0286]

[0287] Synthesis Example 2-1 (Synthesis of Polymer (B-1)) 63 g of acrylic acid, 36 g of 2-ethylhexyl acrylate, and 21.2 g of dimethyl 2,2'-azobis(2-methylpropionate) were added to prepare a monomer solution. 300 g of methyl isobutyl ketone was placed in a reaction vessel under a nitrogen atmosphere, and the mixture was heated to 80°C. While stirring, the monomer solution was added dropwise over 3 hours. The start of the dropwise addition marked the start of the polymerization reaction. After the polymerization reaction was carried out for 6 hours, the mixture was cooled to 30°C or below. 300 g of propylene glycol monomethyl ether was added to the reaction solution, and the methyl isobutyl ketone was removed by concentration under reduced pressure, yielding a propylene glycol monomethyl ether solution of polymer (B-1). The Mw of polymer (B-1) was 6,500.

[0288] Synthesis Example 2-2 (Synthesis of Polymer (B-2)) 66 g of acrylic acid, 34 g of styrene, and 25.1 g of dimethyl 2,2'-azobis(2-methylpropionate) were added to prepare a monomer solution. 300 g of methyl isobutyl ketone was placed in a reaction vessel under a nitrogen atmosphere, and the mixture was heated to 80°C. While stirring, the monomer solution was added dropwise over 3 hours. The start of the dropwise addition marked the start of the polymerization reaction. After the polymerization reaction was carried out for 6 hours, the mixture was cooled to 30°C or below. 300 g of propylene glycol monomethyl ether was added to the reaction solution, and the methyl isobutyl ketone was removed by concentration under reduced pressure, yielding a propylene glycol monomethyl ether solution of polymer (B-2). The Mw of polymer (B-2) was 5,300.

[0289] Synthesis Example 2-3 (Synthesis of Polymer (B-3)) A reaction vessel was charged with 29.1 g of 2,7-dihydroxynaphthalene, 14.8 g of a 37% by mass formaldehyde solution, and 87.3 g of methyl isobutyl ketone under a nitrogen atmosphere and dissolved. 1.0 g of p-toluenesulfonic acid monohydrate was added to the reaction vessel, and the mixture was heated to 85°C and reacted for 4 hours. After completion of the reaction, the reaction solution was transferred to a separatory funnel, and 200 g of methyl isobutyl ketone and 400 g of water were added to wash the organic phase. After separating the aqueous phase, the resulting organic phase was concentrated using an evaporator, and the residue was added dropwise to 500 g of methanol to obtain a precipitate. The precipitate was collected by suction filtration and washed several times with 100 g of methanol. The precipitate was then dried at 60°C for 12 hours using a vacuum dryer to obtain polymer (b-3) represented by the following formula (b-3). The Mw of polymer (b-3) was 3,400.

[0290]

[0291] To a reaction vessel, under a nitrogen atmosphere, 16.8 g of the polymer (b-3), 34.9 g of propargyl bromide, 90 g of methyl isobutyl ketone, and 45.0 g of methanol were added and stirred. Then, 106.9 g of a 25% by mass aqueous solution of tetramethylammonium hydroxide was added, and the reaction was carried out at 50°C for 6 hours. The reaction solution was cooled to 30°C, and 200.0 g of a 5% by mass aqueous solution of oxalic acid was added. After removing the aqueous phase, the resulting organic phase was concentrated using an evaporator, and the residue was added dropwise to 500 g of methanol to obtain a precipitate. The precipitate was collected by suction filtration and washed several times with 100 g of methanol. The mixture was then dried at 60°C for 12 hours using a vacuum dryer to obtain polymer (B-3). The Mw of polymer (B-3) was 4,500.

[0292] Synthesis Example 2-4 (Synthesis of Polymer (B-4)) A reaction vessel was charged with 10.0 g of 3-methylphenol, 6.67 g of 4-methylphenol, 25.0 g of a 37% by mass formaldehyde solution, and 116.3 g of methyl isobutyl ketone under a nitrogen atmosphere and dissolved. 1.33 g of p-toluenesulfonic acid monohydrate was added to the reaction vessel, and the mixture was heated to 85°C and reacted for 4 hours. After completion of the reaction, the reaction solution was transferred to a separatory funnel, and 200 g of methyl isobutyl ketone and 400 g of water were added to wash the organic phase. After separating the aqueous phase, the resulting organic phase was concentrated using an evaporator, and the residue was added dropwise to 500 g of methanol to obtain a precipitate. The precipitate was collected by suction filtration and washed several times with 100 g of methanol. The mixture was then dried at 60°C for 12 hours using a vacuum dryer to obtain Polymer (B-4). The Mw of Polymer (B-4) was 5,400.

[0293] Synthesis Example 2-5 (Synthesis of Polymer (B-5)) A reaction vessel was charged with 10.0 g of catechol, 14.7 g of a 37% by mass formaldehyde solution, and 49.4 g of methyl isobutyl ketone under a nitrogen atmosphere and dissolved. 0.73 g of p-toluenesulfonic acid monohydrate was added to the reaction vessel, and the mixture was heated to 85°C and reacted for 4 hours. After completion of the reaction, the reaction solution was transferred to a separatory funnel, and 200 g of methyl isobutyl ketone and 400 g of water were added to wash the organic phase. After separating the aqueous phase, the resulting organic phase was concentrated using an evaporator, and the residue was added dropwise to 500 g of methanol to obtain a precipitate. The precipitate was collected by suction filtration and washed several times with 100 g of methanol. The mixture was then dried at 60°C for 12 hours using a vacuum dryer to obtain Polymer (B-5). The Mw of Polymer (B-5) was 3,400.

[0294] Synthesis Example 2-6 (Synthesis of Polymer (B-6)) In a nitrogen atmosphere, 10.0 g of glycidyl methacrylate, 2.0 g of dimethyl-2,2-azobis(2-methylpropionate), and 20.4 g of methyl isobutyl ketone were charged into a reaction vessel and dissolved. The mixture was heated to 85°C and reacted for 6 hours. After completion of the reaction, the reaction solution was transferred to a separatory funnel, and 100 g of methyl isobutyl ketone and 200 g of water were added to wash the organic phase. After separating the aqueous phase, the resulting organic phase was concentrated using an evaporator, and the residue was added dropwise to 500 g of methanol to obtain a precipitate. The precipitate was collected by suction filtration and washed several times with 100 g of methanol. The precipitate was then dried at 60°C for 12 hours using a vacuum dryer to obtain polymer (b-6) represented by the following formula (b-6). The Mw of polymer (b-6) was 7,200.

[0295]

[0296] To a reaction vessel, under a nitrogen atmosphere, 10.0 g of the polymer (b-6), 12.0 g of 3,4,5-trihydroxybenzoic acid hydrate, 90 g of methyl isobutyl ketone, and 45.0 g of methanol were added, stirred, and then reacted at 50°C for 6 hours. The reaction solution was cooled to 30°C, and 200.0 g of a 5% by mass aqueous solution of oxalic acid was added. After removing the aqueous phase, the resulting organic phase was concentrated using an evaporator, and the residue was added dropwise to 500 g of methanol to obtain a precipitate. The precipitate was collected by suction filtration and washed several times with 100 g of methanol. The mixture was then dried at 60°C for 12 hours using a vacuum dryer to obtain polymer (B-6). The Mw of polymer (B-6) was 4,500.

[0297] Synthesis Example 2-7 (Synthesis of Polymer (B-7)) In a nitrogen atmosphere, 10.0 g of 2-vinylnaphthalene, 6.09 g of vinylbenzyl alcohol, 2.49 g of butyl acetylate, and 5.97 g of dimethyl-2,2-azobis(2-methylpropionate) were charged into a reaction vessel, heated to 80°C, and reacted for 6 hours. After completion of the reaction, the reaction solution was transferred to a separatory funnel, and 200 g of methyl isobutyl ketone and 400 g of water were added to wash the organic phase. After separating the aqueous phase, the resulting organic phase was concentrated using an evaporator, and the residue was added dropwise to 500 g of methanol to obtain a precipitate. The precipitate was collected by suction filtration and washed several times with 100 g of methanol. The precipitate was then dried at 60°C for 12 hours using a vacuum dryer to obtain Polymer (B-7). The Mw of Polymer (B-7) was 6,400.

[0298] Synthesis Example 2-8 (Synthesis of Polymer (B-8)) In a nitrogen atmosphere, 10.0 g of 4-hydroxybenzaldehyde, 9.02 g of rhizocinol, and 50 g of methanol were charged into a reaction vessel and heated to 80°C. 1.00 g of paratoluenesulfonic acid was added, and the mixture was allowed to react for 6 hours. After completion of the reaction, the reaction solution was transferred to a separatory funnel, and 200 g of methyl isobutyl ketone and 400 g of water were added to wash the organic phase. After separating the aqueous phase, the resulting organic phase was concentrated using an evaporator, and the residue was added dropwise to 500 g of methanol to obtain a precipitate. The precipitate was collected by suction filtration and washed several times with 100 g of methanol. The precipitate was then dried at 60°C for 12 hours using a vacuum dryer to obtain polymer (b-8) represented by the following formula (b-8). The Mw of polymer (b-8) was 3,400.

[0299]

[0300] To a reaction vessel, under a nitrogen atmosphere, 18.0 g of the polymer (b-8), 39.0 g of propargyl bromide, 90 g of methyl isobutyl ketone, and 45.0 g of methanol were added and stirred. Then, 106.9 g of a 25% by mass aqueous solution of tetramethylammonium hydroxide was added, and the reaction was carried out at 50°C for 6 hours. The reaction solution was cooled to 30°C, and 200.0 g of a 5% by mass aqueous solution of oxalic acid was added. After removing the aqueous phase, the resulting organic phase was concentrated using an evaporator, and the residue was added dropwise to 500 g of methanol to obtain a precipitate. The precipitate was collected by suction filtration and washed several times with 100 g of methanol. The mixture was then dried at 60°C for 12 hours using a vacuum dryer to obtain polymer (B-8). The Mw of polymer (B-8) was 4,500.

[0301] Synthesis Example 2-9 (Synthesis of Polymer (B-9)) In a nitrogen atmosphere, 10.0 g of 4,4'-(1-phenylethylidene)diphenol, 6.28 g of biphenylaldehyde, and 49.4 g of methyl isobutyl ketone were charged into a reaction vessel and dissolved. 0.73 g of p-toluenesulfonic acid monohydrate was added to the reaction vessel, and the mixture was heated to 85°C and reacted for 4 hours. After completion of the reaction, the reaction solution was transferred to a separatory funnel, and 200 g of methyl isobutyl ketone and 400 g of water were added to wash the organic phase. After separating the aqueous phase, the resulting organic phase was concentrated using an evaporator, and the residue was added dropwise to 500 g of methanol to obtain a precipitate. The precipitate was collected by suction filtration and washed several times with 100 g of methanol. The mixture was then dried at 60°C for 12 hours using a vacuum dryer to obtain Polymer (B-9). The Mw of Polymer (B-9) was 6,200.

[0302] Synthesis Example 2-10 Synthesis of Polymer (B-10) 8 g of N,N-dimethylacetamide was placed in a three-neck flask equipped with a thermometer, a Dimroth condenser, and a stirrer bar and maintained at 80°C. A mixed solution of 3.3 g of 4-iodostyrene, 0.64 g of vinylbenzyl alcohol, 0.88 g of dimethyl-2,2-azobis(2-methylpropionate), and 4 g of N,N-dimethylacetamide was added dropwise from a feeder over 3 hours. After completion of the dropwise addition, the mixture was aged at 80°C for 3 hours. The resulting polymerization solution was concentrated using an evaporator and then purified by precipitation with a 10-fold amount of methyl isobutyl ketone to obtain 3.15 g of a white solid (yield: 80%). The Mw of the resulting polymer (B-10) was 12,200.

[0303] Synthesis Example 2-11 Synthesis of Polymer (B-11) 8 g of N,N-dimethylacetamide was placed in a three-neck flask equipped with a thermometer, a Dimroth condenser, and a stirrer bar and maintained at 80°C. A mixed solution of 3.3 g of triiodophenoxymethylstyrene, 0.25 g of vinylbenzyl alcohol, 0.34 g of dimethyl-2,2-azobis(2-methylpropionate), and 4 g of N,N-dimethylacetamide was added dropwise from a feeder over 3 hours. After completion of the dropwise addition, the mixture was aged at 80°C for 3 hours. The resulting polymerization solution was concentrated using an evaporator and then purified by precipitation with a 10-fold amount of methyl isobutyl ketone to obtain 2.84 g of a white solid (yield: 80%). The Mw of the resulting polymer (B-11) was 8,200.

[0304] <Preparation of Composition> The polymer [A], polymer [B], solvent [C] and crosslinking agent [D] used in the preparation of the composition are shown below.

[0305] [[A] Polymer] Polymers (A-1) to (A-26) synthesized above

[0306] [[B] Polymer] Polymers (B-1) to (B-11) synthesized above

[0307] [[C] Solvent] C-1: Propylene glycol monomethyl ether acetate C-2: Propylene glycol monomethyl ether C-3: 4-methyl-2-pentanol

[0308] [[D] Crosslinking Agent] D-1: Compound represented by the following formula (D-1) D-2: Compound represented by the following formula (D-2)

[0309]

[0310] Example 1 50 parts by mass of (A-1) as the polymer [A] and 50 parts by mass of (D-2) as the crosslinking agent [D] were dissolved in 1,100 parts by mass of (C-1) and 200 parts by mass of (C-2) as the solvent [C]. The resulting solution was filtered through a polytetrafluoroethylene (PTFE) membrane filter with a pore size of 0.45 μm to prepare composition (J-1).

[0311] Examples 2 to 57 and Comparative Examples 1 to 3 Compositions (J-2) to (J-57) and (CJ-1) to (CJ-3) were prepared in the same manner as in Example 1, except that the types and amounts of each component were used as shown in Table 1 below. In Table 1, a "-" in the "A, B, D" column indicates that the corresponding component was not used.

[0312]

[0313] <Evaluation> Using the compositions prepared above, the solvent resistance and the rectangularity of the resist pattern formed by EUV exposure were evaluated by the following methods. The evaluation results are shown in Table 2 below.

[0314] [Solvent Resistance] The composition prepared above was applied to a 12-inch silicon wafer by spin coating using a spin coater (Tokyo Electron Limited's "CLEANTRACKACT12"). The wafer was then heated at 250°C for 180 seconds in an air atmosphere, followed by cooling at 23°C for 60 seconds to form a resist underlayer film with an average thickness of 5 nm, yielding a substrate with a resist underlayer film formed on the substrate. The substrate with the resist underlayer film obtained above was immersed in 2.38% tetramethylammonium hydroxide (23°C) for 1 minute, and then further immersed in ultrapure water for 1 minute. The average film thicknesses before and after immersion were measured. The absolute value of the value obtained by the equation (X - X) × 100 / X was calculated, where X0 is the average thickness of the resist underlayer film before immersion and X is the average thickness of the resist underlayer film after immersion, and this was used as the film thickness change rate (%). The solvent resistance was evaluated as "A" (good) when the film thickness change rate was less than 1%, "B" (fairly good) when it was 1% or more but less than 10%, and "C" (poor) when it was 10% or more.

[0315] <Preparation of Resist Composition> Resist composition (R-1) was obtained by mixing 100 parts by mass of a polymer having a structural unit (1) derived from 4-hydroxystyrene, a structural unit (2) derived from styrene, and a structural unit (3) derived from 4-t-butoxystyrene (the proportions of the structural units were (1) / (2) / (3)=65 / 5 / 30 (mol %)), 1.0 part by mass of triphenylsulfonium trifluoromethanesulfonate as a radiation-sensitive acid generator, and 4,400 parts by mass of ethyl lactate and 1,900 parts by mass of propylene glycol monomethyl ether acetate as solvents, and filtering the resulting solution through a filter with a pore size of 0.2 μm.

[0316] [Resist pattern rectangularity (EUV exposure)] An organic underlayer film forming material ("HM8006" manufactured by JSR Corporation) was applied to a 12-inch silicon wafer by a spin coating method using a spin coater ("CLEAN TRACK ACT12" manufactured by Tokyo Electron Limited), and then heated at 250°C for 60 seconds to form an organic underlayer film with an average thickness of 100 nm. A silicon-containing film-forming composition ("NFC SOG080" manufactured by JSR Corporation) was applied to this organic underlayer film, heated at 220°C for 60 seconds, and then cooled at 23°C for 30 seconds to form a silicon-containing film with an average thickness of 20 nm. The composition prepared above was applied to the silicon-containing film formed above to form a resist underlayer film. The resist underlayer film formed above was heated at 250°C for 180 seconds, and then cooled at 23°C for 30 seconds to obtain a resist underlayer film with an average thickness of 5 nm. Resist composition (R-1) was applied onto the resist underlayer film formed above, heated at 130°C for 60 seconds, and then cooled at 23°C for 30 seconds to form a resist film with an average thickness of 50 nm. The resist film was irradiated with extreme ultraviolet light using a NXE:3300B (NA 0.3, sigma 0.9, quadrupole illumination, 1:1 line and space mask with a line width of 16 nm on the wafer). After irradiation with extreme ultraviolet light, the substrate was heated at 110°C for 60 seconds and then cooled at 23°C for 60 seconds. The resist film was then developed using a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (20°C to 25°C) by the puddle method, washed with water, and dried to obtain an evaluation substrate on which a resist pattern was formed. A scanning electron microscope (Hitachi High-Technologies Corporation's "SU8220") was used to measure and observe the resist pattern on the evaluation substrate. The rectangularity of the resist pattern was evaluated as "A" (good) if the cross-sectional shape of the pattern was rectangular, "B" (fairly good) if there was a footing on the cross-section of the pattern, and "C" (poor) if there was a residue (defect) on the pattern.

[0317]

[0318] <Evaluation> Using the compositions prepared above, the rectangularity of resist patterns obtained by KrF exposure was evaluated by the following method. The evaluation results are shown in Table 3 below.

[0319] [Resist Pattern Rectangularity (KrF Exposure)] An organic underlayer film forming material (JSR Corporation's "HM8006") was applied to a 12-inch silicon wafer by a spin coating method using a spin coater (Tokyo Electron Limited's "CLEAN TRACK ACT12"), and then heated at 250°C for 60 seconds to form an organic underlayer film with an average thickness of 100 nm. A silicon-containing film-forming composition (JSR Corporation's "NFC SOG800") was applied to this organic underlayer film, heated at 220°C for 60 seconds, and then cooled at 23°C for 30 seconds to form a silicon-containing film with an average thickness of 20 nm. The composition prepared above was applied to the silicon-containing film formed above to form a resist underlayer film. The resist underlayer film formed above was heated at 250°C for 180 seconds, and then cooled at 23°C for 30 seconds to obtain a resist underlayer film with an average thickness of 5 nm. Resist composition (R-1) was applied onto the resist underlayer film, heated at 130°C for 60 seconds, and then cooled at 23°C for 30 seconds to form a resist film with an average thickness of 50 nm. The resist film was irradiated with KrF radiation using a mask (inner 0.75, outer 0.91, dipole illumination, 1:1 line-and-space mask with a line width of 130 nm on the wafer). After irradiation with KrF radiation, the substrate was heated at 110°C for 60 seconds and then cooled at 23°C for 60 seconds. The resist film was then developed using a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (20°C to 25°C) by the puddle method, washed with water, and dried to obtain an evaluation substrate on which a resist pattern was formed. A scanning electron microscope (Hitachi High-Technologies Corporation's "CG5000") was used to measure and observe the resist pattern on the evaluation substrate. The rectangularity of the resist pattern was evaluated as "A" (good) if the cross-sectional shape of the pattern was rectangular, "B" (fairly good) if there was a footing on the cross-section of the pattern, and "C" (poor) if there were residues (defects) on the pattern.

[0320]

[0321] <Evaluation> Using the compositions prepared above, the rectangularity of the resist patterns obtained by EB exposure was evaluated by the following method. The evaluation results are shown in Table 4 below.

[0322] [Resist Pattern Rectangularity (EB Exposure)] An organic underlayer film forming material (JSR Corporation's "HM8006") was applied to a 12-inch silicon wafer by a spin coating method using a spin coater (Tokyo Electron Limited's "CLEAN TRACK ACT12"), and then heated at 250°C for 60 seconds to form an organic underlayer film with an average thickness of 100 nm. A silicon-containing film-forming composition (JSR Corporation's "NFC SOG800") was applied to this organic underlayer film, heated at 220°C for 60 seconds, and then cooled at 23°C for 30 seconds to form a silicon-containing film with an average thickness of 20 nm. The composition prepared above was applied to the silicon-containing film formed above to form a resist underlayer film. The resist underlayer film formed above was heated at 250°C for 180 seconds, and then cooled at 23°C for 30 seconds to obtain a resist underlayer film with an average thickness of 5 nm. Resist composition (R-1) was coated on the resist underlayer film, heated at 130° C. for 60 seconds, and then cooled at 23° C. for 30 seconds to form a resist film with an average thickness of 50 nm. The resist film was then exposed to light using an EB scanner (electron beam lithography system (ELS-F150 manufactured by Elionix, current 1 pA, voltage 150 kV, pattern size 200 nm)). After irradiation with the electron beam, the substrate was heated at 110°C for 60 seconds and then cooled at 23°C for 60 seconds. Thereafter, the substrate was developed by the puddle method using a 2.38 mass% aqueous solution of tetramethylammonium hydroxide (20°C to 25°C), followed by washing with water and drying to obtain an evaluation substrate on which a resist pattern had been formed. A scanning electron microscope (CG5000 manufactured by Hitachi High-Technologies Corporation) was used to measure and observe the resist pattern of the evaluation substrate. The rectangularity of the resist pattern was evaluated as "A" (good) when the cross-sectional shape of the pattern was rectangular, "B" (fairly good) when there was footing on the cross section of the pattern, and "C" (poor) when there was residue (defect) in the pattern.

[0323]

[0324] <Evaluation> Using the compositions prepared above, the rectangularity of resist patterns obtained by EUV exposure was evaluated by the following method. The evaluation results are shown in Table 5 below.

[0325] <Preparation of EUV Exposure Resist Composition (R-2)> Compound (S-1) used in preparing EUV exposure resist composition (R-2) was synthesized according to the procedure shown below. In a reaction vessel, 6.5 parts by mass of isopropyltin trichloride was added to 150 mL of 0.5 N aqueous sodium hydroxide solution while stirring, and the reaction was carried out for 2 hours. The precipitate that formed was collected by filtration, washed twice with 50 parts by mass of water, and then dried to obtain compound (S-1). Compound (S-1) was a hydroxide oxide product (i-PrSnO) of the hydrolysis product of isopropyltin trichloride. （３／２－ｘ／２） (OH) ｘ (where 0<x<3 is the structural unit).

[0326] 2 parts by mass of the compound (S-1) synthesized above and 98 parts by mass of propylene glycol monoethyl ether were mixed, and the resulting mixture was passed through an activated 4 Å molecular sieve to remove residual water, followed by filtration through a filter with a pore size of 0.2 μm to prepare a resist composition for EUV exposure (R-2).

[0327] [Pattern Rectangularity (EUV Exposure)] An organic underlayer film-forming material ("HM8006" manufactured by JSR Corporation) was applied onto a 12-inch silicon wafer by spin coating using a spin coater ("CLEAN TRACK ACT12" manufactured by Tokyo Electron Limited), and then heated at 250°C for 60 seconds to form an organic underlayer film with an average thickness of 100 nm. The resist underlayer film-forming composition prepared above was applied onto this organic underlayer film, and then heated at 220°C for 60 seconds, and then cooled at 23°C for 30 seconds to form a resist underlayer film with an average thickness of 5 nm. Resist composition (R-2) for EUV exposure was applied onto this resist underlayer film by spin coating using the spin coater, and after a predetermined time had elapsed, the resist film was heated at 90°C for 60 seconds, and then cooled at 23°C for 30 seconds to form a resist film with an average thickness of 35 nm. The resist film was exposed to light using an EUV scanner (ASML's "TWINSCAN NXE:3300B" (NA 0.3, sigma 0.9, quadrupole illumination, 1:1 line and space mask with on-wafer line width of 16 nm). After exposure, the substrate was heated at 110°C for 60 seconds and then cooled at 23°C for 60 seconds. Thereafter, the substrate was developed by a puddle method using 2-heptanone (20 to 25°C) and then dried to obtain an evaluation substrate on which a resist pattern was formed. A scanning electron microscope (Hitachi High-Tech's "CG-6300") was used to measure and observe the resist pattern of the evaluation substrate. The pattern rectangularity was evaluated as "A" (good) when the cross-sectional shape of the pattern was rectangular, and as "B" (poor) when there was a footing on the cross section of the pattern.

[0328]

[0329] As can be seen from the results in Tables 2 to 5, the resist underlayer films formed from the compositions of the Examples were superior in solvent resistance and resist pattern rectangularity compared to the resist underlayer films formed from the compositions of the Comparative Examples.

[0330] According to the method for producing a semiconductor substrate of the present invention, a composition for forming a resist underlayer film is used, which can form a resist underlayer film that is excellent in solvent resistance and resist pattern rectangularity, so that semiconductor substrates can be produced efficiently. The composition for forming a resist underlayer film of the present invention can form a film that is excellent in solvent resistance and resist pattern rectangularity. Therefore, these compositions can be suitably used in the production of semiconductor devices, etc.

Claims

1. A polymer having a partial structure represented by the following formula (i): Solvent and A composition for forming a resist underlayer film, comprising: 【Chemical 1】 (In formula (i), Y １ Y is a divalent group selected from the group consisting of a sulfonyl group, a carbonyl group, and an alkanediyl group. ２ is a divalent group selected from the group consisting of a sulfonyl group, a carbonyl group, and a single bond. １ is an alkanediyl group, Y ２ is a sulfonyl group or a carbonyl group. ２ is a single bond, Y １ is a sulfonyl group or a carbonyl group. １ is a monovalent organic group having 1 to 20 carbon atoms. ＋ is a monovalent onium cation. * is a bond to another structure in the polymer.

2. 2. The composition for forming a resist underlayer film according to claim 1, wherein the polymer has a repeating unit represented by the following formula (1): 【Chemistry 2】 (In formula (1), R ａ is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms. １ represents a single bond or a divalent linking group other than an alkanediyl group. １ , Y ２ , R １ and X ＋ has the same meaning as the above formula (i).

3. The above L １ 3. The composition for forming a resist underlayer film according to claim 2, wherein is a divalent aromatic hydrocarbon group having 6 to 20 carbon atoms.

4. The above R １ Is Y ２ The composition for forming a resist underlayer film according to any one of claims 1 to 3, wherein the carbon atom adjacent to

5. 4. The composition for forming a resist underlayer film according to claim 1, wherein the polymer further has a repeating unit represented by the following formula (2): 【Chemistry 3】 (In formula (2), R ３ is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms. ３ is a single bond or a divalent linking group. ４ is a monovalent organic group having 1 to 20 carbon atoms.

6. The above L ３ is a single bond, and the R ４ The composition for forming a resist underlayer film according to claim 5 , wherein is a substituted or unsubstituted monovalent aromatic hydrocarbon group or a substituted or unsubstituted monovalent heterocyclic group.

7. 4. The composition for forming a resist underlayer film according to claim 2, wherein the content of the repeating unit represented by formula (1) in all repeating units constituting the polymer is 1 mol % or more and 100 mol % or less.

8. The composition for forming a resist underlayer film according to any one of claims 1 to 3, wherein a content ratio of the polymer in the composition for forming a resist underlayer film other than the solvent is 10 mass % or more.

9. The composition for forming a resist underlayer film according to any one of claims 1 to 3, further comprising a crosslinking agent.

10. The composition for forming a resist underlayer film according to claim 9 , wherein a content ratio of the crosslinking agent in the composition for forming a resist underlayer film other than the solvent is 10% by mass or more.

11. A step of directly or indirectly applying a composition for forming a resist underlayer film to a substrate; a step of applying a composition for forming a resist film to the resist underlayer film formed in the above-mentioned step of applying the composition for forming a resist underlayer film; a step of exposing the resist film formed in the resist film-forming composition application step to radiation; a step of developing at least the exposed resist film; Equipped with The composition for forming a resist underlayer film, A polymer having a partial structure represented by the following formula (i): Solvent and A method for manufacturing a semiconductor substrate, comprising: 【Chemistry 4】 (In formula (i), Y 1 is a divalent group selected from the group consisting of a sulfonyl group, a carbonyl group, and an alkanediyl group. Y 2 is a divalent group selected from the group consisting of a sulfonyl group, a carbonyl group, and a single bond. However, when Y 1 is an alkanediyl group, Y 2 is a sulfonyl group or a carbonyl group. When Y 2 is a single bond, Y 1 is a sulfonyl group or a carbonyl group. R 1 is a monovalent organic group having 1 to 20 carbon atoms. X + is a monovalent onium cation. * represents a bond to another structure in the polymer.)

12. A method for manufacturing a semiconductor substrate as described in claim 11, wherein the polymer has a repeating unit represented by the following formula (1): 【Chemistry 5】 (In formula (1), R a represents a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms. L 1 represents a single bond or a divalent linking group other than an alkanediyl group. Y 1 , Y 2 , R 1 and X + are each defined as in formula (i) above.) 13. The method for manufacturing a semiconductor substrate according to claim 12, wherein L 1 is a divalent aromatic hydrocarbon group having 6 to 20 carbon atoms.

14. A method for manufacturing a semiconductor substrate described in any one of claims 11 to 13, further comprising a step of heating the resist underlayer film formed by the resist underlayer film forming composition coating step at 200°C or higher before the resist film forming composition coating step.

15. The method for manufacturing a semiconductor substrate according to claim 11, wherein the radiation is a KrF excimer laser, an electron beam, or extreme ultraviolet light.

16. A method for manufacturing a semiconductor substrate described in any one of claims 11 to 13, wherein the film thickness of the resist underlayer film is 20 nm or less.

17. A method for manufacturing a semiconductor substrate according to claim 11, wherein the developer used in the step of developing the exposed resist film is a basic liquid.

18. Before the step of applying the composition for forming a resist underlayer film, The method for producing a semiconductor substrate according to any one of claims 11 to 13, further comprising the step of forming a silicon-containing film directly or indirectly on the substrate.

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