Composition for forming resist underlayer film, method for forming resist pattern using same, and method for manufacturing semiconductor device

Abstract

Provided is a composition for forming a resist underlayer film, which satisfies various other characteristics such as curability, the amount of sublimate generated, planarization, and optical characteristics (reflection suppression during exposure) in addition to etching resistance and heat resistance. A composition for forming a resist underlayer film, the composition containing a novolac resin and a solvent, the novolac resin containing a structural unit (A) having an aromatic ring, the structural unit (A) including one or more structural units represented by formula (A), R1 being a hydrogen atom or a specific substituent, R2 being an optional specific substituent, and R3 being a hydrogen atom or a specific substituent. In the novolac resin, at least some of R1 and R2 are substituents having an alkynyl chain having 2-10 carbon atoms, n represents the number of substituents R2, when there are a plurality of n, the plurality of R2 may be the same as or different from each other, and * represents a linking bond. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to a composition for forming a resist underlayer film suitable for photolithography applications in semiconductor substrate processing, a resist underlayer film obtained from the composition, a method for forming a resist pattern using the 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 part of the structure and an aryl-substituted divalent group such as an aryl-substituted methylene group as a structural unit can achieve a material that achieves both film density and etching resistance. However, although the planarization property is mentioned, no empirical evidence has been conducted.

[0004] Patent Document 2 reports that a polymer obtained by reacting an indole derivative with a mixture of a plurality of specific 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] In addition, it is reported that the resist underlayer film-forming composition comprising a polymer having a 2-arylindole derivative / analog structure and an aryl-substituted methylene group as a structural unit in Patent Document 3 and the resist underlayer film-forming composition comprising a pyrrole novolac resin in Patent Document 4 can form a good resist pattern shape without causing the upper layer portion of the resist underlayer film and the layer coated thereon to mix with each other. Although heat resistance is also mentioned, it is not proven.

[0006] Although the novolac resins with indole structures described in Patent Documents 1 to 3 have excellent etching resistance and heat resistance, they have large deviations from the optical constants usually used as anti-reflection functions. In addition, there are problems with planarization. On the other hand, the novolac resins with pyrrole novolac structures of Patent Document 4 show high refractive index / low absorption coefficient suitable for anti-reflection functions, but considering the various properties required for the high quality and improved properties of the resist lower layer film, such as curability, curing speed, film shrinkage, heat resistance, coating properties on high-height substrates, planarization, embedding, sublimation amount, etching resistance, optical constants, etc., there is still room for improvement.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Application Publication No. 2016-151024

[0010] Patent Document 2: Japanese Patent Application Publication No. 2020-105513

[0011] Patent Document 3: International Publication No. 2013 / 146670 (A1)

[0012] Patent Document 4: International Publication No. 2014 / 208499 (A1) Summary of the invention

[0013] Problems to be solved by the invention

[0014] Therefore, the problem to be solved by the present invention is to provide a composition for forming a resist underlayer film, a resist pattern forming method using the composition for forming a resist underlayer film, and a method for manufacturing a semiconductor device using the composition, wherein the composition for forming a resist underlayer film satisfies the requirements of curability, suppression of the amount of sublimated products produced, and planarization in addition to etching resistance and heat resistance, and also well maintains various other properties such as coating properties, embeddability, and optical properties (reflection suppression during exposure) on high-height substrates having various vapor-deposited films.

[0015] Means of solving problems

[0016] The present invention includes the following aspects. [1]

[0018] A resist underlayer film-forming composition comprising a novolac resin and a solvent,

[0019] The novolac resin contains a structural unit A having an aromatic ring, and the structural unit A contains one or more structural units represented by the following formula (A):

[0020]

[0021] In the formula (A),

[0022] R 1 is a substituent on a hydrogen atom or a nitrogen atom of a pyrrole ring, and the substituent represents:

[0023] (i) hydroxymethyl;

[0024] (ii) a linear, branched or cyclic alkoxymethyl group having 2 to 20 carbon atoms; or

[0025] (iii) a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 10 carbon atoms or an aryl group having 6 to 30 carbon atoms;

[0026] R 2 is an optional substituent on a carbon atom constituting the pyrrole ring, and R 2 express:

[0027] (iv) the same substituent group as described in (iii); or

[0028] (v) an acyl group having 1 to 15 carbon atoms, an alkoxy group having 1 to 15 carbon atoms, an aryloxy group having 6 to 15 carbon atoms, an alkoxycarbonyl group having 1 to 15 carbon atoms, an aryloxycarbonyl group having 7 to 15 carbon atoms, a monosubstituted amino group having 1 to 15 carbon atoms, or a disubstituted amino group having 2 to 30 carbon atoms;

[0029] (vi) hydroxy, nitro, amino, cyano, carboxyl, trifluoromethyl or halogen;

[0030] Wherein, for the above (ii) to (v), they may further have a substituent containing an oxygen atom, a substituent containing a sulfur atom, a substituent containing a nitrogen atom, an aryl group or a halogen group as a substituent, or their hydrocarbon chain part 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,

[0031] In addition, R in novolac resin 1 and R 2 At least a portion of is a substituent having an alkynyl chain having 2 to 10 carbon atoms,

[0032] n represents a substituent R 2 If n is multiple, multiple R 2 Can be the same or different,

[0033] * indicates a connection key. [2]

[0035] The resist underlayer film forming composition according to [1],

[0036] The novolac resin comprises a composite structural unit AB represented by the following formula (AB),

[0037]

[0038] In the formula (AB),

[0039] n represents the number of composite structural units AB,

[0040] The structural unit A is represented by the formula (A) according to claim 1,

[0041] The structural unit B represents a structural unit comprising one or more of the structures represented by the following formula (B1), the structure represented by the following formula (B2), and the structure represented by the following formula (B3),

[0042] * indicates a connection key.

[0043]

[0044] [In formula (B1),

[0045] R 11 and R 12 each independently represents 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 connection key. ]

[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 connection key. ]

[0052]

[0053] [In formula (B3),

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

[0055] X and Y are the same or different and each represents -CR 31 R 32 -Base, R 31 and R32 are the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms,

[0056] x and y represent the number of X and Y respectively, and are independently 0 or 1.

[0057] *-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 *-X x represents the extension from carbon atom 1 (when x=0),

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

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

[0060] * indicates a connection key. ] [3]

[0062] The resist underlayer film-forming composition according to [1] or [2], wherein R 1 and R 2 The alkynyl chain is represented by the formula,

[0063]

[0064] [in,

[0065] * indicates a connection key.

[0066] R 3 is a single bond or a divalent organic group having 1 to 7 carbon atoms,

[0067] R 4 is a hydrogen atom or a monovalent organic group having 1 to 7 carbon atoms,

[0068] R 3 and R 4 The total number of carbon atoms is 0 to 8. ]. [4]

[0070] The resist underlayer film forming composition according to any one of [1] to [3], wherein the solvent contains a solvent with a boiling point of 160° C. or higher. [5]

[0072] The resist underlayer film forming composition according to any one of [1] to [4], further comprising an acid and / or a salt thereof and / or an acid generator. [6]

[0074] The resist underlayer film forming composition according to any one of [1] to [5], further comprising a crosslinking agent. [7]

[0076] The resist underlayer film forming composition according to [6], wherein the crosslinking agent is an aminoplast crosslinking agent or a phenoplast crosslinking agent. [8]

[0078] The resist underlayer film forming composition according to any one of [1] to [7], further comprising a surfactant. [9]

[0080] A resist underlayer film on a semiconductor substrate, which is a fired product of a coating film made from the resist underlayer film-forming composition according to any one of [1] to [8].

[10]

[0082] A method for forming a resist pattern used in semiconductor manufacturing, comprising the steps of applying the resist underlayer film-forming composition described in any one of [1] to [8] on a semiconductor substrate and firing the composition to form a resist underlayer film.

[11]

[0084] A method for manufacturing a semiconductor device comprises the following steps:

[0085] 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 [8];

[0086] a step of forming a resist film on the resist underlayer film;

[0087] 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;

[0088] a step of etching the resist underlayer film through the resist pattern; and

[0089] A step of processing a semiconductor substrate using a patterned resist underlayer film.

[12]

[0091] A method for manufacturing a semiconductor device comprises the following steps:

[0092] 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 [8];

[0093] A step of forming a hard mask on the resist underlayer film;

[0094] A step of further forming a resist film on the hard mask;

[0095] 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;

[0096] a process of etching the hard mask through the resist pattern;

[0097] a step of etching the resist underlayer film through a patterned hard mask; and

[0098] A step of processing a semiconductor substrate through a patterned resist underlayer film.

[13]

[0100] A method for manufacturing a semiconductor device comprises the following steps:

[0101] 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 [8];

[0102] A step of forming a hard mask on the resist underlayer film;

[0103] A step of further forming a resist film on the hard mask;

[0104] 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;

[0105] a process of etching the hard mask through the resist pattern;

[0106] A step of etching the resist underlayer film through a patterned hard mask;

[0107] A step of removing the hard mask; and

[0108] A step of processing a semiconductor substrate through a patterned resist underlayer film.

[14]

[0110] A method for manufacturing a semiconductor device comprises the following steps:

[0111] 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 [8];

[0112] A step of forming a hard mask on the resist underlayer film;

[0113] A step of further forming a resist film on the hard mask;

[0114] 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;

[0115] a process of etching the hard mask through the resist pattern;

[0116] a step of etching the resist underlayer film through the etched hard mask;

[0117] A process of removing the hard mask;

[0118] A step of forming a vapor-deposited film (spacer) on the resist underlayer film after the hard mask is removed;

[0119] A process of processing the vapor-deposited film (spacer) by etching;

[0120] A step of removing the patterned resist underlayer film to leave the patterned vapor-deposited film (spacer); and

[0121] A step of processing a semiconductor substrate via a patterned vapor-deposited film (spacer).

[15]

[0123] The method for manufacturing a semiconductor device according to any one of

[12] to

[14] , wherein the hard mask is formed by coating or vapor deposition of an inorganic material.

[16]

[0125] The method for manufacturing a semiconductor device according to any one of

[11] to

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

[17]

[0127] The method for manufacturing a semiconductor device according to any one of

[13] to

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

[0128] Effects of the Invention

[0129] The novolac resin contained in the resist underlayer film composition as one embodiment of the present invention contains a pyrrole structural unit having an alkynyl group (carbon-carbon triple bond structure, propargyl group, etc.), and can suppress sublimation components because it cures at a low temperature compared to a pyrrole novolac resin without an alkynyl group.

[0130] On the other hand, in the case of novolac resins that begin to cure at low temperatures, the problem of increased film shrinkage due to heat and the problem of impaired flattening and embedding properties are known, and it is difficult to achieve both these characteristics and curability at low temperatures. However, the resist underlayer film of the present invention can achieve both the above characteristics by introducing acetylene groups.

[0131] In addition, it is believed that due to the characteristics of the film having a small shrinkage rate, it has high heat resistance and a small amount of sublimation components, and has good coating properties on silicon wafers and various uneven substrates not only when fired at low temperatures but also when fired at high temperatures.

[0132] In addition, since the polymer itself exhibits self-crosslinking properties even without a crosslinking agent or a curing catalyst, sufficient curing properties can be exhibited even in a nitrogen atmosphere. Therefore, since sufficient curing properties can be obtained both in the air atmosphere used in conventional applications and in a nitrogen atmosphere, the polymer can be widely used in a variety of semiconductor manufacturing processes.

[0133] Furthermore, in terms of suppressing reflection during light exposure, a material showing optical constants of high n / low k at 193 nm is generally required, but these optical properties can be well maintained by introducing an alkynyl group.

[0134] In addition to having the above characteristics, etching resistance can also be adjusted according to the process, so a good pattern shape can be formed. DETAILED DESCRIPTION

[0135] [I. Definition of terms]

[0136] In this specification, the definitions of main terms related to the novolac resin of one embodiment of the present invention are described below. Unless otherwise specified, the following definitions of each term apply to the novolac resin.

[0137] (I-1) "Novolac resin"

[0138] The term "novolak resin" does not only refer to phenol-formaldehyde resin (so-called novolac-type phenol resin) and aniline-formaldehyde resin (so-called novolac-type aniline resin) in a narrow sense, but is used in a broad sense to broadly include polymers formed by forming a covalent bond (substitution reaction, addition 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 carbon or a tertiary carbon, a hydroxyl group, an alkoxy group or a halogen group bonded to an α-position carbon atom (benzyl-position 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 or a sulfur atom on the aromatic ring) in the presence of an acid catalyst or under reaction conditions equivalent thereto.

[0139] 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 between an organic compound containing a carbon atom derived from the aforementioned functional group (sometimes referred to as a "connecting carbon atom") and an aromatic ring in a compound having an aromatic ring via the connecting carbon atom.

[0140] In this specification, as the structural units constituting the "phenolic varnish resin", the terms structural unit A, structural unit B and structural unit C are used. Structural unit A is a structural unit derived from a compound having an aromatic ring. Structural unit B is a structural unit derived from a compound having a functional group that can covalently bond to the aromatic ring of structural unit A. Structural unit C is a structural unit that is equivalent to the bonding method of composite structural unit AB, and is a structural unit derived from a compound having an aromatic ring and having a functional group that can covalently bond to the aromatic ring of structural unit A. Since the bonding method is the same, structural unit C can be replaced by composite structural unit AB.

[0141] (I-2) "Residues"

[0142] "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 by a connecting bond, and may be a monovalent group or a divalent group. For example, if one hydrogen atom is replaced by one connecting bond, it becomes a monovalent organic group, and if two hydrogen atoms are replaced by connecting bonds, it becomes a divalent organic group.

[0143] (I-3) "aromatic ring" (aromatic group, aryl group, arylene group)

[0144] "Aromatic ring" is a concept including aromatic hydrocarbon rings, aromatic heterocycles, and residues thereof [sometimes also 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 types (aromatic monocyclic rings) but also polycyclic types (aromatic polycyclic rings). In the case of polycyclic types, 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 monocyclic heterocyclic rings (heteromonocyclic rings) or monocyclic alicyclic hydrocarbons (alicyclic monocyclic rings).

[0145] Examples of the aromatic ring include benzene, indene, naphthalene, azulene, styrene, toluene, xylene, mesitylene, cumene, anthracene, phenanthrene, triphenylene, benzanthracene, pyrene, Fluorene, biphenyl, coronene, perylenefluoranthene, 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 can be mentioned; furan, pyran, thiophene, pyrrole, N-alkylpyrrole, N-arylpyrrole, imidazole, pyridine, pyrimidine, pyrazine, triazine, thiazole, indole, phenylindole, bisindolefluorene, bisindolebenzofluorene, bisindoledibenzofluorene, purine, quinoline, isoquinoline, benzopyran, thianthracene, phenothiazine, phenanthrene, Aromatic heterocycles such as oxazine, xanthene, acridine, phenazine, carbazole, indolocarbazole, and more typically, furan, thiophene, pyrrole, indole, phenylindole, bisindolefluorene, phenothiazine, carbazole, indolocarbazole, imidazole, pyran, pyridine, pyrimidine, and pyrazine can be cited, but are not limited thereto.

[0146] The aromatic ring (e.g., benzene ring, naphthalene ring, etc.) may optionally have a substituent, and examples of the substituent include a halogen atom, a saturated or unsaturated straight-chain, branched or cyclic hydrocarbon group (-R) (including alkyl, alkenyl, alkynyl, propargyl groups in which the hydrocarbon chain may be interrupted one or more times by oxygen atoms), an alkoxy or aryloxy group (-OR, wherein R represents the aforementioned hydrocarbon group -R), an alkylamino group [-NHR or -NR2 (the two Rs may be the same or different from each other), wherein R represents the aforementioned hydrocarbon group -R, including alkyl, alkenyl, alkynyl, propargyl groups in which the hydrocarbon chain may be interrupted one or more times by oxygen atoms, etc. ], hydroxyl, amino (-NH2), carboxyl, cyano, nitro, ester group (-CO2R or -OCOR, wherein R represents the aforementioned hydrocarbon group -R), amide group (-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 aforementioned hydrocarbon group -R), sulfonyl-containing group (-SO2R, wherein R represents the aforementioned hydrocarbon group -R), mercapto (-SH), sulfur-containing group (-SR, wherein R represents the aforementioned hydrocarbon group -R); organic group containing ether bond [R 11 -OR 11 (R 11 Each independently represents an alkyl group having 1 to 6 carbon atoms such as methyl and ethyl, phenyl, naphthyl, anthracenyl, and pyrenyl. ) represents a residue of an ether compound; for example, an organic group containing an ether bond such as methoxy, ethoxy, and phenoxy], and a substituent such as an aryl group.

[0147] In addition, organic groups having a condensed ring formed by one or more aromatic rings (benzene, naphthalene, anthracene, pyrene, etc.) and one or more aliphatic rings or heterocyclic rings are also included. Moreover, as the so-called aliphatic ring here, cyclobutane, cyclobutene, cyclopentane, cyclopentene, cyclohexane, cyclohexene, methylcyclohexane, methylcyclohexene, cycloheptane, cycloheptene can be listed, and as heterocyclic rings, furan, thiophene, pyrrole, imidazole, pyran, pyridine, pyrimidine, pyrazine, pyrrolidine, piperidine, piperazine, and morpholine can be listed.

[0148] The organic group may have a structure in which two or more aromatic rings are linked together via a divalent linking group such as an alkylene group.

[0149] (I-4) "Heterocyclic ring"

[0150] The concept of "heterocycle" 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 ring is a heteromonocyclic ring, and the remaining monocyclic rings may be aromatic hydrocarbon monocyclic rings or alicyclic monocyclic rings. As aromatic heterocycles, the examples in (I-3) above may be referred to. As with the aromatic ring in (I-3) above, the heterocycle may have a substituent.

[0151] (I-5) "Non-aromatic ring" (aliphatic ring)

[0152] "Non-aromatic monocyclic ring" refers to a monocyclic hydrocarbon that is not aromatic, typically a monocyclic ring of an alicyclic compound. It may also be called an aliphatic monocyclic ring (it may include an aliphatic heteromonocyclic ring and may include an unsaturated bond as long as it is not an aromatic compound). Like the aromatic ring in (I-3) above, the non-aromatic monocyclic ring may have a substituent.

[0153] Examples of the non-aromatic monocyclic ring (aliphatic ring, aliphatic monocyclic ring) include cyclopropane, cyclobutane, cyclobutene, cyclopentane, cyclopentene, cyclohexane, methylcyclohexane, cyclohexene, methylcyclohexene, cycloheptane, cycloheptene and the like.

[0154] "Non-aromatic polycyclic" refers to polycyclic hydrocarbons that are not aromatic, typically polycyclics of alicyclic compounds. Also called aliphatic polycyclic [may include aliphatic heteropolycyclics (at least one of the monocyclics constituting the polycyclics is an aliphatic heterocyclic ring), and may contain unsaturated bonds as long as it is not an aromatic compound]. Non-aromatic polycyclics include non-aromatic bicyclics, non-aromatic tricyclics, and non-aromatic tetracyclics.

[0155] "Non-aromatic bicyclic ring" refers to a condensed ring composed of two monocyclic hydrocarbons that are not aromatic, 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 contain an unsaturated bond as long as it is not an aromatic compound). Examples of non-aromatic bicyclic rings include bicyclopentane, bicyclooctane, bicycloheptene, and the like.

[0156] "Non-aromatic tricyclic ring" refers to a condensed ring composed of three non-aromatic monocyclic hydrocarbons, 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 non-aromatic tricyclic rings include tricyclooctane, tricyclononane, and tricyclodecane.

[0157] "Non-aromatic tetracyclic ring" refers to a condensed ring composed of four non-aromatic monocyclic hydrocarbons, typically four condensed rings of 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 non-aromatic tetracyclic rings include hexahydropyrene and the like.

[0158] (1-6)

[0159] The "carbon atoms constituting the ring (part)" refers to the carbon atoms constituting the ring in the case of a hydrocarbon ring (which may be any of an aromatic ring, an aliphatic ring, and a heterocyclic ring) having no substituent.

[0160] (I-7)

[0161] The "hydrocarbon group" refers to a group formed by removing one or more hydrogen atoms from a hydrocarbon, and the hydrocarbon includes a saturated or unsaturated aliphatic hydrocarbon, a saturated or unsaturated alicyclic hydrocarbon, and an aromatic hydrocarbon.

[0162] (1-8)

[0163] In the chemical structural formula of the structural unit of the phenolic varnish resin in the present application specification, a connecting bond (marked with *) is sometimes recorded for convenience. Unless otherwise specified, the connecting bond can be any bonding position that can be bonded in the structural unit, and there is no limitation on the bonding position in the structural unit.

[0164] [II; Resist underlayer film-forming composition]

[0165] A resist underlayer film-forming composition according to one embodiment of the present invention contains a specific novolac resin and a solvent.

[0166] (IIA) Novolac resin

[0167] (IIA-1)

[0168] The specific novolac resin contained in the resist underlayer film-forming composition according to one embodiment of the present invention includes:

[0169] The structural unit A having an aromatic ring contains one or two or more pyrrole structural units represented by the following formula (A).

[0170]

[0171] Unless otherwise specified, in this specification, * represents a connecting key.

[0172] Furthermore, in the above formula (A), the bond represented by * extends from any carbon atom constituting the pyrrole ring.

[0173] (IIA-1-1)

[0174] R 1 It is a hydrogen atom or a substituent on the nitrogen atom of the pyrrole ring.

[0175] Furthermore, in the case of the substituent, R 1 express:

[0176] (i) hydroxymethyl;

[0177] (ii) a linear, branched or cyclic alkoxymethyl group having 2 to 20 carbon atoms; or

[0178] (iii) a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, or an aryl group having 6 to 30 carbon atoms.

[0179] However, the substituent groups of (ii) and (iii) may be further substituted with specific substituents as described in (IIA-1-4) below, and the hydrocarbon chain may be partially interrupted with a specific divalent functional group.

[0180] (IIA-1-2)

[0181] R 2 is an optional substituent on the carbon atom constituting the pyrrole ring, R 2 express:

[0182] (iv) the same substituent group as in (iii), i.e., a linear, branched, or cyclic alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, or an aryl group having 6 to 30 carbon atoms;

[0183] (v) an acyl group having 1 to 15 carbon atoms (such as acetyl and benzoyl), an alkoxy group having 1 to 15 carbon atoms (such as methoxy and propargyloxy), an aryloxy group having 6 to 15 carbon atoms (such as phenoxy), an alkoxycarbonyl group having 1 to 15 carbon atoms (such as methoxycarbonyl and propargyloxycarbonyl), an aryloxycarbonyl group having 7 to 15 carbon atoms (such as phenoxycarbonyl), a monosubstituted amino group having 1 to 15 carbon atoms [monoalkylamine such as monomethylamino, mono(alkenyl or alkynyl)amine such as monopropargylamino, monoarylamino such as phenylamino], or a disubstituted amino group having 2 to 30 carbon atoms [dialkylamino such as dimethylamino, di(alkenyl or alkynyl)amino such as dipropargylamino]; or

[0184] (vi) hydroxyl, nitro, amino, cyano, carboxyl, trifluoromethyl, or halogen.

[0185] However, the substituent group of (iv) or (v) above may be further substituted with a specific substituent as described in (IIA-1-4) below, and the hydrocarbon chain may be partially interrupted by a specific divalent functional group. For example, an arylalkoxy group such as a benzyloxy group, which is an alkoxy group substituted with a phenyl group as an aryl group, belongs to the substituent group of (v) above.

[0186] Furthermore, n in formula (A) represents a substituent R2 If n is multiple, multiple R 2 When the pyrrole structural unit is located in the polymer chain, n may be an integer of 0 to 2, and when the pyrrole structural unit is located at the end of the polymer chain, n may be an integer of 0 to 3.

[0187] (IIA-1-3)

[0188] Among them, R in phenolic varnish resin 1 and R 2 At least a part of them is a substituent having an alkynyl chain having 2 to 10 carbon atoms.

[0189] Here, the substituent having an alkynyl chain is not limited to the alkynyl group which is the alkynyl chain itself but also includes a functional group having an alkynyl chain as a structural part.

[0190] More specifically, we can cite:

[0191] R in novolac resin 1 At least one part of is an alkynyl group having 2 to 10 carbon atoms, and / or

[0192] In the presence of R 2 In the case of novolac resin, R 2 At least a part of is an alkynyl group having 2 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, an alkynyloxycarbonyl group having 3 to 11 carbon atoms, a monoalkynylamino group having 2 to 10 carbon atoms, or a di(alkynyl)amino group having 4 to 20 carbon atoms.

[0193] Among them, R in the novolac resin is more preferred. 1 At least a part of is an alkynyl group having 2 to 10 carbon atoms.

[0194] However, these substituent groups may be further substituted with a specific substituent as described in (IIA-1-4) below, and the hydrocarbon chain may be partially interrupted with a specific divalent functional group.

[0195] Here, R in the novolac resin 1 and R 2 The term "at least a portion" means that in the absence of R as an optional substituent 2 In the case of R 1 at least a portion of; in the presence of R as an optional substituent 2 In the case of R 1 At least part of R 2 at least a portion of, or R 1 At least part of R 2 at least a portion of.

[0196] Furthermore, the introduction rate of the alkynyl chains in the novolac resin of one embodiment of the present invention is preferably 5% or more. The introduction rate here means the number (%) of alkynyl chains of the pyrrole structural units introduced into the novolac resin, when the number of pyrrole structural units of formula (A) is taken as 100. The introduction rate can be, for example, 1 H-NMR measurement, 13 The introduction rate can be calculated by using an internal standard or the like as needed.

[0197] In addition, from the viewpoint of self-crosslinking properties, the alkynyl chain is preferably an alkynyl chain represented by the following general formula.

[0198]

[0199] Where R 3 is a single bond or a divalent organic group having 1 to 7 carbon atoms, preferably an alkylene group, more preferably a methylene group; R 4 is a hydrogen atom or a monovalent organic group having 1 to 7 carbon atoms, preferably an alkyl group, more preferably a hydrogen atom, R 3 With R 4 The total number of carbon atoms is 0 to 8, more preferably 1 to 3. The organic group means a hydrocarbon group, which may be further substituted with a substituent containing a heteroatom, or the hydrocarbon chain may be partially interrupted by a divalent group containing a heteroatom [see, for example (IIA-1-4)].

[0200] The introduction of the above alkynyl chain into the pyrrole ring structural unit represented by formula (A) can be carried out by any known conventional method. For example, it can be introduced using an alkynylating agent such as a haloalkyne after the novolac resin is produced. In addition, the same resin can be prepared by preparing a monomer introduced with an alkynyl group in advance to synthesize the novolac resin.

[0201] (IIA-1-4)

[0202] The substituent groups of (ii) (iii) of the aforementioned (IIA-1-1) and (iv) (v) of the aforementioned (IIA-1-2) may be further substituted by a substituent containing an oxygen atom (hydroxyl, alkoxy, alkoxyalkyl, alkoxycarbonyl, aryloxy, carboxyl, etc.), a substituent containing a sulfur atom (sulfonic acid, alkylthio, arylthio, alkylsulfonyl, arylsulfonyl, etc.), a substituent containing a nitrogen atom [amino, substituted amino (mono- or di-substituted amino such as monoalkylamine and dialkylamine), amide, cyano, nitro, etc.], an aryl group (preferably an aryl group having 6 to 20 carbon atoms, such as phenyl, pyrene, etc.) or a halogen group.

[0203] In addition, for the substituent groups of (ii) (iii) of (IIA-1-1) and (iv) (v) of (IIA-1-2), the hydrocarbon chain can be partially interrupted by substituents containing oxygen atoms [divalent groups such as -O-, -C(O)-, -C(O)O-, and -OC(O)-], substituents containing sulfur atoms (divalent groups such as -S- and -SO2-), substituents containing nitrogen atoms [divalent groups such as -N(R)C(O)-, -C(O)N(R)-, -OC(O)N(R)-, -N(R)C(O)O-, -N(R)C(O)N(R)-, and -NR-; wherein R's may be the same or different and independently represent a hydrocarbon group having 1 to 30 carbon atoms], or arylene groups (such as phenylene groups).

[0204] It should be noted that the "hydrocarbon chain part" referred to herein refers to a chain (straight or branched) hydrocarbon part, for example, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, an alkoxycarbonyl group having 1 to 15 carbon atoms, an alkoxy group having 1 to 15 carbon atoms, an acyl group having 1 to 15 carbon atoms, a monoalkylamino group having 1 to 15 carbon atoms, and a dialkylamino group having 2 to 30 carbon atoms. Since -O-, -S-, -C(O)-, etc. are inserted between two carbon atoms connected to each other by a single bond in the chain hydrocarbon part (but carbon atoms that do not constitute a part of the ring structure), there is at least one pair of two carbon atoms connected to each other by a single bond (carbon atoms that do not constitute a part of the ring structure) in the chain hydrocarbon part. For example, the entire alkenyl group constitutes a hydrocarbon chain portion, and if there is at least one pair of two carbon atoms connected to each other by a single bond (CH3-CH2-CH2- portion) as in 1-pentenyl, it may be interrupted by a divalent group. Sometimes, as in monopentylamino, pentylcyclohexyl, and p-pentylphenyl, it refers to a part of the substituent (pentyl). On the other hand, sometimes, as in a straight-chain or branched alkyl group, the substituent as a whole becomes a chain hydrocarbon portion.

[0205] (IIA-1-5)

[0206] The novolac resin having an acetylened pyrrole structure can provide a resist underlayer film having better properties than the prior art, as described below.

[0207] By introducing an alkynyl self-crosslinking group such as a propargyl group, it is possible to use it as a resist underlayer film not only in an air atmosphere but also in a nitrogen atmosphere (because there is no oxygen, oxidative curing cannot occur) without the need for a crosslinking agent or a curing catalyst. Therefore, it is a material that can be applied to a wider range of processes than the existing technology.

[0208] In addition, by starting to cure at a low temperature, the sublimation component can be suppressed, but despite curing at a low temperature, the present invention is characterized by having a small film shrinkage (= high heat resistance). It is believed that this is because the film density is increased by forming a three-dimensional cross-linked structure by the alkynyl self-cross-linking group, the heat resistance is increased, and the cross-linked structure formed by the alkynyl self-cross-linking group causes the molecular volume to expand.

[0209] In addition, although the curing speed is increased, in the case of N-alkynylation, the effect of suppressing the increase in viscosity due to the polarity brought by NH and the effect of lowering the Tg of the polymer are shown, and good coating properties can be maintained on high-height substrates, and the flattening characteristics are improved. Therefore, in the pyrrole ring structural unit of formula (A), R 1 is alkynylated (ie, N-alkynylated).

[0210] The embedding property is not impaired by acetylation, and good properties are exhibited.

[0211] The acetylened pyrrole structure exhibits the above-mentioned excellent properties, and is also characterized in that the excellent optical constants (high n / low k@193 nm, preferably n value ≥ 1.3 / k value ≤ 0.7) of the existing pyrrole polymers can be maintained.

[0212] Although having an alkynyl pyrrole structure is a necessary condition, if a variety of pyrrole raw materials, phenol raw materials, amine raw materials, aldehyde raw materials, ketone raw materials, and aldehyde equivalent raw materials are used to prepare the novolac resin, the optical constants and etching resistance can be freely changed while maintaining the above-mentioned characteristics, and the resist underlayer film can be adjusted to adapt to the process.

[0213] It should be noted that these properties are not impaired even when a crosslinking agent or an acid catalyst is added. Therefore, it is expected that the novolac resin having an acetylated pyrrole structure will become a material that can be widely used in various semiconductor manufacturing processes.

[0214] (IIA-1-6)

[0215] Representative specific examples of the pyrrole ring structural unit represented by the formula (A) are listed below. It should be noted that the connecting bonds on the structural unit are omitted.

[0216] In addition, at least a part of the novolac resin contained in the resist underlayer film forming composition of one embodiment of the present invention contains a pyrrole ring structural unit having an alkynyl chain as listed in the following specific examples, such as (i) to (iii) below, but may also contain a pyrrole ring structural unit not having an alkynyl chain as listed in the following (iv).

[0217] (i) R of formula (A) 1 Specific examples of alkynyl chains in

[0218]

[0219]

[0220]

[0221] (ii) R of formula (A) 2 Specific examples of alkynyl chains in

[0222]

[0223] (iii) R of formula (A) 1 and R 2 These two contain specific examples of alkynyl chains.

[0224]

[0225] (iv) Other specific examples

[0226] In each pyrrole ring structural unit listed in (i), a specific example in which the substituent on the pyrrole ring nitrogen atom is replaced by a hydrogen atom can be given. For the sake of simplicity, the representation of each explicit chemical structure is omitted.

[0227] The following specific examples of the structural units can also be additionally listed.

[0228]

[0229] (IIA-1-7)

[0230] The structural unit A may contain one or more other structural units having an aromatic ring other than the structural unit of formula (A) of (IIA-1) as long as the effects of the present invention are not impaired.

[0231] The aromatic ring preferably has 6 to 30 carbon atoms, more preferably 6 to 24 carbon atoms.

[0232] The aromatic ring is preferably one or more benzene rings, naphthalene rings, anthracene rings, pyrene rings; or a condensed ring formed by a benzene ring, naphthalene ring, anthracene ring, pyrene ring and a heterocyclic ring or an aliphatic ring.

[0233] The aromatic ring may optionally have a substituent, and the substituent preferably contains a heteroatom. In addition, for the aromatic ring, two or more aromatic rings may be connected by a linking group, and the linking group preferably contains a heteroatom. As the heteroatom, for example, an oxygen atom, a nitrogen atom, a sulfur atom, etc. can be mentioned.

[0234] The "aromatic ring" is preferably an organic group having 6 to 30, or 6 to 24, carbon atoms and containing at least one hetero atom selected from N, S and O on, within or between the rings.

[0235] Examples of heteroatoms on the ring include nitrogen atoms contained in amino groups (e.g., propargylamino) and cyano groups; oxygen atoms contained in acyl groups, hydroxyl groups, carboxyl groups, and alkoxy groups (e.g., propargyloxy groups) as oxygen-containing substituents; and nitrogen atoms and oxygen atoms contained in nitro groups as oxygen-containing substituents and nitrogen-containing substituents. Examples of heteroatoms contained in the ring include oxygen atoms contained in xanthene groups and nitrogen atoms contained in carbazole groups.

[0236] As heteroatoms contained in the connecting group of two or more aromatic rings, there can be mentioned 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. Structural unit A is preferably a structural unit comprising an aromatic ring having the above-mentioned oxygen-containing substituent, a structural unit having two or more aromatic rings connected by -NH-, or a structural unit having a condensed ring formed by one or more aromatic hydrocarbon rings and one or more heterocyclic rings.

[0237] Examples of skeletons other than the skeleton of formula (A) used in the structural unit A include the following skeletons.

[0238] (Example of amine skeleton)

[0239]

[0240]

[0241]

[0242]

[0243] (Example of phenol skeleton)

[0244]

[0245]

[0246]

[0247] 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 following substituents.

[0248]

[0249]

[0250] As the structural unit A other than formula (A), it is preferably at least one selected from the following structural units. It should be noted that the positions of the two connecting bonds represented in each of the following structural units are only for convenience, and each connecting bond can extend from any possible carbon atom and is not limited to the position.

[0251] (Examples of structural units derived from heterocycles)

[0252]

[0253] (Examples of structural units derived from aromatic hydrocarbons having an oxygen-containing substituent)

[0254]

[0255] (Example of a structural unit derived from an aromatic hydrocarbon linked via -NH-) A structure in which the hydrogen atom on the N of -NH- is substituted may be employed.

[0256]

[0257] (IIA-2)

[0258] The novolac resin preferably includes a composite structural unit AB represented by the following formula (AB).

[0259]

[0260] In the formula (AB), n represents the number of composite structural units AB, and the structural unit A is represented by the formula (A) described in (IIA-1).

[0261] (IIA-2-1) Structural unit B

[0262] Structural unit B is one or more structural units containing a connecting carbon atom [see (I-1)] bonded to the aromatic ring in structural unit A, and contains a structure represented by formula (B1), (B2) or (B3) described in (IIA-2-2) to (IIA-2-4) described later. Structural unit B can connect two structural units A by covalently bonding to a carbon atom on the pyrrole ring of structural unit A.

[0263] In addition, at least one composite structural unit AB can be replaced by one or more structural units C comprising structures represented by formulas (C1), (C2) and (C3) described later, respectively (IIA-2-2-3), (IIA-2-3-2) and (IIA-2-4-3), as a structural unit equivalent thereto.

[0264] (IIA-2-2) Formula (B1)

[0265]

[0266] In formula (B1),

[0267] R 11 and R 12 Each independently represents 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.

[0268] In addition, the two connecting bonds of formula (B1) may be covalently bonded to the pyrrole ring in structural unit A.

[0269] (IIA-2-2-1)

[0270] In the definitions of R and R' in formula (B1), regarding "aromatic ring" and "heterocycle", refer to the above-mentioned (I-3) and (I-4).

[0271] R in formula (B1) 11 and R 12In the definition of "alkyl", for example, 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, 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, Methyl-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, n-decyl.

[0272] R 11 and R 12 Preferably, each of them is independently phenyl, naphthyl, anthracenyl, phenanthrenyl, naphthacene or pyrene.

[0273] (IIA-2-2-2)

[0274] In addition, the structural unit containing the structure represented by formula (B1) may contain, for example, two or three structures of the above formula (B1) that are identical or different from each other and bonded to a divalent or trivalent linking group to form a dimer or trimer structure. In this case, one of the two connecting bonds is bonded to the linking group, as shown in the following formula (B11) in the structure of the above formula (B1).

[0275]

[0276] As the linking group, for example, a linking group having two or three aromatic rings (corresponding to the structural unit 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), for example, divalent or trivalent linking groups of the following formulas (L2) and (L3) can be cited.

[0277]

[0278] [X 1 represents a single bond, a methylene group, an oxygen atom, a sulfur atom, -N(R x1 )-,R x1 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))]

[0279]

[0280] [X 2 represents a methylene group, an oxygen atom, -N(R x2 )-, R x2 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.]

[0281]

[0282] Also exemplified are divalent linking groups such as those represented by the following formula (L4), which can form a covalent bond to a carbon atom through an addition reaction of an alkyne and a ketone.

[0283]

[0284] (IIA-2-2-3)

[0285] It should be noted that R in formula (B1) 11 and R 12 When at least one of them is an aromatic ring, the aromatic ring [for example, when R12 is Ar in the following formula (B12)] may be bonded to another additional structural unit B.

[0286]

[0287] In this case, as in the following formula (C1), when one 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 structural unit A, a structural unit A in another polymer chain, etc.), at least one composite structural unit AB can be replaced by a structural unit C equivalent to the composite structural unit AB. That is, the aromatic ring in formula (C1) [Ar in formula (C1)] can be bonded to another structural unit B, and the remaining bond connecting the carbon atom shown in formula (C1) is bonded to the aromatic ring of the structural unit A, thereby extending the polymer chain.

[0288]

[0289] (IIA-2-2-4)

[0290] Some specific examples of structural unit B including the structure represented by formula (B1) are listed below. * Basically represents the bonding site with structural unit A. Of course, a part of the whole may include the exemplified structure.

[0291]

[0292] (IIA-2-3)

[0293] *-J 1 -Z 0 -J 2 -* (B2) In formula (B2),

[0294] 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 rings or aliphatic rings are linked by a single bond. Examples of the organic group in which two aromatic rings or aliphatic rings are linked by a single bond include divalent residues such as biphenyl, cyclohexylphenyl, and bicyclohexyl.

[0295] J 1 and J 2 Each independently represents a divalent organic group which is directly bonded or may have a substituent. As the divalent organic group, a linear or branched alkylene group having 1 to 6 carbon atoms which may have a hydroxyl group, an aryl group (phenyl, substituted phenyl, etc.) or a halogen group (e.g., fluorine) as a substituent is preferred. Examples of the linear alkylene group include methylene, ethylene, propylene, butylene, pentylene, and hexylene.

[0296] (IIA-2-3-1)

[0297] In addition, the structural unit containing the structure represented by formula (B2) may contain two or three structures of the above formula (B2) that are the same or different from each other and are bonded to a divalent or trivalent linking group to form a dimer or trimer structure, similar to the aforementioned (IIA-2-2-2) regarding formula (B1).

[0298] (IIA-2-3-2)

[0299] It should be noted that, since the embodiment including formula (B2) includes an aromatic ring [Z 0 ], so similarly to (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 also be bonded to other additional structural units B [vertical connecting bonds in formula (B21)].

[0300]

[0301] [In formula (B21),

[0302] Z 0 Ar is an aromatic ring residue having 6 to 30 carbon atoms which may have a substituent or an organic group formed by linking two aromatic rings or aliphatic rings via a single bond, and is an organic group having at least one aromatic ring, from Z 0 Ar The connecting key extending downward from Z 0 Ar The aromatic rings in the

[0303] J 1 and J 2 Same as the definition of formula (B2).]

[0304] In this case, when a link 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, terminal structural unit A, structural unit A in other polymer chains, etc.) as in the following formula (C2), at least one composite structural unit AB can be replaced as a structural unit C equivalent to the composite structural unit AB. That is, the aromatic ring in formula (C2) [Z in formula (C2)] 0 Ar The aromatic ring in the formula (C2) can be bonded to other structural units B, and the remaining connecting bonds connecting carbon atoms shown in formula (C2) are bonded to the aromatic ring of the structural unit A, thereby extending the polymer chain.

[0305]

[0306] [In formula (C2),

[0307] Z 0 Ar , J 1 and J 2 Same as the definition of formula (B21),

[0308] T represents the polymer terminus.]

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

[0310] Some specific examples of the structural unit including the structure represented by formula (B2) are as follows: * represents a bonding site with the structural unit A. Of course, the structural unit may include a part of the structure exemplified as a whole.

[0311]

[0312]

[0313] (IIA-2-4) Formula (B3)

[0314]

[0315] In formula (B3),

[0316] Z is a monocyclic ring or a bicyclic, tricyclic or tetracyclic condensed ring having 4 to 25 carbon atoms which may have a substituent. The carbon number here refers only to the number of carbon atoms constituting the ring skeleton of the monocyclic ring or the bicyclic, tricyclic or tetracyclic condensed ring after removing 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.

[0317] The monocyclic ring is a non-aromatic monocyclic ring; at least one of the monocyclic rings constituting the bicyclic ring, tricyclic ring and tetracyclic ring is a non-aromatic monocyclic ring, and the remaining monocyclic rings may be an aromatic monocyclic ring or a non-aromatic monocyclic ring.

[0318] The monocyclic, bicyclic, tricyclic or tetracyclic condensed ring can further form a condensed ring with one or more aromatic rings to become a pentacyclic or higher condensed ring. The number of carbon atoms in the pentacyclic or higher condensed ring is preferably 40 or less. The number of carbon atoms here refers only to the carbon atoms constituting the ring skeleton of the pentacyclic or higher condensed ring after removing the substituents. When the pentacyclic or higher condensed ring is a heterocyclic ring, the number of heteroatoms constituting the heterocyclic ring is not included.

[0319] X and Y are the same or different, and each represents -CR 31 R 32 -Ki, CR 31 and CR 32are the same or different, and each represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms.

[0320] x and y represent the number of X and Y, respectively, and independently represent 0 or 1.

[0321] *-X x is bonded to any carbon atom (referred to as "carbon atom 1") of the non-aromatic monocyclic ring constituting Z (in the case of x=1) or extends from carbon atom 1 (in the case of x=0),

[0322] Y y -* is bonded to any carbon atom (referred to as "carbon atom 2") of the non-aromatic monocyclic ring constituting Z (when y=1) or extends from carbon atom 2 (when y=0); carbon atom 1 and carbon atom 2 may be the same or different. When they are different, they may belong to the same non-aromatic monocyclic ring or different non-aromatic monocyclic rings.

[0323] In formula (B3), a connecting carbon atom other than carbon atom 1 and carbon atom 2 may be optionally contained [see (IIA-2-4-2) described later]

[0324] It should be noted that, when Z is a condensed ring of tricyclic or higher type, the sequence position relationship in the condensed ring formed by one or two non-aromatic monocyclic rings to which carbon atoms 1 and 2 in formula (B3) respectively belong and the remaining monocyclic ring is arbitrary. When carbon atom 1 and carbon atom 2 respectively belong to different non-aromatic monocyclic rings (referred to as "non-aromatic monocyclic ring 1" and "non-aromatic monocyclic ring 2"), the sequence position relationship between the non-aromatic monocyclic ring 1 and the non-aromatic monocyclic ring 2 in the condensed ring is also arbitrary.

[0325] (IIA-2-4-1)

[0326] 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.

[0327] (IIA-2-4-2)

[0328] Some specific examples of the organic group containing the structure represented by formula (B3) are as follows: The bonding site with the structural unit A is not particularly limited. Of course, a structure in which a part of the whole contains the exemplified structure may also be used.

[0329] It should be noted that there are also examples where the number of connecting bonds (*) is greater than 2, but the remaining connecting bonds can be used for bonding with aromatic rings in other polymer chains, cross-linking, and the like.

[0330]

[0331]

[0332] (IIA-2-4-3)

[0333] It should be noted that when Z in formula (B3) contains an aromatic ring, the aromatic ring [for example, see Ar in formula (B32) below] 1 ] can be bonded to other additional structural units B.

[0334]

[0335] In formula (B32),

[0336] 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 condensed into a ring, as Z and Ar 1 The whole constitutes a bicyclic, tricyclic, tetracyclic or pentacyclic condensed ring having 8 to 25 carbon atoms which may have a substituent. The number of carbon atoms here refers only to the number of carbon atoms constituting the ring skeleton of the bicyclic, tricyclic or tetracyclic condensed ring after removing 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.

[0337] The bicyclic, tricyclic, tetracyclic or pentacyclic organic group can further form a condensed ring with one or more aromatic rings to form a hexacyclic or higher condensed ring. The number of carbon atoms in the hexacyclic or higher condensed ring is preferably 40 or less. The number of carbon atoms here refers only to the number of carbon atoms constituting the ring skeleton of the hexacyclic or higher condensed ring after removing the substituents. When the hexacyclic or higher condensed ring is a heterocyclic ring, the number of heteroatoms constituting the heterocyclic ring is not included.

[0338] In addition, among the cyclic organic groups, Z 1 One or more non-aromatic monocyclic rings and Ar 1 The sequence position relationship of one or more aromatic monocyclic rings is arbitrary. 1 The non-aromatic monocyclic ring of Ar is 2 or more 1 When there are two or more aromatic monocyclic rings, the non-aromatic monocyclic ring belonging to Z1 and the non-aromatic monocyclic ring belonging to Ar 1 The aromatic monocyclic rings can be arranged alternately to form condensed rings.

[0339] In addition, X, Y, x, and y have the same definitions as in formula (B3).

[0340] In this case, when a linking 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 structural unit A, a structural unit A in another polymer chain, etc.) as in the following formula (C3), at least one composite structural unit AB can be replaced as a structural unit C equivalent to the composite structural unit AB. That is, the aromatic ring in formula (C3) [Ar in formula (C3)] 1 ] can be bonded to other structural units B, and the remaining connecting bonds connecting carbon atoms shown in formula (C3) are bonded to the aromatic ring of structural unit A, thereby extending the polymer chain.

[0341]

[0342] [In formula (C3),

[0343] Z 1 ,Ar 1 , X, Y, x and y are the same as defined in formula (B32),

[0344] T represents the polymer terminus.]

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

[0346] 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, which can be a connecting bond among p, k1 and k2, and through p and k1, or p and k2, can become a structural unit C equivalent to the composite structural unit AB.

[0347] It should be noted that k1 and k2 may also function as the structural unit A.

[0348]

[0349] In addition, the following formula (C32) shows an example in which T in formula (C3) represents a phenyl group. In this example, among p, k1, k2, and m that can be a connecting bond, a structural unit C equivalent to the composite structural unit AB can be formed by p and k1, p and k2, or p and m.

[0350] In addition, k1 and k2, k1 and m, or k2 and m may function as the structural unit A.

[0351]

[0352] More specific examples of the structural unit C (one structural unit equivalent to the composite structural unit AB) of the formula (C3) are as follows: * represents a bonding site with the structural unit A.

[0353] In the structural unit C, a link to the structural unit B extends from the aromatic ring in these structures, but in the specific examples described below, this link is omitted. Of course, a structural unit may also contain a part of the exemplified structure as a whole.

[0354]

[0355] In addition, in the above-mentioned specific examples, when there is no linking bond derived from an aromatic ring, it can be a specific example of a polymer terminal.

[0356] (IIA-3)

[0357] 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, etc., wherein A and B have the same meanings as above. R represents a halogen or an alkyl group having about 1 to 3 carbon atoms.

[0358] 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.

[0359] 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 multiple types).

[0360] 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, dimethoxyethane ... The condensation reaction temperature is usually 40°C to 200°C, preferably 100°C to 180°C. The reaction time varies depending on the reaction temperature, but is usually 5 minutes to 50 hours, preferably 5 minutes to 24 hours.

[0361] 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.

[0362] (IIB) Solvent

[0363] The resist underlayer film forming composition according to one embodiment of the present invention contains a solvent.

[0364] The solvent is not particularly limited as long as it can dissolve the specific novolac resin and other optional components added as needed.

[0365] (IIB-1)

[0366] 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-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionate, ethyl propionate, 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, lactate butyl formate, 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, Ethoxyethyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-methoxybutyl acetate, 3-methoxypropyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutyl propionate, 3-methyl-3-methoxybutyl butyrate, methyl acetoacetate, toluene, xylene, methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, 2-heptanone, 3-heptanone, 4-heptanone, 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.

[0367] (IIB-2)

[0368] Furthermore, a combination of 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.

[0369] As such a high boiling point solvent, for example, the following compounds described in International Publication No. 2018 / 131562 (A1) can be preferably used.

[0370]

[0371] [R in formula (i) 1 , R 2 and R 3 Each of them 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 R 1 , R 2 and R 3 They may be the same or different from each other and may be bonded to each other to form a ring structure.]

[0372] Alternatively, 1,6-diacetoxyhexane (boiling point 260° C.) and 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.

[0373] 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 present invention also includes various high boiling point solvents described in paragraphs 0023 to 0031 of the disclosure.

[0374] (IIC) Acid and / or its salt and / or acid generator

[0375] The resist underlayer film-forming composition according to one embodiment of the present invention may optionally contain an acid and / or a salt thereof and / or an acid generator.

[0376] (IIC-1)

[0377] Examples of the acid include p-toluenesulfonic acid, trifluoromethanesulfonic acid, salicylic acid, 5-sulfosalicylic acid, 4-hydroxybenzenesulfonic acid, camphorsulfonic acid, 4-chlorobenzenesulfonic acid, benzenedisulfonic acid, 1-naphthalenesulfonic acid, citric acid, benzoic acid, hydroxybenzoic acid, and naphthoic acid.

[0378] As the salt, a salt of the above-mentioned acid can be used. The salt is not limited, but ammonium derivative salts such as trimethylamine salt and triethylamine salt, pyridine derivative salt, morpholine derivative salt, etc. can be preferably used.

[0379] 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, relative to the total solid content.

[0380] (IIC-2)

[0381] Examples of the acid generator include a thermal acid generator and a photoacid generator.

[0382] (IIC-2-1)

[0383] 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.

[0384] (IIC-2-2)

[0385] The photoacid generator generates acid when the resist is exposed. Therefore, the acidity of the lower film can be adjusted. This is a method to match the acidity of the lower film 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.

[0386] 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.

[0387] As Salt compounds, such as diphenyl iodide Hexafluorophosphate, diphenyl iodide Trifluoromethanesulfonate, diphenyl iodide Nonafluorobutanesulfonate, diphenyl iodide Perfluorooctane sulfonate, diphenyl iodide Camphorsulfonate, di(4-tert-butylphenyl)iodide Camphorsulfonate and di(4-tert-butylphenyl)iodide Iodine triflate and sulfonium salt compounds such as triphenylsulfonium hexafluoroantimonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium camphorsulfonate, and triphenylsulfonium trifluoromethanesulfonate.

[0388] Examples of the sulfonyl imide compound include N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoro-n-butanesulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, and N-(trifluoromethanesulfonyloxy)naphthalimide.

[0389] 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.

[0390] (IIC-2-3)

[0391] The acid generator may be used alone or in combination of two or more.

[0392] 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.

[0393] (IID) Other optional ingredients

[0394] The resist underlayer film-forming composition of one embodiment of the present invention may contain a crosslinking agent, a surfactant, a light absorber, a rheology modifier, an adhesion promoter, and the like, in addition to the above-mentioned components, as necessary.

[0395] (IID-1) Cross-linking agent

[0396] Representative crosslinking agents include aminoplast crosslinking agents and phenoplast crosslinking agents.

[0397] As the crosslinking agent, a crosslinking agent with high heat resistance can be used. As the crosslinking agent with high heat resistance, a compound having an aromatic ring (for example, a benzene ring or a naphthalene ring) in the molecule and containing a crosslinking-forming substituent can be preferably used.

[0398] (IID-1-1)

[0399] As aminoplast crosslinking agents, there can be mentioned highly alkylated, alkoxylated, or alkoxyalkylated melamine, benzoguanamine, glycoluril, urea, polymers thereof, etc. Preferred crosslinking agents are those having 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 be used.

[0400] It is preferably at least one selected from tetramethoxymethyl glycoluril and hexamethoxymethylmelamine.

[0401] Some specific examples are as follows.

[0402]

[0403] (IID-1-2)

[0404] Examples of the phenolic plastic crosslinking agent include highly alkylated, alkoxylated, or alkoxyalkylated aromatic compounds, and polymers thereof. Preferred crosslinking agents are those having at least two crosslinking-forming 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.

[0405] Examples of such a compound include, in addition to the above-mentioned compounds, 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).

[0406]

[0407] 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 listed above can be used. n1 is an integer of 1 to 4, n2 is an integer of 1 to (5-n1), and (n1+n2) is an integer of 2 to 5. n3 is an integer of 1 to 4, n4 is 0 to (4-n3), and (n3+n4) is an integer of 1 to 4. The number of repeating structural units of oligomers and polymers can be used in the range of 2 to 100, or 2 to 50.

[0408] Some specific examples are as follows.

[0409]

[0410]

[0411] (IID-1-3)

[0412] Crosslinking agents such as aminoplast crosslinking agents and phenoplast crosslinking agents may be used alone or in combination of two or more. The aminoplast crosslinking agent may be produced by a known method or a method based thereon, or a commercially available product may be used.

[0413] 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, 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 of the present invention.

[0414] (IID-2) Surfactant

[0415] The resist underlayer film-forming composition of the present invention may contain a surfactant in order to prevent the generation of pinholes, streaks, and the like and to further improve coating properties to surface unevenness.

[0416] 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 octylphenyl ether and polyoxyethylene nonylphenyl 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 fatty acid esters such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate; and nonionic surfactants,

[0417] EF301, EF303, EF352 (manufactured by トーケムプロダクツ Co., Ltd., trade name), メガファックF 171. F173, R-30, R-40 (made by Dainippon Co., Ltd., trade name), Fururo FC430, FC43 1 (trade name manufactured by Sumitomo Solar Co., Ltd.), ASUNALA AG710, SANE S-382, SC101, S Fluorine-based surfactants such as C102, SC103, SC104, SC105, SC106 (trade name manufactured by Asahi Glass Co., Ltd.),

[0418] Organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), etc.

[0419] The amount of these surfactants added is usually 2.0 mass % or less, preferably 1.0 mass % or less, relative to the total solid content of the resist underlayer film-forming composition of the present invention. These surfactants may be added alone or in combination of two or more.

[0420] (IID-3) Other additives

[0421] As the light absorber, for example, commercially available light absorbers described in "Technology and Market of Industrial Pigments" (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 Brightening Agent 112, 135 and 163; CISolvent Orange 2 and 45; CISolvent Red 1, 3, 8, 23, 24, 25, 27 and 49; CIPigment Green 10; CIPigment Brown 2, etc. The light absorber is usually blended in a ratio of 10% by mass or less, preferably 5% by mass or less, relative to the total solid content of the resist underlayer film-forming composition of the present invention.

[0422] The rheology modifier is mainly added for the following purposes: to improve the fluidity of the resist underlayer film-forming composition, especially in the baking process, to improve the uniformity of the film thickness of the resist underlayer film and the filling property of the resist underlayer film-forming composition into the hole. Specific examples include phthalic acid derivatives such as dimethyl phthalate, diethyl phthalate, diisobutyl phthalate, dihexyl phthalate, and butylisodecyl phthalate, adipic acid derivatives such as di-n-butyl adipate, diisobutyl adipate, diisooctyl adipate, and octyldecyl adipate, maleic acid derivatives such as di-n-butyl maleate, diethyl maleate, and dinonyl maleate, oleic acid derivatives such as methyl oleate, butyl oleate, and tetrahydrofurfuryl oleate, or stearic acid derivatives such as n-butyl stearate and glyceryl stearate. 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 of the present invention.

[0423] 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 in particular, 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, ureaazole, thiouracil, mercaptoimidazole, and mercaptopyrimidine, and urea or thiourea compounds such as 1,1-dimethylurea and 1,3-dimethylurea. These adhesion aids are usually blended 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.

[0424] 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 after the solvent is removed from the resist underlayer film-forming composition. The solid content may contain a crosslinkable resin in 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.

[0425] [III: Resist underlayer film]

[0426] The resist underlayer film can be formed using the resist underlayer film-forming composition of the present invention, for example, in the following manner.

[0427] The resist underlayer film-forming composition of one embodiment of the present invention is applied to a substrate (e.g., a silicon wafer substrate, a silicon dioxide-coated substrate (SiO2 substrate), a silicon nitride substrate (SiN substrate), a silicon oxynitride substrate (SiON substrate), a titanium nitride substrate (TiN substrate), a tungsten substrate (W substrate), a glass substrate, an ITO substrate, a polyimide substrate, and a low dielectric constant material (low-k material) coated substrate) used in the manufacture of semiconductor devices 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, thereby forming a resist underlayer film. As firing conditions, it can be appropriately selected from a firing temperature of 80°C to 800°C and a firing time of 0.3 to 60 minutes. Preferably, the firing temperature is 150°C to 400°C and the firing time is 0.5 to 2 minutes. As the atmosphere gas during firing, air can be used, or an inert gas such as nitrogen or argon can be used. 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.

[0428] In addition, a close-fitting layer and / or a silicon-containing layer containing less than 99% by mass or less than 50% by mass of Si can be formed by coating or vapor deposition on the resist lower film of one embodiment of the present invention. For example, a close-fitting layer described in Japanese Patent Publication No. 2013-202982, Patent No. 5827180, a method for forming a composition by spin coating a silicon-containing resist lower film (inorganic resist lower film) described in International Publication No. 2009 / 104552 (A1), and a Si-based inorganic material film formed by a CVD method, etc.

[0429] In addition, by coating a composition for forming an anti-etching underlayer film of one embodiment of the present invention on a semiconductor substrate including a portion with a height difference and a portion without a height difference (a so-called height difference substrate) and firing the composition, the height difference between the portion with a height difference and the portion without a height difference can be reduced.

[0430] [IV: Method for manufacturing semiconductor device]

[0431] (IVA)

[0432] (i)

[0433] A method for manufacturing a semiconductor device according to one embodiment of the present invention includes the following steps:

[0434] A step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film-forming composition of one embodiment of the present invention;

[0435] a step of forming a resist film on the resist underlayer film;

[0436] 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;

[0437] A step of etching the resist underlayer film through the resist pattern to perform patterning;

[0438] and

[0439] A step of processing a semiconductor substrate using a patterned resist underlayer film.

[0440] (ii)

[0441] In addition, a method for manufacturing a semiconductor device according to one embodiment of the present invention includes the following steps:

[0442] A step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film-forming composition of one embodiment of the present invention;

[0443] A step of forming a hard mask on the resist underlayer film;

[0444] A step of further forming a resist film on the hard mask;

[0445] 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;

[0446] A process of etching the hard mask through the resist pattern to perform patterning;

[0447] a step of etching the resist underlayer film through a patterned hard mask to perform patterning; and

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

[0449] (iii)

[0450] In addition, a method for manufacturing a semiconductor device according to 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 of 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 a patterned hard mask to perform patterning;

[0457] A step of removing the hard mask; and

[0458] A step of processing a semiconductor substrate through a patterned resist underlayer film.

[0459] (iv)

[0460] In addition, a method for manufacturing a semiconductor device according to one embodiment of the present invention includes the following steps:

[0461] A step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film-forming composition of one embodiment of the present invention;

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

[0463] A step of further forming a resist film on the hard mask;

[0464] 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;

[0465] A process of etching the hard mask through the resist pattern to perform patterning;

[0466] A step of etching the resist underlayer film through the etched hard mask to perform patterning;

[0467] A process of removing the hard mask;

[0468] A step of forming a vapor-deposited film (spacer) on the resist underlayer film after the hard mask is removed;

[0469] A process of processing the vapor-deposited film (spacer) by etching;

[0470] a step of removing the patterned resist underlayer film to leave the patterned vapor-deposited film (spacer); and

[0471] A step of processing a semiconductor substrate via a patterned vapor-deposited film (spacer).

[0472] The semiconductor substrate can be processed using the manufacturing methods (i) to (iv) above.

[0473] (IVB)

[0474] The step of forming a resist underlayer film using the resist underlayer film-forming composition of one embodiment of the present invention is as described in the above-mentioned [III: Resist underlayer film].

[0475] A hard mask such as a silicon-containing film may be formed as a second resist underlayer film on the resist underlayer film formed in the above steps, and a resist pattern may be formed thereon [the above (IVA) (ii) to (iv)].

[0476] 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, PVD, or ALD, and examples thereof include a SiON film, a SiN film, or a SiO 2 film.

[0477] Furthermore, an anti-reflection film (BARC) may be formed on these hard masks, or a resist shape correction film having no anti-reflection function may be formed.

[0478] In the process forming the resist pattern, exposure is carried out by being transmitted through the mask (photomask) for forming a prescribed pattern or by directly drawing. The exposure source can for example use g-rays, i-rays, KrF excimer lasers, ArF excimer lasers, EUV, electron beams. After exposure, post-exposure heating (Post Exposure Bake) can be carried out as required. Then, developer (for example 2.38 mass % tetramethylammonium hydroxide aqueous solution, butyl acetate) is utilized to develop, and then rinsed with rinse solution or pure water, so as to remove the developer used. Then, the post-baking for the drying of the resist pattern and the improvement of the adhesion with substrate is carried out.

[0479] The etching process performed after forming the resist pattern is performed by dry etching.

[0480] (IVC)

[0481] The resist film may also be patterned by a nanoimprint method or a self-assembled film method.

[0482] In the nanoimprint method, a mold (model) that is transparent to the irradiated light and has a pattern is used to shape the resist composition. In addition, in the self-assembled film method, a self-assembled film that naturally forms a nanoscale regular structure such as a diblock polymer (polystyrene-polymethyl methacrylate, etc.) is used to form a pattern.

[0483] In the nanoimprint method, before applying the curable composition that becomes the resist film, a silicon-containing layer (hard mask layer) can be optionally formed on the resist underlayer film by coating or vapor deposition, and a bonding layer can be further 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 can be applied on the bonding layer.

[0484] (IVD)

[0485] It should be noted that 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. In addition, argon, nitrogen, carbon dioxide, carbonyl sulfide, sulfur dioxide, neon, or nitrogen trifluoride can also be mixed with these gases for use.

[0486] (IVE)

[0487] It should be noted that, for the purpose of simplifying the process and reducing damage to the processed substrate, wet etching is sometimes performed. This can suppress the change in processing dimensions and the reduction in pattern roughness, and the substrate can be processed with a good yield. Therefore, in (IVA) (iii) to (iv) above, the hard mask can be removed by etching or alkaline liquid. In particular, when using an alkaline liquid, there is no limitation on the components, and the following substances are preferably contained as alkaline components.

[0488] 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-di Butylethanolamine, 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]non-5-ene, etc.

[0489] In addition, from the viewpoint of handling, tetramethylammonium hydroxide and tetraethylammonium hydroxide are particularly preferred, and an inorganic base and a quaternary ammonium hydroxide may be used in combination. 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.

[0490] Example

[0491] ○Synthesis of polymers

[0492] As polymers for resist underlayer films, the following compound group A, compound group B, compound group C, catalyst group D, solvent group E, reprecipitation solvent group F, and separation solvent G were used to synthesize structural formulas (S1) to (S17) and (S'1) to (S'17).

[0493] ○ Compound Groups A to C

[0494]

[0495] 〇 Catalyst group D, solvent group E, reprecipitation solvent group F, separation solvent group G

[0496] Methanesulfonic acid: D1

[0497] Tetrabutylammonium iodide: D2

[0498] Cyclohexanone (=CYH): E1

[0499] Tetrahydrofuran (=THF): E2

[0500] 25% sodium hydroxide aqueous solution: E3

[0501] Methanol / ammonia: F1

[0502] Methanol / water: F2

[0503] Butyl acetate / water: G1

[0504] [Synthesis example 1]

[0505] Add 10.0g of A1, 3.6g of C1, 20.5g of C2, and 51.1g of E1 to a flask and stir. Then, add a mixed solution of 12.8g of E1 and 0.3g of D1 dropwise at room temperature / nitrogen and react for about 1 hour. After the reaction stops, reprecipitate with F1 and dry the resin to obtain (S1). The weight average molecular weight Mw obtained by polystyrene conversion using GPC is about 1,700. The obtained resin is dissolved in PGMEA, and ion exchange is performed using a cation exchange resin and an anion exchange resin for 4 hours to obtain a target compound solution. Resins S2 to S17 were synthesized by the same operation.

[0506] [Table 1]

[0507]

[0508]

[0509] [Synthesis Example 18]

[0510] Add 10.0 g of S1, 21.1 g of C15, 1.1 g of D2, 48.3 g of E2, and 21.7 g of E3 to a flask. Heat to 55°C under nitrogen and react for about 20 hours. After the reaction stops, repeatedly perform liquid separation operations with G1, concentrate the organic layer, reprecipitate with F2, and dry to obtain a resin (S'1). The weight average molecular weight Mw obtained by polystyrene conversion measurement using GPC is about 2,100. The obtained resin is dissolved in PGMEA, and ion exchange is performed using a cation exchange resin and an anion exchange resin for 4 hours to obtain a target compound solution. Resins S'2 to S'17 were synthesized by the same operation.

[0511] [Table 2]

[0512]

[0513]

[0514] It should be noted that the above structural formula shows a structure corresponding to the case where all the sites that can be alkynylated are alkynylated.

[0515] ○Preparation of resist underlayer film

[0516] Polymers (S1) to (S17) and (S'1) to (S'17), 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, H1) as a surfactant were mixed in the proportions shown in the following table (the weight ratio of the crosslinking agent, the acid generator and the surfactant is represented when the weight of the polymer is 100; for the solvent, the weight ratio of each solvent is represented when the weight of the total solvent is 100), and filtered with a 0.1 μm polytetrafluoroethylene microfilter to prepare resist underlayer film materials (M1 to M17) and comparative examples (Comparison M1 to M17).

[0517]

[0518] [Table 3-1]

[0519]

[0520] [Table 3-2]

[0521]

[0522] [Table 3-3]

[0523]

[0524] [Solvent resistance test for resist solvents]

[0525] The anti-etching lower film material of Comparative Example 1-17 and Example 1-20 was coated on a silicon wafer using a spin coater, and fired at the specified temperature and specified time described in the table in the atmosphere to form a resist lower film in a manner of about 130 nm in thickness. The formed resist lower film was immersed in PGME / PGMEA=7 / 3 as a general diluent for 60 seconds and then spin dried, and fired at 100°C for 30 seconds to remove the residual solvent, thereby confirming resistance to solvents. The film thickness reduction rate before and after diluent immersion is judged to be 0 (Table 1) when it is less than 1%. The sample judged to be 0 can be judged to show a curability that can be used as a resist lower film.

[0526] [Curing test (confirmation of curing start temperature)]

[0527] The resist lower film materials of Comparative Examples 1-17 and Examples 1-20 were coated on a silicon wafer using a spin coater, and fired at the specified temperature described in the table for 60 seconds in the atmosphere to form a resist lower film with a film thickness of about 130 nm. After the formed resist lower film was immersed in PGME / PGMEA=7 / 3 as a general diluent for 60 seconds, it was spin dried and fired at 100°C for 30 seconds to remove the residual solvent, thereby confirming the resistance to the solvent. The film thickness reduction rate before and after the diluent immersion at each firing temperature is less than the comparative example (the composition corresponding to the embodiment without the introduction of propargyl group) is judged as 0 (Table 1). The sample judged as 0 means that it starts to solidify from the low temperature region relative to the comparative example.

[0528] [Table 4-1]

[0529] (Table 1)

[0530]

[0531] [Table 4-2]

[0532] Comparative Example 10 Compare M10 350℃ / 60sec ○ × × high temperature Comparative Example 11 Compare M11 350℃ / 60sec ○ × × high temperature Comparative Example 12 Compare M12 350℃ / 60sec ○ × × high temperature Comparative Example 13 Compare M13 350℃ / 60sec ○ × × high temperature Comparative Example 14 Compare M14 350℃ / 60sec ○ × × high temperature Comparative Example 15 Compare M15 350℃ / 60sec ○ × × high temperature Comparative Example 16 Compare M16 350℃ / 60sec ○ × × high temperature Comparative Example 17 Compare M17 350℃ / 60sec ○ × × high temperature

[0533] [Solvent resistance test in nitrogen]

[0534] The resist underlayer film materials of Comparative Examples 1-17, Examples 1-4, Example 6, Example 10, Example 12, and Examples 18-19 were coated on a silicon wafer using ACT-8 manufactured by Tokyo Elite Proso Co., Ltd., and fired at the specified temperature and time described in the table under nitrogen to form a 130nm resist underlayer film. After dipping in PGME / PGMEA = 7 / 3 for 60 seconds in the same manner as above, spin drying was performed, and the residual solvent was removed by firing at 100°C for 30 seconds, thereby confirming the resistance to solvents. The film thickness reduction rate before and after diluent dipping was judged to be less than that of the comparative example (the structure without the introduction of propargyl group corresponding to the example) as O (Table 2).

[0535] [Table 5]

[0536] (Table 22)

[0537]

[0538] [Measurement of etching rate]

[0539] Use a spin coater to apply the resist lower film materials of Comparative Examples 1-17 and Examples 1-20 on a silicon wafer, respectively. Sinter on a hot plate at the specified temperature and for the specified time described in the table to form a 130nm resist lower film. As an etching gas, use O2 / N2 gas or CF4 gas to measure the dry etching rate. The dry etching rate ratio described in the table is the dry etching rate ratio of (resist lower film) / (phenol novolac resin film). (Table 3).

[0540] The etcher and etching gas used in the etching measurement are as follows.

[0541] RIE-200NL (manufactured by SAMU): CF4 50sccm

[0542] RIE-200NL (manufactured by SAMU): O2 / N2 10sccm / 200sccm

[0543] [Measurement of optical constants]

[0544] The resist underlayer film materials of Comparative Examples 1-17 and Examples 1-20 were coated on silicon wafers using a spin coater. The resist underlayer films (film thickness 50 nm) were formed by firing on a hot plate at the specified temperature and time described in the table. The refractive index (n value) and optical absorption coefficient (k value, also called attenuation coefficient) of these resist underlayer films at a wavelength of 193 nm were measured using a spectroscopic ellipsometer (Table 3).

[0545] [Film shrinkage measurement]

[0546] The resist lower film materials of Comparative Examples 1-17 and Examples 1-20 were coated on silicon wafers using a spin coater, and then fired at 160°C for 60 seconds, and the film thickness was measured. Then, the film thickness was further measured at 350°C for 60 seconds. For samples whose film thickness difference between the film thickness fired at 160°C and the film thickness fired at 350°C was smaller than that of the comparative example (the structure corresponding to the example without the introduction of the propargyl group), it can be judged that the film shrinkage is small and the heat resistance is excellent, so it is judged to be 0 (Table 3).

[0547] [Table 6-1]

[0548] (Table 3)

[0549]

[0550] [Table 6-2]

[0551] Comparative Example 9 Compare M9 350℃ / 60sec 0.89 0.83 1.42 / 0.38 × Comparative Example 10 Compare M10 350℃ / 60sec 0.90 0.85 1.43 / 0.41 × Comparative Example 11 Compare M11 350℃ / 60sec 0.95 0.91 1.54 / 0.54 × Comparative Example 12 Compare M12 350℃ / 60sec 0.94 0.86 1.53 / 0.43 × Comparative Example 13 Compare M13 350℃ / 60sec 0.96 0.91 1.54 / 0.55 × Comparative Example 14 Compare M14 350℃ / 60sec 0.97 0.89 1.55 / 0.54 × Comparative Example 15 Compare M15 350℃ / 60sec 0.96 0.89 1.54 / 0.55 × Comparative Example 16 Compare M16 350℃ / 60sec 0.97 0.89 1.53 / 0.54 × Comparative Example 17 Compare M17 350℃ / 60sec 0.97 0.89 1.54 / 0.54 ×

[0552] [Coating and Coverage Tests on High-Level Substrates]

[0553] 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 film is sometimes poor compared to a silicon wafer without a high-low. Therefore, a test was conducted to determine whether the high-low substrate can be uniformly coated. Visual confirmation was performed, and the case where uniform coating was possible was judged as ○. The evaluation of flattening was performed using the groove area (dense pattern area) with a groove width of 50nm and a spacing of 100nm in the above-mentioned substrate. The coating thickness of the dense area was compared with that of the area (open area) where no pattern was formed. After the resist lower film forming composition prepared in Comparative Example 1-17 and Example 1-20 was applied to the above-mentioned substrate, it was sintered on a hot plate at the specified temperature and specified time described in the table to form a 130nm resist lower 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 (the coating height difference between the groove area and the open area, referred to as deviation) was measured to evaluate the flattening property. Among them, the flattening property means that the film thickness difference (Iso-dense deviation) 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 the comparative example (the structure without the introduction of the propargyl group corresponding to the embodiment) is judged as o (Table 4).

[0554] [Table 7-1]

[0555] (Table 44

[0556]

[0557] [Table 7-2]

[0558] Comparative Example 6 Compare M6 130nm 350℃ / 60sec <![CDATA[SiO2]]> ○ × Comparative Example 7 Compare M7 130nm 350℃ / 60sec <![CDATA[SiO2]]> ○ × Comparative Example 8 Compare M8 130nm 350℃ / 60sec <![CDATA[SiO2]]> ○ × Comparative Example 9 Compare M9 130nm 350℃ / 60sec <![CDATA[SiO2]]> ○ × Comparative Example 10 Compare M10 130nm 350℃ / 60sec <![CDATA[SiO2]]> ○ × Comparative Example 11 Compare M11 130nm 350℃ / 60sec <![CDATA[SiO2]]> ○ × Comparative Example 12 Compare M12 130nm 3350℃ / 60sec <![CDATA[SiO2]]> ○ × Comparative Example 13 Compare M13 130nm 3350℃ / 60sec <![CDATA[SiO2]]> ○ × Comparative Example 14 Compare M14 130nm 350℃ / 60sec <![CDATA[SiO2]]> ○ × Comparative Example 15 Compare M15 130nm 350℃ / 60sec <![CDATA[SiO2]]> ○ × Comparative Example 16 Compare M16 130nm 350℃ / 60sec <![CDATA[SiO2]]> ○ × Comparative Example 17 Compare M17 130nm 350℃ / 60sec <![CDATA[SiO2]]> ○ ×

[0559] [Embeddability test on high-height substrates]

[0560] 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. The embedding property was evaluated using a groove area (dense pattern area) with a groove width of 50nm and a spacing of 100nm in the above-mentioned substrate. After the composition for forming an anti-etching lower layer film prepared in the embodiments and comparative examples in the following table was applied to the above-mentioned substrate, it was sintered on a heating plate at the specified temperature and specified time described in the table to form a 130nm anti-etching lower layer film. The embedding property of the substrate was observed using a scanning electron microscope (S-4800) manufactured by Hitachi High-Tech Nologis Co., Ltd. The situation where the anti-etching lower layer film can be filled to the bottom of the groove is judged as embedding property ○ (Table 5).

[0561] [Table 8]

[0562] (Table 5)

[0563]

Claims

1. A resist underlayer film-forming composition comprising a novolac resin and a solvent, The novolac resin contains a structural unit A having an aromatic ring, and the structural unit A contains one or more structural units represented by the following formula (A): In the formula (A), R 1 is a substituent on a hydrogen atom or a nitrogen atom of a pyrrole ring, and the substituent represents: (i) hydroxymethyl; (ii) a linear alkoxymethyl group, a branched alkoxymethyl group, or a cyclic alkoxymethyl group having 2 to 20 carbon atoms; or (iii) a linear alkyl group having 1 to 20 carbon atoms, a branched alkyl group, a cyclic alkyl group, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, or an aryl group having 6 to 30 carbon atoms; R 2 is an optional substituent on a carbon atom constituting the pyrrole ring, and R 2 express: (iv) the same substituent group as described in (iii); (v) an acyl group having 1 to 15 carbon atoms, an alkoxy group having 1 to 15 carbon atoms, an aryloxy group having 6 to 15 carbon atoms, an alkoxycarbonyl group having 1 to 15 carbon atoms, an aryloxycarbonyl group having 7 to 15 carbon atoms, a monosubstituted amino group having 1 to 15 carbon atoms, or a disubstituted amino group having 2 to 30 carbon atoms; or (vi) hydroxy, nitro, amino, cyano, carboxyl, trifluoromethyl or halogen; in, For (ii) to (v) above, they may further have a substituent containing an oxygen atom, a substituent containing a sulfur atom, a substituent containing a nitrogen atom, an aryl group or a halogen group as a substituent, or their hydrocarbon chain part 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, In addition, R in novolac resin 1 and R 2 At least a portion of is a substituent having an alkynyl chain having 2 to 10 carbon atoms, n represents a substituent R 2 If n is multiple, multiple R 2 Can be the same or different, * indicates a connection key.

2. The resist underlayer film forming composition according to claim 1, The novolac resin comprises a composite structural unit AB represented by the following formula (AB), In the formula (AB), n represents the number of composite structural units AB, The structural unit A is represented by the formula (A) described in claim 1, The structural unit B represents a structural unit comprising one or more of the structures represented by the following formula (B1), the structure represented by the following formula (B2), and the structure represented by the following formula (B3), * indicates a connection key. In formula (B1), R 11 and R 12 each independently represents 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 connection key. *-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 connection key. In formula (B3), Z is a monocyclic, bicyclic, tricyclic or tetracyclic condensed ring having 4 to 25 carbon atoms and may have a substituent, wherein the monocyclic ring is a non-aromatic monocyclic ring; at least one of the monocyclic rings constituting the bicyclic, tricyclic and tetracyclic rings is a non-aromatic monocyclic ring, and the remaining monocyclic rings may be aromatic monocyclic rings or non-aromatic monocyclic rings, 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 more than five rings, X and Y are the same or different and each represents -CR 31 R 32 -Base, R 31 and R 32 are the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, x and y represent the number of X and Y respectively, and are independently 0 or 1. In the case of x=1, *-X x It is bonded to any carbon atom of the non-aromatic monocyclic ring constituting Z, that is, carbon atom 1. When x=0, *-X x It extends from carbon atom 1. When y=1, Y y -* is bonded to any carbon atom of the non-aromatic monocyclic ring constituting Z, that is, carbon atom 2, and when y=0, Y y -* indicates extension from carbon atom 2, The carbon atom 1 and the carbon atom 2 may be the same or different. If they are different, they may belong to the same non-aromatic monocyclic ring or different non-aromatic monocyclic rings. * indicates a connection key.

3. The resist underlayer film-forming composition according to claim 1, wherein R 1 and R 2 The alkynyl chain is represented by the formula, *-R 3 -C≡C-R 4 in, * indicates a connection key. R 3 is a single bond or a divalent organic group having 1 to 7 carbon atoms, R 4 is a hydrogen atom or a monovalent organic group having 1 to 7 carbon atoms, R 3 and R 4 The total number of carbon atoms is 0-8. 4 . 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. 5 . The resist underlayer film forming composition according to claim 1 , further comprising an acid and / or a salt thereof and / or an acid generator. 6 . The resist underlayer film forming composition according to claim 1 , further comprising a crosslinking agent. 7 . The resist underlayer film-forming composition according to claim 6 , wherein the crosslinking agent is an aminoplast crosslinking agent or a phenoplast crosslinking agent. 8 . The resist underlayer film forming composition according to claim 1 , further comprising a surfactant. 9 . A resist underlayer film on a semiconductor substrate, which is a fired product of a coating film made from the resist underlayer film-forming composition according to claim 1 . 10 . A method for forming a resist pattern used in semiconductor manufacturing, comprising the steps of applying the resist underlayer film-forming composition according to claim 1 on a semiconductor substrate and firing the composition to form a resist underlayer film.

11. 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 8; 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 using a patterned resist underlayer film.

12. 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 8; 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 a patterned hard mask; and A process of adding etching to a semiconductor substrate via a patterned 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 8; 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 a patterned hard mask; A process of removing the hard mask; and A step of processing a semiconductor substrate through a 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 8; 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 step 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 step of processing a semiconductor substrate via a patterned vapor-deposited film, i.e., a spacer. 15 . The method for manufacturing a semiconductor device according to claim 12 , wherein the hard mask is formed by coating or vapor deposition of an inorganic substance. 16 . The method for manufacturing a semiconductor device according to claim 11 , wherein the resist film is patterned by nanoimprinting or self-assembled film. 17 . The method for manufacturing a semiconductor device according to claim 13 , wherein the hard mask is removed by any one of etching and an alkaline chemical solution.

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