Composition for forming resist underlayer film

Abstract

Provided is a composition for forming a resist underlayer film, which satisfies various other characteristics such as curability, the amount of sublimate generated, in-plane uniformity of film thickness, planarity, and embeddability in addition to etching resistance and heat resistance. A composition for forming a resist underlayer film, which contains a novolac resin and a solvent, and wherein: the novolac resin contains a unit structure (A) having an aromatic ring; the unit structure A comprises one or more bis (azaaryl fused ring) structural units which are represented by formula (A) and in which two azaaryl fused rings are bonded via a linking group L; a method for forming a resist pattern using the composition; and a method for manufacturing a semiconductor device. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to a resist underlayer film forming composition suitable for photolithography in semiconductor substrate processing, 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. Background Art

[0002] In recent years, the progress of semiconductor manufacturing processes has been rapidly advancing, and along with this, there has been a strong demand for higher quality and improved properties of resist underlayer films.

[0003] For example, Patent Document 1 reports that a polymer containing a divalent group of a specific heteroaromatic ring containing an indole skeleton in a part of the structure and an aryl-substituted divalent group such as an aryl-substituted methylene group as a structural unit can be made into a material having both film density and etching resistance. However, although the planarization property is mentioned, no evidence is provided.

[0004] Patent Document 2 reports that a polymer obtained by reacting an indole derivative with a specific mixture of multiple aromatic aldehyde compounds can simultaneously ensure the solubility (applicability) of the polymer and the etching resistance and heat resistance of a hard mask layer using the polymer.

[0005] Furthermore, Patent Document 3 reports that a hard mask-forming composition containing a resin having a specific diarylaminobenzyl alcohol derivative as a partial structure can provide an organic film having high etching resistance and excellent solvent resistance and heat resistance.

[0006] In addition, Patent Document 4 reports that a composition for forming a resist underlayer film comprising a polymer having a 2-arylindole derivative / analog structure and an aryl-substituted methylene group as a unit structure can form a good resist pattern shape without mixing the upper layer of the resist underlayer film with the layer coated thereon.

[0007] In addition, Patent Document 5 reports that a resist underlayer film-forming composition containing a compound having a specific bis(polycyclic aromatic)fluorene derivative / analog structure as a structural unit can obtain a resist underlayer film material having high etching resistance, high heat resistance, and high solubility (coating properties).

[0008] However, in order to improve the quality and properties of the resist underlayer film, in addition to etching resistance and heat resistance, various other properties are required, such as curability, the amount of sublimates produced, in-plane uniformity of film thickness, flatness, embedding properties, etc. If these properties are added, there is still room for improvement.

[0009] Prior art literature

[0010] Patent Literature

[0011] Patent Document 1: Japanese Patent Application Publication No. 2016-151024

[0012] Patent Document 2: Japanese Patent Application Publication No. 2020-105513

[0013] Patent Document 3: Japanese Patent Application Publication No. 2021-81686

[0014] Patent Document 4: International Publication No. 2013 / 146670 (A1)

[0015] Patent Document 5: International Publication No. 2018 / 198960 (A1) Summary of the invention

[0016] Problems to be solved by the invention

[0017] Therefore, the problem to be solved by the present invention is to provide a composition for forming a resist underlayer film that satisfies various other properties in addition to etching resistance and heat resistance, such as curability, the amount of sublimates produced, in-plane uniformity of film thickness, flattening properties, and embedding properties, a resist pattern forming method using the resist underlayer film forming composition, and a method for manufacturing a semiconductor device using the composition.

[0018] Means for solving problems

[0019] The present invention includes the following aspects. [1]

[0021] A resist underlayer film-forming composition comprising a novolac resin and a solvent.

[0022] The novolac resin includes a unit structure A having an aromatic ring, wherein the unit structure A includes one or more bis(nitrogen heteroaryl fused ring) structural units represented by the following formula (A), which are structural units in which two nitrogen heteroaryl fused rings are linked via a linking group L.

[0023]

[0024] In the above formula (A),

[0025] L represents a divalent linking group other than a single bond between any two carbon atoms constituting each nitrogen heteroaryl condensed ring,

[0026] R 11 and R 21 The same or different, each independently represents

[0027] (i) a hydrogen atom, or a hydroxymethyl group,

[0028] (ii) an aryl group having 6 to 30 carbon atoms, or

[0029] (iii) a linear, branched or cyclic alkoxymethyl group having 2 to 20 carbon atoms; a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms; an alkenyl group having 2 to 10 carbon atoms; or an alkynyl group having 2 to 10 carbon atoms,

[0030] R 12 and R 22 are the same or different and each independently represents an arbitrarily selected substituent on a carbon atom constituting the nitrogen heteroaryl condensed ring,

[0031] However, the above (ii) or (iii) may be further substituted by a substituent containing an oxygen atom, a substituent containing a sulfur atom, a substituent containing a nitrogen atom, an aryl group or a halogenated group, or the hydrocarbon chain portion of the above (iii) may be further interrupted by a substituent containing an oxygen atom, a substituent containing a sulfur atom, a substituent containing a nitrogen atom or an arylene group,

[0032] n1 and n2 are the same or different and each independently represents R 12 and R 22 The number of substituents can be 0,

[0033] Ar 1 and Ar 2 are the same or different and are each independently a benzene ring or a condensed ring consisting of 2 to 3 benzene rings that forms a condensed ring with the pyrrole ring in formula (A),

[0034] * indicates a bonding bond. [2]

[0036] The resist underlayer film-forming composition according to [1], wherein the novolac resin comprises a composite unit structure AB represented by the following formula (AB):

[0037]

[0038] In the above formula (AB),

[0039] n represents the number of composite unit structures AB,

[0040] The unit structure A is represented by the formula (A) described in claim 1,

[0041] Unit structure B represents one or more unit structures including the structure represented by the following formula (B1), formula (B2) or formula (B3),

[0042] * indicates a bonding bond.

[0043]

[0044] [In formula (B1),

[0045] 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 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,

[0046] * indicates a bonding bond. ]

[0047] *-J 1 -Z 0 -J 2 -* (B2)

[0048] [In formula (B2),

[0049] 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,

[0050] J 1 and J 2 Each independently represents a divalent organic group which is directly bonded or may have a substituent,

[0051] * indicates a bonding bond. ]

[0052]

[0053] [In formula (B3),

[0054] Z is a monocyclic, bicyclic, tricyclic or tetracyclic condensed ring having 4 to 25 carbon atoms and optionally having a substituent, wherein the monocyclic ring is a non-aromatic monocyclic ring; at least one of the monocyclic rings constituting the bicyclic, tricyclic and tetracyclic rings is a non-aromatic monocyclic ring, and the remaining monocyclic rings may be either aromatic or non-aromatic. The monocyclic, bicyclic, tricyclic or tetracyclic condensed ring may further form a condensed ring with one or more aromatic rings to form a condensed ring of at least five rings,

[0055] X and Y are the same or different, indicating -CR 31 R 32 -Base, 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,

[0056] x and y represent the numbers of X and Y, respectively, and each independently represents 0 or 1,

[0057] *-X xis bonded to any carbon atom (referred to as "carbon atom 1") of the non-aromatic monocyclic ring constituting Z (when x=1), or extends from carbon atom 1 (when x=0),

[0058] Y y -* is bonded to any carbon atom (referred to as "carbon atom 2") of the above non-aromatic monocyclic ring constituting Z (when y=1), or extends from carbon atom 2 (when y=0),

[0059] The carbon atom 1 and the carbon atom 2 may be the same or different, and in different cases, may belong to the same non-aromatic monocyclic ring or different non-aromatic monocyclic rings.

[0060] * indicates a bonding bond. ] [3]

[0062] The resist underlayer film-forming composition according to [1], wherein the linking group L is selected from -O-, -S-, -SO2-, -CO-, -CONH-, -COO-, -NH-, -(CR 1 R 2 )m 1 -、-(Ar)m 2 -、-CH2-(Ar)m 2 -CH2- and -(cyclo-R)-,

[0063] R 1 and R 2 are the same or different and each independently represents a hydrogen atom, a hydrocarbon group having 1 to 5 carbon atoms, or an aryl group having 6 to 30 carbon atoms, m 1 represents an integer from 1 to 10,

[0064] Ar represents an arylene group having 6 to 30 carbon atoms, m 2 represents an integer of 1 to 3 which is the number of aromatic rings bonded to each other via single bonds,

[0065] Cyclo-R represents a divalent alicyclic hydrocarbon group having 5 to 8 members which may form a condensed ring with one or two benzene rings or naphthalene rings. [4]

[0067] The resist underlayer film forming composition according to [3], wherein cyclo-R represents a 6- to 8-membered divalent alicyclic hydrocarbon group which may form a condensed ring with one or two benzene rings or naphthalene rings. [5]

[0069] The resist underlayer film forming composition according to [1], wherein R 11 and R 21 At least one part of represents a substituent:

[0070] *-R 3 -C≡CR 4

[0071] [in,

[0072] * indicates a bond,

[0073] R 3 is a single bond or a divalent organic group having 1 to 20 carbon atoms,

[0074] R 4 It is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. ]. [6]

[0076] The resist underlayer film forming composition according to [1], wherein the solvent includes a solvent having a boiling point of 160° C. or higher. [7]

[0078] The resist underlayer film forming composition according to any one of [1] to [6], further comprising an acid and / or a salt thereof and / or an acid generator. [8]

[0080] The resist underlayer film forming composition according to any one of [1] to [7], further comprising a cross-linking agent. [9]

[0082] The resist underlayer film forming composition according to [8], wherein the crosslinking agent is an aminoplast crosslinking agent or a phenoplast crosslinking agent.

[10]

[0084] The resist underlayer film forming composition according to any one of [1] to [9], further comprising a surfactant.

[11]

[0086] A resist underlayer film on a semiconductor substrate is a fired product of a coating film formed from the resist underlayer film-forming composition according to any one of [1] to

[10] .

[12]

[0088] A method for forming a resist pattern used in semiconductor manufacturing, comprising the step of applying the resist underlayer film-forming composition described in any one of [1] to

[10] on a semiconductor substrate and firing the composition to form a resist underlayer film.

[13]

[0090] A method for manufacturing a semiconductor device comprises the following steps:

[0091] A step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film-forming composition according to any one of [1] to

[10] ;

[0092] a step of forming a resist film on the resist underlayer film;

[0093] A process of forming a resist pattern on a resist film by irradiating the resist film with light or electron beams and developing the resist film;

[0094] a step of etching the resist underlayer film through the resist pattern; and

[0095] A step of processing a semiconductor substrate through the patterned resist underlayer film.

[14]

[0097] A method for manufacturing a semiconductor device comprises the following steps:

[0098] A step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film-forming composition according to any one of [1] to

[10] ;

[0099] A step of forming a hard mask on the resist underlayer film;

[0100] A step of further forming a resist film on the hard mask;

[0101] A process of forming a resist pattern on a resist film by irradiating the resist film with light or electron beams and developing the resist film;

[0102] A process of etching the hard mask through the resist pattern;

[0103] A step of etching the resist underlayer film through the patterned hard mask; and

[0104] A step of processing a semiconductor substrate via a patterned resist underlayer film.

[15]

[0106] A method for manufacturing a semiconductor device comprises the following steps:

[0107] A step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film-forming composition according to any one of [1] to

[10] ;

[0108] A step of forming a hard mask on the resist underlayer film;

[0109] A step of further forming a resist film on the hard mask;

[0110] A process of forming a resist pattern on a resist film by irradiating the resist film with light or electron beams and developing the resist film;

[0111] A process of etching the hard mask through the resist pattern;

[0112] A step of etching the resist underlayer film through the patterned hard mask;

[0113] A process of removing the hard mask; and

[0114] A step of processing a semiconductor substrate via a patterned resist underlayer film.

[16]

[0116] A method for manufacturing a semiconductor device comprises the following steps:

[0117] A step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film-forming composition described in any one of [1] to

[10] ;

[0118] A step of forming a hard mask on the resist underlayer film;

[0119] A step of further forming a resist film on the hard mask;

[0120] A process of forming a resist pattern on a resist film by irradiating the resist film with light or electron beams and developing the resist film;

[0121] A process of etching the hard mask through the resist pattern;

[0122] A step of etching the resist underlayer film through the etched hard mask;

[0123] A process of removing the hard mask;

[0124] A step of forming a vapor-deposited film (spacer) on the resist underlayer film after the hard mask is removed;

[0125] A process of processing the vapor-deposited film (spacer) by etching;

[0126] A step of removing the patterned resist underlayer film to leave the patterned vapor-deposited film (spacer); and

[0127] A step of processing a semiconductor substrate via a patterned vapor-deposited film (spacer).

[17]

[0129] The method for manufacturing a semiconductor device according to any one of

[14] to

[16] , wherein the hard mask is formed by coating a composition containing an inorganic substance or by vapor deposition of an inorganic substance.

[18]

[0131] The method for manufacturing a semiconductor device according to any one of

[13] to

[16] , wherein the resist film is patterned by nanoimprinting or self-assembled film.

[19]

[0133] In the method for manufacturing a semiconductor device according to

[15] or

[16] , the hard mask is removed by either etching or an alkaline chemical solution.

[0134] Effects of the Invention

[0135] The novolac resin having a bis(azaaromatic fused ring) derivative [typically a bis(indole) derivative] as a structural unit shown in formula (A) has high heat resistance compared to the conventional novolac resin having an indole compound as a structural unit. Therefore, if used in a resist underlayer film-forming composition, the amount of sublimates during high-temperature firing is small, the in-plane uniformity of the film thickness is very high, and the etching resistance is also high. In addition, it also shows good coating properties on various vapor deposition substrates, thereby having good flattening properties and embedding properties. By further adding additional monomers, the above-mentioned properties can be adjusted, in particular, the resistance during etching processing can be adjusted, and the appropriate optical constants for suppressing reflection during exposure can be adjusted.

[0136] Furthermore, in a more preferred embodiment, when a substance in which an alkylene group such as a propargyl group is introduced into a novolac resin having a bis(azaaromatic fused ring) derivative represented by formula (A) as a structural unit is used in a resist underlayer film-forming composition, self-crosslinking properties that allow curing can be obtained even if no crosslinking agent or acid catalyst is contained in addition to the above, thereby achieving sufficient curing properties not only in an air atmosphere but also in a nitrogen atmosphere.

[0137] In a more preferred embodiment, when an alkylene group such as a propargyl group is introduced into a novolac resin having a bis(azaaryl fused ring) derivative represented by formula (A) as a structural unit and is used in a resist underlayer film-forming composition, since such an alkylene group functions as a crosslinking group, when combined with an acid catalyst or a crosslinking agent, the physical hardness of the film can be increased compared to the usual value, and accordingly, the pattern forming characteristics during etching can also be improved. DETAILED DESCRIPTION

[0138] [I. Definition of terms]

[0139] In this specification, the definitions of main terms related to the novolac resin as one embodiment of the present invention are described below. Unless otherwise specified, the definitions of the following terms apply to the novolac resin.

[0140] (I-1) "Novolac resin"

[0141] The term "novolak resin" is used in a broad sense to include not only phenol / formaldehyde resins (so-called novolac-type phenol resins) and aniline / formaldehyde resins (so-called novolac-type aniline resins) in a narrow sense, but also a polymer formed by covalent bond formation (substitution reaction, addition reaction, condensation reaction, or addition condensation reaction, etc.) between an organic compound having a functional group capable of covalently bonding to 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 halide group bonded to an α-position carbon atom (benzyl carbon atom, etc.) of an alkylaryl group; a carbon-carbon unsaturated bond of divinylbenzene, dicyclopentadiene, etc.] and an aromatic ring in a compound having an aromatic ring (preferably having a substituent containing a heteroatom such as an oxygen atom, a nitrogen atom, a sulfur atom, etc. on the aromatic ring) in the presence of an acid catalyst or under reaction conditions equivalent thereto.

[0142] Therefore, the novolac resin referred to in the present application specification is a polymer formed by connecting a plurality of compounds having aromatic rings, by forming a covalent bond with an aromatic ring in a compound having an aromatic ring via a connecting carbon atom through an organic compound containing a carbon atom derived from the above-mentioned functional group (sometimes referred to as a "connecting carbon atom").

[0143] In this specification, the terms unit structure A, unit structure B, and unit structure C are used as unit structures constituting the "phenolic varnish 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 can covalently bond to the aromatic ring of unit structure A. Unit structure C is a unit structure having an equivalent bonding method to composite unit structure AB, and is a unit structure derived from a compound having an aromatic ring and having a functional group that can covalently bond to the aromatic ring of unit structure A. Since the bonding method is the same, unit structure C can be replaced by composite unit structure AB.

[0144] (I-2) "Residues"

[0145] The so-called "residue" refers to an organic group in which a hydrogen atom bonded to a carbon atom or a heteroatom (nitrogen atom, oxygen atom, sulfur atom, etc.) is replaced with a bond, and can be a monovalent group or a polyvalent group. For example, if one hydrogen atom is replaced with one bond, it becomes a monovalent organic group, and if two hydrogen atoms are replaced with bonds, it becomes a divalent organic group.

[0146] (I-3) "Aromatic ring" (aromatic group, aryl group, arylene group)

[0147] The term "aromatic ring" is a concept including an aromatic hydrocarbon ring, an aromatic heterocycle, and residues thereof [sometimes referred to as "aromatic group", "aryl group" (in the case of a monovalent group) or "arylene group" (in the case of a divalent group)], and includes not only monocyclic rings (aromatic monocyclic rings) but also polycyclic rings (aromatic polycyclic rings). In the case of polycyclic rings, at least one monocyclic ring is an aromatic monocyclic ring, but the remaining monocyclic rings forming a condensed ring with the aromatic monocyclic ring may be a monocyclic heterocyclic ring (heteromonocyclic ring) or a monocyclic alicyclic hydrocarbon (alicyclic monocyclic ring).

[0148] Examples of the aromatic ring include benzene, indene, naphthalene, azulene, styrene, toluene, xylene, mesitylene, cumene, anthracene, phenanthrene, benzo[9,10]phenanthrene, benzanthracene, pyrene, Fluorene, biphenyl, coronene, perylene, fluoranthene, benzo[k]fluoranthene, benzo[b]fluoranthene, benzo[ghi]perylene, coronene, dibenzo[g,p] Aromatic hydrocarbon rings such as acenaphthene, dihydroacenaphthene, tetracene, pentacene, and cyclooctatetraene, more typically, aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and pyrene; furan, pyran, thiophene, pyrrole, N-alkylpyrrole, N-arylpyrrole, imidazole, pyridine, pyrimidine, pyrazine, triazine, thiazole, indole, phenylindole, bisindolefluorene, bisindolebenzofluorene, bisindoledibenzofluorene, purine, quinoline, isoquinoline, chromene, thianthrene, phenothiazine, phenanthrene, phenanthracene ... Aromatic heterocycles such as oxazine, xanthene, acridine, phenazine, carbazole, and indolocarbazole, more typically furan, thiophene, pyrrole, indole, phenylindole, bisindolefluorene, phenothiazine, carbazole, indolocarbazole, imidazole, pyran, pyridine, pyrimidine, and pyrazine can be mentioned, but are not limited to these.

[0149] The aromatic ring (e.g., benzene ring, naphthalene ring, etc.) may optionally have a substituent, and examples of such a substituent include a halogen atom, a saturated or unsaturated straight chain, branched chain or cyclic hydrocarbon group (-R) (which may be interrupted once or more by an oxygen atom in the middle of the hydrocarbon chain. Including alkyl, alkenyl, alkynyl, propargyl, etc.), an alkoxy or aryloxy group (-OR, wherein R represents the above hydrocarbon group -R), an alkylamino group [-NHR or -NR2 (two Rs may be the same or different), wherein R represents the above hydrocarbon group -R, including alkyl, alkenyl, alkynyl, propargyl, etc. which may be interrupted once or more by an oxygen atom in the middle of the hydrocarbon chain] , hydroxyl, amino (-NH2), carboxyl, cyano, nitro, ester (-CO2R or -OCOR, wherein R represents the above hydrocarbon group -R), amide (-NHCOR, -CONHR, -NRCOR (the two Rs may be the same or different) or -CONR2 (the two Rs may be the same or different), wherein R represents the above hydrocarbon group -R), sulfonyl-containing group (-SO2R, wherein R represents the above hydrocarbon group -R or hydroxyl -OH), thiol (-SH), thioether-containing group (-SR, wherein R represents the above hydrocarbon group -R); organic group containing ether bond [R 11 -OR 11 (R 11 Each independently represents a residue of an ether compound represented by an alkyl group having 1 to 6 carbon atoms such as methyl and ethyl, an aryl group such as phenyl, naphthyl, o-aminobenzoyl, and pyrenyl; for example, an organic group containing an ether bond including a methoxy group, ethoxy group, and phenoxy group], and a substituent such as an aryl group.

[0150] Furthermore, organic groups having one or more aromatic rings (benzene, naphthalene, anthracene, pyrene, etc.) and one or more aliphatic rings or heterocyclic condensed rings are also included. In addition, 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.

[0151] The organic group may be an organic group having a structure in which two or more aromatic rings are linked via a divalent linking group such as an alkylene group.

[0152] (I-4) "Heterocyclic ring"

[0153] "Heterocycle" is a concept that includes both aliphatic heterocycles and aromatic heterocycles, and includes not only monocyclic (heteromonocyclic) but also polycyclic (heteropolycyclic). In the case of polycyclic, at least one monocyclic is a heteromonocyclic, and the remaining monocyclics may be aromatic hydrocarbon monocyclics or alicyclic monocyclics. As aromatic heterocycles, the examples of (I-3) above may be referred to. As with the aromatic ring of (I-3) above, it may have a substituent.

[0154] (I-5) "Non-aromatic ring" (aliphatic ring)

[0155] The so-called "non-aromatic monocyclic ring" is a monocyclic hydrocarbon that is not aromatic, typically a monocyclic ring of an alicyclic compound. It can be called an aliphatic monocyclic ring (it can include an aliphatic heteromonocyclic ring and can include an unsaturated bond as long as it is not an aromatic compound). Like the aromatic ring in (I-3) above, it can have a substituent.

[0156] Examples of the non-aromatic monocyclic ring (aliphatic ring, aliphatic monocyclic ring) include cyclopropane, cyclobutane, cyclobutene, cyclopentane, cyclopentene, cyclohexane, methylcyclohexane, cyclohexene, methylcyclohexene, cycloheptane, and cycloheptene.

[0157] The so-called "non-aromatic polycyclic" refers to a polycyclic hydrocarbon that is not aromatic, typically a polycyclic alicyclic compound. It can be called an aliphatic polycyclic [which may include an aliphatic heteropolycyclic (at least one of the monocyclic rings constituting the polycyclic is an aliphatic heterocyclic ring), and may include an unsaturated bond as long as it is not an aromatic compound]. It includes a non-aromatic bicyclic, a non-aromatic tricyclic, and a non-aromatic tetracyclic.

[0158] The so-called "non-aromatic bicyclic ring" refers to a condensed ring composed of two monocyclic hydrocarbons that are not aromatic, and is typically a condensed ring of two alicyclic compounds. In this specification, it is sometimes referred to as an aliphatic bicyclic ring (which may include an aliphatic heterobicyclic ring and may include an unsaturated bond as long as it is not an aromatic compound). Examples of non-aromatic bicyclic rings include dicyclopentane, dicyclooctane, and dicycloheptene.

[0159] The so-called "non-aromatic tricyclic ring" refers to a condensed ring composed of three monocyclic hydrocarbons that are not aromatic, and is typically a condensed ring of three alicyclic compounds (each of which may be a heterocyclic ring and may contain an unsaturated bond as long as it is not an aromatic compound). Examples of the non-aromatic tricyclic ring include tricyclooctane, tricyclononane, and tricyclodecane.

[0160] The so-called "non-aromatic tetracyclic ring" is a condensed ring composed of four monocyclic hydrocarbons that are not aromatic, and is typically a condensed ring of four alicyclic compounds (each of which may be a heterocyclic ring and may contain an unsaturated bond as long as it is not an aromatic compound). Examples of the non-aromatic tetracyclic ring include hexahydropyrene and the like.

[0161] (1-6)

[0162] The "carbon atoms constituting the ring (part)" refers to the carbon atoms constituting the hydrocarbon ring (which may be any of an aromatic ring, an aliphatic ring, and a heterocyclic ring) in a state without a substituent.

[0163] (1-7)

[0164] The term "azaaryl condensed ring" generally refers to a condensed ring of an azaaryl group (a nitrogen-containing aromatic heterocycle) and another aromatic ring. In the present invention, the nitrogen-containing aromatic heterocycle as the azaaryl group is particularly a pyrrole ring.

[0165] The "bis(azaaromatic fused ring) compound" refers to a compound containing a structural unit having two azaaromatic fused rings, and in the present invention, particularly refers to a novolac resin containing a unit structure of the formula (A) referred to in (IIA-1) described later.

[0166] (I-8)

[0167] 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.

[0168] (1-9)

[0169] In the chemical structural formula representing the unit structure of the phenolic varnish resin in the present application specification, a bond (indicated by *) is sometimes recorded for convenience. Unless otherwise specified, such a bond can adopt any bonding position in the unit structure that can be bonded, and the bonding position in the unit structure is not limited at all.

[0170] [II; Resist underlayer film-forming composition]

[0171] A resist underlayer film-forming composition according to one embodiment of the present invention contains a specific novolac resin and a solvent.

[0172] (IIA) Novolac resin

[0173] (IIA-1)

[0174] The specific novolac resin contained in the resist underlayer film forming composition as one embodiment of the present invention includes a unit structure A having an aromatic ring, and the unit structure A includes one or more bis(azaaromatic fused ring) structural units represented by the following formula (A), that is, a structural unit in which two azaaromatic fused rings, preferably two indole rings (for example, 2-phenylindole, etc., which may have a substituent) are linked via a linking group L.

[0175]

[0176] Unless otherwise specified, in the present specification, * represents a bonding bond.

[0177] Furthermore, in the above formula (A), the bond represented by * extends from any carbon atom constituting the nitrogen heteroaryl condensed ring, but preferably from a carbon atom constituting Ar 1and Ar 2 The bond may extend from the pyrrole ring in the nitrogen heteroaryl condensed ring or from the aromatic ring of L when L has an aromatic ring.

[0178] (IIA-1-1)

[0179] In formula (A), L is a divalent linking group other than a single bond. L may be bonded to any carbon atom constituting each nitrogen heteroaryl condensed ring, or may be bonded to Ar. 1 ,Ar 2 , that is, the nitrogen heteroaryl fused ring The pyrrole ring may be bonded to an aromatic carbon atom of the nitrogen heteroaryl condensed ring, but is preferably bonded to a carbon atom constituting the pyrrole ring portion in the nitrogen heteroaryl condensed ring.

[0180] As a preferred linking group, -O-, -S-, -SO2-, -CO-, -CONH-, -COO-, -NH-, -(CR 1 R 2 )m 1 -、-(Ar)m 2 -、-CH2-(Ar)m 2 -CH2- and -(cyclo-R)-.

[0181] R 1 and R 2 are the same or different and each independently represents a hydrogen atom; a hydrocarbon group having 1 to 5 carbon atoms; or an aryl group having 6 to 30 carbon atoms; m 1 Indicates an integer from 1 to 10.

[0182] Ar represents an arylene group having 6 to 30 carbon atoms; m 2 It represents the number of aromatic rings bonded to each other by single bonds, and is an integer of 1 to 3. Examples of such Ar include a divalent benzene ring, a naphthalene ring, an anthracene ring, a pyrene ring, a biphenyl ring, and a terphenyl ring.

[0183] Cyclo-R represents a divalent alicyclic hydrocarbon group having a 5- to 8-membered ring, preferably a 6- to 8-membered ring, which can form a condensed ring with one or two benzene rings or naphthalene rings. In addition, the two bonds of cyclo-R refer to bonds extending from carbon atoms (preferably the same carbon atom, excluding carbon atoms belonging to any condensed benzene ring or condensed naphthalene ring) constituting the ring of the alicyclic hydrocarbon group. As the above-mentioned alicyclic hydrocarbon group, it can be a divalent monocyclic hydrocarbon group derived from cyclohexane, cyclopentane, etc., or it can be a divalent polycyclic hydrocarbon group derived from dicyclopentadiene, etc. In addition, as an alicyclic hydrocarbon group that forms a condensed ring with a benzene ring or a naphthalene ring, a divalent hydrocarbon group derived from tetralin, 9,10-dihydroanthracene, 9,10-dihydrophenanthrene, indane, fluorene, benzocyclobutene, benzofluorene, dibenzofluorene, and dihydroacenaphthene can be exemplified. However, when the alicyclic hydrocarbon group is a divalent hydrocarbon group derived from a 5-membered ring, that is, cyclopentane, the number of benzene rings or naphthalene rings to form a condensed ring is preferably 0 to 2.

[0184] In one embodiment of the present invention, L in the formula (A) may be a structure other than a fluorene ring.

[0185] In one embodiment of the present invention, when L in formula (A) is a fluorene ring, R 11 and R 21 At least a part of is preferably an alkynyl group described below.

[0186] (IIA-1-2)

[0187] Ar 1 and Ar 2 The same or different, each independently is a benzene ring, or a condensed ring composed of 2 to 3 benzene rings, and forms a condensed ring (azaaryl condensed ring) with the pyrrole ring in formula (A). Examples of the condensed ring composed of 2 to 3 benzene rings include a naphthalene ring, an anthracene ring, and a phenanthrene ring. In addition, examples of those having a substituent include biphenyl (phenyl-substituted benzene ring) and terphenyl (biphenyl-substituted benzene ring).

[0188] Ar 1 and Ar 2 A benzene ring is preferred.

[0189] (IIA-1-3)

[0190] R 11 and R 21 It is a substituent on the nitrogen atom of the azaaryl condensed ring, that is, a substituent on the nitrogen atom of the pyrrole ring portion.

[0191] Furthermore, R 11 and R 21 The same or different, each independently represents

[0192] (i) a hydrogen atom, or a hydroxymethyl group,

[0193] (ii) an aryl group having 6 to 30 carbon atoms, or

[0194] (iii) a linear, branched or cyclic alkoxymethyl group having 2 to 20 carbon atoms (such as methoxymethyl); a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms; an alkenyl group having 2 to 10 carbon atoms; or an alkynyl group having 2 to 10 carbon atoms,

[0195] The above (ii) and (iii) may be further substituted with a substituent containing an oxygen atom (hydroxyl, alkoxy, aryloxy, carboxyl, carbonyl, etc.), a substituent containing a sulfur atom (sulfonic acid group, a thioether-containing group, a sulfonyl-containing group, etc.), a substituent containing a nitrogen atom (amino group, substituted amino group (mono- or di-substituted amino groups such as monoalkylamine and dialkylamine), amide group, nitro group, cyano group, etc.), an aryl group (preferably an aryl group having 6 to 15 carbon atoms, such as phenyl, etc.) or a halogenated group. , or the hydrocarbon chain portion of the above (iii) is further interrupted by a substituent containing an oxygen atom (-O-, -C(O)-, -C(O)O-, -OC(O)-, etc.), a substituent containing a sulfur atom (-S-, etc.), a substituent containing a nitrogen atom (-N(R)C(O)-, -C(O)N(R)-, -OC(O)N(R)-, -N(R)C(O)O-, -N(R)C(O)N(R)-, -NR-, etc.), or an arylene group (phenylene, etc.). In the above-mentioned substituents used for interruption, each R is independently the same or different and represents a hydrocarbon group having 1 to 30 carbon atoms.

[0196] In addition, R 11 and R 21 At least one of the following alkynyl groups is:

[0197] *-R 3 -C≡CR 4

[0198] From the viewpoint of self-crosslinking, it is preferred that the above-mentioned "at least a part" is preferably 5 to 100% of the above-mentioned alkynyl group introduction rate to the nitrogen atom of the pyrrole ring part constituting the nitrogen heteroaryl condensed ring. Here, the above-mentioned alkynyl group introduction rate can be, for example, 1 H-NMR measurement, 13 The introduction rate can be calculated by using C-NMR. The introduction rate can be calculated using an internal standard or the like as needed.

[0199] Among them, R 3 is a single bond; or a divalent organic group having 1 to 20 carbon atoms, preferably an alkylene group, more preferably a methylene group; R 4 It is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, preferably an alkyl group, and more preferably a hydrogen atom.

[0200] In addition, the organic group refers to the residue of an organic compound.

[0201] (IIA-1-4)

[0202] R 12 and R 22 The same or different, each independently is an arbitrarily selected substituent on the carbon atom constituting the nitrogen heteroaryl condensed ring, which may be a carbon atom constituting the pyrrole ring part, or an Ar constituting a condensed ring with the pyrrole ring part. 1 ,Ar 2 A carbon atom that is part of an aromatic ring.

[0203] Furthermore, as R 12 and R 22 , for example, the same or different, each independently can be exemplified

[0204] (iv) hydroxyl, nitro, cyano, carboxyl, trifluoromethyl, or halide,

[0205] (v) an aryloxy group having 6 to 15 carbon atoms, an arylalkoxycarbonyl group having 8 to 15 carbon atoms, an aryloxycarbonyl group having 7 to 15 carbon atoms, or an aryl group having 6 to 30 carbon atoms, or

[0206] (vi) an acyl group having 1 to 15 carbon atoms, an alkoxy group having 1 to 15 carbon atoms, an arylalkoxy group having 7 to 15 carbon atoms, an alkoxycarbonyl group having 1 to 15 carbon atoms, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or an alkynyl group having 2 to 10 carbon atoms.

[0207] The above (v) or (vi) may be further substituted with a substituent containing an oxygen atom, a substituent containing a sulfur atom, a substituent containing a nitrogen atom, an aryl group or a halogenated group similar to (ii) or (iii) of (IIA-1-3); or the hydrocarbon chain portion of the above (vi) may be further interrupted with a substituent containing an oxygen atom, a substituent containing a sulfur atom, a substituent containing a nitrogen atom, an arylene group (such as a phenylene group) similar to (iii) of (IIA-1-3).

[0208] In addition, n1 and n2 are the same or different and each independently represents R 12 and R 22 The number of substituents may be 0.

[0209] (IIA-1-5)

[0210] Although not bound by theory, the following is considered to be possible in terms of improving etching resistance, reducing the amount of sublimates, obtaining high uniformity within a surface, good curing properties, good planarization properties, and embedding properties by using the resist underlayer film forming composition as one embodiment of the present invention.

[0211] That is, the novolac resin mixed with the resist underlayer film forming composition which is one embodiment of the present invention contains a bis(azaaromatic condensed ring) structural unit (preferably a bisindole structural unit), and the bis(azaaromatic condensed ring) structural unit is present in a very close position (molecules are easily fixed from the viewpoint of entropy) via L which is a divalent linking group other than a single bond during firing, so a condensed ring is formed during firing.

[0212] The following shows the case where the bis(nitrogen heteroaryl fused ring) structural unit is a bis(indole) structural unit [Ar in formula (A) 1 and Ar 2

[0047] A typical diagram of the expected fused ring formation during firing in the case of a benzene ring.

[0213]

[0214] In Ar 1 and Ar 2 In the case of a condensed ring composed of 2 to 3 benzene rings (e.g., a naphthalene ring, anthracene ring), the same condensed ring formation is also considered. However, in the case of an azaaryl condensed ring such as 2-phenylindole, when all the carbon atoms on the pyrrole ring part as the azaaryl are substituted (in the case of having an aryl substituent such as a phenyl group), it is not easy to consider the bonding formation of the two pyrrole ring parts connected by the linker L in the above-mentioned diagram, but since the condensed ring formation by the additional bonding formation of the two phenyl groups as substituents is considered, the same effect can be expected.

[0215] It is believed that by forming such a condensed ring during firing, the oxidation sites are reduced and highly carbonized, thereby improving etching resistance. In addition, the heat resistance is improved with the formation of the condensed ring, so the amount of sublimates generated is significantly reduced, and the uniformity in the surface can be made high. In addition, it is believed that by forming a condensed ring, the solubility in the solvent is significantly reduced after firing, so the curing property is also improved.

[0216] On the other hand, regarding planarization and embedding properties, it is generally known in the past that the softer the resin, the better the planarization and embedding properties. Rigid molecules have poor planarization and embedding properties. Therefore, it is assumed that if a double (nitrogen heteroaryl condensed ring) skeleton that further forms a condensed ring from the beginning to after firing is used, the embedding and planarization properties are poor. In addition, since the rigid structure is extremely difficult to dissolve in the solvent of the resist lower film, it is also assumed that it is difficult to prepare as a solution. However, in the present application, since it is initially in the form of a double (nitrogen heteroaryl condensed ring), it can be easily dissolved in the solvent of the resist lower film during coating, showing good embedding and planarization properties. After firing, as shown in the above figure, it is believed that it becomes a bulky structure, and even with a rigid skeleton, embedding and planarization properties can be ensured.

[0217] (IIA-1-6)

[0218] Several representative examples of bis(nitrogen heteroaryl fused ring) structural units are listed below.

[0219] In addition, the bonds from the structural unit are omitted. In addition, examples in which hydrogen atoms are bonded to the nitrogen atoms in the nitrogen heteroaryl condensed ring (indole ring) can be cited as representative examples, but at least a part of them can be replaced by R defined in the formula (A) of (IIA-1) above. 11 , R 21 In addition, R defined in the formula (A) of (IIA-1) above may be optionally 12 , R 22 Exemplary substituents.

[0220]

[0221]

[0222]

[0223] (IIA-1-7)

[0224] The bis(azaaryl fused ring) serving as the source of the unit structure A represented by the formula (A) can be synthesized by any known method, and for example, can be synthesized by the following reaction.

[0225]

[0226] (i): Palladium(II) acetate (sodium trifluoromethanesulfonate)

[0227]

[0228] (ii): sodium dodecyl sulfate, ytterbium trifluoromethanesulfonate; or zirconium chloride

[0229]

[0230] (iii): trifluoroacetic acid or sulfuric acid

[0231]

[0232] (iv): (S)-3,3'-bis(2,4,6-triisopropylphenyl)-1,1'-binaphthyl-2,2'-diyl hydrogen phosphate

[0233] (IIA-1-8)

[0234] The unit structure A may include one or more other unit structures having an aromatic ring other than the above-mentioned formula (A) (IIA-1) unless the effects of the present invention are impaired.

[0235] Such an aromatic ring preferably has 6 to 30, more preferably 6 to 24 carbon atoms.

[0236] Preferably, such an aromatic ring is one or more benzene rings, naphthalene rings, anthracene rings, pyrene rings; or a condensed ring of a benzene ring, naphthalene ring, anthracene ring, pyrene ring and a heterocyclic ring or an aliphatic ring (fluorene ring, benzofluorene ring, dibenzofluorene ring, indole ring, carbazole ring, indolocarbazole ring, etc.).

[0237] The aromatic ring may have a substituent group at will, and preferably contains a heteroatom in the substituent group. In addition, the aromatic ring may be connected to two or more aromatic rings by a linking group, and a heteroatom may be contained in the linking group. As the heteroatom, for example, an oxygen atom, a nitrogen atom, a sulfur atom, etc. may be mentioned.

[0238] The "aromatic ring" is preferably an organic group having 6 to 30 carbon atoms, or 6 to 24 carbon atoms, containing at least one hetero atom selected from N, S and O on the ring, within the ring, or between the rings.

[0239] As heteroatoms contained in the ring, for example, nitrogen atoms contained in amino (for example, propargylamino) and cyano groups; oxygen atoms contained in formyl, hydroxyl, carboxyl, alkoxy (for example, propargyloxy) groups as oxygen-containing substituents, nitrogen atoms and oxygen atoms contained in nitro groups as oxygen-containing substituents and nitrogen-containing substituents. As heteroatoms contained in the ring, for example, oxygen atoms contained in xanthene and nitrogen atoms contained in carbazole can be mentioned. As heteroatoms contained in the linking group of two or more aromatic rings, nitrogen atoms, oxygen atoms, and sulfur atoms contained in -NH- bonds, -NHCO- bonds, -O- bonds, -COO- bonds, -CO- bonds, -S- bonds, -SS- bonds, and -SO2- bonds can be mentioned. The unit structure A is preferably a unit structure having the above-mentioned aromatic ring having an oxygen-containing substituent, a unit structure having two or more aromatic rings linked by -NH-, or a unit structure having a condensed ring of one or more aromatic hydrocarbon rings and one or more heterocyclic rings.

[0240] For example, as the skeleton used for the unit structure A other than formula (A), the following skeletons can be exemplified. In the compounds exemplified below, unless otherwise specified, the same substituents as the substituents on the above-mentioned nitrogen heteroaryl groups can be bonded, and the number and substitution positions of the hydroxyl groups in the exemplified compounds having hydroxyl groups are examples, and any number and substitution positions that can be theoretically taken can be used.

[0241] (Example of amine skeleton)

[0242]

[0243]

[0244]

[0245] (Example of phenol skeleton)

[0246]

[0247]

[0248]

[0249]

[0250] Furthermore, the H of NH of the above-mentioned amine skeleton and the H of OH of the phenol skeleton may be substituted with the substituents described below.

[0251]

[0252]

[0253] As the unit structure A other than formula (A), at least one selected from the following is preferred. In addition, the positions of the two bonding bonds shown in each unit structure described below are only shown for convenience, and each may extend from any possible carbon atom, and the position is not limited.

[0254] (Examples of unit structures derived from heterocycles)

[0255]

[0256] (Examples of unit structures derived from aromatic hydrocarbons having oxygen-containing substituents)

[0257]

[0258]

[0259] (Example of a unit structure derived from an aromatic hydrocarbon linked via -NH-)

[0260] -NH- can also take a structure in which the hydrogen atom on N is replaced.

[0261]

[0262] In one embodiment, when L in the formula (A) of (IIA-1) is a fluorene ring, the unit structure A preferably includes one or more other unit structures having an aromatic ring other than the one in the formula (A).

[0263] Examples of the skeleton used as the unit structure include the above-mentioned amine skeleton and phenol skeleton, and preferably the following unit structures can also be exemplified.

[0264] (Examples of unit structures derived from aromatic hydrocarbons having oxygen-containing substituents)

[0265]

[0266] (Examples of unit structures derived from heterocycles or examples of unit structures derived from aromatic hydrocarbons linked via -NH-)

[0267]

[0268] (IIA-2)

[0269] The novolac resin preferably includes a composite unit structure AB represented by the following formula (AB).

[0270]

[0271] In the formula (AB), n represents the number of composite unit structures AB, and the unit structure A is represented by the formula (A) described in the above (IIA-1).

[0272] (IIA-2-1) Unit Structure B

[0273] Unit structure B is one or more unit structures including a connecting carbon atom [see (I-1) above] that is bonded to an aromatic ring in unit structure A, including structures represented by formula (B1), formula (B2) or formula (B3) described in (IIA-2-2) to (IIA-2-4) below. Unit structure B can be covalently bonded to a carbon atom on the nitrogen heteroaryl condensed ring of unit structure A, thereby connecting two unit structures A.

[0274] In addition, at least one composite unit structure AB can be replaced by one or more unit structures C comprising the structures represented by formula (C1), formula (C2) and formula (C3) respectively described later in (IIA-2-2-3), (IIA-2-3-2) and (IIA-2-4-3) as a unit structure equivalent thereto.

[0275] (IIA-2-2) Formula (B1)

[0276]

[0277] In formula (B1),

[0278] R and R' each independently represent a hydrogen atom, an aromatic ring having 6 to 30 carbon atoms which may have a substituent, a heterocyclic ring 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.

[0279] Furthermore, the two bonds of formula (B1) may be covalently bonded to the aromatic ring in unit structure A.

[0280] (IIA-2-2-1)

[0281] In the definitions of R and R' in formula (B1), regarding the "aromatic ring" and the "heterocycle", refer to the above-mentioned (I-3) and (I-4).

[0282] In the definitions of R and R' in formula (B1), examples of "alkyl" include methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclobutyl, 1-methyl-cyclopropyl, 2-methyl-cyclopropyl, n-pentyl, 1-methyl-n-butyl, 2-methyl-n-butyl, 3-methyl-n-butyl, 1,1-dimethyl-n-propyl, 1,2-dimethyl-n-propyl, 2,2-dimethyl-n-propyl, 1-ethyl-n-propyl, cyclopentyl, 1-methyl-cyclobutyl, 2 -methyl-cyclobutyl, 3-methyl-cyclobutyl, 1,2-dimethyl-cyclopropyl, 2,3-dimethyl-cyclopropyl, 1-ethyl-cyclopropyl, 2-ethyl-cyclopropyl, n-hexyl, 1-methyl-n-pentyl, 2-methyl-n-pentyl, 3-methyl-n-pentyl, 4-methyl-n-pentyl, 1,1-dimethyl-n-butyl, 1,2-dimethyl-n-butyl, 1,3-dimethyl-n-butyl, 2,2-dimethyl-n-butyl, 2,3-dimethyl-n-butyl, 3,3-dimethyl-n-butyl, 1-ethyl-n-butyl Butyl, 2-ethyl-n-butyl, 1,1,2-trimethyl-n-propyl, 1,2,2-trimethyl-n-propyl, 1-ethyl-1-methyl-n-propyl, 1-ethyl-2-methyl-n-propyl, cyclohexyl, 1-methyl-cyclopentyl, 2-methyl-cyclopentyl, 3-methyl-cyclopentyl, 1-ethyl-cyclobutyl, 2-ethyl-cyclobutyl, 3-ethyl-cyclobutyl, 1,2-dimethyl-cyclobutyl, 1,3-dimethyl-cyclobutyl, 2,2-dimethyl-cyclobutyl, 2,3-dimethyl-cyclobutyl, 2, 4-dimethyl-cyclobutyl, 3,3-dimethyl-cyclobutyl, 1-n-propyl-cyclopropyl, 2-n-propyl-cyclopropyl, 1-isopropyl-cyclopropyl, 2-isopropyl-cyclopropyl, 1,2,2-trimethyl-cyclopropyl, 1,2,3-trimethyl-cyclopropyl, 2,2,3-trimethyl-cyclopropyl, 1-ethyl-2-methyl-cyclopropyl, 2-ethyl-1-methyl-cyclopropyl, 2-ethyl-2-methyl-cyclopropyl, and 2-ethyl-3-methyl-cyclopropyl, n-heptyl, n-octyl, n-nonyl, and n-decyl.

[0283] Preferably, R and R' are each independently phenyl, naphthyl, anthracenyl, phenanthryl, naphthacene or pyrene.

[0284] (IIA-2-2-2)

[0285] In addition, in the unit structure including the structure shown in formula (B1), for example, two or three structures of the above formula (B1) that are identical or different from each other are combined with a divalent or trivalent linking group to form a dimer or trimer structure. In this case, as shown in the following formula (B11) in each structure of the above formula (B1), one of the two bonds is combined with the above linking group.

[0286]

[0287] As such a linking group, for example, a linking group having two or three aromatic rings (corresponding to unit structure A) can be cited. As specific examples of divalent or trivalent linking groups, in addition to the following divalent linking group (L1) exemplified in the above formula (B11), divalent or trivalent linking groups of the following formula (L2) and formula (L3) can also be cited.

[0288]

[0289] [X 1 represents a single bond, a methylene group, an oxygen atom, a sulfur atom, -N(R 5 )-, R 5 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)).]

[0290]

[0291] [X 2 represents a methylene group, an oxygen atom, -N(R 6 )-, R 6 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.]

[0292]

[0293] Another example is a divalent linking group such as the following formula (L4) which can form a covalent bond with the linking carbon atom by an addition reaction of an acetylide and a ketone.

[0294]

[0295] (IIA-2-2-3)

[0296] When at least one of R and R′ in formula (B1) is an aromatic ring, the aromatic ring may be additionally bonded to another unit structure B [for example, see Ar in formula (B12) below].

[0297]

[0298] In this case, when a bond connecting a carbon atom is bonded to a polymer terminal T (hydrogen atom; various functional groups such as a hydroxyl group and an unsaturated aliphatic hydrocarbon group, a terminal unit structure A, a unit structure A in another polymer chain, etc.) as shown in the following formula (C1), a unit structure C equivalent to the composite unit structure AB may be substituted with at least one composite unit structure AB. That is, the above-mentioned aromatic ring [Ar in formula (C1)] in formula (C1) is bonded to another unit structure B, and is bonded to the aromatic ring of the unit structure A through the bond from the remaining bond connecting the carbon atom shown in formula (C1), thereby extending the polymer chain.

[0299]

[0300] (IIA-2-2-4)

[0301] Some specific examples of the unit structure B including the structure represented by formula (B1) are given below. * Basically represents a bonding site with the unit structure A. Of course, the structure may include the exemplified structure in part of the whole.

[0302]

[0303]

[0304] (IIA-2-3)

[0305] *-J 1 -Z 0 -J 2 -* (B2)

[0306] In formula (B2),

[0307] Z 0 It represents an aromatic ring residue or aliphatic ring residue having 6 to 30 carbon atoms which may have a substituent, or an organic group in which two aromatic or aliphatic rings are linked by a single bond. Examples of the organic group in which two aromatic or aliphatic rings are linked by a single bond include divalent residues such as biphenyl, cyclohexylphenyl, and dicyclohexyl.

[0308] J 1 and J 2Each independently represents a divalent organic group which is directly bonded or may have a substituent. The divalent organic group is preferably a linear or branched alkylene group having 1 to 6 carbon atoms which may be substituted with a hydroxyl group, an aryl group (phenyl, substituted phenyl, etc.) or a halogenated group (e.g., fluorine) as a substituent. Examples of the linear alkylene group include methylene, ethylene, propylene, butylene, pentylene, and hexylene.

[0309] (IIA-2-3-1)

[0310] In addition, in the unit structure including the structure represented by formula (B2), similar to the above-mentioned (IIA-2-2-2) regarding formula (B1), it can include a structure in which two or three structures of the above-mentioned formula (B2) that are the same or different from each other are combined with a divalent or trivalent linking group to form a dimer or trimer structure.

[0311] (IIA-2-3-2)

[0312] In addition, since the formula (B2) includes a solution containing an aromatic ring [Z in the formula (B2) 0 ], so as in (IIA-2-2-3) of the above formula (B1), the aromatic ring [for example, Z of the following formula (B21) 0 Ar The aromatic ring in formula (B21)] may be additionally bonded to other unit structures B [the vertical bonding bond in formula (B21)].

[0313]

[0314] [In formula (B21),

[0315] Z 0 Ar is an aromatic ring residue having 6 to 30 carbon atoms which may have a substituent, or an organic group having at least one aromatic ring in which two aromatic rings or aliphatic rings are connected by a single bond, and from Z 0 Ar The bond extending downward from Z 0 Ar The aromatic ring in

[0316] J 1 and J 2 Same as the definition of formula (B2).]

[0317] In this case, when a bond connecting a carbon atom is bonded to a polymer terminal T (hydrogen atom; various functional groups such as a hydroxyl group and an unsaturated aliphatic hydrocarbon group, a terminal unit structure A, a unit structure A in another polymer chain, etc.) as shown in the following formula (C2), a unit structure C equivalent to the composite unit structure AB may be substituted with at least one composite unit structure AB. That is, the aromatic ring in formula (C2) [Z in formula (C2)] 0 Ar The aromatic ring in the formula (C2) is bonded to the other unit structure B and is bonded to the aromatic ring of the unit structure A via the bond from the remaining connecting carbon atoms shown in the formula (C2), thereby extending the polymer chain.

[0318]

[0319] [In formula (C2),

[0320] Z 0 Ar , J 1 and J 2 Same as the definition of formula (B21),

[0321] T represents the polymer terminus.]

[0322] (IIA-2-3-3)

[0323] Some specific examples of the unit structure including the structure represented by formula (B2) are as follows: * represents a bonding site with the unit structure A. It goes without saying that the unit structure may include the exemplified structure in part of the whole.

[0324]

[0325]

[0326] (IIA-2-4) Formula (B3)

[0327]

[0328] In formula (B3),

[0329] Z is a monocyclic ring or a bicyclic, tricyclic or tetracyclic condensed ring which may have a substituent and has 4 to 25 carbon atoms. The number of carbon atoms herein refers to the number of carbon atoms constituting the ring skeleton of the monocyclic ring or the bicyclic, tricyclic or tetracyclic condensed ring excluding the substituent, and does not include the number of heteroatoms constituting the heterocyclic ring when the monocyclic ring or condensed ring is a heterocyclic ring.

[0330] The monocyclic ring is a non-aromatic monocyclic ring; at least one of the monocyclic rings constituting the bicyclic, tricyclic and tetracyclic rings is a non-aromatic monocyclic ring, and the remaining monocyclic rings may be either an aromatic monocyclic ring or a non-aromatic monocyclic ring.

[0331] The above-mentioned monocyclic, bicyclic, tricyclic or tetracyclic condensed ring may further form a condensed ring with one or more aromatic rings to form a pentacyclic or higher condensed ring, and the number of carbon atoms in the pentacyclic or higher condensed ring is preferably 40 or less. The number of carbon atoms here refers to the number of carbon atoms constituting the ring skeleton of the above-mentioned pentacyclic or higher condensed ring excluding substituents, and does not include the number of heteroatoms constituting the heterocycle when the above-mentioned pentacyclic or higher condensed ring is a heterocycle.

[0332] X and Y are the same or different, indicating -CR 31 R 32 -Base, R 31 and R 32 Each of them is the same or different and represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms.

[0333] x and y represent the numbers of X and Y, respectively, and each independently represents 0 or 1.

[0334] *-X x is bonded to any carbon atom (referred to as "carbon atom 1") of the non-aromatic monocyclic ring constituting Z (when x=1) or extends from carbon atom 1 (when x=0),

[0335] Y y -* is bonded to any carbon atom (referred to as "carbon atom 2") of the above-mentioned non-aromatic monocyclic ring constituting 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 in different cases, may belong to the same non-aromatic monocyclic ring or different non-aromatic monocyclic rings.

[0336] In formula (B3), a connecting carbon atom other than carbon atom 1 and carbon atom 2 may be optionally included [see (IIA-2-4-2) described later]

[0337] In addition, when Z is a condensed ring of tricyclic or higher types, the sequential positional relationship of carbon atoms 1 and 2 in formula (B3) in the condensed ring of one or two non-aromatic monocyclic rings to which they belong and the remaining monocyclic rings is arbitrary. When carbon atom 1 and carbon atom 2 belong to different non-aromatic monocyclic rings (referred to as "non-aromatic monocyclic ring 1" and "non-aromatic monocyclic ring 2", respectively), the sequential positional relationship of the non-aromatic monocyclic ring 1 and the non-aromatic monocyclic ring 2 in the condensed ring is also arbitrary.

[0338] (IIA-2-4-1)

[0339] Similar to the above (IIA-2-2-2) regarding formula (B1), two or three structures of the above formula (B3) which are the same or different from each other may be bonded to a divalent or trivalent linking group to form a dimer or trimer structure.

[0340] (IIA-2-4-2)

[0341] Some specific examples of the organic group including the structure represented by formula (B3) are as follows: The bonding site with the unit structure A is not particularly limited. Of course, the structure may include the exemplified structure in part of the whole.

[0342] In addition, examples where the number of bonds (*) exceeds 2 are also included, and the remaining bonds can be used for bonding with aromatic rings in other polymer chains, crosslinking, and the like.

[0343]

[0344]

[0345] (IIA-2-4-3)

[0346] In addition, when Z in formula (B3) contains an aromatic ring, the aromatic ring [for example, see Ar in formula (B32) below] 1 ] can be additionally combined with other unit structures B.

[0347]

[0348] In formula (B32),

[0349] Z 1 represents at least one non-aromatic monocyclic ring, Ar 1 Represents Z 1 The non-aromatic monocyclic ring of the present invention forms at least one aromatic monocyclic ring of the fused ring, as Z and Ar 1 As a whole, it constitutes a bicyclic, tricyclic, tetracyclic or pentacyclic condensed ring which may have a substituent and has a carbon number of 8 to 25. The number of carbon atoms here refers to the number of carbon atoms constituting the ring skeleton of the bicyclic, tricyclic or tetracyclic condensed ring excluding the substituent, and does not include the number of heteroatoms constituting the heterocyclic ring when the bicyclic, tricyclic or tetracyclic condensed ring is a heterocyclic ring.

[0350] The above-mentioned bicyclic, tricyclic, tetracyclic or pentacyclic organic group may further form a condensed ring with one or more aromatic rings to become a hexacyclic or higher ring. The number of carbon atoms in the hexacyclic or higher ring condensed ring is preferably 40 or less. The number of carbon atoms here refers to the number of carbon atoms constituting the ring skeleton of the above-mentioned pentacyclic or higher ring condensed ring excluding substituents, and does not include the number of heteroatoms constituting the heterocyclic ring when the above-mentioned hexacyclic or higher ring condensed ring is a heterocyclic ring.

[0351] In addition, among the cyclic organic groups, Z 1 One or more non-aromatic monocyclic rings and Ar 1 The sequential position relationship of one or more aromatic monocyclic rings of Z includes any. 1 There are two or more non-aromatic monocyclic rings belonging to Ar 1 When there are two or more aromatic monocyclic rings, Z 1 The non-aromatic monocyclic ring and the Ar 1 The aromatic monocyclic rings may be arranged alternately to form a condensed ring.

[0352] In addition, X, Y, x, and y have the same definitions as in formula (B3).

[0353] In this case, when a bond connecting a carbon atom is bonded to a polymer terminal T (hydrogen atom; various functional groups such as a hydroxyl group and an unsaturated aliphatic hydrocarbon group, a terminal unit structure A, a unit structure A in another polymer chain, etc.) as shown in the following formula (C3), a unit structure C equivalent to the composite unit structure AB may be substituted with at least one composite unit structure AB. That is, the aromatic ring in formula (C3) [Ar in formula (C3)] 1 ] is combined with other unit structures B, and is combined with the aromatic ring of unit structure A via a bond from the remaining connecting carbon atoms shown in formula (C3), thereby extending the polymer chain.

[0354]

[0355] [In formula (C3),

[0356] Z 1 ,Ar 1 , X, Y, x and y are the same as defined in formula (B32),

[0357] T represents the polymer terminus.]

[0358] (IIA-2-4-4)

[0359] As a more specific structure of formula (C3), for example, in the following formula (C31), T in formula (C3) is a hydrogen atom serving as a terminal group, and through p, k1 and k2, or p and k2 that can become bonding bonds, a unit structure C equivalent to the composite unit structure AB can be formed.

[0360] In addition, k1 and k2 can also function as a unit structure A.

[0361]

[0362] In addition, in the following formula (C32), an example is shown in which T of formula (C3) is a phenyl group. In this example, among p, k1, k2 and m that can be a bonding bond, p and k1, p and k2, or p and m can form a unit structure C equivalent to the composite unit structure AB.

[0363] In addition, k1 and k2, k1 and m, or k2 and m can also function as the unit structure A.

[0364]

[0365] More specific examples of the unit structure C (one unit structure equivalent to the composite unit structure AB) of the formula (C3) are as follows: * represents a bonding site with the unit structure A.

[0366] In unit structure C, a bond to unit structure B extends from an aromatic ring in these structures, but such a bond is omitted in the following specific examples. It goes without saying that a unit structure including the exemplified structure in part of the whole may be used.

[0367]

[0368] In addition, in the above-mentioned specific examples, when there is no bond derived from an aromatic ring, it can be a specific example of a polymer terminal.

[0369] (IIA-3)

[0370] The phenolic varnish resin having a structure represented by formula (AB) can be prepared by a known method. For example, it can be prepared by condensing a ring-containing compound represented by HAH with an oxygen-containing compound represented by OHC-B, O=CB, HOB-OH, RO-B-OR, RO-CH2-B-CH2-OR, etc. Here, in the formula, A and B have the same meanings as above. R represents a halogen or an alkyl group having about 1 to 3 carbon atoms.

[0371] The ring-containing compound and the oxygen-containing compound may be used alone or in combination of two or more. In the condensation reaction, the oxygen-containing compound may be used in a ratio of 0.1 to 10 mol, preferably 0.1 to 2 mol, based on 1 mol of the ring-containing compound.

[0372] As the catalyst used in the condensation reaction, inorganic 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 can be used. The amount of the catalyst used varies depending on the type of catalyst used, but is generally 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, relative to 100 parts by mass of the ring-containing compound (or the total amount thereof in the case of a plurality of types).

[0373] 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 substrate and does not hinder the reaction. Examples thereof include 1,2-dimethoxyethane, diethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, tetrahydrofuran, diethylene glycol dimethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol dimethyl ether ... The condensation reaction temperature is usually 40 to 200° C., preferably 100 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.

[0374] 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.

[0375] (IIB) Solvent

[0376] The resist underlayer film forming composition which is one embodiment of the present invention contains a solvent.

[0377] The solvent is not particularly limited as long as it can dissolve the specific novolac resin and other optional components added as necessary.

[0378] (IIB-1)

[0379] Examples of the solvent 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 monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, toluene, xylene, methyl ethyl ketone, cyclopentanone, cyclohexanone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxylate, ethyl hydroxylate, methyl 2-hydroxy-3-methylbutyrate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-methoxypropionate, Ethyl 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 monomethyl 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, pentyl formate, isoamyl formate, methyl acetate, ethyl acetate, pentyl 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, ethyl ethoxy The solvents include ethyl 3-methoxypropionate, 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, 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.

[0380] (IIB-2)

[0381] Furthermore, a solvent having a boiling point of 160°C or higher and a solvent having a boiling point of less than 160°C may be contained in combination.

[0382] As such a high boiling point solvent, for example, the following compounds described in International Publication No. 2018 / 131562 (A1) can be preferably used.

[0383]

[0384] [R in formula (i) 1 , R 2 and R 3 Each represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may be interrupted by an oxygen atom, a sulfur atom or an amide bond, and may be the same or different and may be bonded to each other to form a ring structure.]

[0385] Alternatively, 1,6-diacetoxyhexane (boiling point 260° C.), tripropylene glycol monomethyl ether (boiling point 242° C.) described in JP-A-2021-84974, and various high boiling point solvents described in paragraph 0082 of the publication can be preferably used.

[0386] 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 231°C) and dipropylene glycol monomethyl ether (boiling point 231°C) described in Japanese Patent Application Laid-Open No. 2019-20701 can be preferably used. The solvents include 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-butanediol diacetate (boiling point 232°C), and other high boiling point solvents described in paragraphs 0023 to 0031 of the publication.

[0387] (IIC) Acid and / or its salt and / or acid generator

[0388] The resist underlayer film-forming composition which is one embodiment of the present invention may contain an acid and / or a salt thereof and / or an acid generator.

[0389] (IIC-1)

[0390] Examples of the acid include p-toluenesulfonic acid, trifluoromethanesulfonic acid, salicylic acid, 5-sulfosalicylic acid, 4-phenolsulfonic acid, camphorsulfonic acid, 4-chlorobenzenesulfonic acid, benzenedisulfonic acid, 1-naphthalenesulfonic acid, citric acid, benzoic acid, hydroxybenzoic acid, and naphthoic acid.

[0391] As the salt, the salt of the above acid can also be used. The salt is not limited, and ammonia derivative salts such as trimethylamine salt and triethylamine salt, pyridine derivative salt, morpholine derivative salt, etc. can be preferably used.

[0392] The acid and / or its salt may be used alone or in combination of two or more thereof. The amount thereof is usually 0.0001 to 20% by mass, preferably 0.0005 to 10% by mass, and more preferably 0.01 to 5% by mass, based on the total solid content.

[0393] (IIC-2)

[0394] Examples of the acid generator include a thermal acid generator and a photoacid generator.

[0395] (IIC-2-1)

[0396] Examples of the thermal acid generator include 2,4,4,6-tetrabromocyclohexadienone, benzoin toluenesulfonate, 2-nitrobenzyl toluenesulfonate, K-PURE [registered trademark] CXC-1612, K-PURE CXC-1614, K-PURE TAG-2172, K-PURE TAG-2179, K-PURE TAG-2678, K-PURE TAG2689, K-PURE TAG2700 (manufactured by King Industries), and SI-45, SI-60, SI-80, SI-100, SI-110, SI-150 (manufactured by Sanshin Chemical Industry Co., Ltd.), and other organic sulfonic acid alkyl esters.

[0397] (IIC-2-2)

[0398] The photoacid generator generates acid when the resist is exposed. Therefore, the acidity of the lower film can be adjusted. This is a method for making the acidity of the lower film consistent with the acidity of the upper resist. In addition, by adjusting the acidity of the lower film, the pattern shape of the resist formed on the upper layer can be adjusted.

[0399] Examples of the photoacid generator contained in the resist underlayer film-forming composition of the present invention include: Salt compounds, sulfonimide compounds, and disulfonyldiazomethane compounds, etc.

[0400] As Salt compounds, such as diphenyl iodide Hexafluorophosphate, diphenyl iodide Trifluoromethanesulfonate, diphenyl iodide Nonafluorobutane sulfonate, diphenyl iodide Perfluorooctane sulfonate, diphenyl iodide Camphorsulfonate, bis(4-tert-butylphenyl)iodide Camphorsulfonate and bis(4-tert-butylphenyl)iodide Trifluoromethanesulfonate and other iodine Sulfonium salt compounds, and sulfonium salt compounds such as triphenylsulfonium hexafluoroantimonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium camphorsulfonate and triphenylsulfonium trifluoromethanesulfonate.

[0401] Examples of the sulfonyl imide compound include N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoro-n-butanesulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, and N-(trifluoromethanesulfonyloxy)naphthalimide.

[0402] Examples of the disulfonyldiazomethane compound include bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(2,4-dimethylbenzenesulfonyl)diazomethane, and methylsulfonyl-p-toluenesulfonyldiazomethane.

[0403] (IIC-2-3)

[0404] The acid generator may be used alone or in combination of two or more.

[0405] When the acid generator is used, the ratio thereof is 0.01 to 10 parts by mass, or 0.1 to 8 parts by mass, or 0.5 to 5 parts by mass based on 100 parts by mass of the solid content of the resist underlayer film-forming composition.

[0406] (IID) Any other ingredients

[0407] The resist underlayer film-forming composition as one embodiment of the present invention may contain a crosslinking agent, a surfactant, a light absorber, a rheology regulator, an adhesion promoter, and the like in addition to the above-mentioned agents as necessary.

[0408] (IID-1) Cross-linking agent

[0409] As representative crosslinking agents, aminoplast crosslinking agents and phenoplast crosslinking agents can be exemplified.

[0410] As the crosslinking agent, a crosslinking agent with high heat resistance can be used. As the crosslinking agent with high heat resistance, a compound containing a crosslinking-forming substituent having an aromatic ring (for example, a benzene ring or a naphthalene ring) in the molecule can be preferably used.

[0411] (IID-1-1)

[0412] As aminoplast crosslinking agents, there can be mentioned highly alkylated, alkoxylated, or alkoxyalkylated melamine, benzoguanamine, glycoluril, urea, polymers thereof, etc. Preferred crosslinking agents have at least two crosslinking-forming substituents, such as methoxymethylated glycoluril, butoxymethylated glycoluril, methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguanamine, butoxymethylated benzoguanamine, methoxymethylated urea, butoxymethylated urea, methoxymethylated thiourea, or methoxymethylated thiourea. In addition, condensates of these compounds can also be used.

[0413] It is preferably at least one selected from tetramethoxymethyl glycoluril and hexamethoxymethylmelamine.

[0414] Some specific examples are as follows.

[0415]

[0416] (IID-1-2)

[0417] Examples of the phenolic plastic crosslinking agent include highly alkylated, alkoxylated, or alkoxyalkylated aromatics, and polymers thereof. Preferred crosslinking agents are those having at least two crosslinking substituents in one 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 may also be used.

[0418] Examples of such a compound include, in addition to the above, a compound having a partial structure of the following formula (4) and a polymer or oligomer having a repeating unit of the following formula (5).

[0419]

[0420] The above R 11 , R 12 , R 13 , and R 14It is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and the alkyl groups exemplified above can be used. n1 is an integer of 1 to 4, n2 is an integer of 1 to (5-n1), and (n1+n2) represents an integer of 2 to 5. n3 is an integer of 1 to 4, n4 is 0 to (4-n3), and (n3+n4) represents an integer of 1 to 4. The oligomer and polymer can be used in the range of 2 to 100 or 2 to 50 repeating unit structures.

[0421] Some specific examples are as follows.

[0422]

[0423] (IID-1-3)

[0424] Aminoplast crosslinking agents, phenoplast crosslinking agents and other crosslinking agents may be used alone or in combination of two or more. Aminoplast crosslinking agents may be produced by a known method or a method in accordance therewith, or commercially available products may be used.

[0425] The amount of crosslinking agents such as aminoplast crosslinking agents and phenolic plastic crosslinking agents 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 solid content of the resist underlayer film forming composition according to the present invention.

[0426] (IID-2) Surfactant

[0427] The resist underlayer film-forming composition according to the present invention may contain a surfactant in order to prevent pinholes, streaks, and the like from being generated and to further improve coating properties on uneven surfaces.

[0428] Examples of the surfactant 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 octylphenol ether and polyoxyethylene nonylphenol 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 trioleate, and polyoxyethylene sorbitan tristearate; Sugar alcohol tristearate and other polyoxyethylene sorbitan fatty acid esters, etc.; non-ionic surfactants, Ekotopo EF301, EF303, EF352 (Toko Co., Ltd. Made by プロダクツ, trade name), メガファック F171, F173, R-30, R-40 (made by Dainippon Co., Ltd., trade name), フロラード FC430, Fluorine-based surfactants such as FC431 (trade name, manufactured by Sumitomo Slide Group Co., Ltd.), Asahigard 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.).

[0429] The amount of these surfactants blended is usually 2.0% by mass or less, preferably 1.0% by mass or less, based on the total solid content of the resist underlayer film forming composition according to the present invention. These surfactants may be added alone or in combination of two or more.

[0430] (IID-3) Other additives

[0431] As the light absorber, for example, commercially available light absorbers described in "Industrial Colorant Technology and Market" (published by CMC) and "Dye Handbook" (edited by the Society of Synthetic Organic Chemistry) can be suitably used, for example, CI 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; CI Disperse Orange 1, 5, 13, 25, 29, 30, 31, 44, 57, 72 and 73; CI Disperse Red 1, 5, 7, 13, 17, 19, 43, 50, 54, 58, 65, 72, 73, 88, 117, 137, 143, 199 and 210; CI Disperse Violet 43; CI Disperse Blue 96; CI Fluorescent Brightener 112, 135 and 163; CI Solvent Orange 2 and 45; CI Solvent Red 1, 3, 8, 23, 24, 25, 27 and 49; CI Pigment Green 10; CI Pigment Brown 2, etc. The light absorber is usually blended in a ratio of 10% by mass or less, preferably 5% by mass or less, based on the total solid content of the resist underlayer film-forming composition according to the present invention.

[0432] The rheology modifier is mainly added to improve the fluidity of the resist underlayer film-forming composition, especially in the baking process, to improve the film thickness uniformity of the resist underlayer film and to improve the filling property of the resist underlayer film-forming composition into the inside of the hole. As specific examples, phthalic acid derivatives such as dimethyl phthalate, diethyl phthalate, diisobutyl phthalate, dihexyl phthalate, butyl isodecyl phthalate, adipic acid derivatives such as di-n-butyl adipate, diisobutyl adipate, diisooctyl adipate, octyldecyl adipate, maleic acid derivatives such as di(n-butyl) maleate, diethyl maleate, dinonyl maleate, oleic acid derivatives such as methyl oleate, butyl oleate, tetrahydrofurfuryl oleate, or stearic acid derivatives such as n-butyl stearate and glyceryl stearate can be cited. These rheology control agents are usually blended in a ratio of less than 30 mass % based on the total solid content of the resist underlayer film-forming composition according to the present invention.

[0433] The adhesion aid is mainly added for the purpose of improving the adhesion between the substrate or the resist and the resist underlayer film-forming composition, and particularly for the purpose of preventing 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; silanes such as vinyltrichlorosilane, γ-chloropropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and γ-glycidoxypropyltrimethoxysilane; benzotriazole, benzimidazole, indazole, imidazole, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, and 2-mercaptobenzothiazole. Heterocyclic compounds such as azole, urea, thiouracil, mercaptoimidazole, and mercaptopyrimidine, ureas such as 1,1-dimethylurea and 1,3-dimethylurea, or thiourea compounds. These adhesion promoters are usually mixed in a ratio of less than 5% by mass, preferably less than 2% by mass, relative to the total solid content of the resist underlayer film forming composition of the present invention.

[0434] The solid content of the resist underlayer film forming composition of the present invention is 0.1 to 70% by mass, or 0.1 to 60% by mass. The solid content is the content ratio of all components excluding the solvent from the resist underlayer film forming composition. The crosslinkable resin may be contained in the solid content at a ratio 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.

[0435] [III: Resist underlayer film]

[0436] The resist underlayer film can be formed, for example, as follows using the resist underlayer film-forming composition according to the present invention.

[0437] On a substrate used in the manufacture of semiconductor devices (for example, a silicon wafer substrate, a silicon dioxide-coated substrate (SiO2 substrate), a silicon nitride substrate (SiN substrate), a silicon oxide nitride substrate (SiON substrate), a titanium nitride substrate (TiN substrate), a tungsten substrate (W substrate), a glass substrate, an ITO substrate, a polyimide substrate, and a low dielectric constant material (low-k material) coated substrate, etc.), a resist underlayer film forming composition as one embodiment of the present invention is applied by an appropriate coating method such as a spin coater or a coater, and then fired using a heating means such as a hot plate to form a resist underlayer film. As conditions for firing, a firing temperature of 80°C to 800°C and a firing time of 0.3 to 60 minutes are appropriately selected. Preferably, the firing temperature is 150°C to 400°C and the firing time is 0.5 to 2 minutes. As an atmospheric gas during firing, air can be used, or an inert gas such as nitrogen or argon can be used. In one embodiment, it is particularly preferred that the oxygen concentration is 1% or less. Here, the thickness of the formed lower layer film is, for example, 10 to 1000 nm, 20 to 500 nm, 30 to 400 nm, or 50 to 300 nm. In addition, if a quartz substrate is used as the substrate, a replica of the quartz imprint mold (mold replica) can be produced.

[0438] In addition, it is also possible to form a close-fitting layer and / or a silicon-containing layer comprising less than 99% by mass or less than 50% by mass of Si by coating or vapor deposition on the resist underlayer film as one scheme of the present invention. For example, except for the close-fitting layer recorded in Japanese Unexamined Patent Publication No. 2013-202982, Japanese Patent No. 5827180, and the resist underlayer film (inorganic resist underlayer film) containing silicon recorded in International Publication No. 2009 / 104552 (A1) forming composition by spin coating, it is also possible to form an inorganic material film of Si system by CVD method etc.

[0439] In addition, by coating a composition for forming an anti-etching agent underlayer film as one embodiment of the present invention on a semiconductor substrate having a portion with a height difference and a portion without a height difference (a so-called height difference substrate) and firing the substrate, the height difference between the portion with a height difference and the portion without a height difference can be reduced.

[0440] [IV: Method for manufacturing semiconductor device]

[0441] (IVA)

[0442] (i)

[0443] A method for manufacturing a semiconductor device as one embodiment of the present invention includes the following steps:

[0444] A step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film-forming composition as one embodiment of the present invention;

[0445] a step of forming a resist film on the resist underlayer film;

[0446] A process of forming a resist pattern on a resist film by irradiating the resist film with light or electron beams and developing the resist film;

[0447] A step of etching the resist underlayer film through the resist pattern to perform patterning; and

[0448] A step of processing a semiconductor substrate through the patterned resist underlayer film.

[0449] (ii)

[0450] In addition, a method for manufacturing a semiconductor device as one embodiment of the present invention includes the following steps:

[0451] A step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film-forming composition as one embodiment of the present invention;

[0452] A step of forming a hard mask on the resist underlayer film;

[0453] A step of further forming a resist film on the hard mask;

[0454] A process of forming a resist pattern on a resist film by irradiating the resist film with light or electron beams and developing the resist film;

[0455] A process of etching the hard mask through the resist pattern to perform patterning;

[0456] A step of etching the resist underlayer film through the patterned hard mask to perform patterning; and

[0457] A step of processing a semiconductor substrate via a patterned resist underlayer film.

[0458] (iii)

[0459] In addition, a method for manufacturing a semiconductor device as one embodiment of the present invention includes the following steps:

[0460] A step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film-forming composition as one embodiment of the present invention;

[0461] A step of forming a hard mask on the resist underlayer film;

[0462] A step of further forming a resist film on the hard mask;

[0463] A process of forming a resist pattern on a resist film by irradiating the resist film with light or electron beams and developing the resist film;

[0464] A process of etching the hard mask through the resist pattern to perform patterning;

[0465] A step of etching the resist underlayer film through the patterned hard mask to perform patterning;

[0466] A process of removing the hard mask; and

[0467] A step of processing a semiconductor substrate via a patterned resist underlayer film.

[0468] (iv)

[0469] In addition, a method for manufacturing a semiconductor device as one embodiment of the present invention includes the following steps:

[0470] A step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film-forming composition as one embodiment of the present invention;

[0471] A step of forming a hard mask on the resist underlayer film;

[0472] A step of further forming a resist film on the hard mask;

[0473] A process of forming a resist pattern on a resist film by irradiating the resist film with light or electron beams and developing the resist film;

[0474] A process of etching the hard mask through the resist pattern to perform patterning;

[0475] A step of etching the resist underlayer film through the etched hard mask to perform patterning;

[0476] A process of removing the hard mask;

[0477] A step of forming a vapor-deposited film (spacer) on the resist underlayer film after the hard mask is removed;

[0478] A process of processing the vapor-deposited film (spacer) by etching;

[0479] A step of removing the patterned resist underlayer film to leave the patterned vapor-deposited film (spacer); and

[0480] A step of processing a semiconductor substrate via a patterned vapor-deposited film (spacer).

[0481] The semiconductor substrate can be processed using the manufacturing methods (i) to (iv) above.

[0482] (IVB)

[0483] The step of forming a resist underlayer film using the resist underlayer film-forming composition which is one embodiment of the present invention is as described in the above-mentioned [III: Resist underlayer film].

[0484] On the resist underlayer film formed by the above steps, a hard mask such as a silicon-containing film may be formed as a second resist underlayer film, and a resist pattern [the above (IVA) (ii) to (iv)] may be formed thereon.

[0485] The hard mask may be a coating film of an inorganic substance or the like, or a vapor-deposited film of an inorganic substance or the like formed by a vapor deposition method such as CVD or PVD, and examples thereof include a SiON film, a SiN film, or a SiO 2 film.

[0486] An anti-reflection film (BARC) may be further formed on the hard mask, or a resist shape correction film having no anti-reflection capability may be formed.

[0487] In the above-mentioned process of forming the resist pattern, exposure is carried out by a mask (reticle) for forming a specified pattern or by direct depiction. In the exposure source, for example, g-rays, i-rays, KrF excimer lasers, ArF excimer lasers, EUV, electron beams can be used. After exposure, post-exposure heating (Post Exposure Bake) is performed as required. Then, development is performed by a developer (for example, 2.38% by mass tetramethylammonium hydroxide aqueous solution, butyl acetate), and further rinsed with a rinse solution or pure water, and the developer used is removed. Then, post-baking is performed for the drying of the resist pattern and the adhesion with substrate to improve.

[0488] The etching step performed after the resist pattern is formed is performed by dry etching.

[0489] In addition, the following gases, namely CF4, CHF3, CH2F2, CH3F, C4F6, C4F8, O2, N2O, NO2, H2, and He, can be used in the processing of the hard mask (silicon-containing layer) / resist lower film / substrate. These gases can be used alone or in combination of two or more gases. Furthermore, argon, nitrogen, carbon dioxide, carbonyl sulfide, sulfur dioxide, neon, or nitrogen trifluoride can be mixed with these gases.

[0490] (IVC)

[0491] The resist film can be patterned by a nanoimprint method or a self-assembled film method.

[0492] In the nanoimprint method, the resist composition is molded using a mold (mold) that is transparent and patterned relative to the irradiated light. In addition, in the self-assembled film method, a self-assembled film that naturally forms a nanoscale regular structure using a diblock polymer (polystyrene-polymethyl methacrylate, etc.) is patterned.

[0493] In the nanoimprint method, before applying the curable composition that becomes the resist film, a silicon-containing layer (hard mask layer) can be arbitrarily formed on the resist underlayer film by coating or vapor deposition, and further a bonding layer can be formed on the resist underlayer film or on the silicon-containing layer (hard mask layer) by coating or vapor deposition, and the curable composition that becomes the resist film is applied on the bonding layer.

[0494] (IVD)

[0495] In addition, wet etching is sometimes performed for the purpose of simplifying the process steps and reducing damage to the processed substrate. This can suppress the change in processing dimensions, reduce pattern roughness, and process the substrate with a good yield. Therefore, in the above (IVA)(iii) to (iv), the hard mask can also be removed by etching or alkaline liquid. In particular, when using an alkaline liquid, there is no limitation on the components, and the following are preferably included as alkaline components.

[0496] 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, (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-piperidinol, cyclohexylamine, 1,5-diazabicyclo[4,3,0]nonene-5, etc. In addition, in particular, tetramethylammonium hydroxide and tetraethylammonium hydroxide are particularly preferred from the viewpoint of operation, and an inorganic base can be used in combination with a quaternary ammonium hydroxide. As the inorganic base, an alkali metal hydroxide such as potassium hydroxide, sodium hydroxide, and rubidium hydroxide is preferred, and potassium hydroxide is more preferred.

[0497] Example

[0498] (1) Synthesis of polymers

[0499] The synthesis of polymers of structural formulas (S1) to (S23) and (S'1) to (S'23) used as resist underlayer films and the synthesis of structural formulas (SS1) to (SS2) used as comparative examples used compound group A, compound group B, compound group C, catalyst group D, solvent group E, and reprecipitation solvent group F shown below.

[0500] (1-1) Compound Groups A to C

[0501]

[0502] (1-2) Catalyst group D, solvent group E, reprecipitation solvent group F, separation solvent group G

[0503] Methanesulfonic acid: D1

[0504] Mercaptopropionic acid: D2

[0505] Tetrabutylammonium iodide: D3

[0506] Propylene glycol monomethyl ether acetate (=PGMEA): E1

[0507] N-Methylpyrrolidone (=NMP): E2

[0508] Propylene glycol monomethyl ether (=PGME): E3

[0509] Tetrahydrofuran (=THF): E4

[0510] 25% sodium hydroxide aqueous solution: E5

[0511] Methanol: F1

[0512] Methanol / ammonia: F2

[0513] Methanol / water: F3

[0514] Butyl acetate / water: G1

[0515] [Synthesis example 1]

[0516] A1 17.6g, C1 8.0g, D1 2.1g, D2 1.4g, E2 19.4g, E1 45.3g were added to the flask. Then, it was heated to reflux under nitrogen and reacted for about 16 hours. After the reaction stopped, it was reprecipitated with methanol and the resin was dried to obtain (S1). The weight average molecular weight Mw measured by GPC in terms of polystyrene was about 2,000. The obtained resin was dissolved in PGMEA, and ion exchange was performed for 4 hours using a cation exchange resin and an anion exchange resin to obtain a target compound solution.

[0517]

[0518] [Synthesis Examples 2 to 23]

[0519] By the same operation as in Synthesis Example 1, resins S2 to S23 were synthesized under the conditions shown in Synthesis Examples 2 to 23 in Table 1 below.

[0520] Table 1

[0521]

[0522]

[0523] [Synthesis Example 24]

[0524] S1 10.0g, C11 6.4g, D3 0.3g, E4 25.1g, E5 7.5g were added to the flask. It was heated to 55°C under nitrogen and reacted for about 24 hours. After the reaction stopped, the liquid separation operation was repeated with butyl acetate and water, the organic layer was concentrated, methanol was used to reprecipitate it, and it was dried to obtain a resin (S'1). The weight average molecular weight Mw measured by GPC in terms of polystyrene was about 3,560. The obtained resin was dissolved in PGMEA, and ion exchange was performed for 4 hours using a cation exchange resin and an anion exchange resin to obtain the target compound solution.

[0525]

[0526] [Synthesis Examples 25 to 46]

[0527] By the same operation as in Synthesis Example 24, resins S'2 to S'23 were synthesized under the conditions shown in Synthesis Examples 25 to 46 in Table 2 below.

[0528] Table 2

[0529]

[0530]

[0531] [Comparative Synthesis Examples 1 to 2]

[0532] By the same operation as in Synthesis Example 1, comparative resins SS1 and SS2 were synthesized under the conditions shown in Comparative Synthesis Examples 1 and 2 in Table 3 below.

[0533] Table 3

[0534]

[0535]

[0536] (2) Preparation of resist underlayer film

[0537] Polymers (S1) to (S23) and (S'1) to (S'23), crosslinking agents (CL1 to CL2), acid generators (Ad1 to Ad2), solvents [propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), cyclohexanone (CYH)], and Megaphak R-40 (manufactured by DIC Corporation, G1) as a surfactant were mixed in the weight proportions shown in the following Tables 4-1 to 4-4 (the weight proportions of the crosslinking agent, acid generator and surfactant are shown when the weight of the polymer is taken as 100; for the solvent, the weight proportions of each solvent are shown when the weight of all solvents is taken as 100), and filtered using a 0.1 μm polytetrafluoroethylene microfilter to prepare resist underlayer film materials (M1 to M48, comparison M1 to comparison M3).

[0538]

[0539] Table 4-1

[0540]

[0541] Table 4-2

[0542]

[0543] Table 4-3

[0544]

[0545] Table 4-4

[0546]

[0547] (3) Dissolution test of resist solvent

[0548] The resist underlayer film materials of comparison M1-3 and M1-48 were coated on a silicon wafer using a spin coater, and fired at the specified temperature / prescribed time described in Table 5 in the atmosphere to form a resist underlayer film with a film thickness of about 130 nm. The formed resist underlayer film was immersed in PGME / PGMEA=7 / 3 as a general diluent for 60 seconds to confirm the resistance to the solvent. The case where the reduction rate of the film thickness before and after the diluent immersion was 1% or less was judged as 0 (Tables 5-1 to 5-2).

[0549] In addition, the above-mentioned lower film material was coated on a silicon wafer using ACT-8 manufactured by Tokyo Elektronik Co., Ltd., and sintered under nitrogen at the specified temperature / prescribed time described in the table to form a 130nm resist lower film. As described above, it was immersed in PGME / PGMEA=7 / 3 for 60 seconds to confirm the resistance to solvents. The reduction rate of the film thickness before and after diluent immersion was less than that of the comparative example, which was judged as 0 (Tables 5-1 to 5-2).

[0550] In Table 5-2, the parentheses indicate the reduction rate of the film thickness.

[0551] Table 5-1

[0552]

[0553] Table 5-2

[0554] Embodiment 32 M32 400℃ / 60sec ○ 400℃ / 60sec ○ Embodiment 33 M33 400℃ / 60sec ○ 400℃ / 60sec ○ Embodiment 34 M34 400℃ / 60sec ○ 400℃ / 60sec ○ Embodiment 35 M35 400℃ / 60sec ○ 400℃ / 60sec ○ Embodiment 36 M36 400℃ / 60sec ○ 400℃ / 60sec ○ Embodiment 37 M37 400℃ / 60sec ○ 400℃ / 60sec ○ Embodiment 38 M38 400℃ / 60sec ○ 400℃ / 60sec ○ Embodiment 39 M39 400℃ / 60sec 2 400℃ / 60sec 2 Embodiment 40 M40 400℃ / 60sec ○ 400℃ / 60sec ○ Embodiment 41 M41 400℃ / 60sec ○ 400℃ / 60sec ○ Embodiment 42 M42 400℃ / 60sec ○ 400℃ / 60sec ○ Embodiment 43 M43 400℃ / 60sec ○ 400℃ / 60sec ○ Embodiment 44 M44 400℃ / 60sec ○ 400℃ / 60sec ○ Embodiment 45 M45 400℃ / 60sec ○ 400℃ / 60sec ○ Embodiment 46 M46 400℃ / 60sec ○ 400℃ / 60sec ○ Embodiment 47 M47 400℃ / 60sec ○ 400℃ / 60sec ○ Embodiment 48 M48 400℃ / 60sec ○ 400℃ / 60sec ○ Comparative Example 1 Compare M1 400℃ / 60sec ○(<1％) 400℃ / 60sec ×(100％) Comparative Example 2 Compare M2 400℃ / 60sec ×(45％) 400℃ / 60sec ×(100％) Comparative Example 3 Compare M3 400℃ / 60sec ○(<1％) 400℃ / 60sec ○(<1％)

[0555] It can be seen that the conventional resist underlayer film does not exhibit solvent resistance under the firing condition in a nitrogen atmosphere when a crosslinking agent and a curing catalyst are not included (Comparative Examples 1 to 2). On the other hand, the resist underlayer film (Examples 24 to 46) in which a propargyl group is introduced into the bis(azaaromatic fused ring) structure has self-crosslinking properties, so even if a crosslinking agent and a curing catalyst are not included, solvent resistance can be obtained not only under an air atmosphere but also under the firing condition in a nitrogen atmosphere. Of course, by including a crosslinking agent and a curing catalyst, it can be cured in any atmosphere like a conventional resist underlayer film (Comparative Example 3) (Examples 47 to 48). In addition, the resist underlayer film (Examples 1 to 23) using a polymer without a propargyl group introduced can also be cured in any atmosphere like a conventional resist underlayer film (Comparative Example 3) by using a crosslinking agent and a curing catalyst. In addition, Comparative Example M2 could not be used as a resist underlayer film because solvent resistance was not obtained under the firing conditions in the atmosphere, which are general firing conditions. Therefore, the comparative example M2 was excluded from the subsequent evaluations.

[0556] (4) Determination of etching rate

[0557] The resist underlayer film materials of comparison M1, comparison M3, and M1 to 48 were coated on silicon wafers using a spin coater. The resist underlayer films were fired at the specified temperature / prescribed time listed in the table on a hot plate to form a 130nm resist underlayer film. The dry etching rate was measured using O2 / N2 gas or CF4 gas as etching gas.

[0558] In addition, the numerical value recorded with () in the etching resistance data in Tables 6-1 to 6-2 is the dry etching rate ratio of (resist underlayer film) / (phenol novolac resin film). The case where the etching rate is slow relative to any of Comparative Examples 1 and 3 (Comparative M1 and Comparative M3) is judged as 0 (Tables 6-1 to 6-2).

[0559] In addition, the etcher and etching gas used for the etching measurement were as follows.

[0560] RIE-200NL (manufactured by SAMU): CF4 50sccm

[0561] RIE-200NL (manufactured by SAMU): O2 / N2 10sccm / 200sccm

[0562] (5) Determination of optical constants

[0563] The resist underlayer film materials of comparison M1, comparison M3, and M1 to 48 were coated on silicon wafers using a spin coater. The resist underlayer films (film thickness 50 nm) were formed by firing at the specified temperature / specified time described in the table on a hot plate. The refractive index (n value) and optical absorption coefficient (also called k value, attenuation coefficient) of these resist underlayer films at a wavelength of 193 nm were measured using a spectroscopic ellipsometer (Tables 6-1 to 6-2).

[0564] (6) Evaluation of coating properties

[0565] For the resist underlayer film materials of Comparison M1 and Comparison M3, M1 to 48, the resist underlayer film materials were coated on a silicon wafer using a 12-inch coater manufactured by Tokyo Electron Co., Ltd., and fired at the specified temperature / specified time described in the table in the atmosphere to form a 130nm resist underlayer film. Then, the film thickness of the entire wafer was measured at 49 points on the circumference to evaluate the uniformity of the film thickness within the wafer surface. The case where the ratio of the film thickness swing (maximum film thickness-minimum film thickness) relative to the average film thickness is less than that of any of Comparison Examples 1 and 3 (Comparison M1 and Comparison M3) is judged to be 0. In addition, the so-called small ratio of the film thickness swing means that the uniformity of the film thickness within the wafer surface is higher (Tables 6-1 to 6-2).

[0566] In addition, the numerical values ​​indicated by () in the film thickness uniformity results in Tables 6-1 to 6-2 represent the ratio of the fluctuation range of the film thickness (maximum film thickness - minimum film thickness) to the above-mentioned average film thickness.

[0567] Table 6-1

[0568]

[0569] Table 6-2

[0570]

[0571] (7) Determination of the amount of sublimates

[0572] The amount of sublimates was measured using a sublimate amount measuring device described in International Publication No. 2007 / 111147. The resist underlayer film-forming composition prepared in Comparative M1, Comparative M3, and M1 to 48 was fired at 400°C for 60 seconds to prepare a film thickness of 130 nm. The composition was applied to a silicon wafer, and the amount of sublimates when fired at 300°C was measured. When the amount of sublimates was less than that of any of Comparative Examples 1 and 3 (Comparative M1 and Comparative M3), it was judged as ○ (Tables 7-1 to 7-2).

[0573] In addition, the number in () indicates the amount of sublimates actually observed.

[0574] Table 7-1

[0575]

[0576] Table 7-2

[0577] Embodiment 32 M32 300℃ / 60sec ○ Embodiment 33 M33 300℃ / 60sec ○ Embodiment 34 M34 300℃ / 60sec ○ Embodiment 35 M35 300℃ / 60sec ○ Embodiment 36 M36 300℃ / 60sec ○ Embodiment 37 M37 300℃ / 60sec ○ Embodiment 38 M38 300℃ / 60sec ○ Embodiment 39 M39 300℃ / 60sec ○ Embodiment 40 M40 300℃ / 60sec ○ Embodiment 41 M41 300℃ / 60sec ○ Embodiment 42 M42 300℃ / 60sec ○ Embodiment 43 M43 300℃ / 60sec ○ Embodiment 44 M44 300℃ / 60sec ○ Embodiment 45 M45 300℃ / 60sec ○ Embodiment 46 M46 300℃ / 60sec ○ Embodiment 47 M47 300℃ / 60sec ○ Embodiment 48 M48 300℃ / 60sec ○ Comparative Example 1 Compare M1 300℃ / 60sec ×(3500ng) Comparative Example 3 Compare M3 300℃ / 60sec ×(3100ng)

[0578] (8) Coating / covering test on uneven substrates 1

[0579] As a coating test for a high-low substrate, a SiO2 substrate, a SiN substrate, and a TiN substrate with a film thickness of 200nm were used. In the case of a high-low substrate, the coating property of the resist lower layer film is sometimes deteriorated compared to a silicon wafer without a high-low. Therefore, a test was conducted to determine whether it can be coated unevenly on a high-low substrate. By visual confirmation, the case where it can be coated unevenly was judged as ○. In the groove area (dense pattern area) with a groove width of 50nm and a spacing of 100nm in the above-mentioned substrate, an evaluation of flattening was implemented. A comparison of the coating film thickness of the dense area and the area (open area) where no pattern is formed was performed. After the resist lower layer film forming composition prepared in comparisons M1 and M1 to 48 was applied to the above-mentioned substrate, it was sintered at the specified temperature / specified time described in Table 8 on a hot plate to form a 130nm resist lower layer film. The flattening property of the substrate was observed using a scanning electron microscope (S-4800) manufactured by Hitachi HiTech Nologis Co., Ltd., and the film thickness difference between the groove area (pattern part) and the open area (no pattern part) of the height difference substrate was measured (the coating height difference between the groove area and the open area is called deviation) to evaluate the flattening property. Here, the so-called flattening property means that the film thickness difference (Iso-dense bias) of the coated coating existing on the part where the pattern exists (groove area (pattern part)) and the part where the pattern does not exist (open area (no pattern part)) is small. The case where the deviation is improved relative to Comparative Example 1 (Comparative M1) is judged as ○ (Tables 8-1 to 8-2).

[0580] Table 8-1

[0581]

[0582] Table 8-2

[0583]

[0584] (9) Coating and Covering Test on High-Level Substrates 2

[0585] As a coating test for a high-low substrate, a SiO2 substrate, a SiN substrate, and a TiN substrate with a film thickness of 200nm were used. In the case of a high-low substrate, the coating property of the resist lower layer film is sometimes worse than that of a silicon wafer without a high-low difference. Therefore, a test was conducted to determine whether it can be coated unevenly on a high-low substrate. By visual confirmation, the case where it can be coated unevenly was judged as 0. In the wide groove area with a groove width of 800nm ​​present in the above-mentioned substrate, a flattening evaluation was implemented. A comparison of the coating film thickness of the wide groove area and the area (open area) where no pattern is formed was performed. After the resist lower layer film forming composition prepared in comparisons M3 and M1 to 48 was applied to the above-mentioned substrate, it was sintered on a hot plate at the specified temperature / specified time recorded in the table to form a 130nm resist lower layer film. The evaluation method was carried out in the same manner as in "Coating Property / Coating Property Test 1 for High-Low-Different Substrates" (Tables 9-1 to 9-2). The case where the result was good compared with Comparative Example 3 (Comparative M3) was judged as ○ (Tables 9-1 to 9-2).

[0586] Table 9-1

[0587]

[0588] Table 9-2

[0589]

[0590] (10) Embedment test on high-height substrate

[0591] As a coating test for a high-low substrate, a SiO2 substrate, a SiN substrate, and a TiN substrate with a film thickness of 200nm were used. In the groove area (dense pattern area) with a groove width of 50nm and a spacing of 100nm in the above-mentioned substrate, the embedding property was evaluated. After the resist lower film forming composition prepared in M5, M28-36, M38-40 and comparison M3 was applied to the above-mentioned substrate, the prescribed temperature / prescribed time recorded in the table was fired on a hot plate to form a 130nm resist lower film. The embedding property of the substrate was observed using a scanning electron microscope (S-4800) manufactured by Hitachi High Tech Nologics. The situation where the resist lower film can be filled to the bottom of the groove is judged to be embedding property 0 (Table 10).

[0592] Table 10

[0593]

[0594] As described above, the novolac resin using the bis(azaaromatic fused ring) compound has high heat resistance, so the amount of sublimates during firing is small, which can suppress equipment contamination and can be said to be a material with a small process load. In addition, not only is the film thickness in-plane uniformity very high when coating a silicon wafer without height difference, but it also shows good coating properties on height difference substrates with various vapor-deposited films.

[0595] With higher etching resistance, good planarization, good embedding, by making the monomer change during synthesis, it can be adjusted to the optical constant that can suppress the reflection during exposure according to the device. It is also possible to introduce a self-crosslinking group such as propargyl in the bis (nitrogen heteroaryl condensed ring) compound, so that it is possible to use it as a resist lower film under atmospheric atmosphere and nitrogen atmosphere without the need for a crosslinking agent and a curing catalyst, and therefore it is a material that can be applied in a wide range of processes compared with the past. Of course, it will not damage the characteristics of the above-mentioned bis (nitrogen heteroaryl condensed ring) by introducing a propargyl. Therefore, for a variety of semiconductor manufacturing processes, it is expected to become a material that can be widely used.

Claims

1. A resist underlayer film-forming composition comprising a novolac resin and a solvent, The novolac resin includes a unit structure A having an aromatic ring, wherein the unit structure A includes one or more bis(nitrogen heteroaryl condensed ring) structural units represented by the following formula (A), which are structural units in which two nitrogen heteroaryl condensed rings are connected via a linker L. In the formula (A), L represents a divalent linking group other than a single bond between any two carbon atoms constituting each nitrogen heteroaryl condensed ring, R 11 and R 21 The same or different, each independently represents (i) a hydrogen atom, or a hydroxymethyl group, (ii) an aryl group having 6 to 30 carbon atoms, or (iii) a linear, branched or cyclic alkoxymethyl group having 2 to 20 carbon atoms; a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms; an alkenyl group having 2 to 10 carbon atoms; or an alkynyl group having 2 to 10 carbon atoms, R 12 and R 22 are the same or different and each independently represents an arbitrarily selected substituent on a carbon atom constituting the nitrogen heteroaryl condensed ring, in, The (ii) or (iii) may be further substituted by a substituent containing an oxygen atom, a substituent containing a sulfur atom, a substituent containing a nitrogen atom, an aryl group or a halogenated group, or the hydrocarbon chain portion of the (iii) may be further interrupted by a substituent containing an oxygen atom, a substituent containing a sulfur atom, a substituent containing a nitrogen atom or an arylene group. n1 and n2 are the same or different and each independently represents R 12 and R 22 The number of substituents can be 0, Ar 1 and Ar 2 are the same or different and are each independently a benzene ring or a condensed ring consisting of 2 to 3 benzene rings that forms a condensed ring with the pyrrole ring in formula (A), * indicates a bonding bond.

2. The resist underlayer film-forming composition according to claim 1, wherein the novolac resin comprises a composite unit structure AB represented by the following formula (AB): In the formula (AB), n represents the number of composite unit structures AB, The unit structure A is represented by the formula (A) described in claim 1, Unit structure B represents one or more unit structures including the structure represented by the following formula (B1), formula (B2) or formula (B3), * indicates a bond, In formula (B1), 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 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, * indicates a bond, *-J 1 -Z 0 -J 2 -* (B2) In formula (B2), 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 divalent organic group which is directly bonded or may have a substituent, * indicates a bond, In formula (B3), Z is a monocyclic, bicyclic, tricyclic or tetracyclic condensed ring having 4 to 25 carbon atoms and optionally having a substituent, wherein the monocyclic ring is a non-aromatic monocyclic ring; at least one of the monocyclic rings constituting the bicyclic, tricyclic and tetracyclic rings is a non-aromatic monocyclic ring, and the remaining monocyclic rings may be either aromatic or non-aromatic, and the monocyclic, bicyclic, tricyclic or tetracyclic condensed ring may further form a condensed ring with one or more aromatic rings to form a condensed ring of at least five rings, X and Y are the same or different, indicating -CR 31 R 32 -Base, 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 numbers of X and Y, respectively, and each independently represents 0 or 1, *-x x In the case of x=1, it is bonded to carbon atom 1, or in the case of x=0, it extends from carbon atom 1, wherein carbon atom 1 is any carbon atom of the non-aromatic monocyclic ring constituting Z, Y y -* is bonded to carbon atom 2 when y=1, or extends from carbon atom 2 when y=0, said carbon atom 2 being any carbon atom of said non-aromatic monocyclic ring constituting Z, The carbon atom 1 and the carbon atom 2 may be the same or different, and in different cases, may belong to the same non-aromatic monocyclic ring or different non-aromatic monocyclic rings. * indicates a bonding bond.

3. The resist underlayer film-forming composition according to claim 1, wherein the linking group L is selected from the group consisting of -O-, -S-, -SO2-, -CO-, -CONH-, -COO-, -NH-, -(CR 1 R 2 )m 1 -、-(Ar)m 2 -、-CH2-(Ar)m 2 -CH2- and -(cyclo-R)-, R 1 and R 2 are the same or different and each independently represents a hydrogen atom, a hydrocarbon group having 1 to 5 carbon atoms, or an aryl group having 6 to 30 carbon atoms, m 1 represents an integer from 1 to 10, Ar represents an arylene group having 6 to 30 carbon atoms, m 2 represents an integer of 1 to 3 which is the number of aromatic rings bonded to each other via single bonds, Cyclo-R represents a divalent alicyclic hydrocarbon group having 5 to 8 members which may form a condensed ring with one or two benzene rings or naphthalene rings. 4 . The resist underlayer film forming composition according to claim 3 , wherein cyclo-R represents a divalent alicyclic hydrocarbon group having a 6- to 8-membered ring which may form a condensed ring with one or two benzene rings or naphthalene rings.

5. The resist underlayer film forming composition according to claim 1, wherein R 11 and R 21 At least one part of represents a substituent: *-R 3 -C≡C-R 4 in, * indicates a bond, R 3 is a single bond or a divalent organic group having 1 to 20 carbon atoms, R 4 It is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. 6 . The resist underlayer film forming composition according to claim 1 , wherein the solvent contains a solvent having a boiling point of 160° C. or higher. 7 . The resist underlayer film-forming composition according to claim 1 , further comprising an acid and / or a salt thereof and / or an acid generator. 8 . The resist underlayer film-forming composition according to claim 1 , further comprising a cross-linking agent. 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 . The resist underlayer film forming composition according to claim 1 , further comprising a surfactant. 11 . A resist underlayer film on a semiconductor substrate, which is a fired product of a coating film formed from the resist underlayer film-forming composition according to claim 1 . 12 . A method for forming a resist pattern used in semiconductor production, comprising the step of applying the resist underlayer film-forming composition according to claim 1 onto a semiconductor substrate and firing the composition to form a resist underlayer film.

13. A method for manufacturing a semiconductor device, comprising the following steps: A step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film-forming composition according to any one of claims 1 to 10; a step of forming a resist film on the resist underlayer film; A process of forming a resist pattern on a resist film by irradiating the resist film with light or electron beams and developing the resist film; a step of etching the resist underlayer film through the resist pattern; and A step of processing a semiconductor substrate through the patterned resist underlayer film.

14. A method for manufacturing a semiconductor device, comprising the following steps: A step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film-forming composition according to any one of claims 1 to 10; A step of forming a hard mask on the resist underlayer film; A step of further forming a resist film on the hard mask; A process of forming a resist pattern on a resist film by irradiating the resist film with light or electron beams and developing the resist film; A process of etching the hard mask through the resist pattern; a step of etching the resist underlayer film through the patterned hard mask; and A step of processing a semiconductor substrate via a patterned resist underlayer film.

15. A method for manufacturing a semiconductor device, comprising the following steps: A step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film-forming composition according to any one of claims 1 to 10; A step of forming a hard mask on the resist underlayer film; A step of further forming a resist film on the hard mask; A process of forming a resist pattern on a resist film by irradiating the resist film with light or electron beams and developing the resist film; A process of etching the hard mask through the resist pattern; A step of etching the resist underlayer film through the patterned hard mask; A process of removing the hard mask; as well as A step of processing a semiconductor substrate via a patterned resist underlayer film.

16. A method for manufacturing a semiconductor device, comprising the following steps: A step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film-forming composition according to any one of claims 1 to 10; A step of forming a hard mask on the resist underlayer film; A step of further forming a resist film on the hard mask; A process of forming a resist pattern on a resist film by irradiating the resist film with light or electron beams and developing the resist film; A process of etching the hard mask through the resist pattern; A step of etching the resist underlayer film through the etched hard mask; A process of removing the hard mask; A step of forming a vapor-deposited film, i.e., a spacer, on the resist underlayer film after the hard mask is removed; A process of processing the vapor deposited film, i.e., the spacer, by etching; A step of removing the patterned resist underlayer film to leave the patterned vapor-deposited film, i.e., the spacer; and A process of processing a semiconductor substrate via a patterned vapor-deposited film, i.e., a spacer. 17 . The method for manufacturing a semiconductor device according to claim 14 , wherein the hard mask is formed by coating a composition containing an inorganic substance or vapor deposition of an inorganic substance. 18 . The method for manufacturing a semiconductor device according to claim 13 , wherein the resist film is patterned by a nanoimprint method or a self-assembled film.

19. The method for manufacturing a semiconductor device according to claim 15 or 16, wherein the hard mask is removed by either etching or an alkaline chemical solution.

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