WO2023145923A1 - Resist underlayer film forming composition for nanoimprinting - Google Patents

Abstract

The present invention provides a resist underlayer film forming composition for nanoimprinting, the resist underlayer film forming composition being capable of forming a film which exhibits good planarization properties, while achieving high hydrophobicity and gas permeability by means of firing, and which has improved adhesion to a hydrophobic upper film; and this resist underlayer film forming composition for nanoimprinting is capable of adjusting the optical constants or the etching rate thereof by altering the molecular skeleton of a resin so as to adapt to a process. The present invention provides a resist underlayer film forming composition for nanoimprinting, the resist underlayer film forming composition containing an organic solvent and a compound that has an aromatic ring. If films are formed by firing this composition at the same temperature in the ambient atmosphere and in a nitrogen atmosphere, the difference between the contact angles with pure water of these films is 26 degrees or less.

Description

Composition for forming resist underlayer film for nanoimprint

The present invention provides a composition for forming a resist underlayer film for nanoimprinting, a resist underlayer film which is a cured product of a coating film made of the composition, a method for producing the resist underlayer film, a pattern forming method using the resist underlayer film, and a semiconductor. It relates to a method of manufacturing an apparatus.

In the manufacture of semiconductor devices, MEMS, etc., which require miniaturization, attention is focused on nanoimprint technology that can form fine structures on the order of several nanometers on substrates. In this method, a curable composition (resist composition) is applied to a substrate (wafer), a mold with a fine uneven pattern formed on the surface is pressed, and the resist is cured by heat or light in that state. Then, the uneven pattern of the mold is transferred to the cured resist film, and the mold is separated to form the pattern on the substrate.

In general photo-nanoimprint technology, first, a liquid resist composition is dropped onto a pattern formation area on a substrate using an inkjet method or the like, and the droplets of the resist composition are spread over the substrate (pre-spreading). The resist composition is then molded using a patterned mold that is transparent to the radiation. At this time, the droplets of the resist composition spread over the entire gap between the substrate and the mold due to capillary action (spread). The resist composition is also filled (filled) into the recesses on the mold by capillary action. The time it takes to complete the spread and fill is the fill time. After the filling of the resist composition is completed, light is applied to cure the resist composition, and then the two are separated. By performing these steps, a resist pattern having a predetermined shape is formed on the substrate.

The adhesion between the resist composition and the substrate is important in the release process of photo-nanoimprint technology. If the adhesion between the resist composition and the substrate is low, when the mold is separated in the mold release process, a part of the photocured product obtained by curing the resist composition is peeled off while remaining adhered to the mold. This is because, in some cases, a pattern peeling defect may occur. As a technique for improving the adhesion between the resist composition and the substrate, a technique for forming an adhesion layer, which is a layer for adhering the resist composition and the substrate, between the resist composition and the substrate. is proposed.

In addition, a multilayer process may be applied to ensure workability after patterning in nanoimprinting. Coating-type organic materials, silicone materials, or deposited films by CVD or the like are generally used as materials for the high etching resistance layer applied to the multilayer process. Furthermore, an adhesive layer and a hard mask (silicone) layer containing Si can be formed on the nanoimprint resist underlayer film by coating or vapor deposition. If the adhesion layer and the hard mask (silicone) layer containing Si are hydrophobic and exhibit a high pure water contact angle, the lower layer film is also hydrophobic and exhibits a high pure water contact angle. It is expected that the adhesiveness of the adhesive will increase and it will be difficult to peel off.

In addition, in the nanoimprint process, gas permeability is also regarded as important from the viewpoint of manufacturing throughput. Commonly used gases such as He, H ₂ , N ₂ , CO ₂ and air are relatively hydrophobic gases at room temperature. be done. For this reason, it is preferable that the underlayer film material through which the gas permeates should have a high water contact angle, which can be expected to increase the throughput.

JP 2019-36725 A

Therefore, the problem to be solved by the present invention is to provide a resist underlayer film-forming composition for nanoimprints, which can provide a film having high hydrophobicity and gas permeability by baking, and can improve adhesion to a hydrophobic upper layer film. is to provide

The present invention includes the following.
[1]
A composition for forming a resist underlayer film for nanoimprinting containing an aromatic ring-containing compound and an organic solvent, wherein the composition is fired in the air at the same temperature and pure water when fired in a nitrogen atmosphere. A composition for forming a resist underlayer film for nanoimprints, which forms a film having a contact angle difference of 26 degrees or less.
[2]
The composition for forming a resist underlayer film for nanoimprinting according to [1], wherein the compound containing an aromatic ring is a polymer containing an aromatic ring.
[3]
The composition for forming a resist underlayer film for nanoimprinting according to [2], wherein the polymer containing an aromatic ring is a novolac resin.
[4]
The composition for forming a resist underlayer film for nanoimprinting according to [3], wherein the polymer containing an aromatic ring is a novolak resin containing a unit structure derived from an aromatic hydrocarbon containing a heteroatom.
[5]
The unit structure derived from the heteroatom-containing aromatic hydrocarbon is derived from a heterocyclic ring, an aromatic hydrocarbon having at least one oxygen-containing substituent, or an aromatic hydrocarbon linked by at least one -NH- The composition for forming a resist underlayer film for nanoimprinting according to [4], which has a unit structure that
[6]
The aromatic ring-containing polymer is an optionally substituted aromatic hydrocarbon, or an aromatic ring may be condensed or condensed, and may have a substituent 4 to 12-membered The composition for forming a resist underlayer film for nanoimprinting according to [4] or [5], which is a novolak resin containing a unit structure derived from a monocyclic, bicyclic, or tricyclic compound of
[7]
The composition for forming a resist underlayer film for nanoimprinting according to [1], wherein the polymer is a novolac resin containing a repeating unit structure represented by the following formula (I).

[In formula (I), n represents a number from 1 to 5. A represents an organic group having an aromatic hydrocarbon containing heteroatoms. B represents an organic group having a structure represented by formula (II), (III) or (IV) below.

(In formula (II), R and R′ are each independently a hydrogen atom, an optionally substituted aromatic hydrocarbon group having 6 to 30 carbon atoms, an optionally substituted represents a heterocyclic group having 3 to 30 carbon atoms, or an optionally substituted linear, branched or cyclic alkyl group having 10 or less carbon atoms.)

(In formula (III), X and Y each independently represent an optionally substituted aromatic hydrocarbon group having 6 to 30 carbon atoms, and i and j each independently represent 0 or 1. , p, q, and k represent the number of bonds, p and q each independently represent 0 or 1, p and q are not 0 at the same time, k represents an integer from 0 to 2, Z, together with C, forms a 4- to 12-membered monocyclic, bicyclic, or tricyclic ring which may be condensed with an aromatic ring, may have a substituent, and may contain a heteroatom. .)

(In formula (IV), Ar represents an optionally substituted aromatic hydrocarbon group having 6 to 30 carbon atoms, and J ¹ and J ² are each independently a direct bond or a divalent organic group represents.)]
[8]
2. The resist underlayer film-forming composition according to claim 1, wherein the novolac resin comprises a composite unit structure AB' represented by the following formula (AB).

In the formula (AB),
n represents the number of composite unit structures AB',
A represents an organic group having an aromatic hydrocarbon containing heteroatoms,
B' represents one or more unit structures containing a structure represented by the following formula (B1), (B2) or (B3),
* indicates a binding hand.

[In formula (B1),
R and R' are each independently a hydrogen atom, an optionally substituted aromatic ring residue having 6 to 30 carbon atoms, an optionally substituted heterocyclic group having 3 to 30 carbon atoms Represents a cyclic residue or a linear, branched or cyclic alkyl group having 10 or less carbon atoms which may have a substituent,
* indicates a binding hand. ]

[In formula (B2),
Z ⁰ is selected from the group consisting of an optionally substituted aromatic ring residue or aliphatic ring residue having 6 to 30 carbon atoms, or the aromatic ring residue and the aliphatic ring residue represents an organic group in which the two groups are connected by a single bond,
J ¹ and J ² each independently represent a direct bond or a divalent organic group optionally having a substituent,
* indicates a binding hand. ]

[In formula (B3),
Z is an optionally substituted monocyclic, bicyclic, tricyclic or tetracyclic condensed ring having 4 to 25 carbon atoms, said monocyclic ring being a non-aromatic monocyclic ring; At least one of the monocyclic rings constituting the ring, tricyclic ring and tetracyclic ring is a non-aromatic monocyclic ring, and the remaining monocyclic rings may be aromatic monocyclic or non-aromatic monocyclic rings, and the monocyclic, bicyclic, A tricyclic or tetracyclic condensed ring may further form a condensed ring with one or more aromatic rings to form a pentacyclic or more condensed ring,
X and Y are the same or different and represent a -CR ³¹ R ³² - group, R ³¹ and R ³² are the same or different and represent a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms,
x and y each represent the number of X and Y, each independently representing 0 or 1;

is bonded to any carbon atom 1 constituting the non-aromatic monocyclic ring of Z when x is 1, and extends from carbon atom 1 when x is 0;

is bonded to any carbon atom 2 constituting the non-aromatic monocyclic ring of Z when y is 1, and extends from carbon atom 2 when y is 0;
The carbon atom 1 and the carbon atom 2 may be the same or different, and when different, may belong to the same non-aromatic monocyclic ring or different non-aromatic monocyclic rings,
* indicates a binding hand. ]
[9]
The composition for forming a resist underlayer film for nanoimprints according to any one of [1] to [8], further comprising a surfactant.
[10]
The resist underlayer film-forming composition for nanoimprints according to any one of [1] to [9], further comprising a cross-linking agent.
[11]
The composition for forming a resist underlayer film for nanoimprints according to any one of [1] to [10], further comprising at least one selected from the group consisting of acids, salts thereof and acid generators.
[12]
The composition for forming a resist underlayer film for nanoimprints according to any one of [1] to [11], wherein the solvent has a boiling point of 160° C. or higher.
[13]
A resist underlayer film which is a cured product of a coating film made of the composition for forming a resist underlayer film for nanoimprints according to any one of [1] to [12].
[14]
A method for producing a resist underlayer film, comprising applying the resist underlayer film-forming composition for nanoimprinting according to any one of [1] to [12] onto a semiconductor substrate and baking the composition.
[15]
forming a resist underlayer film on a semiconductor substrate from the composition for forming a resist underlayer film for nanoimprints according to any one of [1] to [12];
applying a curable composition onto the resist underlayer film;
contacting the curable composition with a mold;
A step of irradiating the curable composition with light or an electron beam to form a cured film, and a step of separating the cured film and the mold;
A patterning method comprising:
[16]
The step of applying a curable composition onto the resist underlayer film comprises
Optionally forming a hard mask layer or silicone layer on the resist underlayer film by coating or vapor deposition,
forming an adhesion layer by coating or vapor deposition on the resist underlayer film or on the hard mask layer or silicone layer;
The pattern forming method of [15], comprising applying a curable composition on the adhesion layer.
[17]
forming a resist underlayer film on a semiconductor substrate from the composition for forming a resist underlayer film for nanoimprints according to any one of [1] to [12];
Optionally forming a hard mask layer or silicone layer on the resist underlayer film by coating or vapor deposition;
forming an adhesion layer on the resist underlayer film or on the hard mask layer or silicone layer by coating or vapor deposition;
applying a curable composition onto the adhesion layer or onto the hard mask;
forming a resist pattern by irradiation with light or an electron beam;
A method of manufacturing a semiconductor device, comprising the steps of etching a resist underlayer film, an adhesion layer, and an optionally formed hard mask layer with a formed resist pattern, and processing a semiconductor substrate with the patterned underlayer film. .
[18]
forming a resist underlayer film on a semiconductor substrate from the composition for forming a resist underlayer film for nanoimprints according to any one of [1] to [12];
Optionally, a hard mask layer is formed on the resist underlayer film by coating or vapor deposition, an adhesion layer is formed on the resist underlayer film or the hard mask layer by coating or vapor deposition, and further the hard mask layer. applying a curing composition on top or onto the cling layer;
forming a resist pattern on the resist film by irradiation with light or an electron beam;
etching and patterning the hard mask layer through the resist pattern;
etching and patterning the resist underlayer film through the etched hard mask layer;
removing the hard mask layer;
A step of forming a deposited film (spacer) on the resist underlayer film after removing the hard mask layer,
A step of processing the deposited film (spacer) by etching,
A step of removing the patterned resist underlayer film to leave a patterned deposited film (spacer), and a step of processing the semiconductor substrate through the patterned deposited film (spacer),
A method of manufacturing a semiconductor device comprising:
[19]
The pattern formation method according to [15] or [16], wherein nanoimprinting is performed in an atmosphere containing at least one gas selected from the group consisting of air, oxygen, nitrogen, argon, helium, and carbon dioxide.
[20]
The method of manufacturing a semiconductor device according to [17] or [18], wherein nanoimprinting is performed in an atmosphere containing at least one gas selected from the group consisting of air, oxygen, nitrogen, argon, helium, and carbon dioxide.
[21]
The method for manufacturing a semiconductor device according to [18], wherein the hard mask layer is removed by either etching or an alkaline chemical.

The composition for forming a resist underlayer film for nanoimprinting according to the present invention forms a film having a contact angle difference of 26 degrees or less with respect to pure water when baked in the air at the same temperature and when baked in a nitrogen atmosphere. It is a composition that can form a film that exhibits a high pure water contact angle (=hydrophobicity) and gas permeability over a wide firing temperature range from low to high temperatures. As a result, it is possible to improve the adhesion with the hydrophobic upper layer film, and it is expected that the film exhibits good permeability to the hydrophobic gas. Furthermore, the composition for forming a resist underlayer film according to the present invention exhibits good flattening properties, and by changing the molecular skeleton, it is possible to adjust the optical constant and etching rate to suit the process.

[I. Definition of terms]
In the present specification, definitions of major terms relating to the novolac resin, which is one embodiment of the present invention, will be explained below. The following definitions of terms apply with respect to novolac resins, unless specifically stated otherwise.

(I-1) "novolac resin"
"Novolac resin" means not only phenol-formaldehyde resin (so-called novolak-type phenol resin) and aniline-formaldehyde resin (so-called novolak-type aniline resin) in a narrow sense, but also in the presence of an acid catalyst or under equivalent reaction conditions. , a functional group that enables covalent bonding with an aromatic ring [e.g., an aldehyde group, a ketone group, an acetal group, a ketal group, a hydroxyl group or an alkoxy group bonded to a secondary or tertiary carbon, the α-position carbon of an alkylaryl group a hydroxyl group, an alkoxy group, or a halo group bonded to an atom (such as a benzylic carbon atom); a carbon-carbon unsaturated bond such as divinylbenzene or dicyclopentadiene; By forming a covalent bond with an aromatic ring (having a heteroatom-containing substituent such as an oxygen atom, a nitrogen atom, or a sulfur atom on the aromatic ring) It is used in its broadest sense to broadly encompass the polymerized polymer formed.

Therefore, the novolac resin referred to in the present specification is an organic compound containing a carbon atom (sometimes referred to as a "connected carbon atom") derived from the functional group, but in a compound having an aromatic ring via the connected carbon atom. By forming a covalent bond with the aromatic ring of , the compound having a plurality of aromatic rings is linked to form a polymer.

In this specification, the terms unit structure A, unit structure B, unit structure B', and unit structure C are used as unit structures that constitute the "novolac resin". Unit structure A is a unit structure derived from a compound having an aromatic ring. Unit structure B is a unit structure derived from a compound having a functional group that enables covalent bonding with the aromatic ring of unit structure A. Unit structure C is one unit structure equivalent in bonding mode to composite unit structure AB', has an aromatic ring, and has a functional group capable of covalent bonding with the aromatic ring of unit structure A. It is a unit structure derived from a compound having Since the bonding modes are the same, the unit structure C can be replaced with the composite unit structure A-B'.

(I-2) "Residue"
"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 bond, and even a monovalent group may be For example, replacing one hydrogen atom with one bond will result in a monovalent organic group, and replacing two hydrogen atoms with a bond will result in a divalent organic group.

(I-3) "Aromatic ring" (aromatic group, aryl group, arylene group)
“Aromatic ring” means an aromatic hydrocarbon ring, an aromatic heterocyclic ring, and residues thereof [“aromatic group”, “aryl group” (in the case of a monovalent group) or “arylene group” (two In the case of a valent group)], it is intended to include not only monocyclic (aromatic monocyclic) but also polycyclic (aromatic polycyclic). In the case of a polycyclic ring, at least one monocyclic ring is an aromatic monocyclic ring, and the remaining monocyclic rings forming a condensed ring with the aromatic monocyclic ring may be monocyclic heterocyclic rings (heteromonocyclic rings) or monocyclic rings. It may be an alicyclic hydrocarbon (alicyclic monocyclic).

Aromatic rings include benzene, indene, naphthalene, azulene, styrene, toluene, xylene, mesitylene, cumene, anthracene, phenanthrene, triphenylene, benzanthracene, pyrene, chrysene, fluorene, biphenyl, corannulene, perylene, fluoranthene, benzo[k ]fluoranthene, benzo[b]fluoranthene, benzo[ghi]perylene, coronene, dibenzo[g,p]chrysene, acenaphthylene, acenaphthene, naphthacene, pentacene, cyclooctatetraene, etc., more typically aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, pyrene; , quinoline, isoquinoline, chromene, thianthrene, phenothiazine, phenoxazine, xanthene, acridine, phenazine, carbazole, indolocarbazole, more typically furan, thiophene, pyrrole, imidazole, pyran, pyridine, Non-limiting examples include pyrimidine, pyrazine, pyrrolidine, piperidine, piperazine, morpholine.

Aromatic rings (e.g., benzene ring, naphthalene ring, etc.) may optionally have substituents, and such substituents include halogen atoms, saturated or unsaturated straight-chain, branched or cyclic hydrocarbons. A group (-R) (which may be interrupted by an oxygen atom one or more times in the middle of the hydrocarbon chain, including alkyl groups, alkenyl groups, alkynyl groups, propargyl groups, etc.), an alkoxy group or an aryloxy group ( —OR, where R represents the hydrocarbon group —R), an alkylamino group [—NHR or —NR ₂ (the two Rs may be the same or different), where R is the hydrocarbon group It represents -R and includes an alkyl group, an alkenyl group, an alkynyl group, a propargyl group, etc., which may be interrupted one or more times by an oxygen atom in the middle of the hydrocarbon chain. ], hydroxyl group, amino group (-NH ₂ ), carboxyl group, cyano group, nitro group, ester group (-CO ₂ R or -OCOR, where R represents the hydrocarbon group -R), amide group (- NHCOR, -CONHR, -NRCOR (the two R's may be the same or different) or -CONR ₂ (the two R's may be the same or different), wherein R is said hydrocarbon group -R ), a sulfonyl-containing group (--SO ₂ R, where R represents the hydrocarbon group --R or hydroxyl group --OH), a thiol group (--SH), a sulfide-containing group (--SR, where R represents the represents a hydrocarbon group —R); an organic group containing an ether bond [R ¹¹ -OR ¹¹ (R ¹¹ is each independently an alkyl group having 1 to 6 carbon atoms such as a methyl group or an ethyl group, a phenyl group, aryl groups such as naphthyl group, anthranyl group, pyrenyl group, etc.); groups can be mentioned.

Also included are organic groups having a condensed ring of one or more aromatic rings (benzene, naphthalene, anthracene, pyrene, etc.) and one or more aliphatic or heterocyclic rings. Examples of the aliphatic ring herein include cyclobutane, cyclobutene, cyclopentane, cyclopentene, cyclohexane, cyclohexene, methylcyclohexane, methylcyclohexene, cycloheptane, and cycloheptene. Examples of the heterocyclic ring include furan, thiophene, pyrrole, and imidazole. , pyran, pyridine, pyrimidine, pyrazine, pyrrolidine, piperidine, piperazine, and morpholine.

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

(I-4) “heterocycle”
The term "heterocycle" includes both aliphatic heterocycles and aromatic heterocycles, and is a concept that includes not only monocyclic (heteromonocyclic) but also polycyclic (heteropolycyclic). When polycyclic, at least one monocyclic ring is a heteromonocyclic ring, and the remaining monocyclic rings may be either aromatic hydrocarbon monocyclic rings or alicyclic monocyclic rings. As the aromatic heterocycle, the examples of (I-3) above can be referred to. It may have a substituent similarly to the aromatic ring (I-3).

(I-5) "Non-aromatic ring" (aliphatic ring)
A “non-aromatic monocyclic ring” is a monocyclic hydrocarbon that does not belong to an aromatic group, typically a monocyclic alicyclic compound. It may also be referred to as an aliphatic monocyclic ring (which may include aliphatic heterocyclic monocyclic rings and may contain an unsaturated bond unless it belongs to an aromatic compound). It may have a substituent similarly to the aromatic ring (I-3).

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

"Non-aromatic polycyclic" refers to polycyclic hydrocarbons that do not belong to aromatics, typically polycyclic alicyclic compounds. Aliphatic polycyclic [aliphatic heteropolycyclic (at least one of the monocyclic rings constituting the polycyclic ring is an aliphatic heterocyclic ring) may be included, and unless it belongs to an aromatic compound, it may contain an unsaturated bond You can call it good. Includes non-aromatic bicyclic, non-aromatic tricyclic and non-aromatic tetracyclic rings.

"Non-aromatic bicyclic ring" refers to a condensed ring composed of two monocyclic hydrocarbons not belonging to aromatics, typically a condensed ring of two alicyclic compounds. In the present specification, it may be referred to as an aliphatic bicyclic ring (which may include an aliphatic heterobicyclic ring and may contain an unsaturated bond as long as it does not belong to an aromatic compound). Non-aromatic bicyclic rings include bicyclopentane, bicyclooctane, bicycloheptene, and the like.

"Non-aromatic tricyclic" means a condensed ring composed of three monocyclic hydrocarbons not belonging to the aromatic group, typically three alicyclic compounds (each of which is a heterocyclic may contain an unsaturated bond unless it belongs to an aromatic compound). Non-aromatic tricyclics include tricyclooctane, tricyclononane, tricyclodecane, and the like.

"Non-aromatic tetracyclic ring" means a condensed ring composed of four monocyclic hydrocarbons not belonging to the aromatic group, typically four alicyclic compounds (each of which is a heterocyclic may contain an unsaturated bond unless it belongs to an aromatic compound). Non-aromatic tetracycles include hexadecahydropyrene and the like.

(1-6)
The term "carbon atoms constituting a ring (part)" refers to a hydrocarbon ring (which may be an aromatic ring, an aliphatic ring, or a heterocyclic ring) without a substituent, and means a carbon atom constituting the ring. do.

(I-8)
"Hydrocarbon group" refers to a group formed by removing one or more hydrogen atoms from a hydrocarbon, such hydrocarbons include saturated or unsaturated aliphatic hydrocarbons, saturated or unsaturated alicyclic Formula hydrocarbons, and aromatic hydrocarbons are included.

(1-9)
In the chemical structural formula showing the unit structure of the novolac resin in the specification of the present application, a bond (denoted by *) may be described for convenience, but such a bond is , any bondable bonding position in the unit structure can be adopted, and the bonding position in the unit structure is not limited at all.

[Nanoimprint Resist Underlayer Film-Forming Composition]
The composition for forming a resist underlayer film for nanoimprinting according to the present invention comprises a compound containing an aromatic ring, an organic solvent, and optionally other components. It is a composition that forms a film with a contact angle difference of 26 degrees or less with respect to pure water when the composition is fired in air at the same temperature and when fired in a nitrogen atmosphere.

A compound containing an aromatic ring may be a compound containing no repeating unit structure or a compound (polymer) containing a repeating unit structure.

Polymers containing aromatic rings are not particularly limited, and examples include polyvinyl alcohol, polyacrylamide, (meth)acrylic resins, polyamic acids, polyhydroxystyrenes, polyhydroxystyrene derivatives, and polymethacrylates, each containing an aromatic ring. Copolymer with maleic anhydride, epoxy resin, phenolic resin, novolac resin, resole resin, maleimide resin, polyetheretherketone resin, polyetherketone resin, polyethersulfone resin, polyketone resin, polyester resin, polyether resin At least one selected from the group consisting of urea resin, polyamide, polyimide, cellulose, cellulose derivative, starch, chitin, chitosan, gelatin, zein, sugar skeleton polymer compound, polyethylene terephthalate, polycarbonate, polyurethane and polysiloxane can be done. These resins are used alone or in combination of two or more.

Preferably, the polymer containing aromatic rings is a novolak resin. More preferably, the aromatic ring-containing polymer is a novolak resin containing unit structures derived from heteroatom-containing aromatic hydrocarbons. More preferably, the polymer containing an aromatic ring is an aromatic hydrocarbon that may have a substituent, or an aromatic ring that may be condensed or condensed, and may have a substituent. It is a novolak resin containing a unit structure derived from a 12- to 12-membered monocyclic, bicyclic, or tricyclic compound.
Here, the unit structure derived from the 4- to 12-membered monocyclic, bicyclic, or tricyclic compound optionally having substituent(s) described above can be exemplified by the structures shown below.

The unit structure derived from an aromatic hydrocarbon containing a heteroatom is preferably a heterocyclic ring, an aromatic hydrocarbon having at least one oxygen-containing substituent, or an aromatic hydrocarbon linked by at least one -NH- It is a unit structure derived from hydrogen.

Heterocycles include furan, pyran, thiophene, pyrrole, N-alkylpyrrole, N-arylpyrrole, imidazole, pyridine, pyrimidine, pyrazine, pyrrolidine, piperidine, piperazine, morpholine, triazine, thiazole, indole, phenylindole, purine, quinoline, isoquinoline, chromene, thianthrene, phenothiazine, phenoxazine, xanthene, acridine, phenazine, carbazole, indolocarbazole, etc. More typically, furan, thiophene, pyrrole, imidazole, pyran, pyridine, pyrimidine, pyrazine , pyrrolidine, piperidine, piperazine, morpholine. Heterocyclic rings are halogen atoms, saturated or unsaturated straight chain, branched or cyclic hydrocarbon groups, hydroxyl groups, amino groups, carboxyl groups, cyano groups, nitro groups, alkoxyl groups, ester groups, amide groups, sulfonyl groups. , a sulfide group, an ether group, and an aryl group.

The aromatic hydrocarbon having at least one oxygen-containing substituent is more preferably an aromatic hydrocarbon having at least two oxygen-containing substituents, more preferably an aromatic hydrocarbon having two oxygen-containing substituents. is hydrogen.
Oxygen-containing substituents include hydroxyl groups; hydroxyl groups in which hydrogen atoms are replaced by saturated or unsaturated straight chain, branched or cyclic hydrocarbon groups; and saturated or unsaturated straight chains interrupted one or more times by oxygen atoms. , branched or cyclic hydrocarbon groups, aromatic compounds and the like. In addition to the above oxygen-containing substituents, aromatic hydrocarbons include halogen atoms, saturated or unsaturated linear, branched or cyclic hydrocarbon groups, hydroxyl groups, amino groups, carboxyl groups, cyano groups, nitro groups, alkoxyl groups, It may have substituents such as groups, ester groups, amide groups, sulfonyl groups, sulfide groups, ether groups, and aryl groups.
The aromatic hydrocarbon linked by at least one -NH- is more preferably an aromatic hydrocarbon linked by one -NH-.
Aromatic hydrocarbons include benzene, indene, naphthalene, azulene, styrene, toluene, xylene, mesitylene, cumene, anthracene, phenanthrene, triphenylene, benzanthracene, pyrene, chrysene, fluorene, biphenyl, corannulene, perylene, fluoranthene, benzo[ k]fluoranthene, benzo[b]fluoranthene, benzo[ghi]perylene, coronene, dibenzo[g,p]chrysene, acenaphthylene, acenaphthene, naphthacene, pentacene and the like, but are not limited thereto.
The derived unit structure includes a unit structure formed by replacing some of the constituent atoms of the original compound molecule with other atoms or groups, or by changing bonds.

[Novolak Resin Containing Repeating Unit Structure Represented by Formula (I)]
Preferably, the aromatic ring-containing polymer is a novolak resin containing a repeating unit structure represented by the following formula (I).

[In formula (I), n represents a number from 1 to 5. A represents an organic group having an aromatic hydrocarbon containing heteroatoms. B represents an organic group having a structure represented by formula (II), (III) or (IV) below.

(In formula (II), R and R′ are each independently a hydrogen atom, an optionally substituted aromatic hydrocarbon group having 6 to 30 carbon atoms, an optionally substituted represents a heterocyclic group having 3 to 30 carbon atoms, or an optionally substituted linear, branched or cyclic alkyl group having 10 or less carbon atoms.)

(In formula (III), X and Y each independently represent an optionally substituted aromatic hydrocarbon group having 6 to 30 carbon atoms, and i and j each independently represent 0 or 1. , p, q, and k represent the number of bonds, p and q each independently represent 0 or 1, p and q are not 0 at the same time, k represents an integer from 0 to 2, Z, together with C, forms a 4- to 12-membered monocyclic, bicyclic, or tricyclic ring which may be condensed with an aromatic ring, may have a substituent, and may contain a heteroatom. .)

(In formula (IV), Ar represents an optionally substituted aromatic hydrocarbon group having 6 to 30 carbon atoms, and J ¹ and J ² are each independently a direct bond or a divalent organic group represents.)]

The "organic group having an aromatic hydrocarbon" in the group A refers to a group having a hydrocarbon exhibiting aromaticity. For example, in addition to benzene, cyclooctatetraene, indene, naphthalene, azulene, styrene, toluene, xylene, mesitylene, cumene, anthracene, phenanthrene, naphthacene, triphenylene, benzanthracene, pyrene, chrysene, fluorene, Groups derived from biphenyl, corannulene, perylene, fluoranthene, benzo[k]fluoranthene, benzo[b]fluoranthene, benzo[ghi]perylene, coronene, dibenzo[g,p]chrysene, acenaphthylene, acenaphthene, naphthacene, pentacene, etc. be done. Furthermore, an organic group having a condensed ring of an aromatic ring such as benzene and an aliphatic ring such as cyclobutane, cyclobutene, cyclopentane, cyclopentene, cyclohexane, cyclohexene, methylcyclohexane, methylcyclohexene, cycloheptane, and cycloheptene; and an aromatic ring such as furan, thiophene, pyrrole, imidazole, pyran, pyridine, pyrimidine, pyrazine, pyrrolidine, piperidine, piperazine and morpholine.

Preferably, the "aromatic hydrocarbon-containing organic group" in group A has from 6 to 30, or from 6 to 24 carbon atoms.
Preferably, the “organic group having an aromatic hydrocarbon” for Group A is an organic group having one or more benzene rings, naphthalene rings, or condensed rings of benzene rings and heterocyclic or aliphatic rings.
Aromatic hydrocarbons may be linked to each other by an alkylene group, an ether group, an ester group, an amide group, a sulfonyl group, a sulfide group, a ketone group, or the like.

The "organic group having an aromatic hydrocarbon" in group A may contain a heteroatom. It preferably contains a heteroatom.
Heteroatoms include, for example, oxygen atoms, nitrogen atoms, sulfur atoms, and the like.
Preferably, the "organic group having an aromatic hydrocarbon" in the group A has 6 to 30 carbon atoms containing at least one heteroatom selected from N, S and O on, in or between the rings. , or 6 to 24 organic groups. Examples of heteroatoms contained on the ring include amino groups (e.g., propargylamino groups), nitrogen atoms contained in cyano groups, formyl groups, hydroxy groups, carboxyl groups, and alkoxy groups (e.g., propargyloxy groups). oxygen atoms contained in the nitro group, and nitrogen and oxygen atoms contained in the nitro group. The heteroatom contained in the ring includes, for example, an oxygen atom contained in xanthene and a nitrogen atom contained in carbazole. Heteroatoms contained between rings include -NH-bond, -NHCO-bond, -O-bond, -COO-bond, -CO-bond, -S-bond, -SS-bond and -SO ₂ -bond. nitrogen atoms, oxygen atoms, and sulfur atoms contained in

Preferably, the "organic group having an aromatic hydrocarbon containing a heteroatom" in the group A is the above-described heterocyclic ring, an aromatic hydrocarbon having an oxygen-containing substituent, and an aromatic hydrocarbon linked by -NH- Including the unit structure derived from.

Substituents include halogen atoms, saturated or unsaturated linear, branched or cyclic hydrocarbon groups which may contain heteroatoms, hydroxyl groups, amino groups, carboxyl groups, cyano groups, nitro groups, alkoxyl groups, esters. groups, amide groups, sulfonyl groups, sulfide groups, ether groups, aryl groups, etc., but are not limited to these as long as they do not impair the effects of the present invention.

Preferably, group A is at least one selected from the following.
In addition, the compounds shown below are examples, and the present invention is not limited to these. Moreover, the above-described substituent may be bonded to any position on those aromatic rings.

(Example of amine skeleton)

(Example of phenol skeleton)

Further, NH of the amine skeleton and H of OH of the phenol skeleton may be replaced with substituents described below.

Group A is preferably at least one selected from the following.

(Example of unit structure derived from heterocycle)

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

(Example of unit structure derived from aromatic hydrocarbon linked by -NH-)

In the definitions of R and R' in formula (II), the "substituent", "aromatic hydrocarbon", and "heterocyclic ring" are as described above.

In the definition of R and R′ in formula (II), the “alkyl group” includes, for example, methyl group, ethyl group, n-propyl group, i-propyl group, cyclopropyl group, n-butyl group, i- butyl group, s-butyl group, t-butyl group, cyclobutyl group, 1-methyl-cyclopropyl group, 2-methyl-cyclopropyl group, n-pentyl group, 1-methyl-n-butyl group, 2-methyl- n-butyl group, 3-methyl-n-butyl group, 1,1-dimethyl-n-propyl group, 1,2-dimethyl-n-propyl group, 2,2-dimethyl-n-propyl group, 1-ethyl -n-propyl group, cyclopentyl group, 1-methyl-cyclobutyl group, 2-methyl-cyclobutyl group, 3-methyl-cyclobutyl group, 1,2-dimethyl-cyclopropyl group, 2,3-dimethyl-cyclopropyl group, 1-ethyl-cyclopropyl group, 2-ethyl-cyclopropyl group, n-hexyl group, 1-methyl-n-pentyl group, 2-methyl-n-pentyl group, 3-methyl-n-pentyl group, 4- methyl-n-pentyl group, 1,1-dimethyl-n-butyl group, 1,2-dimethyl-n-butyl group, 1,3-dimethyl-n-butyl group, 2,2-dimethyl-n-butyl group , 2,3-dimethyl-n-butyl group, 3,3-dimethyl-n-butyl group, 1-ethyl-n-butyl group, 2-ethyl-n-butyl group, 1,1,2-trimethyl-n -propyl group, 1,2,2-trimethyl-n-propyl group, 1-ethyl-1-methyl-n-propyl group, 1-ethyl-2-methyl-n-propyl group, cyclohexyl group, 1-methyl- cyclopentyl group, 2-methyl-cyclopentyl group, 3-methyl-cyclopentyl group, 1-ethyl-cyclobutyl group, 2-ethyl-cyclobutyl group, 3-ethyl-cyclobutyl group, 1,2-dimethyl-cyclobutyl group, 1,3 -dimethyl-cyclobutyl group, 2,2-dimethyl-cyclobutyl group, 2,3-dimethyl-cyclobutyl group, 2,4-dimethyl-cyclobutyl group, 3,3-dimethyl-cyclobutyl group, 1-n-propyl-cyclopropyl group, 2-n-propyl-cyclopropyl group, 1-i-propyl-cyclopropyl group, 2-i-propyl-cyclopropyl group, 1,2,2-trimethyl-cyclopropyl group, 1,2,3- trimethyl-cyclopropyl group, 2,2,3-trimethyl-cyclopropyl group, 1-ethyl-2-methyl-cyclopropyl group, 2-ethyl-1-methyl-cyclopropyl group, 2-ethyl-2-methyl- cyclopropyl, 2-ethyl-3-methyl-cyclopropyl, n-heptyl, n-octyl, n-nonyl and n-decyl.

Preferably, R and R' are each independently phenyl, naphthalenyl, anthracenyl, phenanthrenyl, naphthacenyl, pyrenyl.

Some specific examples of the organic group containing the structure represented by formula (II) are as follows. * indicates the bonding site with the group A. Needless to say, a structure including the illustrated structure as a part of the whole may be used.

In formula (III), X and Y each independently represent an optionally substituted aromatic hydrocarbon group having 6 to 30 carbon atoms; i, j and k each independently represent 0 or 1; show. Aromatic hydrocarbon groups are divalent. "Aromatic hydrocarbon" is as described above.
In the formula (III), the 4- to 12-membered monocyclic ring formed by Z together with C includes cyclopropane, cyclobutane, cyclopentane, cyclohexane, cyclohexene and the like, and the bicyclic ring includes bicyclopentane, bicyclooctane and bicycloheptene. etc., and the tricyclic ring includes tricyclooctane, tricyclononane, tricyclodecane and the like.
Aromatic rings which may be condensed into monocyclic, bicyclic or tricyclic rings include benzene ring, naphthalene ring, anthracene ring, pyrene ring and the like. One or more of these may be condensed.

Some specific examples of the organic group containing the structure represented by formula (III) are as follows. The bonding site with group A is not particularly limited. Needless to say, a structure including the illustrated structure as a part of the whole may be used.

In the definition of Ar in formula (IV), "aromatic hydrocarbon" is as described above.
In the definitions of J ¹ and J ² , the “divalent organic group” is preferably a linear or It is a branched alkylene group. Examples of linear alkylene groups include methylene, ethylene, propylene, butylene, pentylene, and hexylene groups.

Some specific examples of the organic group containing the structure represented by formula (IV) are as follows. * indicates the bonding site with the group A. Needless to say, a structure including the illustrated structure as a part of the whole may be used.

n is a number from 1-5, 1-4, or 1-3, preferably 1, 2, 3, 4, or 5, more preferably 1, 2, 3, or 4, most preferably 1, 2 or 3.

[Synthesis method]
A novolac resin having a repeating unit structure represented by formula (I) can be prepared by a known method. For example, a ring-containing compound represented by HAH and OHC-B, O=C-B, HO-B-OH, RO-B-OR, RO-CH ₂ -B-CH ₂ -OR, etc. It can be prepared by condensing the represented oxygen-containing compound (wherein A and B are as defined above, and R represents a halogen or an alkyl group having about 1 to 3 carbon atoms). One kind of the ring-containing compound and the oxygen-containing compound may be used together, or two or more kinds thereof may be used in combination. In this condensation reaction, the oxygen-containing compound can be used in an amount of 0.1 to 10 mol, preferably 0.1 to 2 mol, per 1 mol of the ring-containing compound.

Examples of catalysts used in the condensation reaction include mineral acids such as sulfuric acid, phosphoric acid and perchloric acid; Carboxylic acids such as sulfonic acids, formic acid and oxalic acid can be used. The amount of the catalyst used varies depending on the type of catalyst used, but is usually 0.001 to 10,000 parts by mass, preferably 0.001 to 10,000 parts by mass, per 100 parts by mass of the ring-containing compound (in the case of multiple types, the total of them). 01 to 1,000 parts by mass, more preferably 0.05 to 100 parts by mass.

The condensation reaction can be carried out without a solvent, but it 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 inhibit the reaction. For example, 1,2-dimethoxyethane, diethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, tetrahydrofuran, dioxane, 1,2-dichloromethane, 1,2-dichloroethane, toluene, N-methylpyrrolidone, dimethylformamide and the like. mentioned. The condensation reaction temperature is usually 40°C to 200°C, preferably 100°C to 180°C. Although the reaction time varies depending on the reaction temperature, it is usually 5 minutes to 50 hours, preferably 5 minutes to 24 hours.

The weight average molecular weight of the novolak resin according to the present invention is usually 500-100,000, preferably 600-50,000, 700-10,000, or 800-8,000.

(IIA) novolac resin (IIA-2)
The novolac resin preferably has the following formula (AB):

It includes a composite unit structure AB' represented by.

In formula (AB), n represents the number of composite unit structures A-B', and unit structure A is the same as group A in formula (I) above.

(IIA-2-1) Unit structure B'
Unit structure B 'is one or two or more unit structures containing a connecting carbon atom [see (I-1) above] that bonds to an aromatic ring in unit structure A, and (IIA-2-2) described later. to (IIA-2-4), including structures represented by formulas (B1), (B2), or (B3).

In addition, at least one composite unit structure AB' is equivalent to one unit structure (IIA-2-2-3), (IIA-2-3-2), (IIA-2-4 -3) may be replaced with one or more unit structures C including structures represented by formulas (C1), (C2) and (C3) respectively.

(IIA-2-2) Formula (B1)

In formula (B1),
R and R' are each independently a hydrogen atom, an optionally substituted aromatic ring having 6 to 30 carbon atoms, and an optionally substituted heterocyclic ring having 3 to 30 carbon atoms. , or an optionally substituted linear, branched or cyclic alkyl group having 10 or less carbon atoms.

In addition, the two bonding hands of formula (B1) can be covalently bonded to the aromatic ring in unit structure A.

(IIA-2-2-1)
In the definition of R and R′ in formula (B1), the above (I-3) and (I-4) can be referred to for the “aromatic ring” and “heterocyclic ring”.

In the definition of R and R' in formula (B1), the "alkyl group" includes, for example, methyl group, ethyl group, n-propyl group, i-propyl group, cyclopropyl group, n-butyl group, i- butyl group, s-butyl group, t-butyl group, cyclobutyl group, 1-methyl-cyclopropyl group, 2-methyl-cyclopropyl group, n-pentyl group, 1-methyl-n-butyl group, 2-methyl- n-butyl group, 3-methyl-n-butyl group, 1,1-dimethyl-n-propyl group, 1,2-dimethyl-n-propyl group, 2,2-dimethyl-n-propyl group, 1-ethyl -n-propyl group, cyclopentyl group, 1-methyl-cyclobutyl group, 2-methyl-cyclobutyl group, 3-methyl-cyclobutyl group, 1,2-dimethyl-cyclopropyl group, 2,3-dimethyl-cyclopropyl group, 1-ethyl-cyclopropyl group, 2-ethyl-cyclopropyl group, n-hexyl group, 1-methyl-n-pentyl group, 2-methyl-n-pentyl group, 3-methyl-n-pentyl group, 4- methyl-n-pentyl group, 1,1-dimethyl-n-butyl group, 1,2-dimethyl-n-butyl group, 1,3-dimethyl-n-butyl group, 2,2-dimethyl-n-butyl group , 2,3-dimethyl-n-butyl group, 3,3-dimethyl-n-butyl group, 1-ethyl-n-butyl group, 2-ethyl-n-butyl group, 1,1,2-trimethyl-n -propyl group, 1,2,2-trimethyl-n-propyl group, 1-ethyl-1-methyl-n-propyl group, 1-ethyl-2-methyl-n-propyl group, cyclohexyl group, 1-methyl- cyclopentyl group, 2-methyl-cyclopentyl group, 3-methyl-cyclopentyl group, 1-ethyl-cyclobutyl group, 2-ethyl-cyclobutyl group, 3-ethyl-cyclobutyl group, 1,2-dimethyl-cyclobutyl group, 1,3 -dimethyl-cyclobutyl group, 2,2-dimethyl-cyclobutyl group, 2,3-dimethyl-cyclobutyl group, 2,4-dimethyl-cyclobutyl group, 3,3-dimethyl-cyclobutyl group, 1-n-propyl-cyclopropyl group, 2-n-propyl-cyclopropyl group, 1-i-propyl-cyclopropyl group, 2-i-propyl-cyclopropyl group, 1,2,2-trimethyl-cyclopropyl group, 1,2,3- trimethyl-cyclopropyl group, 2,2,3-trimethyl-cyclopropyl group, 1-ethyl-2-methyl-cyclopropyl group, 2-ethyl-1-methyl-cyclopropyl group, 2-ethyl-2-methyl- cyclopropyl, 2-ethyl-3-methyl-cyclopropyl, n-heptyl, n-octyl, n-nonyl and n-decyl.

Preferably, R and R' are each independently phenyl, naphthalenyl, anthracenyl, phenanthrenyl, naphthacenyl, pyrenyl.

(IIA-2-2-2)
Further, in the unit structure containing the structure represented by formula (B1), for example, two or three structures of formula (B1) that are the same or different from each other are combined with a divalent or trivalent linking group, , dimeric or trimeric structures. In this case, one of the two bonding hands is bonded to the linking group as shown in the following formula (B11) in each structure of formula (B1).

Examples of such a linking group include a linking group having two or three aromatic rings (corresponding to unit structure A). Specific examples of divalent or trivalent linking groups include the following divalent linking groups (L1) exemplified in formula (B11) above:

[X ¹ represents a single bond, a methylene group, an oxygen atom, a sulfur atom, -N(R ⁵ )-, and R ⁵ is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms (chain hydrocarbon, cyclic hydrocarbon represents hydrogen (which may be aromatic or non-aromatic). ]
In addition, for example, divalent or trivalent linking groups of the following formulas (L2) and (L3) can be exemplified.

[X ² represents a methylene group, an oxygen atom or -N(R ⁶ )-, and R ⁶ is a hydrogen atom, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, or an aromatic hydrocarbon group having 5 to 20 carbon atoms represents a group. ]

A divalent linking group such as the following formula (L4), which can form a covalent bond with a linking carbon atom through an addition reaction between acetylide and a ketone, can also be exemplified.

(IIA-2-2-3)
Note that when at least one of R and R' in formula (B1) is an aromatic ring, the aromatic ring [for example, see Ar in formula (B12) below] is additionally combined with another unit structure B' You may

In this case, the following formula (C1):

One of the connecting carbon atoms is a polymer terminal T (hydrogen atom; hydroxyl group, various functional groups such as unsaturated aliphatic hydrocarbon groups, terminal unit structure A, unit structure A in other polymer chains etc.), it can be replaced with at least one composite unit structure AB' as one unit structure C equivalent to the composite unit structure AB'. That is, the aromatic ring [Ar in formula (C1)] in formula (C1) and another unit structure B' are bonded, and the bonds from the remaining connecting carbon atoms shown in formula (C1) The polymer chain may be extended by manually bonding to the aromatic ring of the unit structure A.

(IIA-2-2-4)
Some specific examples of the unit structure B' containing the structure represented by formula (B1) are as follows. * basically indicates a binding site with the unit structure A. Needless to say, a structure including the illustrated structure as a part of the whole may be used.

(IIA-2-3)

In formula (B2),
Z ⁰ is selected from the group consisting of an optionally substituted aromatic ring residue or aliphatic ring residue having 6 to 30 carbon atoms, or the aromatic ring residue and the aliphatic ring residue represents an organic group in which two groups are linked by a single bond. The organic group in which two groups selected from the group consisting of the aromatic ring residue and the aliphatic ring residue are linked by a single bond includes bivalent divalent groups such as biphenyl, cyclohexylphenyl, and bicyclohexyl. residues can be mentioned.

J ¹ and J ² each independently represent a direct bond or a divalent organic group which may have a substituent. The divalent organic group preferably has 1 to 6 carbon atoms optionally substituted by a hydroxyl group, an aryl group (phenyl group, substituted phenyl group, etc.) or a halo group (eg, fluorine) as a substituent. is a linear or branched alkylene group. Examples of linear alkylene groups include methylene, ethylene, propylene, butylene, pentylene, and hexylene groups.

(IIA-2-3-1)
Further, in the unit structure containing the structure represented by formula (B2), two or three of the above formulas (B2 ) may include a structure that is bound to a divalent or trivalent linking group to form a dimer or trimer structure.

(IIA-2-3-2)
Since formula (B2) includes an embodiment containing an aromatic ring [Z ⁰ of formula (B2)], the same as (IIA-2-2-3) of formula (B1) above, An aromatic ring [for example, an aromatic ring in Z ⁰ _Ar in formula (B21) below] may additionally bond to another unit structure B' [longitudinal bond in formula (B21)] .

[In formula (B21),
Z ⁰ _Ar is an optionally substituted aromatic ring residue having 6 to 30 carbon atoms, or two groups selected from the group consisting of the aromatic ring residue and the aliphatic ring residue is an organic group having at least one aromatic ring linked by a single bond, wherein the bond extending downward from Z ⁰ _Ar extends from the aromatic ring in Z ⁰ _Ar ,
J ¹ and J ² are the same as defined in formula (B2). ]
In this case, the following formula (C2):

[In formula (C2),
Z ⁰ _Ar , J ¹ and J ² are the same as defined in formula (B21),
T represents a polymer terminal. ]
One of the connecting carbon atoms is a polymer terminal T (hydrogen atom; hydroxyl group, various functional groups such as unsaturated aliphatic hydrocarbon groups, terminal unit structure A, unit structure A in other polymer chains etc.), it can be replaced with at least one composite unit structure AB' as one unit structure C equivalent to the composite unit structure AB'. That is, the aromatic ring in formula (C2) [the aromatic ring in Z ⁰ _Ar in formula (C2)] and another unit structure B' are bonded, and the remaining The polymer chain may be extended by bonding with the aromatic ring of the unit structure A with the bond from the linking carbon atom.

(IIA-2-3-3)
Some specific examples of the unit structure containing the structure represented by formula (B2) are as follows. * indicates a binding site with the unit structure A. Needless to say, it may be a unit structure that partially includes the illustrated structure.

(IIA-2-4) Formula (B3)

In formula (B3),
Z is a monocyclic ring having 4 to 25 carbon atoms which may have a substituent, or a condensed bicyclic, tricyclic or tetracyclic ring. The number of carbon atoms referred to herein means only the number of carbon atoms constituting the ring skeleton of a monocyclic, bicyclic, tricyclic or tetracyclic condensed ring excluding substituents, and the monocyclic or condensed ring When the ring is heterocyclic, the number of heteroatoms that make up the heterocyclic ring is not included.

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 nonaromatic monocyclic ring, and the remaining monocyclic rings are aromatic monocyclic or non-aromatic monocyclic rings. It may be an aromatic monocyclic ring.

The monocyclic, bicyclic, tricyclic or tetracyclic condensed ring may further form a condensed ring with one or more aromatic rings to form a pentacyclic or more condensed ring, The carbon number of the pentacyclic or higher condensed ring is preferably 40 or less. excluding the number of heteroatoms constituting the heterocyclic ring when the condensed ring of five or more rings is a heterocyclic ring.

X and Y are the same or different and represent a -CR ³¹ R ³² - group, and R ³¹ and R ³² are the same or different and represent a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms.

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

is bonded to any carbon atom (referred to as “carbon atom 1”) constituting said non-aromatic monocyclic ring of Z (when x=1) or extends from carbon atom 1 (when x=0 ),

is bonded to any carbon atom (referred to as “carbon atom 2”) constituting said non-aromatic monocyclic ring of 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, and if different, they may belong to the same non-aromatic monocyclic ring or to different non-aromatic monocyclic rings. .

Further, in formula (B3), it may optionally contain a linking carbon atom other than carbon atoms 1 and 2 [see (IIA-2-4-2) below]
When Z is a tricyclic or higher condensed ring, in the condensed ring of one or two non-aromatic monocyclic rings to which carbon atoms 1 and 2 in formula (B3) belong respectively and the remaining monocyclic ring The permutation positional relationship is arbitrary, and when carbon atom 1 and carbon atom 2 belong to different non-aromatic monocyclic rings (referred to as “non-aromatic monocyclic ring 1” and “non-aromatic monocyclic ring 2” respectively), the non-aromatic monocyclic ring The permutation positional relationship in the condensed ring of the aromatic single ring 1 and the non-aromatic single ring 2 is also arbitrary.

(IIA-2-4-1)
Similar to (IIA-2-2-2) above for formula (B1), two or three identical or different structures of formula (B3) above are bound to a divalent or trivalent linking group. , may be in a dimeric or trimeric structure.

(IIA-2-4-2)
Some specific examples of the organic group containing the structure represented by formula (B3) are as follows. The binding site with the unit structure A is not particularly limited. Needless to say, a structure including the illustrated structure as a part of the whole may be used.

In addition, although examples in which the number of bonding hands (*) exceeds 2 are also included, this surplus bonding hand can be used for bonding with an aromatic ring in another polymer chain, cross-linking, etc. .

(IIA-2-4-3)
In addition, when Z in formula (B3) contains an aromatic ring, the aromatic ring [see, for example, Ar ¹ in formula (B32) below] may be additionally bonded to another unit structure B'. .

In formula (B32),
Z ¹ represents at least one non-aromatic monocyclic ring, Ar ¹ represents at least one aromatic monocyclic ring forming a condensed ring with the non-aromatic monocyclic ring of Z ¹ , and Z and Ar ¹ together represent a substituent constitutes a bicyclic, tricyclic, tetracyclic or pentacyclic condensed ring having 8 to 25 carbon atoms. The number of carbon atoms referred to herein means only the number of carbon atoms constituting the ring skeleton of a bicyclic, tricyclic or tetracyclic condensed ring excluding substituents. When a fused ring in a formula is a heterocyclic ring, the number of heteroatoms that make up the heterocyclic ring is not included.

The bicyclic, tricyclic, tetracyclic or pentacyclic organic group may further form a condensed ring with one or more aromatic rings to form a hexacyclic or higher ring, and the hexacyclic or higher The number of carbon atoms in the condensed ring is preferably 40 or less. The number of heteroatoms constituting the heterocyclic ring is not included when the condensed ring above the cyclic ring is a heterocyclic ring.

Moreover, in the cyclic organic group, one or more non-aromatic monocyclic rings belonging to Z ¹ and one or more aromatic monocyclic rings belonging to Ar ¹ may have any order positional relationship. For example, when there are two or more non-aromatic monocyclic rings belonging to ^Z1 and two or more aromatic monocyclic rings belonging to ^Ar1 , the non-aromatic monocyclic ring belonging to ^Z1 and the aromatic monocyclic ring belonging to ^Ar1 are may be arranged alternately to form a condensed ring.

Also, X, Y, x, and y are the same as defined in formula (B3).

In this case, the following formula (C3):

[In formula (C3),
Z ¹ , Ar ¹ , X, Y, x and y are the same as defined in formula (B32),
T represents a polymer terminal. ]
One of the connecting carbon atoms is a polymer terminal T (hydrogen atom; hydroxyl group, various functional groups such as unsaturated aliphatic hydrocarbon groups, terminal unit structure A, unit structure A in other polymer chains etc.), it can be replaced with at least one composite unit structure AB' as one unit structure C equivalent to the composite unit structure AB'. That is, the aromatic ring [Ar ¹ in formula (C3)] in formula (C3) and another unit structure B′ are bonded, and the bonds from the remaining connecting carbon atoms shown in formula (C3) The polymer chain may be extended by bonding to the aromatic ring of the unit structure A with the hand of .

(IIA-2-4-4)
As a more specific structure of formula (C3), for example, in the following formula (C31), T in formula (C3) is a hydrogen atom that is a terminal group, and p, k ₁ and k ₂ that can serve as a bond Of these, p and k ₁ or p and k ₂ can form one unit structure C equivalent to the composite unit structure AB'.

Note that it can also function as the unit structure A by _k1 and _k2 .

Further, in the following formula (C32), T in formula (C3) is an example of a phenyl group. In this example, p and k ₁ , p and k ₂ , or p and m among p, k ₁ , k ₂ and m that can be a bond, make one unit equivalent to the composite unit structure AB′ Structure C can be obtained.

Note that it can also function as the unit structure A by k ₁ and k ₂ , k ₁ and m, or k ₂ and m.

Some more specific examples of the unit structure C (one unit structure equivalent to the composite unit structure AB') of formula (C3) are as follows. * indicates a binding site with the unit structure A.

In the unit structure C, a bond connecting to the unit structure B' extends from the aromatic ring in these structures, but such a bond is omitted in the specific examples below. Needless to say, it may be a unit structure that partially includes the illustrated structure.

In the above specific example, when there is no bond from the aromatic ring, it can be a specific example of the terminal of the polymer.

(IIA-3)
A novolak resin having a structure represented by formula (AB) can be prepared by a known method. For example, a ring-containing compound represented by HAH and OHC-B', O=C-B', HOB'-OH, RO-B'-OR, RO-CH ₂ -B'-CH ₂ - It can be prepared by condensing an oxygen-containing compound represented by OR or the like. Here, in the formula, A and B' have the same meanings as above. R represents a halogen or an alkyl group having about 1 to 3 carbon atoms.

The ring-containing compound and the oxygen-containing compound may be used either singly or in combination of two or more. In this condensation reaction, the oxygen-containing compound can be used in an amount of 0.1 to 10 mol, preferably 0.1 to 2 mol, per 1 mol of the ring-containing compound.

Examples of catalysts used in the condensation reaction include mineral acids such as sulfuric acid, phosphoric acid and perchloric acid; Carboxylic acids such as sulfonic acids, formic acid and oxalic acid can be used. The amount of the catalyst to be used varies depending on the type of catalyst used, but it is usually 0.001 to 10,000 parts by mass, preferably 0.000 parts by mass, per 100 parts by mass of the ring-containing compound (in the case of multiple types, the total of them). 01 to 1,000 parts by mass, more preferably 0.05 to 100 parts by mass.

The condensation reaction can be carried out without a solvent, but it 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 inhibit the reaction. For example, 1,2-dimethoxyethane, diethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, tetrahydrofuran, dioxane, 1,2-dichloromethane, 1,2-dichloroethane, toluene, N-methylpyrrolidone, dimethylformamide and the like. mentioned. The condensation reaction temperature is usually 40°C to 200°C, preferably 100°C to 180°C. Although the reaction time varies depending on the reaction temperature, it is usually 5 minutes to 50 hours, preferably 5 minutes to 24 hours.

The weight average molecular weight of the novolac resin according to one aspect of the present invention is usually 500-100,000, preferably 600-50,000, 700-10,000, or 800-8,000.

(IID) Other Optional Components The resist underlayer film-forming composition of one embodiment of the present invention optionally contains a cross-linking agent, a surfactant, a light absorber, a rheology modifier, an adhesion aid, etc., in addition to the above. be able to.

[solvent]
The composition for forming a resist underlayer film for nanoimprints according to the present invention contains a solvent. The solvent is not particularly limited as long as it can dissolve the compound containing an aromatic ring and optional components added as necessary. In particular, since the composition for forming a resist underlayer film for nanoimprinting according to the present invention is used in the form of a uniform solution, it is recommended to use a solvent that is commonly used in the lithography process together, considering its coating performance. be done.

Such solvents include, for example, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, methyl isobutyl carbinol, propylene glycol monobutyl ether, propylene glycol monomethyl Ether acetate, propylene glycol monoether ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, toluene, xylene, methyl ethyl ketone, cyclopentanone, cyclohexanone, ethyl 2-hydroxypropionate, 2-hydroxy-2-methylpropion Ethyl Acetate, Ethyl Ethoxyacetate, Ethyl Hydroxyacetate, Methyl 2-hydroxy-3-methylbutanoate, Methyl 3-methoxypropionate, Ethyl 3-methoxypropionate, Ethyl 3-ethoxypropionate, Methyl 3-ethoxypropionate, Pyruvine Methyl acid, 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 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, lactic acid Propyl, isopropyl lactate, butyl lactate, isobutyl lactate, methyl formate, ethyl formate, propyl formate, isopropyl formate, butyl formate, isobutyl formate, amyl formate, isoamyl formate, methyl acetate, ethyl acetate, amyl acetate, isoamyl acetate, hexyl acetate, Methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, butyl propionate, isobutyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, isopropyl butyrate, butyl butyrate, isobutyl butyrate, ethyl hydroxyacetate, 2-hydroxy- ethyl 2-methylpropionate, methyl 3-methoxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutyrate, ethyl methoxyacetate, ethyl ethoxyacetate, 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 rate, 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, γ-butyrolactone and the like can be mentioned. These solvents can be used alone or in combination of two or more.

Among these, more preferred are propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and propylene glycol monopropyl ether acetate, and propylene glycol monomethyl ether and propylene. Glycol monomethyl ether acetate is more preferred.

Also, a solvent having a boiling point of 160° C. or higher can be included. For example, the following compounds described in WO2018/131562A1 can be used.

(R ¹ , R ² and R ³ in formula (i) each represent a hydrogen atom, an oxygen atom, a sulfur atom or an alkyl group having 1 to 20 carbon atoms which may be interrupted by an amide bond, and are the same They may be present or different, and may be combined with each other to form a ring structure.)

Alternatively, 1,6-diacetoxyhexane (boiling point 260° C.), tripropylene glycol monomethyl ether (boiling point 242° C.), and other various high boiling points described in paragraph 0082 of JP-A-2021-84974. A solvent can preferably be used.

Alternatively, dipropylene glycol monomethyl ether acetate (boiling point 213° C.), diethylene glycol monoethyl ether acetate (boiling point 217° C.), diethylene glycol monobutyl ether acetate (boiling point 247° C.), dipropylene glycol dimethyl ether (boiling point 171°C), dipropylene glycol monomethyl ether (boiling point 187°C), dipropylene glycol monobutyl ether (boiling point 231°C), tripropylene glycol monomethyl ether (boiling point 242°C), γ-butyrolactone (boiling point 204°C), benzyl alcohol (boiling point 205°C), propylene carbonate (boiling point 242°C), tetraethylene glycol dimethyl ether (boiling point 275°C), 1,6-diacetoxyhexane (boiling point 260°C), dipropylene glycol (boiling point 230°C), 1,3-butylene glycol Diacetate (boiling point: 232° C.) and other various high boiling point solvents described in paragraphs 0023 to 0031 of the publication can be preferably used.

The composition for forming a resist underlayer film for nanoimprinting according to the present invention may contain optional components other than the above. Each component will be described below.

[Crosslinking agent]
The composition for forming a resist underlayer film for nanoimprints according to the present invention can contain a cross-linking agent. Examples of the cross-linking agent include melamine-based, substituted urea-based, or polymer-based thereof. Preferred are crosslinkers having at least two crosslink-forming substituents, methoxymethylated glycoluril (e.g., tetramethoxymethylglycoluril), butoxymethylated glycoluril, methoxymethylated melamine, butoxymethylated melamine, methoxy Compounds such as methylated benzogwanamine, butoxymethylated benzogwanamine, methoxymethylated urea, butoxymethylated urea, or methoxymethylated thiourea. Condensates of these compounds can also be used.

Also, a cross-linking agent with high heat resistance can be used as the cross-linking agent. As a highly heat-resistant cross-linking agent, a compound containing a cross-linking substituent having an aromatic ring (eg, benzene ring, naphthalene ring) in the molecule can be preferably used.

Examples of this compound include compounds having a partial structure of the following formula (4), and polymers or oligomers having repeating units of the following formula (5).

The above R ¹¹ , R ¹² , R ¹³ and R ¹⁴ are hydrogen atoms or alkyl groups having 1 to 10 carbon atoms, and the above examples can be used for these alkyl groups. n1 is an integer of 1-4, n2 is an integer of 1-(5-n1), and (n1+n2) is an integer of 2-5. n3 is an integer of 1-4, n4 is 0-(4-n3), and (n3+n4) is an integer of 1-4. Oligomers and polymers can be used in the range of 2 to 100 or 2 to 50 repeating unit structures.

Compounds, polymers and oligomers of formulas (4) and (5) are exemplified below.

The above compounds are available as products of Asahi Organic Chemical Industry Co., Ltd. and Honshu Chemical Industry Co., Ltd. For example, among the above crosslinking agents, the compound of formula (4-23) is Honshu Chemical Industry Co., Ltd., trade name TMOM-BP, and the compound of formula (4-20) is Asahi Organic Chemical Industry Co., Ltd., trade name TM. - BIP-A.

The amount of the cross-linking agent added varies depending on the coating solvent used, the substrate used, the required solution viscosity, the required film shape, etc., but it is 0.001% by mass or more and 0.01% by mass based on the total solid content. % or more, 0.05% by mass or more, 0.5% by mass or more, or 1.0% by mass or more, and 80% by mass or less, 50% by mass or less, 40% by mass or less, 20% by mass or less, or 10% by mass % or less. These cross-linking agents may cause a cross-linking reaction due to self-condensation, but when cross-linkable substituents are present in the above aromatic ring-containing compound of the present invention, they cause a cross-linking reaction with those cross-linkable substituents. be able to.

[Acid and/or its salt and/or acid generator]
The composition for forming a resist underlayer film for nanoimprints according to the present invention can contain an acid and/or a salt thereof and/or an acid generator.

Examples of acids include p-toluenesulfonic acid, trifluoromethanesulfonic acid, salicylic acid, 5-sulfosalicylic acid, 4-phenolsulfonic acid, camphorsulfonic acid, 4-chlorobenzenesulfonic acid, benzenedisulfonic acid, 1-naphthalenesulfonic acid, citric acid, acid, benzoic acid, hydroxybenzoic acid, naphthalenecarboxylic acid and the like.

As the salt, the salt of the acid described above can also be used. Although the salt is not limited, ammonium derivative salts such as trimethylamine salt and triethylamine salt, pyridine derivative salts, morpholine derivative salts and the like can be preferably used.

Only one type of acid and/or its salt can be used, or two or more types can be used in combination. The blending amount is generally 0.0001 to 20% by mass, preferably 0.0005 to 10% by mass, more preferably 0.01 to 5% by mass, based on the total solid content.

Examples of acid generators include thermal acid generators and photoacid generators.

Thermal acid generators include 2,4,4,6-tetrabromocyclohexadienone, benzoin tosylate, 2-nitrobenzyl tosylate, K-PURE (registered trademark) CXC-1612, CXC-1614, and TAG. -2172, TAG-2179, TAG-2678, TAG2689, 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.

The photoacid generator produces acid when the resist is exposed to light. Therefore, the acidity of the underlayer film can be adjusted. This is one way to match the acidity of the underlayer film to that of the overlying resist. Also, the pattern shape of the resist formed on the upper layer can be adjusted by adjusting the acidity of the lower layer film.

Examples of the photoacid generator contained in the resist underlayer film-forming composition for nanoimprints of the present invention include onium salt compounds, sulfonimide compounds, and disulfonyldiazomethane compounds.

Onium salt compounds include diphenyliodonium hexafluorophosphate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-normal butanesulfonate, diphenyliodonium perfluoro-normal octane sulfonate, diphenyliodonium camphorsulfonate, bis(4-tert-butylphenyl)iodonium camphor. iodonium salt compounds such as sulfonates and bis(4-tert-butylphenyl)iodonium trifluoromethanesulfonate, and triphenylsulfonium hexafluoroantimonate, triphenylsulfonium nonafluoro-normal butanesulfonate, triphenylsulfonium camphorsulfonate and triphenylsulfonium trifluoromethane Examples include sulfonium salt compounds such as sulfonate.

Examples of sulfonimide compounds include N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoro-normalbutanesulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide and N-(trifluoromethanesulfonyloxy)naphthalimide. mentioned.

Examples of disulfonyldiazomethane compounds include bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, and bis(2,4-dimethylbenzenesulfonyl). ) diazomethane, and methylsulfonyl-p-toluenesulfonyl diazomethane.

Only one type of acid generator can be used, or two or more types can be used in combination.

When an acid generator is used, its proportion is 0.01 to 10 parts by weight, or 0.1 to 8 parts by weight, or It is 0.5 to 5 parts by mass.

[Other ingredients]
The composition for forming a resist underlayer film for nanoimprints of the present invention can be blended with a surfactant in order to prevent pinholes, striations, etc. from occurring and to further improve coatability against surface unevenness. Examples of surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene oleyl ether, polyoxyethylene octylphenol ether, and polyoxyethylene nonylphenol ether. Polyoxyethylene alkyl allyl ethers such as polyoxyethylene/polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, sorbitan tristearate, etc. sorbitan fatty acid esters, polyoxyethylene sorbitan such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate Nonionic surfactants such as fatty acid esters, Ftop EF301, EF303, EF352 (manufactured by Tochem Products Co., Ltd., trade names), Megaface F171, F173, R-40, R-40N, R-40LM (DIC stock company, product name), Florard FC430, FC431 (manufactured by Sumitomo 3M Co., Ltd., product name), Asahiguard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd., product name) ), organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), and the like. The blending amount of these surfactants is usually 2.0% by mass or less, preferably 1.0% by mass or less, based on the total solid content of the resist underlayer film-forming composition. These surfactants may be used alone or in combination of two or more. When a surfactant is used, its proportion is 0.0001 to 5 parts by weight, or 0.001 to 1 part by weight, or 0 parts by weight with respect to 100 parts by weight of the solid content of the nanoimprint resist underlayer film-forming composition. 0.01 to 0.5 parts by mass.

A light absorber, a rheology modifier, an adhesion aid, and the like can be added to the composition for forming a resist underlayer film for nanoimprints of the present invention. Rheology modifiers are effective in improving the fluidity of the Underlayer film-forming composition. Adhesion aids are effective in improving the adhesion between the semiconductor substrate or resist and the underlying film.

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

The rheology modifier mainly improves the fluidity of the resist underlayer film-forming composition for nanoimprinting, and particularly in the baking process, improves the uniformity of the film thickness of the resist underlayer film and the inside of the holes. It is added for the purpose of increasing the fillability of the Specific examples include phthalic acid derivatives such as dimethyl phthalate, diethyl phthalate, diisobutyl phthalate, dihexyl phthalate, and butyl isodecyl phthalate; Maleic acid derivatives such as normal butyl maleate, diethyl maleate and dinonyl maleate; oleic acid derivatives such as methyl oleate, butyl oleate and tetrahydrofurfuryl oleate; and stearic acid derivatives such as normal butyl stearate and glyceryl stearate. can. These rheology modifiers are usually blended in a ratio of less than 30% by mass based on the total solid content of the resist underlayer film-forming composition for nanoimprints.

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 for nanoimprinting, and especially for the purpose of preventing the resist from peeling off during development. Specific examples include chlorosilanes such as trimethylchlorosilane, dimethylmethylolchlorosilane, methyldiphenylchlorosilane, chloromethyldimethylchlorosilane, trimethylmethoxysilane, dimethyldiethoxysilane, methyldimethoxysilane, dimethylmethylolethoxysilane, diphenyldimethoxysilane, Alkoxysilanes such as enyltriethoxysilane, silazanes such as hexamethyldisilazane, N,N'-bis(trimethylsilyl)urea, dimethyltrimethylsilylamine, trimethylsilylimidazole, methyloltrichlorosilane, γ-chloropropyltrimethoxysilane, γ -Aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane and other silanes, benzotriazole, benzimidazole, indazole, imidazole, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, urazole , thiouracil, mercaptoimidazole, and mercaptopyrimidine; ureas such as 1,1-dimethylurea and 1,3-dimethylurea; and thiourea compounds. These adhesion aids are added at a ratio of usually less than 5% by mass, preferably less than 2% by mass, based on the total solid content of the resist underlayer film-forming composition for nanoimprints.

The solid content of the resist underlayer film-forming composition for nanoimprinting according to the present invention is usually 0.1 to 70% by mass, preferably 0.1 to 60% by mass. The solid content is the content ratio of all components except for the solvent in the resist underlayer film-forming composition for nanoimprinting. The ratio of the compound containing the aromatic ring in the solid content is 1 to 100% by mass, 1 to 99.9% by mass, 50 to 99.9% by mass, 50 to 95% by mass, 50 to 90% by mass. preferred in order.

One measure for evaluating whether the composition for forming a resist underlayer film for nanoimprints is in a uniform solution state is to observe the permeability of a specific microfilter. The forming composition passes through a microfilter with a pore size of 0.1 μm and presents a uniform solution state.

Examples of the microfilter material include fluorine-based resins such as PTFE (polytetrafluoroethylene) and PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), PE (polyethylene), UPE (ultra-high molecular weight polyethylene), PP ( polypropylene), PSF (polysulfone), PES (polyethersulfone), and nylon, but PTFE (polytetrafluoroethylene) is preferred.

The compound containing an aromatic ring according to the present invention is mixed with a solvent and other optional components to form a resist underlayer film-forming composition for nanoimprinting, applied onto a substrate (silicon wafer), and baked at a predetermined temperature to form a film. to form The film is characterized in that the difference between the contact angle to pure water when baked in the air at the same temperature and the contact angle to pure water when baked in a nitrogen atmosphere is within 26 degrees.

A method for producing a resist underlayer film, a pattern forming method, and a method for producing a semiconductor device using the composition for forming a resist underlayer film for nanoimprinting according to the present invention will be described below.

[Manufacturing method of resist underlayer film for nanoimprint]
Substrates used in the manufacture of semiconductor devices (e.g., silicon wafer substrates, silicon dioxide coated substrates ( _SiO2 substrates), silicon nitride substrates (SiN substrates), silicon oxynitride substrates (SiON substrates), titanium nitride substrates (TiN substrates) substrate), a tungsten substrate (W substrate), a glass substrate, an ITO substrate, a polyimide substrate, and a low dielectric constant material (low-k material) coated substrate, etc.), the present invention is applied by an appropriate coating method such as a spinner or a coater. A resist underlayer film is formed by applying the resist underlayer film-forming composition for nanoimprinting and then baking the resist underlayer film. Air may be used as the atmosphere gas during firing, or an inert gas such as nitrogen or argon may be used. In one aspect, it is particularly preferred that the oxygen concentration is 1% or less. The firing conditions are 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. Here, the film thickness of the lower layer film to be formed is, for example, 10 to 1000 nm, 20 to 500 nm, 30 to 400 nm, or 50 to 300 nm. Also, if a quartz substrate is used as the substrate, a replica of a quartz imprint mold (mold replica) can be produced.

Further, the composition for forming a resist underlayer film for nanoimprinting according to the present invention is applied onto a semiconductor substrate having a portion having a step and a portion having no step (a so-called stepped substrate), and baked to obtain a substrate having the step. The step between the portion and the portion without the step can be reduced. There is no upper limit to the step, but it is preferably less than 10 nm, 30 nm, 50 nm, 70 nm, 80 nm, 90 nm, or 100 nm or less.

In addition, a hard mask (silicone) layer is optionally formed by coating or vapor deposition on the resist underlayer film for nanoimprinting according to the present invention, and the hard mask (silicone) layer is formed on the resist underlayer film or (if present) the hard mask (silicone) layer. An adhesion layer can be formed thereon by coating or vapor deposition. The hard mask (silicone) layer preferably contains 99 wt% or less, or 50 wt% or less of Si. For example, the adhesive layer described in JP-A-2013-202982 and Japanese Patent No. 5827180, the method of forming a silicon-containing resist underlayer film (inorganic resist underlayer film) composition described in WO2009/104552A1 by spin coating. , a Si-based inorganic material film can be formed by a CVD method or the like.

[Pattern formation method]
The pattern forming method according to the present invention comprises:
a step of forming a resist underlayer film from the composition for forming a resist underlayer film for nanoimprinting according to the present invention;
applying a curable composition onto the resist underlayer film;
contacting the curable composition with a mold;
A step of irradiating the curable composition with light or an electron beam to form a cured film, and a step of separating the cured film and the mold;
including.

[Curable composition]
The photoresist to be formed on the resist underlayer film is not particularly limited as long as it is sensitive to the light used for exposure. Both negative and positive photoresists can be used. Examples include APEX-E (trade name) manufactured by Shipley, PAR710 (trade name) manufactured by Sumitomo Chemical Co., Ltd., SEPR430 (trade name) manufactured by Shin-Etsu Chemical Co., Ltd., and the like. Also, for example, Proc. SPIE, Vol. 3999, 330-334 (2000), Proc. SPIE, Vol. 3999, 357-364 (2000), and Proc. SPIE, Vol. 3999, 365-374 (2000).

[Step of applying curable composition]
This step is a step of applying a curable composition onto the resist underlayer film formed by the method for producing a resist underlayer film according to the present invention. Examples of methods for applying the curable composition include an inkjet method, a dip coating method, an air knife coating method, a curtain coating method, a wire bar coating method, a gravure coating method, an extrusion coating method, a spin coating method, and a slit scanning method. etc. can be used. An inkjet method is suitable for applying the curable composition as droplets, and a spin coating method is suitable for applying the curable composition. In this step, an adhesion layer may be formed by coating or vapor deposition on the resist underlayer film, and the curable composition may be applied thereon, and a hard mask (silicone) layer and an adhesion layer may be sequentially applied on the resist underlayer film. Alternatively, it can be formed by vapor deposition and the curable composition applied thereon.

[Step of Contacting Curable Composition with Mold]
In this step, the curable composition and the mold are brought into contact. For example, when a liquid curable composition is brought into contact with a mold having a master pattern for transferring the pattern shape, a liquid film is formed in which the curable composition fills the recesses of the fine pattern on the mold surface. be done.

Considering the process of irradiating light or electron beams, which will be described later, it is recommended to use a mold with a light-transmitting material as a base material. Specifically, the mold base material is preferably glass, quartz, PMMA, optically transparent resin such as polycarbonate resin, transparent metal deposition film, flexible film such as polydimethylsiloxane, photocured film, metal film, and the like. The mold base material is more preferably quartz because it has a small coefficient of thermal expansion and a small pattern distortion.

The fine pattern on the surface of the mold preferably has a pattern height of 4 nm or more and 200 nm or less. A certain degree of pattern height is necessary to improve the processing accuracy of the substrate, but the lower the pattern height, the stronger the force to separate the mold from the cured film in the later-described step of separating the cured film and the mold. Also, the number of defects remaining on the mask side due to the resist pattern being torn off is small. It is recommended to select and adopt an appropriately balanced pattern height in consideration of these factors.

In addition, due to the elastic deformation of the resist pattern due to the impact when the mold is peeled off, adjacent resist patterns may come into contact with each other and the resist patterns may adhere or be damaged. This can sometimes be avoided by setting the pattern height to about twice or less than the pattern width (aspect ratio of 2 or less).

In order to improve the releasability between the curable composition and the surface of the mold, the mold can be surface-treated in advance. Examples of the surface treatment method include a method of applying a release agent to the surface of the mold to form a release agent layer. Release agents include silicone release agents, fluorine release agents, hydrocarbon release agents, polyethylene release agents, polypropylene release agents, paraffin release agents, montan release agents, carnauba and a release agent. Preferred are fluorine-based and hydrocarbon-based release agents. Commercially available products include OPTOOL (registered trademark) DSX manufactured by Daikin Industries, Ltd., for example. The releasing agents may be used singly or in combination of two or more.

In this step, the pressure applied to the curable composition when bringing the mold and the curable composition into contact is not particularly limited. A pressure of 0 MPa or more and 100 MPa or less is recommended. The pressure is preferably 0 MPa or higher and 50 MPa or lower, 30 MPa or lower, or 20 MPa or lower.

When the pre-spreading of droplets of the curable composition is in progress in the previous step (the step of applying the curable composition), the spreading of the curable composition in this step is quickly completed. As a result, the contact time between the mold and the curable composition can be shortened. The contact time is not particularly limited, but is preferably 0.1 seconds or more, 600 seconds or less, 3 seconds or less, or 1 second or less. If the contact time is too short, the spread and fill may be insufficient, resulting in defects called unfilled defects.

This step can be performed under any of an atmospheric atmosphere, a reduced pressure atmosphere, and an inert gas atmosphere, but is preferably performed under a pressure of 0.0001 atmosphere or more and 10 atmospheres or less. In order to prevent the curing reaction from being affected by oxygen and moisture, it is recommended to perform the curing under a reduced pressure atmosphere or an inert gas atmosphere. Specific examples of inert gases that can be used to create the inert gas atmosphere include nitrogen, argon, helium, carbon dioxide, CFCs, HCFCs, HFCs, or mixtures thereof. At least one gas selected from the group consisting of nitrogen, argon, helium, and carbon dioxide is preferred.

This step may be performed in an atmosphere containing condensable gas (hereinafter referred to as "condensable gas atmosphere"). In this specification, the condensable gas is condensed by the capillary pressure generated at the time of filling the concave portion of the fine pattern formed on the mold and the gap between the mold and the substrate together with the curable composition. It is a gas that liquefies. Note that the condensable gas exists as a gas in the atmosphere before the curable composition and the mold come into contact with each other in this step. When this step is performed in a condensable gas atmosphere, the gas filled in the recesses of the fine pattern is liquefied by the capillary pressure generated by the curable composition, and the bubbles disappear, resulting in excellent filling properties. The condensable gas may dissolve in the curable composition.

The boiling point of the condensable gas is not limited as long as it is equal to or lower than the atmospheric temperature in this step, but is preferably -10°C or higher, or +10°C or higher and +23°C or lower.

The vapor pressure of the condensable gas at the atmospheric temperature in this process is not particularly limited as long as it is equal to or lower than the mold pressure. It is preferably in the range of 0.1 MPa to 0.4 MPa.

Specific examples of condensable gases include chlorofluorocarbons (CFCs) such as trichlorofluoromethane, fluorocarbons (FCs), hydrochlorofluorocarbons (HCFCs), 1,1,1,3,3-pentafluoropropane (CHF ₂ CH ₂ CF ₃ , HFC-245fa, PFP), hydrofluoroethers (HFE) such as pentafluoroethyl methyl ether (CF ₃ CF ₂ OCH ₃ , HFE-245mc), and the like.

The condensable gas may be used singly or in combination of two or more. These condensable gases may also be mixed with non-condensable gases such as air, nitrogen, carbon dioxide, helium and argon. Air and helium are preferable as the non-condensable gas to be mixed with the condensable gas.

[Step of irradiating the curable composition with light or an electron beam to form a cured film]
In this step, the curable composition is irradiated with light or an electron beam to form a cured film. That is, the curable composition filled in the fine pattern of the mold is irradiated with light or an electron beam through the mold, and the curable composition filled in the fine pattern of the mold is cured as it is, thereby forming a pattern. A cured film having a shape is obtained.

The light or electron beam is selected according to the sensitivity wavelength of the curable composition. Specifically, extreme ultraviolet light with a wavelength of 13.5 nm or more and 400 nm or less, ultraviolet light, X-rays, electron beams, or the like can be appropriately selected and used. Light or electron beam light sources include, for example, high-pressure mercury lamps, ultra-high pressure mercury lamps, low-pressure mercury lamps, deep-UV lamps, carbon arc lamps, chemical lamps, metal halide lamps, xenon lamps, KrF excimer lasers, ArF excimer lasers, and F2 excimer lasers. , CO2 laser, and the like. The number of light sources may be one or plural. Irradiation may be performed on the entire curable composition filled in the fine pattern of the mold, or may be performed only on a partial region. The light irradiation may be performed intermittently a plurality of times over the entire region on the substrate, or may be continuously irradiated over the entire region. It is also possible to irradiate a part of the substrate for the first time and irradiate a different area for the second time. After that, development can be carried out by a known method.

The cured film thus obtained preferably has a pattern with a size of 1 nm or more, or 10 nm or more, 10 mm or less, or 100 μm or less.

[Step of separating cured film and mold]
In this step, the cured film and the mold are separated. By separating the cured film having the pattern shape from the mold, the cured film having the pattern shape which is the reverse pattern of the fine pattern formed on the mold can be obtained in a self-supporting state.

As a method for separating the cured film having a pattern shape from the mold, any means for moving the cured film and the mold in a relatively separating direction can be used as long as a part of the cured film having a pattern shape is not physically damaged. It is not particularly limited, and various conditions are not particularly limited. For example, the substrate may be fixed and the mold may be moved away from the substrate for peeling, or the mold may be fixed and the substrate is moved away from the mold for peeling. Alternatively, the substrate and the mold may be pulled and moved in opposite directions for separation.

In addition, when the step of contacting the curable composition and the mold described above is performed in a condensable gas atmosphere, when separating the cured film and the mold in this step, the pressure at the interface where the cured film and the mold come into contact The condensable gas evaporates as the . As a result, the release force, which is the force required to separate the cured film and the mold, can be reduced.

Through the above steps, it is possible to prepare a cured film having a desired concave-convex pattern shape derived from the concave-convex shape of the mold at a desired position.

[Method for manufacturing a semiconductor device]
The pattern of the photoresist (upper layer) formed by the pattern forming method of the present invention is used as a protective film to process the inorganic lower layer film (intermediate layer), and then the patterned inorganic lower layer film is used as a protective film, Processing of the resist underlayer film (lower layer) is performed. Finally, the semiconductor substrate is processed using the resist underlayer film as a protective film. An adhesion layer may be applied to the upper layer of the resist underlayer film or the inorganic underlayer film, and this is also processed in the same manner as described above.

(IVA)
(i)
A method for manufacturing a semiconductor device, which is one embodiment of the present invention, comprises:
a step of forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film for nanoimprinting, which is one aspect of the present invention;
applying a curable composition onto the resist underlayer film;
contacting the curable composition with a mold;
A step of forming a cured film by irradiating the curable composition with light or an electron beam;
and separating the cured film and the mold.

(ii)
The step of applying a curable composition onto the resist underlayer film comprises
Optionally forming a hard mask layer on the resist underlayer film by coating or vapor deposition,
forming an adhesion layer by coating or vapor deposition on the resist underlayer film or the hard mask layer;
applying a curable composition on the cling layer or on the hard mask.

(iii)
Further, a method for manufacturing a semiconductor device according to one aspect of the present invention includes:
a step of forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film for nanoimprinting, which is one aspect of the present invention;
Optionally forming a hard mask layer on the resist underlayer film by coating or vapor deposition,
forming an adhesion layer by coating or vapor deposition on the resist underlayer film or the hard mask layer;
further applying a curing composition onto the hard mask layer or onto the adhesion layer;
A step of forming a resist pattern on the resist film of the curable composition by irradiation with light or an electron beam;
A step of etching a resist underlayer film using the formed resist pattern and a step of processing a semiconductor substrate using the patterned underlayer film are included.

(iv)
Further, a method for manufacturing a semiconductor device according to one aspect of the present invention includes:
a step of forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film for nanoimprinting, which is one aspect of the present invention;
Optionally, a hard mask layer is formed on the resist underlayer film by coating or vapor deposition, an adhesion layer is formed on the resist underlayer film or the hard mask layer by coating or vapor deposition, and further the hard mask layer. applying a curing composition on top or onto the cling layer;
forming a resist pattern on the resist film by irradiation with light or an electron beam;
etching and patterning the hard mask layer through the resist pattern;
etching and patterning the resist underlayer film through the etched hard mask layer;
removing the hard mask;
A step of forming a deposited film (spacer) on the resist underlayer film after removing the hard mask layer,
A step of processing the deposited film (spacer) by etching,
A step of removing the patterned resist underlayer film to leave a patterned deposited film (spacer), and a step of processing the semiconductor substrate through the patterned deposited film (spacer).

A semiconductor substrate can be processed using the above manufacturing methods (i) to (iv). In the manufacturing methods (i) to (iv), in the step of etching the resist underlayer film using the formed resist pattern, the resist underlayer is formed through an optionally formed hard mask layer, adhesion layer, or both. The case of etching a film is also included.

In the nanoimprint method, before applying the curable composition that becomes a resist film, optionally a silicon-containing layer (hard mask layer) is formed on the resist underlayer film by coating or vapor deposition, and further on the resist underlayer film or An adhesion layer may be formed by coating or vapor deposition on the silicon-containing layer (hard mask layer), and a curable composition that will form a resist film may be applied onto the adhesion layer.

(IVB)
The step of forming a resist underlayer film using the resist underlayer film-forming composition for nanoimprinting, which is one aspect of the present invention, is as described in the above [Method for producing a resist underlayer film for nanoimprinting].

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

The hard mask layer may be a coating film of an inorganic substance or the like, or a deposited film of an inorganic substance or the like formed by a vapor deposition method such as CVD or PVD, and examples thereof include a SiON film, a SiN film and a _SiO2 film.

Furthermore, an antireflection film (BARC) may be formed on this hard mask layer, or a resist shape correction film having no antireflection ability may be formed.

In the process of forming the resist pattern, exposure is performed through a mask (reticle) for forming a predetermined pattern or by direct writing. For example, g-rays, i-rays, KrF excimer lasers, ArF excimer lasers, EUV, and electron beams can be used as exposure sources. After exposure, post-exposure baking is performed as necessary. After that, if necessary, it may be optionally developed with a developing solution (e.g., 2.38% by mass aqueous tetramethylammonium hydroxide solution, butyl acetate), and further rinsed with a rinsing solution or pure water to remove the used developing solution. . After that, post-baking may be performed in order to dry the resist pattern and improve adhesion to the base.

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

The following gases, namely CF ₄ , CHF ₃ , CH ₂ F ₂ , CH ₃ F, C ₄ F ₆ , C ₄ F ₈ , O ₂ , N _{2 ,} are used for the processing of hard masks, resist underlayer films, and substrates. O, _NO2 , _H2 , He can be used. These gases may be used alone or in combination of two or more. Furthermore, these gases can be mixed with argon, nitrogen, carbon dioxide, carbonyl sulfide, sulfur dioxide, neon, or nitrogen trifluoride.

(IVD)
Wet etching may be performed for the purpose of simplifying the process steps and reducing damage to the processed substrate. This leads to suppression of fluctuations in processing dimensions and reduction in pattern roughness, making it possible to process substrates with high yield. Therefore, in (IVA) (iii) to (iv), the hard mask can be removed by either etching or alkaline chemicals. In particular, when an alkaline chemical solution is used, there are no restrictions on the components, but the alkaline component preferably contains the following.

Examples of alkali components include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, methyltripropylammonium hydroxide, methyltributylammonium hydroxide, and ethyltrimethylammonium. hydroxide, dimethyldiethylammonium hydroxide, benzyltrimethylammonium hydroxide, hexadecyltrimethylammonium hydroxide, and (2-hydroxyethyl)trimethylammonium hydroxide, monoethanolamine, diethanolamine, triethanolamine, 2 -(2-aminoethoxy)ethanol, N,N-dimethylethanolamine, N,N-diethylethanolamine, N,N-dibutylethanolamine, N-methylethanolamine, N-ethylethanolamine, N-butylethanolamine , N-methyldiethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, tetrahydrofurfurylamine, N-(2-aminoethyl)piperazine, 1,8-diazabicyclo[5.4.0]undecene-7, 1, 4-diazabicyclo[2.2.2]octane, hydroxyethylpiperazine, piperazine, 2-methylpiperazine, trans-2,5-dimethylpiperazine, cis-2,6-dimethylpiperazine, 2-piperidinemethanol, cyclohexylamine, 1 ,5-diazabicyclo[4,3,0]nonene-5 and the like. Tetramethylammonium hydroxide and tetraethylammonium hydroxide are particularly preferred from the viewpoint of handling, and an inorganic base may be used in combination with the quaternary ammonium hydroxide. As the inorganic base, alkali metal hydroxides such as potassium hydroxide, sodium hydroxide and rubidium hydroxide are preferable, and potassium hydroxide is more preferable.

In addition, an organic antireflection film can be formed on the upper layer of the resist underlayer film before forming the photoresist. The antireflection coating composition used there is not particularly limited, and can be used by arbitrarily selecting from those commonly used in the lithography process. The antireflection film can be formed by coating with a coater and baking.

The underlayer film formed from the composition for forming a resist underlayer film is applied to a substrate on which a line-and-space pattern, a via-hole pattern, or a pillar pattern has been formed in a pre-process or a post-process, and fills spaces and holes without gaps. Can be used as an embedding material. It can also be used as a planarizing material for planarizing the uneven surface of a semiconductor substrate.

It is generally known that when a resist underlayer film for nanoimprinting is baked in the atmosphere, the surface of the resist underlayer film is oxidized by oxygen and becomes hydrophilic. On the other hand, since the inside of the resist underlayer film is not affected by oxidation, the surface tends to be hydrophilic and the inside tends to be hydrophobic. Therefore, membrane surface evaluation alone is insufficient to understand true gas permeability.
Gas permeability is generally expressed as the product of solubility coefficient and diffusion coefficient. By making the surface hydrophobic, it is possible to improve the solubility coefficient for gases. On the other hand, uniformity of the resist underlayer film is considered important for improving gas permeability. A resist underlayer film having a hydrophilic surface and a hydrophobic interior has a two-layer structure (hydrophilic layer/hydrophobic layer) when viewed in detail. Therefore, in order for the gas to pass through the resist underlayer film, the process of dissolution and diffusion is repeated at the boundary between the hydrophilic layer and the hydrophobic layer. If the surface and the inside can be in the same state, that is, in a highly uniform state, the dissolution and diffusion steps can be performed in one step, so it is thought that gas permeation will occur efficiently. Therefore, by making the surface of the resist underlayer film hydrophobic and ensuring uniformity, the throughput of the nanoimprint process is dramatically improved.
As in the Examples section below, in order to reproduce the contact angle inside the resist underlayer film, baking was performed under nitrogen (oxygen concentration less than 1%) to eliminate the influence of oxygen as much as possible. The difference in the contact angle of the resist underlayer film to pure water is obtained by baking at 100°C and baking under nitrogen. It can be reasonably predicted that a resist underlayer film having a smaller contact angle difference is less likely to be affected by oxygen and has better gas permeability.

The present invention will be described in more detail below with reference to Synthesis Examples, Examples and Comparative Examples, but the present invention is not limited only to the following Examples.

[Synthesis of polymer]
Synthesis of structural formulas (S1) to (S29) as polymers used for the resist underlayer film, and synthesis of structural formula (S'1) as a comparative example are performed by the following compound group A, compound group B, compound group C, and catalyst group. D, solvent group E, and reprecipitation solvent group F were used.

(Compound Groups A to C)

(Catalyst group D)
Methanesulfonic acid: D1
p-toluenesulfonic acid monohydrate: D2
Tetrabutylammonium iodide: D3

(Solvent group E)
Propylene glycol monomethyl ether acetate (= PGMEA): E1
Propylene glycol monomethyl ether (= PGME): E2
Toluene: E3
1,4-dioxane: E4
Tetrahydrofuran: E5
Sodium hydroxide aqueous solution: E6

(Reprecipitation solvent group F)
Methanol: F1
Methanol/water: F2

(Separating solvent group G)
Methyl isobutyl ketone/water: G1

Synthesis example 1
A flask was charged with 10.0 g of phenylnaphthylamine, 8.2 g of 9-fluorenone, 1.3 g of methanesulfonic acid, and 19.5 g of propylene glycol monomethyl ether acetate. It was then heated to reflux under nitrogen and allowed to react for about 14 hours. After stopping the reaction, the precipitate was reprecipitated with methanol and dried to obtain a resin (S1). The weight average molecular weight Mw measured by GPC in terms of polystyrene was about 1,900. The resulting resin was dissolved in cyclohexanone, and ion exchange was performed using a cation exchange resin and an anion exchange resin for 4 hours to obtain a target compound solution.

The weight average molecular weight of the polymer is the result of measurement by gel permeation chromatography (hereinafter abbreviated as GPC). A GPC apparatus manufactured by Tosoh Corporation was used for the measurement, and the measurement conditions and the like are as follows.
Apparatus: HLC-8320GPC manufactured by Tosoh Corporation
GPC column: TSKgel Super-MultiporeHZ-N (2 columns)
Column temperature: 40°C
Flow rate: 0.35 mL/min Eluent: THF
Standard sample: Polystyrene

Synthesis Examples 2 to 24, Comparative Synthesis Example 1
Compound group A, compound group B, compound group C, catalyst group D, solvent group E, and reprecipitation solvent group F were changed to synthesize polymers used for the resist underlayer film. The experimental procedure is the same as in Synthesis Example 1. Synthesis was performed under the following conditions to obtain Example Polymers (S2) to (S24) and Comparative Example Polymer (S'1).

Synthesis example 25
A flask was charged with 15.0 g of reprecipitated resin (S18), 10.5 g of propargyl bromide, 4.9 g of tetrabutylammonium iodide, 34.2 g of tetrahydrofuran, and 11.4 g of a 25% aqueous sodium hydroxide solution. It was then heated to 55° C. under nitrogen and allowed to react for about 15 hours. After stopping the reaction, the liquid separation operation was repeated with methyl isobutyl ketone and water, and the organic layer was concentrated, redissolved in PGMEA, reprecipitated with methanol, and dried to obtain a resin (S25). The resulting resin was dissolved in PGMEA, and ion exchange was performed using a cation exchange resin and an anion exchange resin for 4 hours to obtain a target compound solution.

Synthesis Examples 26-29
Compound group A, compound group B, compound group C, catalyst group D, solvent group E, reprecipitation solvent group F, and liquid separation solvent group G were variously changed to synthesize polymers used for resist underlayer films. The experimental procedure is the same as in Synthesis Example 25. Polymers (S24) to (S29) were obtained by synthesizing under the following conditions.

[Preparation of resist underlayer film-forming composition]
Polymers (S1) to (S29) and (S'1), crosslinkers (CR1 to CR3), acid generators (Ad1 to Ad2), solvents (propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME) , Cyclohexanone (CYH)) and Megafac R-40 (manufactured by DIC Corporation, G1) as a surfactant in the proportions (mass parts) shown in the table below, and filtered through a 0.1 μm polytetrafluoroethylene microfilter. By doing so, resist underlayer film-forming compositions (M1 to M30, comparative M1) were prepared.

[Elution test into resist solvent]
Each of the resist underlayer film-forming compositions of Comparative Example 1-2 and Example 1-31 was coated on a silicon wafer using a spin coater, and baked on a hot plate at a predetermined temperature and for a predetermined time shown in the table, A resist underlayer film was formed so as to have a film thickness of about 200 nm. The formed resist underlayer film was immersed in a general-purpose thinner, PGME/PGMEA=7/3, for 60 seconds to confirm the resistance to the solvent. A film thickness reduction rate of 1% or less before and after immersion in thinner was judged to be good (o), and a film thickness of 1% or more was judged to be bad (x) (Table 1).

[Contact angle measurement]
The resist underlayer film-forming compositions of Comparative Example 1-2 and Example 1-31 were applied onto a silicon wafer using ACT-8 manufactured by Tokyo Electron Co., Ltd., and heated in the atmosphere at a predetermined temperature described in the table. It was baked for a period of time to form a resist underlayer film of 200 nm. Thereafter, a contact angle meter (DM701) manufactured by Kyowa Interface Science Co., Ltd. was used to measure the contact angle to pure water. The amount of pure water dropped was 3.0 μm, and 5 points were measured 3 seconds after dropping, 5 points were measured 5 seconds after dropping, and 5 points were measured 7 seconds after dropping, and the average value of 15 points in total was taken as the contact angle. Another silicon wafer was prepared and the same operation as above was performed under a nitrogen atmosphere. Baking in a nitrogen atmosphere reproduces the state of the inside of the resist underlayer film baked in the air (the portion not affected by oxygen). It was evaluated by comparing the contact angle difference of the same material sintered under air and under nitrogen (Table 1).

[Measurement of etching rate]
The etcher and etching gas used for the etching measurement are as follows.
RIE-200NL (manufactured by Samco): CF ₄ 50 sccm
RIE-200NL (manufactured by Samco): O ₂ /N ₂ 10 sccm/200 sccm

Each of the resist underlayer film-forming compositions of Comparative Example 1-2 and Example 1-31 was applied onto a silicon wafer using a spin coater. It was baked on a hot plate at a predetermined temperature and for a predetermined period of time shown in the table to form a resist underlayer film of 200 nm. The dry etching rate was measured using O ₂ /N ₂ gas or CF ₄ gas as etching gas (Table 2). Compared to the comparative example, the case where the etching rate was slow was judged to be good (o), and the case where it was fast was judged to be bad (x).

[Applicability evaluation]
The resist underlayer film-forming compositions of Comparative Example 1-2 and Example 31 were coated on a silicon wafer using ACT-8 manufactured by Tokyo Electron Co., Ltd., and baked in the air at a predetermined temperature and for a predetermined time shown in the table. Then, a resist underlayer film of 200 nm was formed. After that, the film surface (wafer center and edge) was observed using an optical microscope to confirm that there was no problem in coatability. The term "problem" as used herein means the occurrence of cissing or pinholes on the film surface, or the formation of irregularities that are not normally observed on the coating film surface (Table 2). A case where there was no problem in coating property was judged to be good (◯).

As described above, the difference in contact between the materials shown in the examples in air and in nitrogen is smaller than that in the comparative example, so the difference in quality change between the surface of the resist underlayer film and the inside of the resist underlayer film is small. As a result, fluctuations in the solubility coefficient and the diffusion coefficient that govern the gas diffusion coefficient are less likely to occur in the resist underlayer film, so that a difference in gas permeability between the surface of the resist underlayer film and the inside of the resist underlayer film is less likely to occur. As a result, the gas permeability of the entire resist underlayer film is improved. In addition, the examples show good coating performance in the wafer like the comparative examples, and also show excellent etching resistance to both F-based gases and O-based gases.

The composition for forming a resist underlayer film for nanoimprinting according to the present invention forms a film having a contact angle difference of 26 degrees or less with respect to pure water when baked in the air at the same temperature and when baked in a nitrogen atmosphere. It is a composition that can form a film that exhibits a high pure water contact angle (=hydrophobicity) and gas permeability over a wide firing temperature range from low to high temperatures. As a result, it is possible to improve the adhesion with the hydrophobic upper layer film, and it is expected that the film exhibits good permeability to the hydrophobic gas.

Claims (23)

1. A composition for forming a resist underlayer film for nanoimprinting containing an aromatic ring-containing compound and an organic solvent, wherein the composition is fired in the air at the same temperature and pure water when fired in a nitrogen atmosphere. A composition for forming a resist underlayer film for nanoimprints, which forms a film having a contact angle difference of 26 degrees or less.
2. The composition for forming a resist underlayer film for nanoimprinting according to claim 1, wherein the compound containing an aromatic ring is a polymer containing an aromatic ring.
3. The composition for forming a resist underlayer film for nanoimprinting according to claim 2, wherein the polymer containing an aromatic ring is a novolac resin.
4. The composition for forming a resist underlayer film for nanoimprinting according to claim 3, wherein the polymer containing an aromatic ring is a novolak resin containing a unit structure derived from an aromatic hydrocarbon containing a heteroatom.
5. The unit structure derived from the heteroatom-containing aromatic hydrocarbon is derived from a heterocyclic ring, an aromatic hydrocarbon having at least one oxygen-containing substituent, or an aromatic hydrocarbon linked by at least one -NH- 5. The composition for forming a resist underlayer film for nanoimprinting according to claim 4, which has a unit structure that
6. The aromatic ring-containing polymer is an optionally substituted aromatic hydrocarbon, or an aromatic ring may be condensed or condensed, and may have a substituent 4 to 12-membered 5. The composition for forming a resist underlayer film for nanoimprinting according to claim 4, which is a novolac resin containing a unit structure derived from a monocyclic, bicyclic, or tricyclic compound of .
7. 2. The composition for forming a resist underlayer film for nanoimprinting according to claim 1, wherein the polymer is a novolac resin containing a repeating unit structure represented by the following formula (I).
   

   

   
   [In formula (I), n represents a number from 1 to 5. A represents an organic group having an aromatic hydrocarbon containing heteroatoms. B represents an organic group having a structure represented by formula (II), (III) or (IV) below.
   

   

   
   (In formula (II), R and R′ are each independently a hydrogen atom, an optionally substituted aromatic hydrocarbon group having 6 to 30 carbon atoms, an optionally substituted represents a heterocyclic group having 3 to 30 carbon atoms, or an optionally substituted linear, branched or cyclic alkyl group having 10 or less carbon atoms.)
   

   

   
   (In formula (III), X and Y each independently represent an optionally substituted aromatic hydrocarbon group having 6 to 30 carbon atoms, and i and j each independently represent 0 or 1. , p, q, and k represent the number of bonds, p and q each independently represent 0 or 1, p and q are not 0 at the same time, k represents an integer from 0 to 2, Z, together with C, forms a 4- to 12-membered monocyclic, bicyclic, or tricyclic ring which may be condensed with an aromatic ring, may have a substituent, and may contain a heteroatom. .)
   

   

   
   (In formula (IV), Ar represents an optionally substituted aromatic hydrocarbon group having 6 to 30 carbon atoms, and J ¹ and J ² each independently have a direct bond or a substituent, represents a divalent organic group that may be
8. 2. The resist underlayer film-forming composition according to claim 1, wherein the novolac resin comprises a composite unit structure AB' represented by the following formula (AB).
   

   

   
   In the formula (AB),
   n represents the number of composite unit structures AB',
   A represents an organic group having an aromatic hydrocarbon containing heteroatoms,
   B' represents one or more unit structures containing a structure represented by the following formula (B1), (B2) or (B3),
   * indicates a binding hand.
   

   

   
   [In formula (B1),
   R and R' are each independently a hydrogen atom, an optionally substituted aromatic ring residue having 6 to 30 carbon atoms, an optionally substituted heterocyclic group having 3 to 30 carbon atoms Represents a cyclic residue or a linear, branched or cyclic alkyl group having 10 or less carbon atoms which may have a substituent,
   * indicates a binding hand. ]
   

   

   
   [In formula (B2),
   Z ⁰ is selected from the group consisting of an optionally substituted aromatic ring residue or aliphatic ring residue having 6 to 30 carbon atoms, or the aromatic ring residue and the aliphatic ring residue represents an organic group in which the two groups are connected by a single bond,
   J ¹ and J ² each independently represent a direct bond or a divalent organic group optionally having a substituent,
   * indicates a binding hand. ]
   

   

   
   [In formula (B3),
   Z is an optionally substituted monocyclic, bicyclic, tricyclic or tetracyclic condensed ring having 4 to 25 carbon atoms, said monocyclic ring being a non-aromatic monocyclic ring; At least one of the monocyclic rings constituting the ring, tricyclic ring and tetracyclic ring is a non-aromatic monocyclic ring, and the remaining monocyclic rings may be aromatic monocyclic or non-aromatic monocyclic rings, and the monocyclic, bicyclic, A tricyclic or tetracyclic condensed ring may further form a condensed ring with one or more aromatic rings to form a pentacyclic or more condensed ring,
   X and Y are the same or different and represent a -CR ³¹ R ³² - group, R ³¹ and R ³² are the same or different and represent a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms,
   x and y each represent the number of X and Y, each independently representing 0 or 1;
   

   

   
   is bonded to any carbon atom 1 constituting the non-aromatic monocyclic ring of Z when x is 1, and extends from carbon atom 1 when x is 0;
   

   

   
   is bonded to any carbon atom 2 constituting the non-aromatic monocyclic ring of Z when y is 1, and extends from carbon atom 2 when y is 0;
   The carbon atom 1 and the carbon atom 2 may be the same or different, and when different, may belong to the same non-aromatic monocyclic ring or different non-aromatic monocyclic rings,
   * indicates a binding hand. ]
9. The composition for forming a resist underlayer film for nanoimprinting according to claim 1, further comprising a surfactant.
10. The composition for forming a resist underlayer film for nanoimprinting according to claim 1, further comprising a cross-linking agent.
11. The composition for forming a resist underlayer film for nanoimprinting according to claim 1, further comprising at least one selected from the group consisting of acids, salts thereof and acid generators.
12. The composition for forming a resist underlayer film for nanoimprinting according to claim 1, wherein the solvent has a boiling point of 160°C or higher.
13. A resist underlayer film that is a cured product of a coating film made of the composition for forming a resist underlayer film for nanoimprints according to any one of claims 1 to 12.
14. A method for producing a resist underlayer film, comprising applying the resist underlayer film-forming composition for nanoimprinting according to any one of claims 1 to 12 onto a semiconductor substrate and baking the composition.
15. forming a resist underlayer film on a semiconductor substrate from the composition for forming a resist underlayer film for nanoimprinting according to any one of claims 1 to 12;
    applying a curable composition onto the resist underlayer film;
    contacting the curable composition with a mold;
    A step of irradiating the curable composition with light or an electron beam to form a cured film, and a step of separating the cured film and the mold;
    A patterning method comprising:
16. The step of applying a curable composition onto the resist underlayer film comprises
    Optionally forming a hard mask layer on the resist underlayer film by coating or vapor deposition,
    forming an adhesion layer by coating or vapor deposition on the resist underlayer film or the hard mask layer;
    16. The patterning method of claim 15, comprising applying a curable composition over the adhesion layer or over the hard mask.
17. forming a resist underlayer film on a semiconductor substrate from the composition for forming a resist underlayer film for nanoimprinting according to any one of claims 1 to 12;
    optionally forming a hard mask layer on the resist underlayer film by coating or vapor deposition;
    forming an adhesion layer on the resist underlayer film or the hard mask layer by coating or vapor deposition;
    applying a curable composition onto the adhesion layer or onto the hard mask;
    forming a resist pattern by irradiation with light or an electron beam;
    A method of manufacturing a semiconductor device, comprising the steps of etching a resist underlayer film with a formed resist pattern and processing a semiconductor substrate with the patterned underlayer film.
18. forming a resist underlayer film on a semiconductor substrate from the composition for forming a resist underlayer film for nanoimprinting according to any one of claims 1 to 12;
    Optionally, a hard mask layer is formed on the resist underlayer film by coating or vapor deposition, an adhesion layer is formed on the resist underlayer film or the hard mask layer by coating or vapor deposition, and further the hard mask layer. applying a curing composition on top or onto the cling layer;
    forming a resist pattern on the resist film by irradiation with light or an electron beam;
    etching and patterning the hard mask layer through the resist pattern;
    etching and patterning the resist underlayer film through the etched hard mask layer;
    removing the hard mask layer;
    A step of forming a deposited film (spacer) on the resist underlayer film after removing the hard mask layer,
    A step of processing the deposited film (spacer) by etching,
    A step of removing the patterned resist underlayer film to leave a patterned deposited film (spacer), and a step of processing the semiconductor substrate through the patterned deposited film (spacer),
    A method of manufacturing a semiconductor device comprising:
19. The pattern forming method according to claim 15, wherein nanoimprinting is performed in an atmosphere containing at least one gas selected from the group consisting of air, oxygen, nitrogen, argon, helium, and carbon dioxide.
20. The method of manufacturing a semiconductor device according to claim 16, wherein nanoimprinting is performed in an atmosphere containing at least one gas selected from the group consisting of air, oxygen, nitrogen, argon, helium, and carbon dioxide.
21. The pattern forming method according to claim 17, wherein nanoimprinting is performed in an atmosphere containing at least one gas selected from the group consisting of air, oxygen, nitrogen, argon, helium, and carbon dioxide.
22. The method for manufacturing a semiconductor device according to claim 18, wherein nanoimprinting is performed in an atmosphere containing at least one gas selected from the group consisting of air, oxygen, nitrogen, argon, helium, and carbon dioxide.
23. 19. The method of manufacturing a semiconductor device according to claim 18, wherein the hard mask is removed by either etching or an alkaline chemical.