Self cross-linkable polymer and resist underlayer film-forming composition

Abstract

Provided is a polymer resin material capable of forming a thermally cured film at a lower temperature without a cross-linking agent or cross-linking catalyst.　A self-cross-linkable polymer comprising unit structures A that have an aromatic ring and unit structures B that are organic groups with a connecting carbon atom, wherein: at least one kind of unit structure A is (i) a unit structure in which an -NR- bond connects at least two aromatic rings, (ii) a unit structure comprising a heterocyclic structure having at least one -NR- bond as a ring structural element, or (iii) a unit structure comprising an aromatic ring that has at least one -NR2 substituent group; R is a hydrogen atom or alkoxymethyl group; at least some of the Rs in the entire polymer are alkoxymethyl groups; and the connecting carbon atom is a carbon atom in a unit structure B that forms a covalent bond with an aromatic ring in a unit structure A and is a carbon atom that does not form an aromatic ring.

Description

Self-crosslinking polymer and resist underlayer film-forming composition

[0001] The present invention relates to a polymer resin suitable for lithography in semiconductor substrate processing, a resist underlayer film-forming composition containing the polymer resin, a resist underlayer film obtained from the resist underlayer film-forming composition, a method for forming a resist pattern using the resist underlayer film-forming composition, and a method for manufacturing a semiconductor device using the composition.

[0002] In recent years, there has been a demand for even higher quality semiconductor process materials, including resist underlayer films, in the lithography process for manufacturing semiconductor devices.

[0003] For example, in order to form such a thermosetting film, a resist underlayer film-forming composition contains, in addition to a polymer resin as a main component, a crosslinkable compound (crosslinking agent) and a catalyst (crosslinking catalyst) for promoting the crosslinking reaction. However, without such a crosslinking agent or crosslinking catalyst, a thermosetting film cannot usually be formed unless it is heated to an ultra-high temperature. However, if there were a polymer resin material that could form a thermosetting film at a lower temperature without a crosslinking agent or crosslinking catalyst, the process would be simpler and more cost-effective. Furthermore, the inclusion of a crosslinking agent or crosslinking catalyst can result in reduced etching resistance, an increase in sublimation components, changes in optical constants, and deterioration of planarization and embeddability. Therefore, there is a strong demand for a material design that does not include these components to form a resist underlayer film.

[0004] Patent Documents 1 and 2 disclose polymers containing a substituent having a carbon-carbon triple bond, such as a propargyl group, on a nitrogen atom as a polymer to be incorporated into an organic film-forming composition. It is believed that such carbon-carbon triple bonds are used as intermolecular cross-linking groups, and that they can form cured films even in inert gases, exhibiting high etching resistance and good embedding and planarization properties. However, these patent documents feature polymers containing a carbon-carbon triple bond on a nitrogen atom, and do not disclose other self-cross-linking polymers. Furthermore, there is no mention of sublimation components or coatability on uneven substrates.

[0005] JP 2019-41059 A JP 2019-44022 A

[0006]

[0010] Therefore, the problem to be solved by the present invention is to provide a polymer resin material that can form a thermosetting film by either low-temperature baking or high-temperature baking in an air atmosphere or a nitrogen atmosphere without the need for a crosslinking agent or a crosslinking catalyst, using a polymer having an alkoxymethyl group such as a MOM group (methoxymethyl group) on a nitrogen atom, and a resist underlayer film-forming composition containing the polymer resin, which can reduce the number of components constituting the material and are therefore advantageous in terms of cost. More preferably, the problem to be solved by the present invention is to provide a polymer resin material that not only has high etching resistance and good embedding and planarization properties, but also reduces the sublimate components generated during baking and exhibits good coatability on uneven substrates, and a resist underlayer film-forming composition containing the polymer resin.

[0007] The present invention encompasses the following: [1] A self-crosslinking polymer comprising: (A) one or more unit structures A having an aromatic ring; and (B) one or more unit structures B which are organic groups having one or more linking carbon atoms, wherein at least one of the unit structures A is: (i) a unit structure comprising a structure in which at least one -NR- bond connects at least two aromatic rings, (ii) a unit structure comprising a heterocycle having at least one -NR- bond as a ring component, wherein if the heterocycle is not an aromatic heterocycle, it forms a condensed ring with a first aromatic ring and / or is substituted with a substituent comprising a second aromatic ring, or (iii) at least one -NR ２ A self-crosslinking polymer comprising a unit structure containing at least one aromatic ring having a substituent, wherein R is a hydrogen atom or an alkoxymethyl group, and at least a portion of R in the entire polymer is an alkoxymethyl group, and the linking carbon atom is a carbon atom in unit structure B that forms a covalent bond with the aromatic ring in unit structure A, but is not part of the aromatic ring. [2] The self-crosslinking polymer according to claim 1, which is a novolak resin. [3] The unit structure A is one of the following unit structures (I-1) to (I-5): and positional isomers thereof, wherein (I-1) to (I-5) above may optionally further have a substituent, wherein R in (I-1) to (I-5) above is the same as defined in [1], wherein each Ar in (I-1) above may be the same or different and represent an aromatic ring which may have a substituent, and wherein (I-2) to (I-5) above represents an aromatic ring moiety in the fused ring which may have a substituent, and each may be the same or different from each other, and in the above (I-4), X represents CR １ R ２ , O, S, or NR'; R' is the same as the definition of R in claim 1, and may be the same as or different from R in the above chemical formula (I-4); R １ and R ２ are the same or different and are an aromatic ring residue or an aliphatic hydrocarbon group having 1 to 3 carbon atoms, represents a heterocyclic moiety in a fused ring compound, which may have a substituent, and Y is a substituent containing an aromatic ring, and may be a substituent on either the aromatic ring moiety or the heterocyclic moiety. [4] The self-crosslinking polymer according to any one of [1] to [3] above, wherein the unit structure B is a unit structure containing a structure represented by the following (II), (III), or (IV): (In formula (II), R and R' each independently represent a hydrogen atom, an aromatic ring residue having 6 to 30 carbon atoms which may have a substituent, a heterocyclic ring residue having 3 to 30 carbon atoms which may have a substituent, or a linear, branched, or cyclic alkyl group having 10 or less carbon atoms which may have a substituent.) [In formula (III), Z represents a monocyclic, bicyclic, tricyclic, or tetracyclic fused ring having 4 to 25 carbon atoms, which may have a substituent, and the monocyclic ring is a non-aromatic monocyclic ring; at least one of the monocyclic rings constituting the bicyclic, tricyclic, or tetracyclic ring is a non-aromatic monocyclic ring, and the remaining monocyclic rings may be aromatic or non-aromatic monocyclic rings; the monocyclic, bicyclic, tricyclic, or tetracyclic fused ring may further form a fused ring with one or more aromatic rings to form a pentacyclic or higher fused ring; X and Y are the same or different and each represent -CR 31 R 32 represents a - group, and R31 and R 32 are the same or different and represent a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms; x and y represent the number of X and Y, respectively, and each independently represents 0 or 1; is bonded to any carbon atom (referred to as "carbon atom 1") constituting the non-aromatic monocyclic ring of Z (when x = 1) or extends from carbon atom 1 (when x = 0), is bonded to any carbon atom (referred to as "carbon atom 2") constituting the non-aromatic monocycle of Z (when y = 1) or extends from carbon atom 2 (when y = 0), and carbon atom 1 and carbon atom 2 may be the same or different, and if different, they may belong to the same non-aromatic monocycle or different non-aromatic monocycles, and * indicates a bond.] [In formula (IV), Z ０ represents an aromatic ring residue or an aliphatic ring residue having 6 to 30 carbon atoms, which may have a substituent, or an organic group in which two aromatic ring residues or aliphatic ring residues are linked by a single bond; J １ and J ２ each independently represents a direct bond or a divalent organic group which may have a substituent.] [5] The formula (III) is the following formula (III-1): [In formula (III-1), Z represents a 4- to 17-membered monocyclic, bicyclic, tricyclic, or tetracyclic organic group which may have a substituent, and the monocyclic group is a non-aromatic monocyclic group; at least one of the monocyclic groups constituting the bicyclic, tricyclic, or tetracyclic group is a non-aromatic monocyclic group, and the remaining monocyclic groups may be either aromatic or non-aromatic monocyclic groups; one or more aromatic rings may be fused to or fused with the monocyclic, bicyclic, tricyclic, or tetracyclic organic group to form a pentacyclic or higher ring; C and C' each represent a carbon atom in the atomic group constituting the cyclic moiety of any of the non-aromatic monocyclic groups represented by Z, and the non-aromatic monocyclic groups to which C and C' belong may be the same or different; n represents the number of carbon atoms C' and represents an integer of 0 to 2; p, q, p', and q' represent the number of bonds and each independently represent 0 or 1; when n is 0, p and q are 1; When n is 1 or 2, at least one of p and q, and at least one of p' and q' of each C' are each 1; when n is 2, the non-aromatic monocycles to which the two C's belong may be the same or different, and when they are the same, the two C's may or may not be directly bonded; X, Y, X', and Y' may be the same or different, and each represent -CR 1 R 2 represents a - group, and R 1 and R 2are the same or different and represent a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms; when n is 2, two X' may be the same or different, two Y' may be the same or different, and x, y, x', and y' represent the numbers of X, Y, X', and Y', respectively, and each independently represent 0 or 1. [6] The self-crosslinking polymer according to any one of [1] to [5] above, wherein an end group of the self-crosslinking polymer is an aromatic ring residue having 6 to 30 carbon atoms which may have a substituent, an unsaturated hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, a hydroxyl group, or a hydrogen atom. [7] A resist underlayer film-forming composition comprising a thermal acid generator, the self-crosslinking polymer according to any one of [1] to [6] above, and a solvent. [8] The resist underlayer film-forming composition according to [7] above, further comprising a crosslinking agent. [9] The resist underlayer film-forming composition according to [8] above, wherein the crosslinking agent is an aminoplast crosslinking agent or a phenoplast crosslinking agent.

[10] The resist underlayer film-forming composition according to [9] above, wherein the aminoplast crosslinking agent is a highly alkylated, alkoxylated, or alkoxyalkylated melamine, benzoguanamine, glycoluril, urea, or a polymer thereof.

[11] The resist underlayer film-forming composition according to [9] above, wherein the phenoplast crosslinking agent is a highly alkylated, alkoxylated, or alkoxyalkylated aromatic compound, or a polymer thereof.

[12] The resist underlayer film-forming composition according to any one of [7] to

[11] above, wherein the solvent is a compound having an alcoholic hydroxyl group or a compound having a group capable of forming an alcoholic hydroxyl group.

[13] The resist underlayer film forming composition according to

[12] above, wherein the compound having an alcoholic hydroxyl group or the compound having a group capable of forming an alcoholic hydroxyl group is a propylene glycol-based solvent, an oxyisobutyric acid ester-based solvent, or a butylene glycol-based solvent.

[14] The resist underlayer film-forming composition according to

[12] above, wherein the compound having an alcoholic hydroxyl group or the compound having a group capable of forming an alcoholic hydroxyl group is propylene glycol monomethyl ether, cyclohexanone, propylene glycol monomethyl ether acetate, ethyl lactate, or methyl 2-hydroxy-2-methylpropionate.

[15] The resist underlayer film-forming composition according to any one of [7] to

[14] above, further comprising a surfactant.

[16] A resist underlayer film, which is a baked product of a coating film formed on a semiconductor substrate, comprising the resist underlayer film-forming composition according to any one of [7] to

[15] above.

[17] A method for forming a resist pattern used in semiconductor production, comprising the step of applying the resist underlayer film-forming composition according to any one of [7] to

[15] above onto a semiconductor substrate and baking the coating film.

[18] A method for manufacturing a semiconductor device, comprising: a step of forming a resist underlayer film on a semiconductor substrate from the resist underlayer film-forming composition according to any one of [7] to

[15] above; a step of forming a resist film thereon; a step of forming a resist pattern by irradiating with light or an electron beam and developing, a step of etching the resist underlayer film using the formed resist pattern; and a step of processing a semiconductor substrate using the patterned resist underlayer film.

[19] A method for manufacturing a semiconductor device, comprising: a step of forming a resist underlayer film on a semiconductor substrate from the resist underlayer film-forming composition according to any one of [7] to

[15] above; a step of forming a hard mask thereon; a step of further forming a resist film thereon; a step of forming a resist pattern by irradiating with light or an electron beam and developing, a step of etching the hard mask using the formed resist pattern, a step of etching the resist underlayer film using the patterned hard mask, and a step of processing a semiconductor substrate using the patterned resist underlayer film.

[20] A method for manufacturing a semiconductor device, comprising: a step of forming a resist underlayer film on a semiconductor substrate from the resist underlayer film-forming composition according to any one of items [7] to

[15] above; a step of forming a hard mask thereon; a step of further forming a resist film thereon; a step of forming a resist pattern by irradiating with light or an electron beam and developing; a step of etching the hard mask using the formed resist pattern; a step of etching the resist underlayer film using the patterned hard mask; a step of removing the hard mask; and a step of processing a semiconductor substrate using the patterned resist underlayer film.

[21] A method for manufacturing a semiconductor device, comprising the steps of: forming a resist underlayer film on a semiconductor substrate from the resist underlayer film-forming composition according to any one of [7] to

[15] above; forming a hard mask thereon; further forming a resist film thereon; forming a resist pattern by irradiating with light or an electron beam and developing; etching the hard mask using the formed resist pattern; etching the resist underlayer film using the patterned hard mask; removing the hard mask; and forming a vapor-deposited film (spacer) on the resist underlayer film after hard mask removal; processing the vapor-deposited film (spacer) by etching; removing the patterned resist underlayer film to leave the patterned vapor-deposited film (spacer); and processing the semiconductor substrate through the patterned vapor-deposited film (spacer).

[22] The manufacturing method according to any one of

[19] to

[21] above, wherein the hard mask is formed by coating or vapor-depositing an inorganic material.

[23] The manufacturing method of any one of

[18] to

[21] above, wherein the resist film is patterned by a nanoimprint method or a self-assembled film.

[24] The manufacturing method of a semiconductor device of

[20] or

[21] above, wherein the hard mask is removed by etching or an alkaline chemical solution.

[0008] The self-crosslinking polymer of one embodiment of the present invention can form a thermoset film by either low-temperature baking or high-temperature baking in an air atmosphere or a nitrogen atmosphere without containing a crosslinking agent or a crosslinking catalyst, and can reduce the components constituting the material, which is advantageous in terms of cost. Furthermore, in a more preferred embodiment, a polymer resin material containing the self-crosslinking polymer of one embodiment of the present invention and a resist underlayer film-forming composition containing the polymer resin not only have high etching resistance and good embedding and planarization properties, but also reduce the sublimate components generated during baking and exhibit good coatability to uneven substrates.

[0009] [1. Definitions of Terms] In this specification, definitions of main terms related to the novolac resin, which is one embodiment of the present invention, are explained below. Unless otherwise specified, the following definitions of each term apply to the novolac resin.

[0010] (1-1) "Novolac Resin" The term "novolac resin" is used in a broad sense to encompass not only phenol-formaldehyde resins (so-called novolac-type phenolic resins) and aniline-formaldehyde resins (so-called novolac-type aniline resins) in the narrow sense, but also polymers formed generally in the presence of an acid catalyst or under reaction conditions equivalent thereto by forming a covalent bond (substitution reaction, addition reaction, condensation reaction, addition-condensation reaction, or the like) between an organic compound having a functional group capable of forming a covalent bond with an aromatic ring [for example, an aldehyde group, a ketone group, an acetal group, a ketal group, a hydroxyl group or an alkoxy group bonded to a secondary or tertiary carbon, a hydroxyl group, an alkoxy group or a halo group bonded to the α-carbon atom (e.g., the benzylic carbon atom) of an alkylaryl group, or a carbon-carbon unsaturated bond such as in divinylbenzene or dicyclopentadiene] and an aromatic ring in a compound having an aromatic ring (preferably having a heteroatom-containing substituent such as an oxygen atom, a nitrogen atom or a sulfur atom on the aromatic ring).

[0011] Therefore, the novolac resin referred to in this specification is a polymer formed by linking compounds having a plurality of aromatic rings together, with an organic compound containing a carbon atom derived from the functional group (sometimes referred to as a "linking carbon atom") forming a covalent bond with an aromatic ring in a compound having an aromatic ring via the linking carbon atom.

[0012] In this specification, the terms unit structure A, unit structure B, and unit structure C are used as unit structures constituting a "novolac resin." Unit structure A is a unit structure derived from a compound having an aromatic ring. Unit structure B is a unit structure derived from a compound having a functional group that enables covalent bonding with the aromatic ring of unit structure A. Unit structure C is a unit structure equivalent in bonding mode to composite unit structure A-B, and is a unit structure derived from a compound having an aromatic ring and a functional group that enables covalent bonding with the aromatic ring of unit structure A. Because the bonding modes are the same, unit structure C can be replaced with composite unit structure A-B.

[0013] (1-2) "Residue" A "residue" refers to an organic group in which a hydrogen atom bonded to a carbon atom or heteroatom (such as a nitrogen atom, oxygen atom, or sulfur atom) is replaced with a bonding hand, and may be a monovalent or polyvalent group. For example, replacing one hydrogen atom with one bonding hand results in a monovalent organic group, and replacing two hydrogen atoms with bonding hands results in a divalent organic group.

[0014] (1-3) "Aromatic Ring" (Aromatic Group, Aryl Group, Arylene Group) The term "aromatic ring" is a concept that encompasses aromatic hydrocarbon rings, aromatic heterocycles, and residues thereof [sometimes referred to as "aromatic groups," "aryl groups" (in the case of monovalent groups), or "arylene groups" (in the case of divalent groups)], and encompasses not only monocyclic (aromatic monocycles) but also polycyclic (aromatic polycycles). In the case of polycycles, at least one monocycle is an aromatic monocycle, but the remaining monocycles that form a condensed ring with the aromatic monocycle may be a monocyclic heterocycle (heteromonocycle) or a monocyclic alicyclic hydrocarbon (alicyclic monocycle).

[0015] Examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, indene, naphthalene, azulene, styrene, toluene, xylene, mesitylene, cumene, anthracene, phenanthrene, triphenylene, benzanthracene, pyrene, chrysene, fluorene, biphenyl, corannulene, perylene, fluoranthene, benzo[k]fluoranthene, benzo[b]fluoranthene, benzo[ghi]perylene, coronene, dibenzo[g,p]chrysene, acenaphthylene, acenaphthene, naphthacene, pentacene, and cyclooctatetraene, more typically aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and pyrene; and aromatic hydrocarbon rings such as furan, pyran, pyridine, pyrimidine, pyrazine, thiophene, and pyrrolidone. aromatic heterocycles such as indole, N-alkylpyrrole, N-arylpyrrole, imidazole, pyridine, pyrimidine, pyrazine, triazine, thiazole, indole, phenylindole, bisindolefluorene, bisindolebenzofluorene, bisindoledibenzofluorene, purine, quinoline, isoquinoline, chromene, thianthrene, phenothiazine, phenoxazine, xanthene, acridine, phenazine, carbazole, and indolocarbazole, and more typically, furan, thiophene, pyrrole, indole, phenylindole, bisindolefluorene, phenothiazine, carbazole, and indolocarbazole, but are not limited thereto.

[0016] The aromatic ring (for example, a benzene ring, a naphthalene ring, etc.) may have an optional substituent, and such substituents include a halogen atom, a saturated or unsaturated linear, branched, or cyclic hydrocarbon group (-R) (the hydrocarbon chain may be interrupted one or more times by an oxygen atom, and includes an alkyl group, an alkenyl group, an alkynyl group, a propargyl group, etc.), an alkoxy group or an aryloxy group (-OR, where R represents the hydrocarbon group -R), an alkylamino group [-NHR or -NR ２(Two R's may be the same or different), where R's represent the hydrocarbon group -R, and include alkyl groups, alkenyl groups, alkynyl groups, propargyl groups, etc., whose hydrocarbon chains may be interrupted one or more times by oxygen atoms.], hydroxyl groups, amino groups (-NH ２ ), carboxyl group, cyano group, nitro group, ester group (-CO ２ R or -OCOR, where R represents the hydrocarbon group -R), an amide group (-NHCOR, -CONHR, -NRCOR (two Rs may be the same or different), or -CONR ２ (two R's may be the same or different), where R's represent the hydrocarbon group -R), a sulfonyl-containing group (-SO ２ R, where R represents the hydrocarbon group -R or a hydroxyl group -OH), a thiol group (-SH), a sulfide-containing group (-SR, where R represents the hydrocarbon group -R); an organic group containing an ether bond [R １１ -O-R １１ (R １１ each independently represents an alkyl group having 1 to 6 carbon atoms, such as a methyl group or an ethyl group, or an aryl group, such as a phenyl group, a naphthyl group, an anthranyl group or a pyrenyl group. Examples of substituents include residues of ether compounds represented by the formula (I); organic groups containing an ether bond, such as a methoxy group, an ethoxy group or a phenoxy group; and aryl groups.

[0017] Furthermore, organic groups having one or more condensed rings of aromatic rings (such as benzene, naphthalene, anthracene, and pyrene) with one or more aliphatic or heterocyclic rings are also included. Examples of the aliphatic rings include cyclobutane, cyclobutene, cyclopentane, cyclopentene, cyclohexane, cyclohexene, methylcyclohexane, methylcyclohexene, cycloheptane, and cycloheptene, and examples of the heterocyclic rings include furan, thiophene, pyrrole, imidazole, pyran, pyridine, pyrimidine, pyrazine, pyrrolidine, piperidine, piperazine, and morpholine.

[0018] It may also be an organic group having a structure in which two or more aromatic rings are linked by a divalent linking group such as an alkylene group.

[0019] (1-4) "Heterocycle" The term "heterocycle" encompasses both aliphatic heterocycles and aromatic heterocycles, and is a concept that encompasses not only monocyclic (heteromonocyclic) but also polycyclic (heteropolycyclic). In the case of a polycyclic, at least one monocyclic ring is a heteromonocyclic ring, but the remaining monocyclic rings may be aromatic hydrocarbon monocyclic or alicyclic monocyclic. For the aromatic heterocycle, the examples in (1-3) above can be referred to. As with the aromatic ring in (1-3) above, it may have a substituent.

[0020] (1-5) "Non-aromatic ring" (aliphatic ring) A "non-aromatic monocycle" refers to a monocyclic hydrocarbon that does not belong to the aromatic group, and is typically a monocycle of an alicyclic compound. It may also be called an aliphatic monocycle (which may include an aliphatic heteromonocycle, or may contain an unsaturated bond as long as it does not belong to the aromatic compound). As with the aromatic ring in (1-3) above, it may have a substituent.

[0021] Examples of non-aromatic monocyclic rings (aliphatic rings, aliphatic monocyclic rings) include cyclopropane, cyclobutane, cyclobutene, cyclopentane, cyclopentene, cyclohexane, methylcyclohexane, cyclohexene, methylcyclohexene, cycloheptane, and cycloheptene.

[0022] "Non-aromatic polycyclic rings" refer to polycyclic hydrocarbons that are not aromatic, and are typically polycyclic alicyclic compounds. They may also be called aliphatic polycyclic rings (which may include aliphatic heterocyclic rings (where at least one of the monocyclic rings constituting the polycyclic ring is an aliphatic heterocyclic ring), or may contain unsaturated bonds as long as they do not belong to the aromatic compound category). They include non-aromatic bicyclic rings, non-aromatic tricyclic rings, and non-aromatic tetracyclic rings.

[0023] "Non-aromatic bicycle" refers to a fused ring composed of two monocyclic hydrocarbons that are not aromatic, typically two fused rings of an alicyclic compound. In this specification, it is also referred to as an aliphatic bicycle (which may include an aliphatic heterobicycle, and may contain unsaturated bonds as long as it does not belong to the aromatic compound). Examples of non-aromatic bicycles include bicyclopentane, bicyclooctane, and bicycloheptene.

[0024] A "non-aromatic tricyclic ring" refers to a fused ring composed of three monocyclic hydrocarbons that are not aromatic, and is typically a fused ring of three alicyclic compounds (each of which may be a heterocyclic ring or may contain an unsaturated bond as long as it is not an aromatic compound). Examples of non-aromatic tricyclic rings include tricyclooctane, tricyclononane, and tricyclodecane.

[0025] The term "non-aromatic tetracyclic ring" refers to a fused ring composed of four monocyclic hydrocarbons that are not aromatic, and is typically a fused ring of four alicyclic compounds (each of which may be a heterocyclic ring or may contain an unsaturated bond as long as it is not an aromatic compound). Examples of non-aromatic tetracyclic rings include hexadecahydropyrene.

[0026] (1-6) The term "carbon atoms constituting a ring (moiety)" refers to the carbon atoms constituting a hydrocarbon ring (which may be an aromatic ring, an aliphatic ring, or a heterocyclic ring) that does not have a substituent.

[0027] (1-7) The term "hydrocarbon group" refers to a group formed by removing one or more hydrogen atoms from a hydrocarbon, and such hydrocarbons include saturated or unsaturated aliphatic hydrocarbons, saturated or unsaturated alicyclic hydrocarbons, and aromatic hydrocarbons.

[0028] (1-8) In the chemical structural formula showing the unit structure of the novolac resin in this specification, a bond (indicated by *) may be shown for convenience. However, unless otherwise specified, such a bond may be at any available bonding position in the unit structure, and does not in any way limit the bonding position in the unit structure.

[0029] [2. Self-Crosslinking Polymer [1]] (2-1) A self-crosslinking polymer according to one embodiment of the present invention is a self-crosslinking polymer including: (A) one or more types of unit structures A having an aromatic ring; and (B) one or more types of unit structures B which are organic groups having one or more linking carbon atoms.

[0030] At least one type of unit structure A among the unit structures A is: (i) a unit structure including a structure in which at least one -NR- bond connects at least two aromatic rings; (ii) a unit structure including a heterocycle having at least one -NR- bond as a ring component, and when the heterocycle is not an aromatic heterocycle, it forms a condensed ring with a first aromatic ring and / or is substituted with a substituent including a second aromatic ring; or (iii) at least one -NR ２ It is a unit structure containing at least one aromatic ring having a substituent. Here, R is a hydrogen atom or an alkoxymethyl group, and at least a portion of the R in the entire polymer is an alkoxymethyl group, which can impart self-crosslinking properties. The alkoxy in the alkoxymethyl group is preferably a hydrocarbon group having 1 to 10 carbon atoms, more preferably a hydrocarbon group having 1 to 3 carbon atoms, and most preferably a methoxymethyl group.

[0031] At least a portion of the R in the entire polymer is an alkoxymethyl group, and the proportion of alkoxymethyl groups contained therein is adjusted from the viewpoint of imparting the desired self-crosslinking property. One linking carbon atom in unit structure B [see (1-1) above] may (i) form a covalent bond with each of the aromatic rings of two unit structures A, or (ii) be covalently bonded to the aromatic ring of one unit structure A and a polymer terminal group. In the latter case (ii), unit structure B contains at least two, more preferably two, linking carbon atoms. Furthermore, a linking carbon atom is a carbon atom in unit structure B that forms a covalent bond with the aromatic ring in unit structure A to form a covalent bond between unit structure A and unit structure B, but that does not constitute an aromatic ring. Note that the covalent bond with the aromatic ring of unit structure A also includes a covalent bond with the aromatic ring of unit structure C, which is equivalent to the composite unit structure A-B in which one unit structure A and one unit structure B are bonded, as described below [(2-4-3-3), (2-4-5-3), and (2-4-6)].

[0032] (2-2) The self-crosslinking polymer according to one embodiment of the present invention is preferably a novolak resin [see (1-1) above]. Therefore, the novolak resin referred to in the present specification is a polymer formed by linking compounds having multiple aromatic rings together, by forming a covalent bond between an organic compound (unit structure B) containing a carbon atom (corresponding to a "linking carbon atom") derived from a functional group and an aromatic ring (unit structure A) in the compound having an aromatic ring.

[0033] (2-3; Unit Structure A) (2-3-1) The unit structure A of the self-crosslinking polymer according to one embodiment of the present invention is one or more unit structures having an aromatic ring, and at least one of the unit structures A is selected from the group consisting of: (i) a unit structure including a structure in which at least one -NR- bond connects at least two aromatic rings, (ii) a unit structure including a heterocycle having at least one -NR- bond as a ring component, wherein when the heterocycle is not an aromatic heterocycle, it forms a condensed ring with a first aromatic ring and / or is substituted with a substituent including a second aromatic ring, or (iii) at least one -NR ２A unit structure containing at least one aromatic ring having a substituent. Here, R is a hydrogen atom or an alkoxymethyl group, and at least a portion of the R in the entire polymer is an alkoxymethyl group. The linkage of aromatic rings by an -NR- bond in (i) above does not necessarily require that the -NR- bond be directly covalently bonded to the aromatic ring, and also includes an embodiment in which the -NR- bond is indirectly covalently bonded via a divalent organic group (e.g., a divalent hydrocarbon chain). It also includes an embodiment in which multiple -NR- bonds are linked together by a divalent organic group (e.g., a divalent hydrocarbon chain), and two aromatic rings are linked by the multiple -NR- bonds thus linked. Furthermore, the unit structure containing a heterocycle in (ii) above also includes an embodiment in which the heterocycle is a fused ring of one or more first aromatic rings, or an embodiment in which the heterocycle or the fused ring is substituted with a substituent containing a second aromatic ring. Furthermore, the substitution of the fused ring with the substituent may be substitution at the heterocyclic moiety or at the first aromatic ring moiety. However, when the heterocycle is not an aromatic heterocycle, it forms a fused ring with a first aromatic ring and / or is substituted with a substituent containing a second aromatic ring. This is because the unit structure A is a unit structure having an aromatic ring. Specific examples of the -NR- bond contained in the aromatic ring include aromatic rings such as pyrrole rings and fused aromatic rings such as carbazole rings. In addition, the -NR in (iii) above may be substituted with a substituent containing a second aromatic ring. ２ The unit structure containing a substituted aromatic ring may contain, as the heteroatom-containing substituent, —NR ２ It is an embodiment having an aromatic ring (including not only an aromatic hydrocarbon ring but also an aromatic heterocyclic ring) having a substituent, and -NR ２ Of the two R in the substituent, at least one is preferably an alkoxymethyl group, and more preferably one is an alkoxymethyl group. The aromatic ring is preferably a fused ring consisting of a plurality of aromatic monocycles.

[0034] (2-3-2) (2-3-2-1) Of the unit structures A, (i) a unit structure containing a structure in which at least one —NR— bond connects at least two aromatic rings is represented by the following formula (I-1): [wherein Ar may be the same or different and represent an aromatic ring, and R represents a hydrogen atom or an alkoxymethyl group.] is a typical unit structure, but the following formulae (I-2) and (I-3): [ represents an aromatic ring moiety in the fused ring which may have a substituent, and each may be the same or different, and R represents a hydrogen atom or an alkoxymethyl group. and its positional isomers [ represents an aromatic ring moiety in the fused ring which may have a substituent, and each may be the same or different, and R represents a hydrogen atom or an alkoxymethyl group.] This also includes an embodiment in which multiple aromatic rings linked by an —NR— bond are bonded by a single bond to form a separate ring, as in the unit structure of

[0035] (2-3-2-2) Furthermore, among the unit structures A, (ii) unit structures containing a heterocycle having at least one —NR— bond as a ring component include, for example, the units represented by formulae (I-4) and (I-5): [ represents an aromatic ring moiety in the fused ring which may have a substituent, and each may be the same or different from each other; R represents a hydrogen atom or an alkoxymethyl group; X represents C(R １ ) (R ２ ), O, S, or NR'; R' has the same definition as R and may be the same as or different from R; R １ and R ２ are the same or different and represent an aliphatic hydrocarbon group having 1 to 3 carbon atoms. [ represents an aromatic ring moiety in the fused ring which may have a substituent, and each may be the same or different from each other, represents a heterocyclic moiety in the fused ring compound, which may have a substituent; R represents a hydrogen atom or an alkoxymethyl group; and Y is a substituent containing an aromatic ring, and may be a substituent on either the aromatic ring moiety or the heterocyclic moiety. The aromatic ring in Y may be directly bonded to the fused ring in formula (I-5), or may be bonded to the fused ring in formula (I-5) via a divalent organic group. The aromatic ring in Y may be directly bonded to the fused ring in formula (I-5), or may be indirectly bonded via a divalent linking group (for example, a divalent hydrocarbon group). The bond extending from Y to another unit structure preferably extends from the aromatic ring of Y.

[0036] (2-3-3) Preferably, the unit structure A containing an —NR— bond is at least one selected from the following:

[0037] (2-3-4) For the "aromatic ring" in the unit structure A of the self-crosslinking polymer according to one embodiment of the present invention, see (1-3) above. Preferably, the "aromatic ring" in the unit structure A of the self-crosslinking polymer according to one embodiment of the present invention has 6 to 30 or 6 to 24 carbon atoms. Preferably, the "aromatic ring" in the unit structure A of the self-crosslinking polymer according to one embodiment of the present invention is one or more benzene rings, naphthalene rings, anthracene rings, or pyrene rings; or a condensed ring of a benzene ring, a naphthalene ring, an anthracene ring, or a pyrene ring with a heterocycle or an aliphatic ring.

[0038] (2-3-5) The aromatic ring in the unit structure A of the self-crosslinking polymer according to one embodiment of the present invention may further have a substituent, as long as the effect of the present invention is not impaired. For such a substituent, see (1-3) above.

[0039] (2-3-6) Preferably, -NR- bond or NR ２ The unit structure A having a substituent is at least one selected from the following:

[0040] Among the above-mentioned skeletons, the following skeletons are more preferable.

[0041] (2-3-7) The unit structure A has an -NR- bond or an NR ２ The copolymer may optionally contain a unit structure that does not have a substituent (where R is a hydrogen atom or an alkoxymethyl group), and examples thereof include the following:

[0042] (Examples of amine skeletons)

[0043] (Example of a phenol skeleton)

[0044] In particular, -NR- bonds and NR ２ Although the unit structure A is other than the unit structure A having a substituent, the unit structure A having a preferred phenol skeleton may include, for example, the following unit structures.

[0045] (2-3-8) In addition, when R=H in the NR of the skeleton of the unit structure A of (2-3-6), H of NH of the amine skeleton, NR ２ Among the substituents, NH when R=H ２ At least one H in the above and H in the OH of the phenol skeleton of (2-3-7) may be replaced with the following substituents.

[0046] (2-3-9) As will be explained later in (2-4-3-3), (2-4-5-3), (2-4-6), etc., it has a structure that can function as unit structure B, but since the structure has an aromatic ring, it may optionally function as unit structure A; or as one unit structure C equivalent to a composite unit structure AB in which one unit structure A and one unit structure B are bonded.

[0047] (2-4; Unit Structure B) (2-4-1) The unit structure B of the self-crosslinking polymer according to one embodiment of the present invention is one or more unit structures that are organic groups having one or more linking carbon atoms. Linking carbon atoms are as described above in (1-1). Preferably, the unit structure B of the polymer is a 4- to 17-membered monocyclic, bicyclic, tricyclic, or tetracyclic organic group that may have a substituent, wherein the monocyclic ring is a non-aromatic monocyclic ring; at least one of the monocyclic rings constituting the bicyclic, tricyclic, or tetracyclic ring is a non-aromatic monocyclic ring, and the remaining monocyclic rings have a unit structure containing an organic group that may be either an aromatic monocyclic ring or a non-aromatic monocyclic ring. Furthermore, one or more aromatic rings may be fused or fused to the monocyclic, bicyclic, tricyclic, or tetracyclic organic group to form a pentacyclic or higher ring. Furthermore, the one or more linking carbon atoms are covalently bonded not to carbon atoms constituting an aromatic monocyclic ring, but to the aromatic ring of the unit structure A [or unit bond C], thereby bonding the unit structure A [or unit bond C] to the unit structure B.

[0048] (2-4-2) Preferably, the unit structure B represents one or more unit structures including a structure represented by the following formula (II), (III), or (IV). Such unit structures also include unit structures in which two or three identical or different structures represented by these formulas are linked by a divalent or trivalent linking group [see (2-4-4-3) below]. The unit structure B is covalently bonded to a carbon atom on the aromatic ring of the unit structure A via a bond in the following formula (II), (III), or (IV), for example, thereby bonding the unit structure A [or unit bond C] to the unit structure B. [In formula (II), R and R′ each independently represent a hydrogen atom, an aromatic ring residue having 6 to 30 carbon atoms which may have a substituent, a heterocyclic ring residue having 3 to 30 carbon atoms which may have a substituent, or a linear, branched, or cyclic alkyl group having 10 or less carbon atoms which may have a substituent.] [In formula (III), Z represents a monocyclic, bicyclic, tricyclic, or tetracyclic fused ring having 4 to 25 carbon atoms, which may have a substituent, and the monocyclic ring is a non-aromatic monocyclic ring; at least one of the monocyclic rings constituting the bicyclic, tricyclic, or tetracyclic ring is a non-aromatic monocyclic ring, and the remaining monocyclic rings may be aromatic or non-aromatic monocyclic rings; the monocyclic, bicyclic, tricyclic, or tetracyclic fused ring may further form a fused ring with one or more aromatic rings to form a pentacyclic or higher fused ring; X and Y are the same or different and each represent -CR 31 R 32 represents a - group, and R 31 and R 32 are the same or different and represent a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms; x and y represent the number of X and Y, respectively, and each independently represents 0 or 1; is bonded to any carbon atom (referred to as "carbon atom 1") constituting the non-aromatic monocyclic ring of Z (when x = 1) or extends from carbon atom 1 (when x = 0), is bonded to any carbon atom (referred to as "carbon atom 2") constituting the non-aromatic monocycle of Z (when y = 1) or extends from carbon atom 2 (when y = 0), and carbon atom 1 and carbon atom 2 may be the same or different, and if different, they may belong to the same non-aromatic monocycle or different non-aromatic monocycles, and * indicates a bond.] [In formula (IV), Z ０ represents an aromatic ring residue or an aliphatic ring residue having 6 to 30 carbon atoms, which may have a substituent, or an organic group in which two aromatic ring residues or aliphatic ring residues are linked by a single bond; J １ and J ２ each independently represents a direct bond or a divalent organic group which may have a substituent.

[0049] (2-4-3) (2-4-3-1) The unit structure B is represented by formula (II) In the definitions of R and R' in formula (II), "substituents", "aromatic rings", and "heterocycles" are the same as those explained in (1-3) and (1-4) above. In the definitions of R and R' in formula (II), "alkyl groups" include, for example, methyl groups, ethyl groups, n-propyl groups, i-propyl groups, cyclopropyl groups, n-butyl groups, i-butyl groups, s-butyl groups, t-butyl groups, cyclobutyl groups, 1-methyl-cyclopropyl groups, 2-methyl-cyclopropyl groups, n-pentyl groups, 1-methyl-n-butyl groups, 2-methyl-n-butyl groups, 3-methyl-n-butyl groups, 1,1-dimethyl-n-propyl groups, 1,2-dimethyl-n-propyl groups, 2,2-dimethyl-n-propyl ... Methyl-n-propyl group, 1-ethyl-n-propyl group, cyclopentyl group, 1-methyl-cyclobutyl group, 2-methyl-cyclobutyl group, 3-methyl-cyclobutyl group, 1,2-dimethyl-cyclopropyl group, 2,3-dimethyl-cyclopropyl group, 1-ethyl-cyclopropyl group, 2-ethyl-cyclopropyl group, n-hexyl group, 1-methyl-n-pentyl group, 2-methyl-n-pentyl group, 3-methyl-n-pentyl group, 4-methyl-n-pentyl group, 1,1-dimethyl-n-butyl group, 1,2-di Methyl-n-butyl group, 1,3-dimethyl-n-butyl group, 2,2-dimethyl-n-butyl group, 2,3-dimethyl-n-butyl group, 3,3-dimethyl-n-butyl group, 1-ethyl-n-butyl group, 2-ethyl-n-butyl group, 1,1,2-trimethyl-n-propyl group, 1,2,2-trimethyl-n-propyl group, 1-ethyl-1-methyl-n-propyl group, 1-ethyl-2-methyl-n-propyl group, cyclohexyl group, 1-methyl-cyclopentyl group, 2-methyl-cyclopentyl group, 3-methyl-cyclohexyl group cyclopentyl group, 1-ethyl-cyclobutyl group, 2-ethyl-cyclobutyl group, 3-ethyl-cyclobutyl group, 1,2-dimethyl-cyclobutyl group, 1,3-dimethyl-cyclobutyl group, 2,2-dimethyl-cyclobutyl group, 2,3-dimethyl-cyclobutyl group, 2,4-dimethyl-cyclobutyl group, 3,3-dimethyl-cyclobutyl group, 1-n-propyl-cyclopropyl group, 2-n-propyl-cyclopropyl group, 1-i-propyl-cyclopropyl group, 2-i-propyl-cyclopropyl group, 1,2,Examples of such cyclopropyl groups include 2-trimethylcyclopropyl, 1,2,3-trimethylcyclopropyl, 2,2,3-trimethylcyclopropyl, 1-ethyl-2-methylcyclopropyl, 2-ethyl-1-methylcyclopropyl, 2-ethyl-2-methylcyclopropyl, and 2-ethyl-3-methylcyclopropyl groups, as well as n-heptyl, n-octyl, n-nonyl, and n-decyl groups. Preferably, R and R' are each independently phenyl, naphthalenyl, anthracenyl, phenanthrenyl, naphthacenyl, or pyrenyl.

[0050] (2-4-3-2) In principle, the two bonds in formula (II) bond to aromatic rings in other structures having aromatic rings [corresponding to unit structure A or C], but at the polymer terminals, they bond to polymer end groups [see (2-4-7) below]. Furthermore, in unit structures containing a structure represented by formula (II), for example, two or three identical or different structures of formula (II) may be bonded to a divalent or trivalent linking group to form a dimer or trimer structure. In this case, one of the two bonds in each structure of formula (II) above bonds to the linking group. Examples of such linking groups include linking groups having two or three aromatic rings (corresponding to unit structure A). Specific examples of divalent or trivalent linking groups can be found in (2-4-4-3) below.

[0051] (2-4-3-3) Note that, when at least one of R and R' in formula (II) is an aromatic ring, if such aromatic ring is bonded to another unit structure B and is also bonded to the aromatic ring of unit structure A through one bond in formula (II), it can be a unit structure C equivalent to the composite unit structure A-B, and can replace at least a part of the composite unit structure A-B. Therefore, such a unit structure C can be included in a unit structure containing a structure represented by formula (II). In this case, it is considered that the other bond in formula (II) is bonded, for example, to a polymer terminal group or to an aromatic ring in another polymer chain to form a crosslink. Such an embodiment of unit structure C is explained in more detail with respect to formula (V) in (2-4-6) below. Note that, in this specification, when a bond with unit structure A is mentioned, it may be interpreted as including a bond with the aromatic ring in unit structure C, even if not explicitly stated. Furthermore, in this specification, when a bond with unit structure B is mentioned, it may be interpreted as including a bond with the linking carbon atom in unit structure C, even if not explicitly stated.

[0052] (2-4-3-4) Some specific examples of organic groups containing a structure represented by formula (II) are as follows. * indicates the bonding site with the unit structure A. Needless to say, the structure may contain the exemplified structure as a part of the whole.

[0053] (2-4-4) (2-4-4-1) The unit structure B is represented by formula (III) In the formula (III), Z is a monocyclic ring or a bicyclic, tricyclic or tetracyclic fused ring having 4 to 25 carbon atoms, which may have a substituent. The number of carbon atoms referred to here means only the number of carbon atoms constituting the ring skeleton of the monocyclic ring or the bicyclic, tricyclic or tetracyclic fused ring excluding the substituent, and does not include the number of heteroatoms constituting the heterocyclic ring when the monocyclic ring or the fused ring is a heterocyclic ring.

[0054] The monocycle is a non-aromatic monocycle; at least one of the monocycles constituting the bicycle, tricycle, or tetracycle is a non-aromatic monocycle, and the remaining monocycles may be aromatic or non-aromatic monocycles.

[0055] The monocyclic or bicyclic, tricyclic, or tetracyclic fused ring may further form a fused ring with one or more aromatic rings to form a pentacyclic or higher fused ring, and the number of carbon atoms in the pentacyclic or higher fused ring is preferably 40 or less. The number of carbon atoms referred to here means only the number of carbon atoms constituting the ring skeleton of the pentacyclic or higher fused ring excluding substituents, and does not include the number of heteroatoms constituting the heterocyclic ring when the pentacyclic or higher fused ring is a heterocyclic ring.

[0056] X and Y may be the same or different and each represent -CR 31 R 32 represents a - group, and R 31 and R 32 are the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms.

[0057] x and y represent the numbers X and Y, respectively, and each independently represents 0 or 1.

[0058] is bonded to any carbon atom (referred to as "carbon atom 1") constituting the non-aromatic monocyclic ring of Z (when x = 1) or extends from carbon atom 1 (when x = 0), is bonded to any carbon atom (referred to as "carbon atom 2") constituting the non-aromatic monocycle of Z (when y = 1) or extends from carbon atom 2 (when y = 0), and carbon atom 1 and carbon atom 2 may be the same or different, and when different, they may belong to the same non-aromatic monocycle or different non-aromatic monocycles.

[0059] Furthermore, formula (III) may optionally contain linking carbon atoms other than carbon atom 1 and carbon atom 2 [see (2-4-4-4) below]. When Z is a tricyclic or higher fused ring, the permutation positional relationship in the fused ring between one or two non-aromatic monocycles to which carbon atoms 1 and 2 in formula (III) respectively belong and the remaining monocycles is arbitrary, and when carbon atom 1 and carbon atom 2 belong to different non-aromatic monocycles (referred to as "non-aromatic monocycle 1" and "non-aromatic monocycle 2," respectively), the permutation positional relationship in the fused ring between non-aromatic monocycle 1 and non-aromatic monocycle 2 is also arbitrary. (2-4-4-2) An example of a unit structure that is one aspect of formula (III) is formula (III-1) represented below. In formula (III-1), Z represents a 4- to 17-membered monocyclic, bicyclic, tricyclic, or tetracyclic organic group which may have a substituent, and of the one or more monocyclic rings constituting the organic group, at least one monocyclic ring is a non-aromatic monocyclic ring, and the organic group may have a maximum of four non-aromatic monocyclic rings. The other monocyclic rings are aromatic rings, and may further form fused rings with additional aromatic monocyclic rings to form a polycyclic organic group having a pentacyclic or higher ring structure. Here, the non-aromatic monocyclic ring refers to a monocyclic ring which is not aromatic, and is typically an aliphatic monocyclic ring (which may include an aliphatic heteromonocyclic ring). For non-aromatic monocyclic rings, see (1-5) above. Examples of aromatic monocyclic rings or aromatic rings include those exemplified in (1-3) above, but preferred examples include a benzene ring, a naphthalene ring, an anthracene ring, and a pyrene ring which may have a substituent, and examples of the substituents include those exemplified in (1-3) above. In the non-aromatic monocycle, C and C' in formula (III) [so-called linking carbon atoms in (1-1) above] can be present, each representing one carbon atom among the atomic group constituting the cyclic portion. Among these, the linking carbon atom C is always present, but the linking carbon atom C' is optional, and n in formula (III) representing the number of C' is 0 to 2, preferably 0. X, Y, X', and Y' may be the same or different and represent -CR 1 R 2 represents a - group, and R 1 and R 2are the same or different and represent a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms, but are merely optional linking groups, and therefore x, y, x', and y', which represent the numbers X, Y, X', and Y' (0 or 1), may all be 0. p, q, p', and q' represent the number of bonds and each independently represents 0 or 1, but 0 means that the bond is replaced with a hydrogen atom. In principle, these bonds bond to aromatic rings of other structures having aromatic rings (corresponding to unit structure A or C), but at the polymer terminals, they bond to polymer terminal groups [see (2-4-7) below]. Since at least two bonds are required to form a polymer chain, when n is 0, p and q are 1; when n is 1, provided that there is at least one bond extending from C and C' (so-called connecting carbon atoms), at least one of p and q and at least one of p' and q' is 1; similarly, when n is 2, at least one of p and q and at least one of p' and q' of each C' is 1. When there are two or more bonds, these extra bonds may be bonded, for example, to a polymer end group or to an aromatic ring in another polymer chain to form a crosslink.

[0060] (2-4-4-3) Two or three identical or different structures of formula (III) may be bonded to a divalent or trivalent linking group to form a dimer or trimer structure. In this case, one of p or q, which is a bond in each structure of formula (III), is bonded to the linking group. Then, n is not 0, and one bond is provided from the linking carbon atom C and at least one bond is provided from the linking carbon atom C'. Examples of such linking groups include linking groups having two or three aromatic rings among the unit structures that can be used as unit structure A, and examples thereof include divalent or trivalent linking groups of the following formula: [X １ represents a single bond, a methylene group, an oxygen atom, a sulfur atom, or —N(R １ )-, R １ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms (including chain hydrocarbons and cyclic hydrocarbons (which may be aromatic or non-aromatic)). [X ２ is a methylene group, an oxygen atom, -N(R ２ )-, R ２ represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, or an aromatic hydrocarbon group having 5 to 20 carbon atoms.

[0061] Alternatively, divalent linking groups such as those shown below, which can form a covalent bond with the linking carbon atom by an addition reaction between an acetylide and a ketone, can also be exemplified.

[0062] (2-4-4-4) Specific examples of organic groups containing the structure represented by formula (III) are as follows: Needless to say, the structure may contain the exemplified structure as a part of the whole.

[0063] (2-4-5) (2-4-5-1) The unit structure B is represented by formula (IV) When Z in formula (IV) ０ In the definition of J, the terms "aromatic ring," "substituent," and "aliphatic ring" are the same as those explained in (1-3) and (1-5) above. In addition, examples of organic groups in which two aromatic ring residues or aliphatic ring residues are linked by a single bond include divalent residues such as biphenyl, cyclohexylphenyl, and bicyclohexyl. １ and J ２ In the definition of the divalent organic group, the "divalent organic group" is preferably a linear or branched alkylene group having 1 to 6 carbon atoms, which may have a hydroxyl group or a halo group (e.g., fluorine) as a substituent. Examples of linear alkylene groups include methylene, ethylene, propylene, butylene, pentylene, and hexylene groups.

[0064] (2-4-5-2) Two or three identical or different structures of formula (IV) may be bonded to a divalent or trivalent linking group to form a dimer or trimer structure. In this case, one of the two bonds in each structure of formula (IV) is bonded to the linking group. Examples of such linking groups include linking groups having two or three aromatic rings among the unit structures that can be used as unit structure A. For specific examples of divalent or trivalent linking groups, see (2-4-4-3) above.

[0065] (2-4-5-3) Note that formula (IV) includes embodiments containing an aromatic ring. In such embodiments, if the aromatic ring of formula (IV) is bonded to another unit structure B and one bond of formula (IV) is bonded to the aromatic ring of unit structure A, this can be used to form a unit structure C equivalent to the composite unit structure A-B, and can replace at least one composite unit structure AB. Therefore, such a unit structure C can be included in a unit structure containing a structure represented by formula (IV). In this case, the other bond of formula (IV) can be, for example, bonded to a polymer terminal group or to an aromatic ring in another polymer chain to form a crosslink. Such an embodiment of unit structure C is described in more detail in (2-4-6) below for formula (V).

[0066] (2-4-5-4) Some specific examples of unit structures containing the structure represented by formula (IV) are as follows. * indicates the bonding site with unit structure A. Needless to say, the unit structure may contain the exemplified structure as a part of the whole.

[0067] (2-4-6) (2-4-6-1) As in the embodiments (2-4-3-3) and (2-4-5-3), Z in the formula (III) is an aromatic ring Ar １ In the case where the compound includes the compound represented by formula (III), an example of a unit structure C that is derived from the compound represented by formula (III) and is equivalent to the composite unit structure A-B and can replace at least a part of the composite unit structure A-B is a unit structure including a structure represented by formula (V) below.

[0068] In formula (V), Z １ is at least one non-aromatic monocyclic ring, Ar １ is Z １ and Z and Ar represent at least one aromatic monocyclic ring forming a condensed ring with a non-aromatic monocyclic ring of the formula １ The group as a whole constitutes a bicyclic, tricyclic, tetracyclic, or pentacyclic fused ring, optionally having a substituent, having 8 to 25 carbon atoms. The number of carbon atoms referred to here means only the number of carbon atoms constituting the ring skeleton of the bicyclic, tricyclic, or tetracyclic fused ring, excluding substituents, and does not include the number of heteroatoms constituting the heterocyclic ring when the bicyclic, tricyclic, or tetracyclic fused ring is a heterocyclic ring.

[0069] The bicyclic, tricyclic, tetracyclic, or pentacyclic organic group may further form a fused ring with one or more aromatic rings to form a hexacyclic or higher ring, and the hexacyclic or higher fused ring preferably has 40 or less carbon atoms. The number of carbon atoms referred to here means only the number of carbon atoms constituting the ring skeleton of the hexacyclic or higher fused ring excluding substituents, and does not include the number of heteroatoms constituting the heterocyclic ring when the hexacyclic or higher fused ring is a heterocyclic ring.

[0070] In addition, Z in the cyclic organic group １ and one or more non-aromatic monocyclic rings belonging to the group １ The order and positional relationship of one or more aromatic monocyclic rings belonging to the formula (I) includes any order. １ two or more non-aromatic monocyclic rings belonging to Ar １ When there are two or more aromatic monocyclic rings belonging to Z １ and non-aromatic monocyclic rings belonging to Ar １ and aromatic monocyclic rings belonging to the formula (I) may be arranged alternately to form a condensed ring.

[0071] Furthermore, X, Y, x, and y are defined as in formula (III).

[0072] One embodiment of formula (V) is represented by formula (V-1) below. [In formula (V-1), Z １ , Ar １, X, Y, x, and y are the same as those defined in formula (V), and T represents a polymer terminal.] In formula (V-1), when one bond of the linking carbon atom is bonded to a polymer terminal T (hydrogen atom; various functional groups such as a hydroxyl group or an unsaturated aliphatic hydrocarbon group, a terminal unit structure A, a unit structure A in another polymer chain, etc.), it can also be replaced with at least one composite unit structure A-B as one unit structure C equivalent to the composite unit structure A-B. That is, the aromatic ring in formula (V-1) [Ar in formula (V-1)] １ and another unit structure B are bonded to the aromatic ring of the unit structure A via a bond from the remaining linking carbon atom shown in formula (V-1), thereby extending the polymer chain. Alternatively, as one embodiment of formula (V), another unit structure C equivalent to the composite unit structure A-B can also be a unit structure containing a structure of the following formula (V-2): In the formula (V-2), Z １ is at least one non-aromatic monocyclic ring, Ar １ represents at least one aromatic monocyclic ring, Z and Ar １ The whole constitutes a cyclic organic group which is an 8- to 17-membered bicyclic or higher fused ring which may have a substituent. The arrangement and order of each aromatic monocycle and non-aromatic monocycle in the cyclic organic group are arbitrary. Here, the terms "non-aromatic monocycle", "aromatic monocycle" and "aromatic ring" are explained in (1-3) and (1-5) above. The non-aromatic monocycle can have C in formula (V-2) [the so-called linking carbon atom in (1-1) above] which represents one carbon atom among the group of atoms constituting the cyclic portion. X and Y may be the same or different and represent -CR 1 R 2 represents a - group, and R 1 and R 2 are the same or different and represent a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms, but since they are merely optional linking groups, x and y, which represent the numbers of X and Y (0 or 1), may all be 0. T represents a polymer end group or an aromatic ring residue Ar ２ The aromatic ring residue is the same as that in (2-4-4-1) above.

[0073] p represents one bond for a covalent bond with the aromatic ring of unit structure A (which may also include the aromatic ring in unit structure C). On the other hand, k and m represent the number of bonds for a covalent bond with unit structure B (which may also include unit structure C), and each independently k represents 0 to 2, m represents 0 or 1, and at least one of k and m is not 0 (when k or m is 0, this means that the bond is replaced with a hydrogen atom). Therefore, formula (V-2) may be used as a unit structure C equivalent to composite unit structure A-B, and may replace at least a part of composite unit structure A-B. Note that when k is 2, or when k is 1 and m is 1, the extra bond will form a polymer end group or a crosslink with another polymer chain.

[0074] (2-4-6-2) A more specific structure of the unit structure C including the structure of formula (V), particularly (V-1) or (V-2), will be described. For example, in the following structure, T is a hydrogen atom that is a terminal group, and p and k are １ , or p and k ２ By this, it is possible to obtain a single unit structure C equivalent to the composite unit structure AB. １ Tok ２ It can also function as unit structure A. In the following structural example, T is a phenyl group. １ , p and k ２ , or p and m can be one unit structure C equivalent to the composite unit structure AB. １ Tok ２ , k １ and m or k ２ and m, it can also function as a unit structure A.

[0075] (2-4-6-3) Some specific examples of unit structure C of formula (V) (one unit structure equivalent to composite unit structure A-B) are as follows. * indicates the bonding site with unit structure A. In unit structure C, a bond extending from the aromatic ring in these structures to unit structure B is separately provided, but in the specific examples below, such a bond is omitted. Needless to say, unit structures that include the exemplified structures as part of the whole may also be used. In the above specific examples, when no bond extends from the aromatic ring, it is a specific example of a polymer terminal.

[0076] (2-4-7) At the polymer terminal, the structural unit B forms a covalent bond with a polymer terminal group. Such a polymer terminal group may or may not be an aromatic ring derived from the structural unit A. Examples of the polymer terminal group include an aromatic ring residue having 6 to 30 carbon atoms which may have a substituent, an unsaturated hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, a hydroxyl group, or a hydrogen atom.

[0077] (2-5: Novolac Resin Synthesis Method) The novolac resin, which is one embodiment of the present invention, can be prepared by known methods. For example, it can be prepared by condensing an aromatic ring-containing compound represented by H-A-H with an oxygen-containing compound represented by OHC-B, O=C-B, HO-B-OH, RO-B-OR, or the like. In the formula, -A- corresponds to unit structure A, and -C(B)- or -B- corresponds to unit structure B. R represents an alkyl group having approximately 1 to 3 carbon atoms. Both the aromatic ring-containing compound and the oxygen-containing compound may be used alone or in combination of two or more. In this condensation reaction, the oxygen-containing compound can be used in a ratio of 0.1 to 10 moles, preferably 0.1 to 2 moles, per mole of the aromatic ring-containing compound. Examples of catalysts that can be used in the condensation reaction include mineral acids such as sulfuric acid, phosphoric acid, and perchloric acid; organic sulfonic acids such as p-toluenesulfonic acid, p-toluenesulfonic acid monohydrate, methanesulfonic acid, and trifluoromethanesulfonic acid; and carboxylic acids such as formic acid and oxalic acid. The amount of catalyst used varies depending on the type of catalyst used, but is typically 0.001 to 10,000 parts by mass, preferably 0.01 to 1,000 parts by mass, and more preferably 0.05 to 100 parts by mass per 100 parts by mass of the aromatic ring-containing compound (or the total amount if multiple types are used). The condensation reaction can be carried out without a solvent, but is usually carried out using a solvent. The solvent is not particularly limited as long as it can dissolve the reaction substrates and does not inhibit the reaction. Examples of suitable solvents include 1,2-dimethoxyethane, diethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, tetrahydrofuran, tetrahydropyran, 4-methyltetrahydropyran, dioxane, 1,2-dichloromethane, 1,2-dichloroethane, toluene, N-methylpyrrolidone, and dimethylformamide. The condensation reaction temperature is usually 40°C to 200°C, preferably 100°C to 180°C. The reaction time varies depending on the reaction temperature, but is usually 5 minutes to 50 hours, preferably 5 minutes to 24 hours. The weight-average molecular weight of the novolac resin according to one embodiment of the present invention is usually 500 to 100,000, preferably 600 to 50,000, 700 to 10,000, or 800 to 8,000.

[0078] [3. Resist Underlayer Film Forming Composition [7]] (3-1) A resist underlayer film forming composition according to one embodiment of the present invention comprises a thermal acid generator, a self-crosslinking polymer [1], and a solvent. Optionally, the composition may further comprise a crosslinking agent or a surfactant. The self-crosslinking polymer [1] has already been described above in [2. Self-crosslinking polymer [1]].

[0079] (3-2: Thermal Acid Generator) (3-2-1) Any thermal acid generator can be used as long as it does not impair the effects of the present invention, but preferably, a thermal acid activator of the following formula (1) can be used. Here, in formula (1), A １ is an optionally substituted linear, branched, or cyclic saturated or unsaturated aliphatic hydrocarbon group, or an optionally substituted aromatic ring residue, preferably a methyl group, a trifluoromethyl group, a naphthyl group, a norbornanylmethyl group, a dimethylphenyl group, or a tolyl group. Regarding the "aromatic ring" and the "residue," see (1-3) and (1-2) above, respectively. In formula (1), n ​​represents the number of sulfonate anion groups, and is 1 or 2, preferably 1. In formula (1), B １ is one or more counter bases, and is a mono-acid base or represents the mono-acid base portion of a di-acid base or tri-acid base. １ When is a diacid or triacid, B １ There are two or three equivalents to A, which are covalently bonded to each other. １ and B １ The pair base B may be linked to the pair base B via a single bond or a linking group. １ Among these, it is preferable that at least one base has a pKa higher than that of pyridine. Specific examples of bases having a pKa higher than that of pyridine, preferably a pKa of 6.5 or higher, in the present invention include N-methylmorpholine, N,N-diethylaniline, N-isobutylmorpholine, and N-allylmorpholine.

[0080] For measuring pKa, for example, the pKa value in water, preferably at 25°C, can be measured and compared by potentiometric titration [see, for example, S. Xu et al., "Dissociation constants of alkanolamines," Can. J. Chem. 71, 1048 (1993)]. Reference can also be made to R. Linnell, J. Org. Chem. 1960, 25, 2, 290-290; Mujio Kotake, editor: "Great Organic Chemistry, Supplementary Volume 2, Handbook of Organic Chemistry Constants," p. 584 (1963), (Asakura Shoten); H.K. Hall Jr. et al., Tetrahedron Letters 53 (2012) 1830-1832.

[0081] (3-2-2) Preferably, the paired base B in the formula (1) of (3-2-1) １ is R I R II R III N. [Wherein, R I and R II each independently represents a hydrogen atom or an optionally substituted linear or branched saturated or unsaturated aliphatic hydrocarbon group; R I and R II may form a ring via a heteroatom or without a heteroatom, or may form a ring via an aromatic ring, and the heteroatom is preferably an oxygen atom, a nitrogen atom, or a sulfur atom; R III represents a hydrogen atom, an optionally substituted aromatic ring residue, or an optionally substituted linear or branched saturated or unsaturated aliphatic hydrocarbon group; R I and R II does not form a ring, R III is a hydrogen atom or an aromatic ring residue which may be substituted. More preferably, the counter base B in formula (1) of component (a) is １ teeth, [In formula (2), R １ and R ２ R each independently represents an optionally substituted linear or branched, saturated or unsaturated aliphatic hydrocarbon group;３ represents a hydrogen atom or an optionally substituted aromatic group, preferably an optionally substituted phenyl, naphthyl, anthracenyl, pyrenyl, or phenanthrenyl group, or a cyclic amine compound of the following formula (III): [In formula (3), R represents a hydrogen atom; an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, a hydroxyalkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 40 carbon atoms, an organic group containing an ether bond, an organic group containing a ketone bond, or an organic group containing an ester bond, which may be substituted with a nitro group, a cyano group, an amino group, a carboxyl group, a hydroxyl group, an amide group, an aldehyde group, a (meth)acryloyl group, a halogen atom (e.g., a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), or an alkoxy group having 1 to 10 carbon atoms; an organic group containing an ether bond, an organic group containing a ketone bond, or an organic group containing an ester bond; or a group comprising a combination thereof; R' represents an aromatic ring, which is an aromatic ring fused with the ring of the cyclic amine in formula (3), or and R ａ and R ｂ each independently represents an optionally substituted alkylene group, X represents O, S, SO ２ , CO, CONH, COO, or NH, and n and m are each independently 2, 3, 4, 5, or 6. Preferably, R in formula (III) is a hydrogen atom, a methyl group, an ethyl group, an isobutyl group, an allyl group, or a cyanomethyl group. Preferably, R' in formula (II) is wherein n and m are each independently 2, 3, 4, 5, or 6.

[0082] (3-2-3) A in formula (1) of (3-2-1) １ or R in the definition of (3-2-2) I R II R III R in N I , R II , R III In the definition of R １ R ２ R ３ R in N １ , R ２Examples of the "straight-chain, branched, saturated aliphatic hydrocarbon group" in the definition of (1) include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, an s-butyl group, a t-butyl group, an n-pentyl group, a 1-methyl-n-butyl group, a 2-methyl-n-butyl group, a 3-methyl-n-butyl group, a 1,1-dimethyl-n-propyl group, a 1,2-dimethyl-n-propyl group, a 2,2-dimethyl-n-propyl group, a 1-ethyl-n-propyl group, an n-hexyl group, a 1-methyl-n-pentyl group, a 2-methyl-n-pentyl group, Examples include a 3-methyl-n-pentyl group, a 4-methyl-n-pentyl group, a 1,1-dimethyl-n-butyl group, a 1,2-dimethyl-n-butyl group, a 1,3-dimethyl-n-butyl group, a 2,2-dimethyl-n-butyl group, a 2,3-dimethyl-n-butyl group, a 3,3-dimethyl-n-butyl group, a 1-ethyl-n-butyl group, a 2-ethyl-n-butyl group, a 1,1,2-trimethyl-n-propyl group, a 1,2,2-trimethyl-n-propyl group, a 1-ethyl-1-methyl-n-propyl group, and a 1-ethyl-2-methyl-n-propyl group.

[0083] In addition, A in the formula (1) of (3-2-1) １Examples of the "cyclic saturated aliphatic hydrocarbon group" in the above formula include a cyclopropyl group, a cyclobutyl group, a 1-methylcyclopropyl group, a 2-methylcyclopropyl group, a cyclopentyl group, a 1-methylcyclobutyl group, a 2-methylcyclobutyl group, a 3-methylcyclobutyl group, a 1,2-dimethylcyclopropyl group, a 2,3-dimethylcyclopropyl group, a 1-ethylcyclopropyl group, a 2-ethylcyclopropyl group, a cyclohexyl group, a 1-methylcyclopentyl group, a 2-methylcyclopentyl group, a 3-methylcyclopentyl group, a 1-ethylcyclobutyl group, a 2-ethylcyclobutyl group, a 3-ethylcyclobutyl group, a 1,2-dimethylcyclobutyl group, a 1,3 dimethylcyclobutyl group, 2,2-dimethylcyclobutyl group, 2,3-dimethylcyclobutyl group, 2,4-dimethylcyclobutyl group, 3,3-dimethylcyclobutyl group, 1-n-propylcyclopropyl group, 2-n-propylcyclopropyl group, 1-i-propylcyclopropyl group, 2-i-propylcyclopropyl group, 1,2,2-trimethylcyclopropyl group, 1,2,3-trimethylcyclopropyl group, 2,2,3-trimethylcyclopropyl group, 1-ethyl-2-methylcyclopropyl group, 2-ethyl-1-methylcyclopropyl group, 2-ethyl-2-methylcyclopropyl group, and 2-ethyl-3-methylcyclopropyl group.

[0084] In addition, A in the formula (1) of (3-2-1) １ or R in the definition of (3-2-2) I R II R III R in N I , R II , R III or R in formula (2) １ , R ２Examples of the "straight-chain, branched, unsaturated aliphatic hydrocarbon group" in the definition of (1) include ethenyl group, 1-propenyl group, 2-propenyl group, 1-methyl-1-ethenyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, 2-methyl-1-propenyl group, 2-methyl-2-propenyl group, 1-ethylethenyl group, 1-methyl-1-propenyl group, 1-methyl-2-propenyl group, 1-pentenyl group, 2-pentenyl group, 3-pentenyl group, 4-pentenyl group, 1-n-propylethenyl group, 1-methyl-1-butenyl group, 1-methyl-2-butenyl group, 1-methyl-3-butenyl group, 2-ethyl-2-propenyl group, 2-methyl-1-butenyl group, 2-methyl-2-butenyl group, 2-methyl-3-butenyl group, 3-methyl-1-butenyl group, 3-methyl-2-butenyl group, 3-methyl-3-butenyl group, 1,1-dimethyl-2-propenyl group, 1-i-propylethenyl group, 1,2-dimethyl-1-propenyl group, 1,2-dimethyl-2-propenyl group, 1-hexenyl group, 2-hexenyl group, 3-hexenyl group, 4-hexenyl group, 5-hexenyl group, 1-methyl-1-pentenyl group, 1-methyl-2- pentenyl group, 1-methyl-3-pentenyl group, 1-methyl-4-pentenyl group, 1-n-butylethenyl group, 2-methyl-1-pentenyl group, 2-methyl-2-pentenyl group, 2-methyl-3-pentenyl group, 2-methyl-4-pentenyl group, 2-n-propyl-2-propenyl group, 3-methyl-1-pentenyl group, 3-methyl-2-pentenyl group, 3-methyl-3-pentenyl group, 3-methyl-4-pentenyl group, 3-ethyl-3-butenyl group, 4-methyl-1-pentenyl group, 4-methyl-2-pentenyl group, 4-methyl-3-pentenyl group, 4- Methyl-4-pentenyl group, 1,1-dimethyl-2-butenyl group, 1,1-dimethyl-3-butenyl group, 1,2-dimethyl-1-butenyl group, 1,2-dimethyl-2-butenyl group, 1,2-dimethyl-3-butenyl group, 1-methyl-2-ethyl-2-propenyl group, 1-s-butylethenyl group, 1,3-dimethyl-1-butenyl group, 1,3-dimethyl-2-butenyl group, 1,3-dimethyl-3-butenyl group, 1-i-butylethenyl group, 2,2-dimethyl-3-butenyl group, 2,3-dimethyl-1-butenyl group, 2,3-dimethyl-2-butenyl group,Examples of such alkyl groups include a 3-dimethyl-3-butenyl group, a 2-i-propyl-2-propenyl group, a 3,3-dimethyl-1-butenyl group, a 1-ethyl-1-butenyl group, a 1-ethyl-2-butenyl group, a 1-ethyl-3-butenyl group, a 1-n-propyl-1-propenyl group, a 1-n-propyl-2-propenyl group, a 2-ethyl-1-butenyl group, a 2-ethyl-2-butenyl group, a 2-ethyl-3-butenyl group, a 1,1,2-trimethyl-2-propenyl group, a 1-t-butylethenyl group, a 1-methyl-1-ethyl-2-propenyl group, a 1-ethyl-2-methyl-1-propenyl group, a 1-ethyl-2-methyl-2-propenyl group, a 1-i-propyl-1-propenyl group, and a 1-i-propyl-2-propenyl group.

[0085] In addition, A in the formula (1) of (3-2-1) １ In the definition of the above, examples of the "cyclic unsaturated aliphatic hydrocarbon group" include a 1-cyclopentenyl group, a 2-cyclopentenyl group, a 3-cyclopentenyl group, a 1-methyl-2-cyclopentenyl group, a 1-methyl-3-cyclopentenyl group, a 2-methyl-1-cyclopentenyl group, a 2-methyl-2-cyclopentenyl group, a 2-methyl-3-cyclopentenyl group, a 2-methyl-4-cyclopentenyl group, a 2-methyl-5-cyclopentenyl group, a 2-methylene-cyclopentyl group, a 3-methyl-1-cyclopentenyl group, a 3-methyl-2-cyclopentenyl group, a 3-methyl-3-cyclopentenyl group, a 3-methyl-4-cyclopentenyl group, a 3-methyl-5-cyclopentenyl group, a 3-methylene-cyclopentyl group, a 1-cyclohexenyl group, a 2-cyclohexenyl group, and a 3-cyclohexenyl group.

[0086] In addition, A in the formula (1) of (3-2-1) １or in the definition of R in formula (3) of (3-2-2), examples of the aromatic hydrocarbon group include a phenyl group, an o-methylphenyl group, an m-methylphenyl group, a p-methylphenyl group, a 2,3-dimethylphenyl group, a 2,4-dimethylphenyl group, a 2,5-dimethylphenyl group, a 2,6-dimethylphenyl group, a 3,4-dimethylphenyl group, a 3,5-dimethylphenyl group, an o-chlorophenyl group, an m-chlorophenyl group, a p-chlorophenyl group, an o-fluorophenyl group, a ... Examples of such groups include a fluorophenyl group, a p-fluorophenyl group, an o-methoxyphenyl group, a p-methoxyphenyl group, a p-nitrophenyl group, a p-cyanophenyl group, an α-naphthyl group, a β-naphthyl group, an o-biphenylyl group, an m-biphenylyl group, a p-biphenylyl group, a 1-anthryl group, a 2-anthryl group, a 9-anthryl group, a 1-phenanthryl group, a 2-phenanthryl group, a 3-phenanthryl group, a 4-phenanthryl group, a 9-phenanthryl group, a 1-pyrenyl group, a 2-pyrenyl group, and a 3-pyrenyl group.

[0087] In addition, A in the formula (1) of (3-2-1) １ In the definition of the above, examples of the aromatic heterocyclic residue among the "aromatic ring residue" include a furanyl group, a thiophenyl group, a pyrrolyl group, an imidazolyl group, a pyranyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyrrolidinyl group, a piperidinyl group, a piperazinyl group, a morpholinyl group, a quinuclidinyl group, an indolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a chromenyl group, a thianthrenyl group, a phenothiazinyl group, a phenoxazinyl group, a xanthenyl group, an acridinyl group, a phenazinyl group, and a carbazolyl group.

[0088] R I R II R III R in N III In the definition of R １ R ２ R ３ R in N ３ The "aromatic ring" or "aromatic ring" in the definition of the above is the same as exemplified above.

[0089] In addition, A in the formula (1) of (3-2-1) １or R in the definition of (3-2-2) I R II R III R in N I , R II , R III or R in the formula (2) of (3-2-2) １ , R ２ , R ３ or R in the definition of (3-2-2) ａ , R ｂ In the definition of the formula (I), examples of the substituent corresponding to "optionally substituted" include a nitro group, an amino group, a cyano group, a sulfo group, a hydroxy group, a carboxyl group, an aldehyde group, a propargylamino group, a propargyloxy group, a halogen atom, an alkoxy group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, an aryl group having 6 to 40 carbon atoms, an organic group containing an ether bond, an organic group containing a ketone bond, an organic group containing an ester bond, or a combination thereof.

[0090] For the organic group containing an ether bond, the organic group containing a ketone bond, and the organic group containing an ester bond, see the examples in (3-2-4) below.

[0091] Examples of the "alkoxy group" in the definition of R in formula (3) of (3-2-2) above include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, an i-butoxy group, an s-butoxy group, a t-butoxy group, an n-pentyloxy group, a 1-methyl-n-butoxy group, a 2-methyl-n-butoxy group, a 3-methyl-n-butoxy group, a 1,1-dimethyl-n-propoxy group, a 1,2-dimethyl-n-propoxy group, a 2,2-dimethyl-n-propoxy group, a 1-ethyl-n-propoxy group, an n-hexyloxy group, a 1-methyl-n-pentyloxy group, a 2-methyl-n-pentyl ...butoxy group, a 2-methyl-n-butoxy group, a 2-methyl-n-butoxy group, a 2-methyl-n-butoxy group, a 2-methyl-n-butoxy group, a 2-methyl-n-butoxy group, a 2-methyl-n-butoxy group, a 2-methyl-n-butoxy Examples of the alkyl group include an alkyloxy group, a 3-methyl-n-pentyloxy group, a 4-methyl-n-pentyloxy group, a 1,1-dimethyl-n-butoxy group, a 1,2-dimethyl-n-butoxy group, a 1,3-dimethyl-n-butoxy group, a 2,2-dimethyl-n-butoxy group, a 2,3-dimethyl-n-butoxy group, a 3,3-dimethyl-n-butoxy group, a 1-ethyl-n-butoxy group, a 2-ethyl-n-butoxy group, a 1,1,2-trimethyl-n-propoxy group, a 1,2,2-trimethyl-n-propoxy group, a 1-ethyl-1-methyl-n-propoxy group, and a 1-ethyl-2-methyl-n-propoxy group.

[0092] In the definition of R in formula (3) of (3-2-2), or R ａ , R ｂ The "alkylene group" in the definition of (3-2-3) can be exemplified by alkylene groups obtained by replacing a hydrogen atom of an alkyl group exemplified by the "straight-chain or branched saturated aliphatic hydrocarbon group" and the "cyclic saturated aliphatic hydrocarbon group" in this section with an additional bond.

[0093] Furthermore, with regard to the "alkenyl group" in the definition of R in formula (3) of (3-2-2) above, reference can be made to the examples of the "linear or branched unsaturated aliphatic hydrocarbon group" and the "cyclic unsaturated aliphatic hydrocarbon group" in this section (3-2-3).

[0094] Furthermore, the "hydroxyalkyl group" in the definition of R in formula (3) of (3-2-2) above can be exemplified by the following organic groups: * in the formula represents the carbon atom to which the bond extends.

[0095] Furthermore, the "alkynyl group" in the definition of R in formula (II) of (3-2-2) above includes modes bonded to an aliphatic hydrocarbon chain (bonded to the end of the chain or inserted into the middle of the chain), modes further containing a heteroatom (oxygen atom, nitrogen atom, etc.), and modes in which multiple alkynyl groups are linked, and examples thereof include the following organic groups: * in the formula represents the carbon atom to which the bond extends.

[0096] The following example shows an embodiment in which a heteroatom is bonded to the middle of the R chain.

[0097] (3-2-4) The "organic group containing an ether bond" in the definition of R in the formula (3) of (3-2-2) above is R １１ -O-R １１ (R １１ are each independently an alkyl group having 1 to 6 carbon atoms, such as a methyl group or an ethyl group, an alkylene group, a phenyl group, a phenylene group, a naphthyl group, a naphthylene group, an anthranyl group, or a pyrenyl group.) Examples of the organic groups include organic groups containing an ether bond, such as a methoxy group, an ethoxy group, or a phenoxy group. The "organic group containing a ketone bond" in the definition of R in formula (3) of (3-2-2) above can be a residue of an ether compound represented by the formula (3). ２１ -C(=O)-R ２１ (R ２１ each independently represents an alkyl group having 1 to 6 carbon atoms, such as a methyl group or an ethyl group, an alkylene group, a phenyl group, a phenylene group, a naphthyl group, a naphthylene group, an anthranyl group, or a pyrenyl group.) Examples of the organic group containing a ketone bond, such as an acetoxy group or a benzoyl group, can be mentioned. The "organic group containing an ester bond" in the definition of R in formula (3) of (3-2-2) above can be a residue of a ketone compound represented by the formula (3). ３１ -C(=O)O-R ３１ (R ３１each independently represents an alkyl group having 1 to 6 carbon atoms, such as a methyl group or an ethyl group, an alkylene group, a phenyl group, a phenylene group, a naphthyl group, a naphthylene group, an anthranyl group, or a pyrenyl group.) Examples of such organic groups include organic groups containing an ester bond, such as methyl ester, ethyl ester, and phenyl ester.

[0098] (3-2-5) Examples of the thermal acid generator represented by formula (1) include, but are not limited to, any combination of at least one of the examples of counter base cations and at least one of the examples of sulfonate anions shown below, in such a way that the charge is neutral.

[0099] (3-2-5-1: Examples of counter base cations)

[0100] (3-2-5-2: Examples of sulfonate anions)

[0101] (3-2-6) More specifically, examples of thermal acid generators that are combinations of counter base cations and sulfonate anions include, but are not limited to, the following.

[0102] (3-2-7) The amount of the thermal acid generator is 0.0001 to 20% by mass, preferably 0.0005 to 10% by mass, and more preferably 0.01 to 3% by mass, based on the total solid content in the resist underlayer film-forming composition. The thermal decomposition initiation temperature, i.e., the thermal acid generation temperature, of the thermal acid generator according to one embodiment of the present invention is preferably 50°C or higher, more preferably 100°C or higher, and even more preferably 150°C or higher, and is preferably 400°C or lower.

[0103] (3-3: Solvent) (3-3-1) The resist underlayer film-forming composition of one embodiment of the present invention contains a solvent. The solvent is not particularly limited as long as it can dissolve the thermal acid generator, the self-crosslinking polymer [1], and any optional components added as needed. In particular, when the resist underlayer film-forming composition is used in a homogeneous solution state for nanoimprinting, it is recommended to use a solvent commonly used in lithography processes in combination with the resist underlayer film-forming composition, taking into account its coating performance. Examples of such solvents include methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, methyl isobutyl carbinol, propylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoether ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, Methyl pyruvate, ethyl pyruvate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dipropyl ether, propylene glycol dibutyl ether, ethyl lactate, propyl lactate,Isopropyl lactate, butyl lactate, isobutyl lactate, methyl formate, ethyl formate, propyl formate, isopropyl formate, butyl formate, isobutyl formate, amyl formate, isoamyl formate, methyl acetate, ethyl acetate, amyl acetate, isoamyl acetate, hexyl acetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, butyl propionate, isobutyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, isopropyl butyrate, butyl butyrate, isobutyl butyrate, ethyl hydroxyacetate, methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, methyl 3-methoxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutyrate, ethyl methoxyacetate, ethoxy Examples of suitable solvents include ethyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-methoxybutyl acetate, 3-methoxypropyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutyl propionate, 3-methyl-3-methoxybutyl butyrate, methyl acetoacetate, toluene, xylene, methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, 2-heptanone, 3-heptanone, 4-heptanone, cyclopentanone, cyclohexanone, N,N-dimethylformamide, N-methylacetamide, N,N-dimethylacetamide, N-methylpyrrolidone, 4-methyl-2-pentanol, and γ-butyrolactone. These solvents may be used alone or in combination of two or more.

[0104] (3-3-2) From the viewpoint of uniform dissolution of the acid thermal generator, the self-crosslinking polymer [1], and further optional components (such as an aminoplast crosslinking agent or a phenoplast crosslinking agent), a compound having an alcoholic hydroxyl group or a compound having a group capable of forming an alcoholic hydroxyl group is preferred as the solvent. Preferred examples of such solvents include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monopropyl ether, and propylene glycol monomethyl ether. Examples of the solvent include ethyl acetate, propylene glycol monoethyl ether, propylene glycol monoethyl ether acetate, propylene glycol propyl ether acetate, cyclopentanone, cyclohexanone, ethyl 2-hydroxypropionate, methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl acetate, butyl acetate, ethyl lactate, and butyl lactate.Among these, propylene glycol-based solvents (such as propylene glycol monomethyl ether), oxyisobutyric acid ester-based solvents (such as methyl 2-hydroxy-2-methylpropionate), or butylene glycol-based solvents are preferred, and among these, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, methyl 2-hydroxy-2-methylpropionate, ethyl lactate, and cyclohexanone are more preferred, with propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, methyl 2-hydroxy-2-methylpropionate, ethyl lactate, and cyclohexanone being most preferred.

[0105] (3-3-3) In addition, a solvent having a boiling point of 160° C. or higher may be included. For example, the following compound described in WO 2018 / 131562 (A1) can be used. (R in formula (i) １ , R ２ and R ３each represents a hydrogen atom, an oxygen atom, a sulfur atom, or an alkyl group having 1 to 20 carbon atoms which may be interrupted by an amide bond, and may be the same or different from each other and may be bonded to each other to form a ring structure.) Alternatively, 1,6-diacetoxyhexane (boiling point 260°C) and tripropylene glycol monomethyl ether (boiling point 242°C) described in JP-A-2021-84974, as well as various other high-boiling point solvents described in paragraph 0082 of the same publication, can be preferably used. Alternatively, dipropylene glycol monomethyl ether acetate (boiling point 213°C), diethylene glycol monoethyl ether acetate (boiling point 217°C), diethylene glycol monobutyl ether acetate (boiling point 247°C), dipropylene glycol dimethyl ether (boiling point 171°C), dipropylene glycol monomethyl ether (boiling point 187°C), dipropylene glycol monobutyl ether (boiling point 231°C), tripropylene glycol monomethyl ether (boiling point 242°C), γ-butyrolactone (boiling point 204°C), benzyl alcohol (boiling point 205°C), propylene carbonate (boiling point 242°C), tetraethylene glycol dimethyl ether (boiling point 275°C), 1,6-diacetoxyhexane (boiling point 260°C), dipropylene glycol (boiling point 230°C), 1, 3-butylene glycol diacetate (boiling point 232° C.) and various other high boiling point solvents described in paragraphs 0023 to 0031 of the publication can be preferably used.

[0106] (3-4: Other Optional Components) In addition to the above, the resist underlayer film-forming composition according to the present invention may contain a crosslinking agent, a surfactant, a light absorber, a rheology adjuster, an adhesion aid, and the like, if necessary.

[0107] (3-4-1: Aminoplast Crosslinking Agents) Examples of aminoplast crosslinking agents include highly alkylated, alkoxylated, or alkoxyalkylated melamine, benzoguanamine, glycoluril, urea, and polymers thereof. Crosslinking agents having at least two crosslink-forming substituents are preferred, such as methoxymethylated glycoluril, butoxymethylated glycoluril, methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguwanamine, butoxymethylated benzoguwanamine, methoxymethylated urea, butoxymethylated urea, methoxymethylated thiourea, and methoxymethylated thiourea. Condensates of these compounds can also be used.

[0108] Furthermore, a crosslinking agent with high heat resistance can be used as the crosslinking agent. A compound containing a crosslinking substituent having an aromatic ring (e.g., a benzene ring or a naphthalene ring) in the molecule can be preferably used as the crosslinking agent with high heat resistance. Preferably, the crosslinking agent is at least one selected from the group consisting of tetramethoxymethylglycoluril and hexamethoxymethylmelamine. The aminoplast crosslinking agent may be used alone or in combination of two or more. The aminoplast crosslinking agent may be produced by a method known per se or a method equivalent thereto, or a commercially available product may be used. The amount of the aminoplast crosslinking agent used varies depending on the coating solvent used, the base substrate used, the required solution viscosity, the required film shape, etc., but is 0.001% by mass or more, 0.01% by mass or more, 0.05% by mass or more, 0.5% by mass or more, or 1.0% by mass or more, and 80% by mass or less, 50% by mass or less, 40% by mass or less, 20% by mass or less, or 10% by mass or less, based on the total solids content of the resist underlayer film-forming composition of one embodiment of the present invention. Some specific examples are as follows:

[0109] (3-4-2: Phenoplast Crosslinking Agents) Examples of phenoplast crosslinking agents include highly alkylated, alkoxylated, or alkoxyalkylated aromatic compounds, polymers thereof, and the like. Preferred are crosslinking agents having at least two crosslink-forming substituents per molecule, such as 2,6-dihydroxymethyl-4-methylphenol, 2,4-dihydroxymethyl-6-methylphenol, bis(2-hydroxy-3-hydroxymethyl-5-methylphenyl)methane, bis(4-hydroxy-3-hydroxymethyl-5-methylphenyl)methane, 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane, bis(3-formyl-4-hydroxyphenyl)methane, bis(4-hydroxy-2,5-dimethylphenyl)formylmethane, and α,α-bis(4-hydroxy-2,5-dimethylphenyl)-4-formyltoluene. Condensates of these compounds can also be used. Furthermore, crosslinking agents with high heat resistance can be used as the crosslinking agent. As a crosslinking agent with high heat resistance, a compound containing a crosslinking substituent having an aromatic ring (e.g., a benzene ring or a naphthalene ring) in the molecule can be preferably used. The phenoplast crosslinking agent may be used alone or in combination of two or more types. The phenoplast crosslinking agent may be produced by a method known per se or a method equivalent thereto, or a commercially available product may be used.

[0110] The amount of the phenoplast crosslinking agent used varies depending on the coating solvent used, the base substrate used, the required solution viscosity, the required film shape, etc., but is 0.001 mass % or more, 0.01 mass % or more, 0.05 mass % or more, 0.5 mass % or more, or 1.0 mass % or more, and 80 mass % or less, 50 mass % or less, 40 mass % or less, 20 mass % or less, or 10 mass % or less, relative to the total solids content of the resist underlayer film-forming composition that is one embodiment of the present invention. In addition to the above, other examples of such compounds include compounds having a partial structure of the following formula (4) and polymers or oligomers having a repeating unit of the following formula (5). The above R １１ , R １２ , R １３ , and R １４is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and the above-mentioned examples of these alkyl groups can be used. n1 is an integer of 1 to 4, n2 is an integer of 1 to (5-n1), and (n1+n2) is an integer of 2 to 5. n3 is an integer of 1 to 4, n4 is an integer of 0 to (4-n3), and (n3+n4) is an integer of 1 to 4. Oligomers and polymers having a repeating unit structure number of 2 to 100 or 2 to 50 can be used.

[0111] Some specific examples are as follows:

[0112] (3-4-3: Surfactant) A surfactant may be blended into the resist underlayer film-forming composition of one embodiment of the present invention in order to prevent pinholes, striations, and the like from occurring and to further improve coatability against surface unevenness.

[0113] Examples of surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oleyl ether; polyoxyethylene alkyl aryl ethers such as polyoxyethylene octyl phenol ether and polyoxyethylene nonyl phenol ether; polyoxyethylene-polyoxypropylene block copolymers; sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, and sorbitan tristearate; polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan monostearate; Examples of suitable surfactants include nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters, such as polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate; fluorosurfactants such as EFTOP EF301, EF303, and EF352 (trade names, manufactured by Tochem Products Co., Ltd.), Megafac F171, F173, R-30, and R-40 (trade names, manufactured by Dainippon Ink Co., Ltd.), Fluorad FC430 and FC431 (trade names, manufactured by Sumitomo 3M Limited), Asahiguard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, and SC106 (trade names, manufactured by Asahi Glass Co., Ltd.); and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.). The amount of these surfactants to be added is usually 2.0 mass % or less, and preferably 1.0 mass % or less, based on the total solid content of the resist underlayer film-forming composition of one embodiment of the present invention. These surfactants may be added alone or in combination of two or more.

[0114] (3-4-4: Other Additives) In addition to the crosslinking catalyst that is a thermal acid generator such as that represented by Formula (1), the resist underlayer film-forming composition of one embodiment of the present invention may also contain, as a catalyst for promoting the crosslinking reaction, acidic compounds such as citric acid, thermal acid generators such as 2,4,4,6-tetrabromocyclohexadienone, benzoin tosylate, 2-nitrobenzyl tosylate, and other organic sulfonic acid alkyl esters, onium salt-based photoacid generators such as bis(4-t-butylphenyl)iodonium trifluoromethanesulfonate and triphenylsulfonium trifluoromethanesulfonate, halogen-containing compound-based photoacid generators such as phenyl-bis(trichloromethyl)-s-triazine, and sulfonic acid-based photoacid generators such as benzoin tosylate and N-hydroxysuccinimide trifluoromethanesulfonate.

[0115] Examples of the light absorber include commercially available light absorbers described in "Technology and Market of Industrial Dyes" (CMC Publishing) and "Dye Handbook" (edited by the Society of Organic Synthetic Chemistry), such as C.I. Disperse Yellow 1, 3, 4, 5, 7, 8, 13, 23, 31, 49, 50, 51, 54, 60, 64, 66, 68, 79, 82, 88, 90, 93, 102, 114, and 124; C.I. Disperse Orange 1, 5, 13, 25, 29, 30, 31, 44, 57, 72, and 73; C.I. C.I. Disperse Red 1, 5, 7, 13, 17, 19, 43, 50, 54, 58, 65, 72, 73, 88, 117, 137, 143, 199, and 210; C.I. Disperse Violet 43; C.I. Disperse Blue 96; C.I. Fluorescent Brightening Agent 112, 135, and 163; C.I. Solvent Orange 2 and 45; C.I. Solvent Red 1, 3, 8, 23, 24, 25, 27, and 49; C.I. Pigment Green 10; C.I. Pigment Brown 2, etc. can be suitably used. The light-absorbing agent is usually blended in an amount of 10% by mass or less, and preferably 5% by mass or less, based on the total solid content of the resist underlayer film-forming composition according to the present invention.

[0116] The rheology modifier is added mainly to improve the fluidity of the resist underlayer film-forming composition, particularly in the baking process, to improve the film thickness uniformity of the resist underlayer film and the ability of the resist underlayer film-forming composition to fill holes. Specific examples include phthalic acid derivatives such as dimethyl phthalate, diethyl phthalate, diisobutyl phthalate, dihexyl phthalate, and butyl isodecyl phthalate; adipic acid derivatives such as di-n-butyl adipate, diisobutyl adipate, diisooctyl adipate, and octyldecyl adipate; maleic acid derivatives such as di-n-butyl maleate, diethyl maleate, and dinonyl maleate; oleic acid derivatives such as methyl oleate, butyl oleate, and tetrahydrofurfuryl oleate; and stearic acid derivatives such as n-butyl stearate and glyceryl stearate. These rheology modifiers are typically blended in an amount of less than 30% by mass based on the total solids content of the resist underlayer film-forming composition of the present invention. The adhesion promoter is added mainly for the purpose of improving the adhesion between the substrate or resist and the resist underlayer film-forming composition, and particularly to prevent the resist from peeling off during development.Specific examples include chlorosilanes such as trimethylchlorosilane, dimethylvinylchlorosilane, methyldiphenylchlorosilane, and chloromethyldimethylchlorosilane; alkoxysilanes such as trimethylmethoxysilane, dimethyldiethoxysilane, methyldimethoxysilane, dimethylvinylethoxysilane, diphenyldimethoxysilane, and phenyltriethoxysilane; silazanes such as hexamethyldisilazane, N,N'-bis(trimethylsilyl)urea, dimethyltrimethylsilylamine, and trimethylsilylimidazole; and vinyltrichlorosilane. Examples of the adhesion aid include silanes such as silane, γ-chloropropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and γ-glycidoxypropyltrimethoxysilane; heterocyclic compounds such as benzotriazole, benzimidazole, indazole, imidazole, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, urazole, thiouracil, mercaptoimidazole, and mercaptopyrimidine; and ureas such as 1,1-dimethylurea and 1,3-dimethylurea, or thiourea compounds. These adhesion aids are blended in an amount of usually less than 5% by mass, and preferably less than 2% by mass, based on the total solids content of the resist underlayer film-forming composition of the present invention.

[0117] The resist underlayer film-forming composition according to one embodiment of the present invention has a solids content of 0.1 to 70% by mass, or 0.1 to 60% by mass. The solids content is the content of all components of the resist underlayer film-forming composition excluding the solvent. The solids content may contain a crosslinkable resin in an amount of 1 to 99.9% by mass, or 50 to 99.9% by mass, or 50 to 95% by mass, or 50 to 90% by mass.

[0118] [4: Resist Underlayer Film

[16] ] A resist underlayer film can be formed as follows using the resist underlayer film-forming composition [7] according to one embodiment of the present invention. ２The resist underlayer film-forming composition [7] according to one embodiment of the present invention is applied onto a substrate (e.g., a silicon nitride substrate (SiN substrate), a silicon oxynitride substrate (SiON substrate), a titanium nitride substrate (TiN substrate), a tungsten substrate (W substrate), a glass substrate, an ITO substrate, a polyimide substrate, or a substrate coated with a low dielectric constant material (low-k material)) by a suitable application method such as a spinner or coater, and then baked using a heating means such as a hot plate to form a resist underlayer film. Baking conditions are appropriately selected from a baking temperature of 80°C to 600°C and a baking time of 0.3 to 60 minutes. Preferably, the baking temperature is 150°C to 400°C, more preferably 150°C to 350°C, and the baking time is 0.5 to 2 minutes. The atmospheric gas during baking may be air, or an inert gas such as nitrogen or argon. In one embodiment, it is particularly preferable that the oxygen concentration is 1% or less. The thickness of the underlayer film formed here is, for example, 10 to 1000 nm, 20 to 500 nm, 30 to 400 nm, or 50 to 300 nm. Furthermore, if a quartz substrate is used as the substrate, a replica of the quartz imprint mold (mold replica) can be produced.

[0119] Furthermore, an adhesion layer and / or a silicone layer containing 99% by mass or less, or 50% by mass or less of Si can be formed by coating or vapor deposition on the resist underlayer film according to one embodiment of the present invention. For example, the adhesion layer described in JP-A-2013-202982 and Japanese Patent No. 5827180 can be formed by spin coating using a silicon-containing resist underlayer film (inorganic resist underlayer film)-forming composition described in WO 2009 / 104552 (A1), or a Si-based inorganic material film can be formed by CVD or the like.

[0120] Furthermore, by applying the resist underlayer film-forming composition [7] according to one embodiment of the present invention to a semiconductor substrate having a portion with a step and a portion without a step (a so-called stepped substrate) and baking the composition, the step between the portion with a step and the portion without a step can be reduced.

[0121] [5: Manufacturing Method of Semiconductor Device

[18] to

[21] ] (5-1) (i) A manufacturing method of a semiconductor device, which is one aspect of the present invention, includes: a step of forming a resist underlayer film using the resist underlayer film-forming composition [7], which is one aspect of the present invention; a step of forming a resist film on the formed resist underlayer film; a step of forming a resist pattern by irradiating the formed resist film with light or an electron beam and developing it; a step of etching and patterning the resist underlayer film through the formed resist pattern; and a step of processing a semiconductor substrate through the patterned resist underlayer film.

[0122] (ii) A method for manufacturing a semiconductor device according to one aspect of the present invention includes the steps of: forming a resist underlayer film using the resist underlayer film-forming composition [7] according to one aspect of the present invention; forming a hard mask on the formed resist underlayer film; forming a resist film on the formed hard mask; irradiating the formed resist film with light or an electron beam and developing it to form a resist pattern; etching and patterning the hard mask through the formed resist pattern; etching and patterning the resist underlayer film through the patterned hard mask; and processing a semiconductor substrate through the patterned resist underlayer film. (iii) A method for manufacturing a semiconductor device according to one aspect of the present invention includes the steps of: forming a resist underlayer film using the resist underlayer film-forming composition [7] according to one aspect of the present invention; forming a hard mask thereon; further forming a resist film thereon; forming a resist pattern by irradiating with light or an electron beam and developing; etching the hard mask using the formed resist pattern; etching the resist underlayer film using the patterned hard mask; removing the hard mask; and processing a semiconductor substrate using the patterned resist underlayer film.(iv) A method for manufacturing a semiconductor device, which is an aspect of the present invention, includes: a step of forming a resist underlayer film using the resist underlayer film-forming composition [7], which is an aspect of the present invention; a step of forming a hard mask thereon; a step of further forming a resist film thereon; a step of forming a resist pattern by irradiating with light or an electron beam and developing; a step of etching the hard mask using the formed resist pattern; a step of etching the resist underlayer film using the patterned hard mask; a step of removing the hard mask; a step of forming a vapor-deposited film (spacer) on the resist underlayer film after removing the hard mask; a step of processing the vapor-deposited film (spacer) by etching; a step of removing the patterned resist underlayer film to leave the patterned vapor-deposited film (spacer); and a step of processing a semiconductor substrate via the patterned vapor-deposited film (spacer).

[0123] (5-2) The step of forming a resist underlayer film using the resist underlayer film-forming composition according to one embodiment of the present invention is as described above in [4: Resist Underlayer Film

[16] ]. A hard mask such as a silicon-containing film may be formed as a second resist underlayer film on the resist underlayer film formed by the above step, and a resist pattern may be formed thereon. This second resist underlayer film may be a coated film, or a SiON film, SiN film, or SiO film formed by a vapor deposition method such as CVD or PVD. ２ Furthermore, an anti-reflective coating (BARC) may be formed on the second resist underlayer film as a third resist underlayer film, and the third resist underlayer film may be a resist shape correction film that does not have anti-reflective properties.

[0124] In the step of forming the resist pattern, exposure is performed through a mask (reticle) for forming a predetermined pattern or by direct writing. Examples of exposure sources that can be used include g-line, i-line, KrF excimer laser, ArF excimer laser, EUV, and electron beam. After exposure, post-exposure baking is performed as needed. The resist is then developed with a developer (e.g., a 2.38% by mass aqueous solution of tetramethylammonium hydroxide, butyl acetate), and then rinsed with a rinse solution or pure water to remove the used developer. Post-baking is then performed to dry the resist pattern and enhance adhesion to the underlayer.

[0125] The etching process performed after the resist pattern formation is performed by dry etching. The etching gas used for the dry etching is, for example, CHF 2 O 3 for the second resist underlayer film (organopolysiloxane film). ３ , C.F. ４ , C ２ F ６ For the first resist underlayer film formed from the resist underlayer film-forming composition of the present invention, for example, O ２ , N ２ O, NO ２ For surfaces having steps or recesses and / or protrusions, for example, CHF ３ , C.F. ４ , C ２ F ６ Furthermore, these gases may be mixed with argon, nitrogen or carbon dioxide.

[0126] (5-3) The resist film may be patterned by a nanoimprint method or a self-assembled film method.

[0127] In the nanoimprint method, a resist composition is molded using a patterned mold that is transparent to irradiated light, while in the self-assembled film method, a pattern is formed using a self-assembled film that naturally forms a regular structure on the nanometer order, such as a diblock polymer (e.g., polystyrene-polymethyl methacrylate).

[0128] In the nanoimprint method, before applying the curable composition that will become a resist film, a silicon layer (hard mask layer) may be optionally formed on the resist underlayer film by coating or vapor deposition, and further an adhesion layer may be formed on the resist underlayer film or the silicon layer (hard mask layer) by coating or vapor deposition, and the curable composition that will become a resist film may be applied on the adhesion layer.

[0129] (5-4) In addition, wet etching may be performed to simplify the process and reduce damage to the processed substrate. This leads to suppression of fluctuations in processing dimensions and reduction of pattern roughness, making it possible to process the substrate with high yield. Therefore, in the above (5-1) (iii) (iv), the hard mask can be removed by either etching or an alkaline chemical solution. In particular, when an alkaline chemical solution is used, there are no restrictions on the components, but it is preferable that the alkaline component contains the following:

[0130] Examples of the alkaline component include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, methyltripropylammonium hydroxide, methyltributylammonium hydroxide, ethyltrimethylammonium hydroxide, dimethyldiethylammonium hydroxide, benzyltrimethylammonium hydroxide, hexadecyltrimethylammonium hydroxide, and (2-hydroxyethyl)trimethylammonium hydroxide, monoethanolamine, diethanolamine, triethanolamine, 2-(2-aminoethoxy)ethanol, N,N-dimethylethanolamine, N,N-diethylethanolamine, N , N-dibutylethanolamine, N-methylethanolamine, N-ethylethanolamine, N-butylethanolamine, N-methyldiethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, tetrahydrofurfurylamine, N-(2-aminoethyl)piperazine, 1,8-diazabicyclo[5.4.0]undecene-7, 1,4-diazabicyclo[2.2.2]octane, hydroxyethylpiperazine, piperazine, 2-methylpiperazine, trans-2,5-dimethylpiperazine, cis-2,6-dimethylpiperazine, 2-piperidinemethanol, cyclohexylamine, 1,5-diazabicyclo[4.3.0]nonene-5, etc. Furthermore, particularly from the viewpoint of handling, tetramethylammonium hydroxide and tetraethylammonium hydroxide are particularly preferred, and an inorganic base may be used in combination with the quaternary ammonium hydroxide. As the inorganic base, alkali metal hydroxides such as potassium hydroxide, sodium hydroxide, rubidium hydroxide, etc. are preferred, with potassium hydroxide being more preferred.

[0131] [Synthesis of Polymer] Polymers having structural formulas (S1) to (S12) before introduction of an alkoxymethyl group such as a MOM group (methoxymethyl group) were synthesized using Compound Group A, Compound Group B, Catalyst Group C, Solvent Group D, and Reprecipitation Solvent Group E shown below.

[0132] ○Compound groups A to B

[0133] Catalyst group C, solvent group D, reprecipitation solvent group E Methanesulfonic acid: C1 3-mercaptopropionic acid: C2 1,4-dioxane: D1 4-methyltetrahydrofuran (MTHP): D2 Propylene glycol monomethyl ether acetate (=PGMEA): D3 Methanol: E1 Water: E2

[0134] Synthesis Example 1: 18.0 g of carbazole, 16.8 g of 1-naphthaldehyde, 8.28 g of methanesulfonic acid, 0.9 g of 3-mercaptopropionic acid, and 100.5 g of 1,4-dioxane were placed in a flask. The mixture was then allowed to react under reflux in a nitrogen atmosphere for approximately 2 hours. After the reaction was stopped, the mixture was reprecipitated in methanol and dried to obtain a resin (S1). The weight-average molecular weight Mw measured in terms of polystyrene by GPC was approximately 3,170.

[0135] [Synthesis Examples 1 to 12] Polymers before introduction of the MOM group were synthesized by variously changing the compound group A, compound group B, catalyst group C, solvent group D, and reprecipitation solvent group E. The experimental procedures were the same as in Synthesis Example 1. Polymers (S1) to (S12) were obtained by synthesis under the following conditions.

[0136]

[0137] [Synthesis of MOM Group-Introduced Polymers] The MOM group-introduced polymers of structural formulas (SM1) to (SM11) used in the resist underlayer film were synthesized by introducing MOM groups into polymers (S1) to (S11).

[0138] Synthesis Example 13: 5.0 g of polymer (S1) and 20.0 g of N,N-dimethylformamide were placed in a flask and cooled to 0°C in an ice bath. Subsequently, 0.7 g of sodium hydride (55%) and 1.3 g of chloromethyl methyl ether were added, followed by stirring for approximately 30 minutes. The mixture was then removed from the ice bath and aged for 22 hours while slowly warming to room temperature. After the reaction was stopped, the mixture was reprecipitated with methanol and dried to obtain resin (SM1). The weight-average molecular weight Mw measured by GPC in terms of polystyrene was approximately 3,572. The obtained resin was dissolved in PGMEA or cyclohexanone (CYH), and ion exchange was performed for 4 hours using a cation exchange resin and an anion exchange resin to obtain a solution of the target compound.

[0139] Synthesis Examples 13 to 23 MOM group-introduced polymers for use in resist underlayer films were synthesized by varying the amount of solvent and base. The experimental procedures were the same as in Synthesis Example 12. MOM group-introduced polymers (SM1) to (SM11) were obtained under the following conditions.

[0140]

[0141] [Preparation of Resist Underlayer Film] Polymers (SM1) to (SM11) or polymers (S1) to (S12), solvents (propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), cyclohexanone (CYH), crosslinkers (CR1 to CR2), acid generator (Ad1), and Megafac R-30NML (DIC Corporation, F1) as a surfactant) were mixed in the weight ratios shown in the table below (relative weights of components other than the solvent when polymer is taken as 100 g; for the solvents, relative weights when the total amount of solvent is taken as 100 g), and the mixture was filtered through a 0.1 μm polytetrafluoroethylene microfilter to prepare resist underlayer film materials (M1 to M13, Comparative M1 to Comparative M14).

[0142]

[0143] [Resist Solvent Dissolution Test] The resist underlayer film material of the example was applied to a silicon wafer using a spin coater and baked for 60 seconds to form a resist underlayer film with a thickness of 65 nm. The formed resist underlayer film was immersed in a general-purpose thinner, PGME (propylene glycol monomethyl ether) / PGMEA (7 / 3), for 60 seconds, and then baked at 100°C for 30 seconds. The baking temperature at which solvent resistance was exhibited was determined by comparing the film thickness before and after immersion in thinner. The comparative example was baked for 60 seconds at the baking temperature at which solvent resistance was exhibited to form a resist underlayer film with a thickness of 65 nm, and the solvent resistance was confirmed by operating in the same manner as described above. When self-crosslinking properties are imparted to the polymer by the introduction of MOM groups, solvent resistance is exhibited at lower temperatures compared to polymers without MOM groups. When the baking temperature at which the film thickness reduction rate before and after immersion in thinner was 1% or less was lower than that of the comparative example, the result was judged to be good. The underlayer film material was also applied to a silicon wafer using an ACT-8 coating made by Tokyo Electron Limited, and baked under nitrogen at the specified temperature for the specified time shown in the table to form a 65 nm resist underlayer film. As above, the wafer was immersed in a 7 / 3 PGME / PGMEA mixture for 60 seconds, followed by baking at 100°C for 30 seconds. The film thickness before and after immersion in thinner was compared to confirm the solvent resistance. Cases where the rate of film thickness reduction before and after immersion in thinner was smaller than that of the comparative example were evaluated as "good" (Table 1).

[0144] From the above, it was confirmed that the introduction of MOM groups into a polymer that does not have self-crosslinking properties can impart self-crosslinking properties. Furthermore, the samples (Comparative Examples 1-10) that showed significant elution into the resist solvent when baked under air, which is a typical baking condition, could not be used as resist underlayer films. Therefore, Comparative Examples 11-13 were used as comparative examples in the following evaluations.

[0145] [Optical Constant Measurement] The solutions of the resist underlayer film-forming compositions prepared in the comparative examples and examples were applied to silicon wafers using a spin coater. They were baked on a hot plate at the predetermined temperatures and for the predetermined times shown in the tables to form resist underlayer films with a film thickness of 50 nm. The refractive index (n value) and optical absorption coefficient (k value, also called extinction coefficient) of these resist underlayer films at a wavelength of 193 nm were measured using a spectroscopic ellipsometer (Table 2).

[0146]

[0147] [Measurement of Etching Rate] The resist underlayer film materials of the comparative examples and examples were applied onto a silicon wafer using a spin coater. They were baked on a hot plate at the predetermined temperature for the predetermined time shown in the table to form a resist underlayer film of 65 nm. O was used as the etching gas. ２ / N ２ Gas or CF ４ The dry etching rate was measured using the gas (Table 3). When the etching rate was slower than that of the comparative example, it was judged as ◯, and when it was faster, it was judged as ×.

[0148] The etcher and etching gas used in the etching measurement were as follows: RIE-200NL (manufactured by Samco): CF ４ 50 sccm RIE-200NL (manufactured by Samco): O ２ / N ２　 10sccm / 200sccm

[0149]

[0150] [Coating and Covering Test on Stepped Substrate] As a coating test on a stepped substrate, a 100 nm thick SiO ２Substrates were used. In the case of uneven substrates, the coatability of the resist underlayer film may deteriorate depending on the type of substrate. Therefore, whether the uneven substrate could be evenly coated was tested. Even coating was rated as "good." Planarization was evaluated in a trench area (dense pattern area) with a trench width of 50 nm and a pitch of 100 nm present in the substrate. The coating film thickness in the dense area was compared with that in an area where no pattern was formed (open area). The resist underlayer film-forming compositions prepared in the comparative examples and examples were applied to the substrate, and then baked on a hot plate at the specified temperature and for the specified time shown in the table to form a 65 nm resist underlayer film. The planarization of this substrate was observed using a scanning electron microscope (S-4800) manufactured by Hitachi High-Technologies Corporation, and the planarization was evaluated by measuring the film thickness difference between the trench area (patterned area) and the open area (non-patterned area) of the uneven substrate (the coating step between the trench area and the open area, referred to as "bias"). Here, planarization means that the difference in film thickness (iso-dense bias) of the coating material present on the upper surface between the area where the pattern exists (trench area (pattern area)) and the area where the pattern does not exist (open area (no pattern area)) is small. The cases where the bias was improved compared to the comparative example were judged as ○ (Table 4).

[0151]

[0152] [Test for embedding ability into uneven substrate] As a coating test for uneven substrate, a 100 nm thick SiO ２ Substrates were used. The embeddability was evaluated in trench areas (dense pattern areas) present in the substrates, each having a trench width of 50 nm and a pitch of 100 nm. The resist underlayer film-forming compositions prepared in the comparative examples and examples were applied to the substrates, and then baked on a hot plate at the predetermined temperatures and for the predetermined times shown in the table to form resist underlayer films of 65 nm. The embeddability of these substrates was observed using a scanning electron microscope (S-4800) manufactured by Hitachi High-Technologies Corporation. The embeddability was evaluated as good when the resist underlayer film was able to fill the trenches to the bottom (Table 5).

[0153]

[0154] [Measurement of the amount of sublimated product] The amount of sublimated product was measured using the sublimated product amount measuring device described in International Publication No. 2007 / 111147. Each of the resist underlayer film-forming compositions prepared in the comparative examples and examples was applied to a silicon wafer, and the amount of sublimated product was measured when the film thickness reached 65 nm after baking at 300°C for 60 seconds. When the amount of sublimated product was smaller than that of the comparative example, it was judged as O (Table 6).

[0155]

[0156] As described above, unlike conventional materials, the materials of the examples exhibit curability in air and nitrogen without the addition of a crosslinking agent or curing catalyst, and can therefore be considered to have self-crosslinking properties. Naturally, they can also be used with crosslinkers and curing catalysts, as in conventional materials. Furthermore, the optical constants and etching resistance of this material can be freely adjusted by modifying the polymer skeleton, enabling the suppression of reflection during exposure. This not only enables the formation of good resist patterns, but also shows better etching resistance than the comparative examples against fluorine-based and oxygen-based gases, which are the main etching gases. Furthermore, the materials exhibit good coatability on various vapor-deposited films, and are also good at embedding and planarizing substrates with fine steps. Additionally, the amount of sublimation is low, resulting in low equipment contamination. Therefore, it is expected that these materials will be widely applicable to diverse semiconductor manufacturing processes.

Claims

1. (A) one or more unit structures A having an aromatic ring; (B) and one or more unit structures B, each of which is an organic group having one or more linking carbon atoms, At least one type of unit structure A among the unit structures A is (i) A unit structure containing a structure in which at least one -NR- bond connects at least two aromatic rings, (ii) A unit structure containing a heterocycle having at least one -NR- bond as a ring component, wherein if the heterocycle is not an aromatic heterocycle, it forms a fused ring with a first aromatic ring and / or is substituted with a substituent containing a second aromatic ring; or (iii) At least one -NR ２ A unit structure including at least one aromatic ring having a substituent, R is a hydrogen atom or an alkoxymethyl group, and at least a portion of R in the entire polymer is an alkoxymethyl group; A self-crosslinking polymer in which the linking carbon atom is a carbon atom in unit structure B that forms a covalent bond with the aromatic ring in unit structure A, but is not a carbon atom that constitutes an aromatic ring.

2. 10. The self-crosslinking polymer of claim 1 which is a novolac resin.

3. The unit structure A is the following unit structures (I-1) to (I-5): 【Chemistry 75】 and positional isomers thereof, 【Transformation 76】 is selected from The above (I-1) to (I-5) may optionally further have a substituent, In the above (I-1) to (I-5), R is the same as defined in claim 1, In the above (I-1), each Ar may be the same or different and represent an aromatic ring which may have a substituent, Among the above (I-2) to (I-5), 【Chemical 77】 represents an aromatic ring moiety in the fused ring which may have a substituent, and each may be the same or different from each other, In the above (I-4), X is CR １ R ２ , O, S, or NR'; R' is the same as the definition of R in claim 1, and may be the same as or different from R in the above chemical formula (I-4); R １ and R ２ are the same or different and are each an aromatic ring residue or an aliphatic hydrocarbon group having 1 to 3 carbon atoms, In the above (I-5) 【Transformation 78】 represents an optionally substituted heterocyclic moiety in a fused ring compound, Y is a substituent containing an aromatic ring, and may be a substituent of either the aromatic ring moiety or the heterocyclic ring moiety; The self-crosslinking polymer of claim 1.

4. The self-crosslinking polymer according to claim 1, wherein the unit structure B is a unit structure containing a structure represented by the following (II), (III), or (IV): 【Transformation 79】 (In formula (II), R and R' each independently represent a hydrogen atom, an aromatic ring residue having 6 to 30 carbon atoms which may have a substituent, a heterocyclic ring residue having 3 to 30 carbon atoms which may have a substituent, or a linear, branched, or cyclic alkyl group having 10 or less carbon atoms which may have a substituent.) 【Chemistry 80】 [In formula (III), Z is a monocyclic, bicyclic, tricyclic or tetracyclic fused ring having 4 to 25 carbon atoms which may have a substituent, and the monocyclic ring is a non-aromatic monocyclic ring; at least one of the monocyclic rings constituting the bicyclic, tricyclic or tetracyclic ring is a non-aromatic monocyclic ring, and the remaining monocyclic rings may be aromatic or non-aromatic monocyclic rings; the monocyclic, bicyclic, tricyclic or tetracyclic fused ring may further form a fused ring with one or more aromatic rings to form a pentacyclic or higher fused ring; X and Y may be the same or different and each represent -CR 31 R 32 represents a - group, and R 31 and R 32 are the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, x and y represent the number of X and Y, respectively, and each independently represents 0 or 1; 【Chemistry 81】 is bonded to any carbon atom (referred to as "carbon atom 1") constituting the non-aromatic monocyclic ring of Z (when x = 1) or extends from carbon atom 1 (when x = 0), 【Chemistry 82】 is bonded to any carbon atom (referred to as "carbon atom 2") constituting the non-aromatic monocyclic ring of Z (when y = 1) or extends from carbon atom 2 (when y = 0), the carbon atom 1 and the carbon atom 2 may be the same or different, and when they are different, they may belong to the same non-aromatic monocycle or different non-aromatic monocycles; * indicates a bond. 【Chemistry 83】 [In formula (IV), Z ０ represents an aromatic ring residue or an aliphatic ring residue having 6 to 30 carbon atoms, which may have a substituent, or an organic group in which two aromatic ring residues or aliphatic ring residues are linked by a single bond; J １ and J ２ each independently represents a direct bond or a divalent organic group which may have a substituent.

5. The formula (III) is the following formula (III-1): 【Chemical 84】 [In formula (III-1), Z is a 4- to 17-membered monocyclic, bicyclic, tricyclic, or tetracyclic organic group which may have a substituent, and the monocyclic group is a non-aromatic monocyclic group; at least one of the monocyclic groups constituting the bicyclic, tricyclic, or tetracyclic group is a non-aromatic monocyclic group, and the remaining monocyclic groups may be either aromatic or non-aromatic monocyclic groups; The monocyclic, bicyclic, tricyclic, and tetracyclic organic groups may further be fused with one or more aromatic rings to form pentacyclic or higher rings, C and C' each represent one carbon atom in the group of atoms constituting the cyclic moiety of any of the non-aromatic monocycles represented by Z, and the non-aromatic monocycles to which C and C' belong may be the same or different; n is the number of carbon atoms C′ and represents an integer of 0 to 2; p, q, p', and q' represent the number of bonds, each independently representing 0 or 1; when n is 0, p and q are 1; When n is 1 or 2, at least one of p and q, and at least one of p' and q' of each C' are each 1; when n is 2, the non-aromatic monocycles to which the two C's belong may be the same or different, and when they are the same, the two C's may or may not be directly bonded to each other; X, Y, X', and Y' may be the same or different and each represent -CR 1 R 2 represents a - group, and R 1 and R 2 are the same or different and each represent a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms, when n is 2, two X' may be the same or different, and two Y' may be the same or different, x, y, x', and y' represent the numbers X, Y, X', and Y', respectively, and each independently represents 0 or 1.] 5. The self-crosslinking polymer of claim 4, wherein

6. The self-crosslinking polymer according to claim 1, wherein an end group of the self-crosslinking polymer is an aromatic ring residue having 6 to 30 carbon atoms which may have a substituent, an unsaturated hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, a hydroxyl group, or a hydrogen atom.

7. A resist underlayer film-forming composition comprising a thermal acid generator, the self-crosslinking polymer according to any one of claims 1 to 6, and a solvent.

8. The resist underlayer film forming composition according to claim 7 , further comprising a crosslinking agent.

9. 9. The resist underlayer film forming composition according to claim 8, wherein the crosslinking agent is an aminoplast crosslinking agent or a phenoplast crosslinking agent.

10. 10. The resist underlayer film forming composition according to claim 9, wherein the aminoplast crosslinker is a highly alkylated, alkoxylated, or alkoxyalkylated melamine, benzoguanamine, glycoluril, urea, or polymer thereof.

11. 10. The resist underlayer film forming composition according to claim 9, wherein the phenoplast crosslinker is a highly alkylated, alkoxylated, or alkoxyalkylated aromatic compound, or a polymer thereof.

12. 8. The resist underlayer film forming composition according to claim 7, wherein the solvent is a compound having an alcoholic hydroxyl group or a compound having a group capable of forming an alcoholic hydroxyl group.

13. 13. The resist underlayer film forming composition according to claim 12, wherein the compound having an alcoholic hydroxyl group or the compound having a group capable of forming an alcoholic hydroxyl group is a propylene glycol-based solvent, an oxyisobutyric acid ester-based solvent, or a butylene glycol-based solvent.

14. 13. The resist underlayer film forming composition according to claim 12, wherein the compound having an alcoholic hydroxyl group or the compound having a group capable of forming an alcoholic hydroxyl group is propylene glycol monomethyl ether, cyclohexanone, propylene glycol monomethyl ether acetate, ethyl lactate, or methyl 2-hydroxy-2-methylpropionate.

15. The resist underlayer film forming composition according to claim 7 , further comprising a surfactant.

16. A resist underlayer film, which is a baked product of a coating film comprising the resist underlayer film-forming composition according to claim 7 on a semiconductor substrate.

17. A method for forming a resist pattern used in the manufacture of semiconductors, comprising the step of applying the resist underlayer film-forming composition according to claim 7 onto a semiconductor substrate and baking the composition to form a resist underlayer film.

18. A step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film-forming composition according to claim 7; forming a resist film thereon; a step of forming a resist pattern by irradiating with light or an electron beam and developing; Etching the resist underlayer film using the formed resist pattern; and A process for processing a semiconductor substrate using a patterned resist underlayer film. A method for manufacturing a semiconductor device comprising:

19. A step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film-forming composition according to claim 7; forming a hard mask thereon; a step of forming a resist film thereon; a step of forming a resist pattern by irradiating with light or an electron beam and developing; Etching the hard mask using the formed resist pattern; Etching the resist underlayer film with a patterned hard mask; and A process for processing a semiconductor substrate using a patterned resist underlayer film. A method for manufacturing a semiconductor device comprising:

20. A step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film-forming composition according to claim 7; forming a hard mask thereon; a step of forming a resist film thereon; a step of forming a resist pattern by irradiating with light or an electron beam and developing; Etching the hard mask using the formed resist pattern; Etching the resist underlayer film with a patterned hard mask; removing the hard mask; and A process for processing a semiconductor substrate using a patterned resist underlayer film. A method for manufacturing a semiconductor device comprising:

21. A step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film-forming composition according to claim 7; forming a hard mask thereon; a step of forming a resist film thereon; a step of forming a resist pattern by irradiating with light or an electron beam and developing; Etching the hard mask using the formed resist pattern; Etching the resist underlayer film with a patterned hard mask; removing the hard mask; and forming a vapor-deposited film (spacer) on the resist underlayer film after removing the hard mask; A process of processing the vapor-deposited film (spacer) by etching; removing the patterned resist underlayer film to leave a patterned vapor-deposited film (spacer); and A method for manufacturing a semiconductor device, comprising: processing a semiconductor substrate through a patterned vapor-deposited film (spacer).

22. The method according to claim 19, wherein the hard mask is formed by coating or vapor deposition of an inorganic material.

23. The manufacturing method according to claim 18, wherein the resist film is patterned by a nanoimprint method or a self-assembled film.

24. The method for manufacturing a semiconductor device according to claim 20, wherein the hard mask is removed by etching or an alkaline chemical solution.

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