Pattern forming method, composition for forming resist underlayer film and resist underlayer film

Abstract

To provide a method for forming a pattern capable of improving sensitivity compared to conventional methods in an EB exposure method and an EUV exposure method and further to provide a composition for forming a resist underlayer film and a resist underlayer film suitably used for the pattern forming method.SOLUTION: There is provided a method for forming a pattern which comprises: a step of forming a resist underlayer film on a semiconductor substrate using a composition for forming a resist underlayer film for EB or EUV lithography, a step of forming a resist film for EB or EUV lithography on the resist underlayer film; a step of irradiating the resist film with UV; and a step of selectively irradiating the UV-irradiated resist film with EB or EUV, followed by developing the resist film to obtain a resist pattern.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a pattern forming method, a composition for forming a resist underlayer film, and a resist underlayer film.

Background Art

[0002] In semiconductor devices such as LSIs (Large Scale Integrated Circuits), with the improvement of integration density, the formation of fine patterns has been required, and in recent years, the minimum pattern size has reached 100 nm or less. The formation of fine patterns in such semiconductor devices has been realized by shortening the wavelength of the light source in the exposure apparatus and improving the resist material. Currently, a liquid immersion exposure method is being performed in which exposure is performed through water using an ArF (argon fluoride) excimer laser beam having a wavelength of 193 nm, which is deep ultraviolet light, as the light source. Also, various ArF-compatible resist materials based on acrylic resins have been developed for the resist material.

[0003] Furthermore, as a next-generation exposure technology, studies on an EB exposure method using an electron beam (EB) or an EUV (extreme ultraviolet) exposure method using soft X-rays having a wavelength of 13.5 nm as the light source are in progress, and the pattern size is 30 nm or less, and further miniaturization is progressing. However, with such miniaturization of the pattern size, the wobbling (LER; Line edge roughness) of the resist pattern sidewall and the non-uniformity (LWR: Line width roughness) of the resist pattern width have increased, and there is an increasing concern about the adverse effects on device performance. Although studies have been made to suppress these by optimizing the exposure apparatus, the resist material, the process conditions, etc., sufficient results have not been obtained. Note that LWR and LER are related, and by improving LWR, LER is also improved.

[0004] In order to solve the above problems, an invention related to a resist underlayer film which is a fired product of a coating film of a composition for forming a resist underlayer film containing a polymer having at least one of a unit structure having a polycyclic aromatic hydrocarbon structure and a unit structure having a maleimide structure is disclosed (see Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In pattern formation in the EB exposure method or EUV exposure method, while improving LWR and LER as described above, there is also a demand for higher sensitivity that enables pattern formation even when the exposure energy is lowered.

[0007] The present invention provides a pattern formation method capable of improving sensitivity more than before in the EB exposure method or EUV exposure method. Further, a composition for forming a resist underlayer film and a resist underlayer film suitably used in the above pattern formation method are provided.

Means for Solving the Problems

[0008] As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved, and have completed the present invention having the following gist. That is, the present invention includes the following. [1] A step of forming a resist underlayer film on a semiconductor substrate using a composition for forming a resist underlayer film for EB or EUV lithography, A step of forming a resist film for EB or EUV lithography on the resist underlayer film, A step of irradiating the resist film with UV, A step of selectively irradiating the resist film irradiated with UV with EB or EUV, and then developing the resist film to obtain a resist pattern; A patterning method comprising the same. [2] The step of irradiating with UV irradiates with UV at 1 mJ / cm 2 ~100 mJ / cm 2 The patterning method according to [1], wherein the irradiation is performed. [3] The patterning method according to [1] or [2], wherein baking is performed in the step of obtaining the resist pattern. [4] The composition for forming a resist underlayer film contains at least one polymer selected from the group consisting of a polymer (A) having a ring structure in which at least one is a heterocycle in the main chain, a polymer (B) having one or more polymerizable multiple bonds selected from the group consisting of a carbon-carbon double bond, a carbon-carbon triple bond, a carbon-nitrogen double bond, and a carbon-nitrogen triple bond in the side chain, a polymer (C) having a polycyclic aromatic hydrocarbon structure in the side chain, and a polymer (D) having an aromatic hydrocarbon structure having 6 to 40 carbon atoms in the main chain. The patterning method according to any one of [1] to [3]. [5] The patterning method according to [4], wherein the polymer (A) is a polymer (Y) having a repeating unit represented by the following formula (Y).

Chemical formula

Chemical formula

Chemical formula

[10] The polymer (D) is represented by the following formula (Q): [Chemical formula] (In formula (Q), Ar represents an optionally substituted aromatic ring group having 6 to 40 carbon atoms, L 0 represents a single bond, an ester bond, an ether bond, an optionally substituted alkylene group having 1 to 10 carbon atoms, or an optionally substituted alkenylene group having 2 to 10 carbon atoms, T 0 represents a single bond, an ester bond, an ether bond, an optionally substituted alkylene group having 1 to 10 carbon atoms, or an optionally substituted alkenylene group having 2 to 10 carbon atoms, However, L 0 and T 0 are different from each other, n R's 0 each independently represent a hydroxy group, a halogen atom, a nitro group, a cyano group, an amino group, or a monovalent organic group, n represents an integer from 0 to 5, * represents a bond.) The pattern forming method according to [4], which contains a structure represented by the formula.

[11] The polymer (D) is represented by the following formula (Q-1): [Chemical formula] (In formula (Q-1), Ar represents an optionally substituted aromatic ring having 6 to 40 carbon atoms, and L 1 represents a single bond, an ester bond, an ether bond, an alkylene group having 1 to 10 carbon atoms, or an alkenylene group having 2 to 10 carbon atoms, and n represents an integer of 1 to 3.) The pattern forming method according to

[10] , which contains a structure represented by the formula at the terminal. A composition for forming a resist underlayer film used in the pattern forming method according to any one of

[12] [1] to

[11] . A resist underlayer film, which is a fired product of a coating film of the composition for forming a resist underlayer film according to

[13]

[12] .

Advantages of the Invention

[0009] According to the present invention, in an EB exposure method or an EUV exposure method, a pattern forming method capable of improving sensitivity more than before can be provided. Further, a composition for forming a resist underlayer film and a resist underlayer film suitably used in the above pattern forming method can be provided.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0011] (Pattern Forming Method) The pattern forming method of the present invention includes at least the following steps. · A step of forming a resist underlayer film on a semiconductor substrate using a composition for forming a resist underlayer film for EB or EUV lithography (hereinafter referred to as step A), · A step of forming an EB or EUV lithography resist film on the resist underlayer film (hereinafter referred to as step B), · A step of irradiating the resist film with UV (hereinafter referred to as step C), and ·A step of selectively irradiating an EB or EUV onto a resist film irradiated with UV, and then developing the resist film to obtain a resist pattern (hereinafter referred to as step D). The pattern forming method of the present invention may further include the following steps. ·A step of etching a resist underlayer film using the resist pattern as a mask (hereinafter referred to as step E).

[0012] The pattern forming method of the present invention includes step D of irradiating an EB or EUV onto the resist film irradiated with UV in step C to obtain a resist pattern. That is, before step D of irradiating an EB or EUV for pattern formation, it includes step C of irradiating UV onto the resist film on the resist underlayer film. According to the pattern forming method having the step of irradiating UV in step C in addition to step D as in the present invention, it is possible to achieve a reduction in exposure dose (higher sensitivity) in pattern formation in step D. Hereinafter, steps A to E will be described in order.

[0013] <Step A: Step of forming a resist underlayer film> In step A, a resist underlayer film is formed on a semiconductor substrate using a composition for forming a resist underlayer film for EB or EUV lithography The film thickness of the resist film is not particularly limited, but is preferably 200 nm or less, more preferably 150 nm or less, still more preferably 100 nm or less, and particularly preferably 80 nm or less. Also, the film thickness of the resist film is preferably 10 nm or more, more preferably 20 nm or more, and still more preferably 30 nm or more.

[0014] The composition for the resist underlayer film preferably contains at least one polymer selected from the group consisting of a polymer (A) having a ring structure in which at least one is a heterocycle in the main chain, a polymer (B) having one or more polymerizable multiple bonds selected from the group consisting of a carbon-carbon double bond, a carbon-carbon triple bond, a carbon-carbon double bond, and a carbon-nitrogen triple bond in the side chain, a polymer (C) having a polycyclic aromatic hydrocarbon structure in the side chain, and a polymer (D) having an aromatic hydrocarbon structure having 6 to 40 carbon atoms in the main chain. In the present invention, a suitable composition for the resist underlayer film will be described in detail below.

[0015] <Step B: Step of forming a resist film> In Step B, a resist film for EB or EUV lithography is formed on the resist underlayer film. Usually, a resist film is formed on the resist underlayer film. The resist formed by coating and baking on the resist underlayer film by a known method is not particularly limited as long as it responds to EB or EUV used for irradiation. Either a negative photoresist or a positive photoresist can be used. In this specification, a resist that responds to EB is also referred to as a photoresist. The photoresist may be either an organic resist or a metal resist, with a metal resist being preferred. This is because a metal resist has better resolution than an organic resist, is more likely to produce small patterns, and has good etching transferability (resistance during transfer to the substrate). For example, examples of photoresists include positive photoresists composed of a novolak resin and 1,2-naphthoquinone diazide sulfonic acid ester, chemically amplified photoresists composed of a binder having a group that decomposes by an acid to increase the alkali dissolution rate and a photoacid generator, chemically amplified photoresists composed of a low molecular compound that decomposes by an acid to increase the alkali dissolution rate of the photoresist, an alkali-soluble binder, and a photoacid generator, and chemically amplified photoresists composed of a binder having a group that decomposes by an acid to increase the alkali dissolution rate, a low molecular compound that decomposes by an acid to increase the alkali dissolution rate of the photoresist, and a photoacid generator, and resists containing a metal element. Examples include products with the trade names V146G manufactured by JSR Corporation, APEX-E manufactured by Shipley Company, PAR710 manufactured by Sumitomo Chemical Co., Ltd., and AR2772 and SEPR430 manufactured by Shin-Etsu Chemical Co., Ltd. Further, for example, fluorine atom-containing polymer-based photoresists as described in Proc. SPIE, Vol. 3999, 330-334 (2000), Proc. SPIE, Vol. 3999, 357-364 (2000), and Proc. SPIE, Vol. 3999, 365-374 (2000) can be mentioned.

[0016] In addition, resist compositions such as those described in WO2019 / 188595, WO2019 / 187881, WO2019 / 187803, WO2019 / 167737, WO2019 / 167725, WO2019 / 187445, WO2019 / 167419, WO2019 / 123842, WO2019 / 054282, WO2019 / 058945, WO2019 / 058890, WO2019 / 039290, WO2019 / 044259, WO2019 / 044231, WO2019 / 026549, WO2018 / 193954, WO2019 / 172054, WO2019 / 021975, WO2018 / 230334, WO2018 / 194123, JP 2018-180525, WO2018 / 190088, JP 2018-070596, JP 2018-028090, JP 2016-153409, JP 2016-130240, JP 2016-108325, JP 2016-047920, JP 2016-035570, JP 2016-035567, JP 2016-035565, JP 2019-101417, JP 2019-117373, JP 2019-052294, JP 2019-008280, JP 2019-008279, JP 2019-003176, JP 2019-003175, JP 2018-197853, JP 2019-191298, JP 2019-061217, JP 2018-045152, JP 2018-022039, JP 2016-090441, JP 2015-10878, JP 2012-168279, JP 2012-022261, JP 2012-022258, JP 2011-043749, JP 2010-181857, JP 2010-128369, WO2018 / 031896, JP 2019-113855, WO2017 / 156388, WO2017 / 066319, JP 2018-41099, WO2016 / 065120, WO2015 / 026482, JP 2016-29498, JP 2011-253185, etc., so-called resist compositions such as resist compositions, radiation-sensitive resin compositions, and high-resolution patterning compositions based on organometallic solutions, and metal-containing resist compositions can be used, but are not limited thereto.

[0017] Examples of the resist composition include the following compositions.

[0018] A resin A having a repeating unit having an acid-decomposable group in which a polar group is protected by a protecting group that is eliminated by the action of an acid, and a compound represented by the following general formula (21), a photosensitive or radiation-sensitive resin composition.

[0019]

Chemical formula

[0020] A metal-containing film-forming composition for extreme ultraviolet or electron beam lithography, containing a compound having a metal-oxygen covalent bond and a solvent, wherein the metal element constituting the compound belongs to the 3rd to 7th periods of Groups 3 to 15 of the periodic table.

[0021] A radiation-sensitive resin composition containing a polymer having a first structural unit represented by the following formula (31) and a second structural unit containing an acid-dissociable group represented by the following formula (32), and an acid generator.

[0022]

Chemical formula

[0023] A resist composition containing a resin (A1) containing a structural unit having a cyclic carbonate structure, a structural unit represented by the following formula, and a structural unit having an acid labile group, and an acid generator.

[0024]

Chemical formula

[0025] Examples of the resist film include the following.

[0026] A resist film containing a base resin containing a repeating unit represented by the following formula (a1) and / or a repeating unit represented by the following formula (a2), and a repeating unit that generates an acid bonded to the polymer main chain upon exposure.

[0027]

Chemical formula

[0028] Examples of the resist material include the following.

[0029] A resist material containing a polymer having a repeating unit represented by the following formula (b1) or formula (b2).

[0030]

Chemical formula

[0031] A resist material comprising a base resin containing a polymer containing a repeating unit represented by the following formula (a).

[0032] [Chemical formula] (In formula (a), R A is a hydrogen atom or a methyl group. R 1 is a hydrogen atom or an acid-labile group. R 2 is a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, or a halogen atom other than bromine. X 1 is a single bond, a phenylene group, or a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms which may contain an ester group or a lactone ring. X 2 is -O-, -O-CH2- or -NH-. m is an integer of 1 to 4. u is an integer of 0 to 3. However, m + u is an integer of 1 to 4.)

[0033] A resist composition which generates an acid upon exposure and whose solubility in a developer changes by the action of the acid, A substrate component (A) whose solubility in a developer changes due to the action of an acid and a fluorine additive component (F) that exhibits decomposability with an alkaline developer are contained. A resist composition containing the fluorine additive component (F) contains a fluororesin component (F1) having a structural unit (f1) containing a base-dissociable group and a structural unit (f2) containing a group represented by the following general formula (f2-r-1).

[0034] [Chemical formula] [In formula (f2-r-1), Rf 21 is independently a hydrogen atom, an alkyl group, an alkoxy group, a hydroxyl group, a hydroxyalkyl group, or a cyano group. n” is an integer from 0 to 2. * represents a bond.]

[0035] The above structural unit (f1) includes a structural unit represented by the following general formula (f1-1) or a structural unit represented by the following general formula (f1-2).

[0036] [Chemical formula] [In formulas (f1-1) and (f1-2), R is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. X is a divalent linking group having no acid-dissociable site. A aryl is a divalent aromatic cyclic group which may have a substituent. X 01 is a single bond or a divalent linking group. R 2 are independently organic groups having a fluorine atom.]

[0037] Examples of the coating, coating solution, and coating composition include the following.

[0038] A coating containing a metal oxo-hydroxone network having an organic ligand by a metal-carbon bond and / or a metal carboxylate bond.

[0039] Inorganic oxo / hydroxy-based composition.

[0040] A coating solution comprising an organic solvent; a first organometallic composition represented by the formula R z SnO (2-(z / 2)-(x / 2)) (OH) x (where 0 < z ≦ 2 and 0 < (z + x) ≦ 4), the formula R’ n SnX 4-n (where n = 1 or 2), or a mixture thereof, where R and R’ are independently hydrocarbyl groups having 1 to 31 carbon atoms, and X is a ligand having a hydrolyzable bond to Sn or a combination thereof; and a hydrolyzable metal compound represented by the formula MX’ v (where M is a metal selected from Groups 2 to 16 of the Periodic Table of the Elements, v is a number from 2 to 6, and X’ is a ligand having a hydrolyzable M-X bond or a combination thereof), a coating solution containing a hydrolyzable metal compound.

[0041] A coating solution comprising an organic solvent and a first organometallic compound represented by the formula RSnO (3 / 2-x / 2) (OH) x (where 0 < x < 3), wherein the solution contains about 0.0025 M to about 1.5 M of tin, and R is an alkyl group or cycloalkyl group having 3 to 31 carbon atoms, and the alkyl group or cycloalkyl group is bonded to tin at a secondary or tertiary carbon atom.

[0042] An inorganic pattern-forming precursor aqueous solution comprising a mixture of water, metal oxide cations, polyatomic inorganic anions, and a radiation-sensitive ligand containing peroxide groups.

[0043] <Step C: Irradiating the resist film with UV> In Step C, the resist film is irradiated with UV. The irradiation with UV may be performed on a part of the resist film, and it is preferably performed on the entire surface of the resist film. The step of irradiating with UV is preferably carried out by irradiating with UV at 1 mJ / cm 2 ~100 mJ / cm 2 . It is particularly preferable to irradiate with UV at 3 mJ / cm 2 or more, and even more preferably to irradiate with UV at 5 mJ / cm 2 or more. Also, it is particularly preferable to irradiate with UV at 30 mJ / cm 2 or less, and even more preferably to irradiate with UV at 20 mJ / cm 2 or more. When the irradiation energy of UV is at or above the lower limit value, it is easy to achieve low exposure (high sensitivity) of pattern formation in step D. There is no problem even if the irradiation energy of UV exceeds the upper limit value, but in consideration of energy reduction, it is preferably below the upper limit value.

[0044] <Step D: Step of obtaining a resist pattern> In step D, the resist film irradiated with UV is selectively irradiated with EB or EUV, and then the resist film is developed to obtain a resist pattern. The irradiation of EB or EUV is performed, for example, through a mask (reticle) for forming a predetermined pattern. The resist underlayer film of the present invention is applied for EB (electron beam) or EUV (extreme ultraviolet ray: 13.5 nm) irradiation, and is preferably applied for EUV (extreme ultraviolet ray) exposure. The irradiation energy of EB or EUV is not particularly limited. The irradiation energy of EB is preferably 0.01 mC / cm 2 ~50 mC / cm 2 , and more preferably 0.01 mC / cm 2 ~10 mC / cm 2 . The irradiation energy of EUV is preferably 1 mJ / cm 2 ~500 mJ / cm 2 , and more preferably 10 mJ / cm 2 ~100 mJ / cm 2 . According to the pattern formation method of the present invention having step C, even when the irradiation energy of EB or EUV is set to a low energy such as 4 mC / cm 2 or less, it tends to form a pattern well.

[0045] In Process D, it is preferable to perform a post-exposure bake (PEB). The bake may be performed after irradiation with EB or EUV and before development. The bake is performed under conditions appropriately selected, for example, from a heating temperature of 70°C to 280°C and a heating time of 0.3 minutes to 10 minutes.

[0046] For developing the organic resist, for example, an alkaline developer is used. Examples of the development temperature include 5°C to 50°C. Examples of the development time include 10 seconds to 300 seconds. Examples of the alkaline developer include aqueous solutions of alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, etc., primary amines such as ethylamine, n-propylamine, etc., secondary amines such as diethylamine, di-n-butylamine, etc., tertiary amines such as triethylamine, methyldiethylamine, etc., alcohol amines such as dimethylethanolamine, triethanolamine, etc., quaternary ammonium salts such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, choline, etc., cyclic amines such as pyrrole, piperidine, etc. Further, an appropriate amount of alcohols such as isopropyl alcohol and surfactants such as nonionic surfactants can be added to the aqueous solutions of the above alkalis and used. Among these, preferred developers are aqueous solutions of quaternary ammonium salts, more preferably aqueous solutions of tetramethylammonium hydroxide and aqueous solutions of choline. Further, surfactants and the like can also be added to these developers. Instead of the alkaline developer, development can also be performed with an organic solvent such as butyl acetate, and a method of developing the portions where the alkali dissolution rate of the photoresist has not improved can be used.

[0047] An organic solvent can be used as a developer for a metal resist, and development is carried out with a developer (solvent) after irradiation with light or an electron beam. Thereby, for example, when a negative-type metal-containing resist film is used, the unexposed portion of the metal-containing resist film is removed, and a pattern of the metal-containing resist film is formed. Examples of the developing solution (organic solvent) include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl 3-methoxypropionate, etc.Furthermore, a surfactant or the like can be added to these developers. As the development conditions, the temperature is appropriately selected from 5°C to 50°C, and the time is appropriately selected from 10 seconds to 600 seconds.

[0048] <Step E: Step of etching the resist underlayer film> The pattern forming method of the present invention may further include the following Step E. In this step, the resist underlayer film is etched using the resist pattern formed in Step D as a mask. The etching may be dry etching or wet etching, but dry etching is preferably used. When the inorganic film is formed on the surface of the used semiconductor substrate, the surface of the inorganic film is exposed. When the inorganic film is not formed on the surface of the used semiconductor substrate, the surface of the semiconductor substrate is exposed. Thereafter, through a step of processing the semiconductor substrate by a known method (dry etching method or the like), a semiconductor device can be manufactured.

[0049] Next, the resist underlayer film forming composition used in the pattern forming method described above, and the resist underlayer film, which is a fired product of the coating film of the resist underlayer film forming composition, will be described below.

[0050] (Resist underlayer film forming composition) The resist underlayer film forming composition of the present embodiment preferably contains at least one polymer selected from the group consisting of a polymer (A) having a ring structure in which at least one is a heterocycle in the main chain, a polymer (B) having one or more polymerizable multiple bonds selected from the group consisting of a carbon-carbon double bond, a carbon-carbon triple bond, a carbon-nitrogen double bond, and a carbon-nitrogen triple bond in the side chain, a polymer (C) having a polycyclic aromatic hydrocarbon structure in the side chain, and a polymer (D) having an aromatic hydrocarbon structure having 6 to 40 carbon atoms in the main chain. The resist underlayer film forming composition may contain two or more different polymers among the above. The composition for forming a resist underlayer film of the present embodiment can further contain a solvent, a crosslinking agent, and a curing catalyst in addition to the polymer. And other additives can be contained as long as the effects of the present invention are not impaired.

[0051] <<Polymer (A)>> As described above, the polymer (A) has a ring structure having at least one heterocycle in the main chain. Note that the polymer (A) is a polymer having a structure different from those of the polymer (B), the polymer (C), and the polymer (D).

[0052] The polymer (A) is preferably a polymer (Y) having a repeating unit represented by the following formula (Y).

[0053] [Chemical formula] (In formula (Y), A1, A2, A3, A4, A5, and A6 each represent a hydrogen atom, a methyl group, or an ethyl group. X1 represents the following formula (Y2), the following formula (Y3), the following formula (Y4), or the following formula (Y0). Q represents the following formula (Y5) or the following formula (Y6).)

[0054] [Chemical formula] (In formula (Y2), formula (Y3), formula (Y4), and formula (Y0), R1 and R2 each represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 3 to 6 carbon atoms, a benzyl group, or a phenyl group, and the alkyl group having 1 to 6 carbon atoms, the alkenyl group having 3 to 6 carbon atoms, the benzyl group, and the phenyl group may be substituted with a group selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, a halogen atom, an alkoxy group having 1 to 6 carbon atoms, a nitro group, a cyano group, a hydroxy group, a carboxy group, and an alkylthio group having 1 to 6 carbon atoms. Further, R1 and R2 may be bonded to each other to form a ring having 3 to 6 carbon atoms. R3 represents a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 3 to 6 carbon atoms, a benzyl group or a phenyl group, and the phenyl group may be substituted with a group selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, a halogen atom, an alkoxy group having 1 to 6 carbon atoms, a nitro group, a cyano group, a hydroxy group, and an alkylthio group having 1 to 6 carbon atoms. * represents a bond. *1 represents a bond that binds to a carbon atom. *2 represents a bond that binds to a nitrogen atom.)

[0055]

Chemical formula

[0056] Examples of the repeating unit represented by formula (Y) include repeating units represented by the following formulas (Y-1) to (Y-20).

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chem.

[0057] In formula (Y-20), R is an alcohol residue (an organic group other than the hydroxy group of the alcohol), and this R represents an alkyl group, an ether group, or a combination thereof. Examples of the above R include an alkyl group, an alkoxyalkyl group, etc.

[0058] Examples of the polymer (Y) include the polymers described in International Publication No. WO2013 / 018802 pamphlet. The content of International Publication No. WO2013 / 018802 pamphlet is incorporated herein to the same extent as if fully set forth.

[0059] The polymer (Y) is preferably produced by the reaction of a compound represented by the following formula (Y7) and a compound represented by the following formula (Y8).

Chem.

[0060] The reaction between the compound represented by formula (Y7) and the compound represented by formula (Y8) is preferably carried out in a solution state dissolved in an organic solvent such as benzene, toluene, xylene, ethyl lactate, butyl lactate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and N-methylpyrrolidone. And in this reaction, it is also possible to use a quaternary ammonium salt such as benzyltriethylammonium chloride, tetrabutylammonium chloride, and tetraethylammonium bromide as a catalyst. The reaction temperature and reaction time of this reaction are not limited and may be changed according to the compounds used, concentration, etc. It may be appropriately selected from the range of a reaction time of 0.1 to 100 hours and a reaction temperature of 20°C to 200°C. When using a catalyst, it can be used in the range of 0.001 to 30% by mass based on the total mass of the compounds used.

[0061] Also, the ratio of the compounds represented by formula (Y7) and formula (Y8) used in the reaction may be any ratio. The ratio of the two compounds is preferably [compound represented by formula (Y7):compound represented by formula (Y8)] = 3:1 to 1:3 in molar ratio, and more preferably 3:2 to 2:3.

[0062] The weight average molecular weight of the polymer (Y) is not particularly limited, but is preferably 1,000 to 30,000, more preferably 2,000 to 20,000, and particularly preferably 3,000 to 15,000.

[0063] <<Polymer (B)>> As described above, the polymer (B) has one or more polymerizable multiple bonds selected from the group consisting of carbon-carbon double bonds, carbon-carbon triple bonds, carbon-nitrogen double bonds, and carbon-nitrogen triple bonds in the side chain.

[0064] The polymer (B) is an organic polymer. The polymer (B) may be a homopolymer or a copolymer.

[0065] Polymer (B) has, for example, a (meth)acryloyl group, a vinylaryl group (e.g., a styryl group), a vinyloxy group, an allyl group, etc. as the group having the polymerizable multiple bond on its side chain. Note that Polymer (B) is a polymer having a structure different from those of Polymer (A), Polymer (C), and Polymer (D).

[0066] Polymer (B) is, for example, Polymer (B-1) formed by polymerizing the polymerizable unsaturated bond of a compound having a group having a polymerizable unsaturated bond. Polymer (B-1) may be a homopolymer or a copolymer. Examples of the group having a polymerizable unsaturated bond include a (meth)acryloyl group, a vinylaryl group (e.g., a styryl group), a vinyloxy group, an allyl group, etc.

[0067] For example, in Polymer (B), the polymerizable multiple bond is bonded to the main chain of Polymer (B) via a linking group having a structure obtained by reacting an epoxy group and a nucleophilic functional group. Examples of the nucleophilic functional group include one or more selected from the group consisting of a carboxy group, a hydroxy group, an amino group, and a thiol group. The hydroxy group may be a phenolic hydroxy group or may not be a phenolic hydroxy group. When an epoxy group and a carboxy group react, they react as follows to form the following structure (S1). [Chemical formula] (In the formula, * represents a bond.)

[0068] Further, for example, in the polymer (B), the polymerizable multiple bond is bonded to the main chain of the polymer (B) via a linking group having a structure obtained by reacting an isocyanate group and a nucleophilic functional group. In this case, examples of the nucleophilic functional group include one or more selected from the group consisting of a hydroxy group, an amino group, and a thiol group. The hydroxy group may be a phenolic hydroxy group or may not be a phenolic hydroxy group.

[0069] The polymer (B) preferably has a structural unit represented by the following formula (Z).

Chemical formula

[0070] Examples of the alkyl group having 1 to 10 carbon atoms include 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 group, 2-ethyl-3-methyl-cyclopropyl group, n-heptyl group, cycloheptyl group, norbornyl group, n-octyl group, cyclooctyl group, n-nonyl group, isobornyl group, tricyclononyl group, n-decyl group, adamantyl group, tricyclodecyl group and the like can be mentioned. Among these, a methyl group is preferable.,

[0071] L 1 When L is a linking group, the number of carbon atoms of the linking group is not particularly limited, and for example, 1 to 10 can be mentioned., L 1 When L is a linking group, examples of the linking group include a linking group having a structure obtained by reacting an epoxy group with a nucleophilic functional group, a linking group having a structure obtained by reacting an isocyanate group with a nucleophilic functional group, and the like.,

[0072] L 1 Examples of L include the following linking groups (L1-1) to (L1-11).

Chemical formula

Chemical formula

[0073] L 2 is a monovalent group having a polymerizable multiple bond. The monovalent group may be the polymerizable multiple bond itself., The number of carbon atoms of the monovalent group is not particularly limited, and for example, it may be 1 to 20, or it may be 1 to 10.,

[0074] L 2 Examples of L include the following monovalent groups (L2-1) to (L2-81). [Chemical formula] [Chemical formula] [Chemical formula] [Chemical formula] [Chemical formula] [Chemical formula] [Chemical formula] [Chemical formula] (In the formula, * represents a bond.)

[0075] Examples of the combinations of the linking groups (L1-1) to (L1-9) and the monovalent groups (L2-1) to (L2-7) include the following combinations. · The combination of (L1-1) and (L2-1) · The combination of (L1-1) and (L2-2) · The combination of (L1-1) and (L2-7) · The combination of (L1-2) and (L2-3) · The combination of (L1-2) and (L2-4) · The combination of (L1-2) and (L2-7) · The combination of (L1-3) and (L2-3) · The combination of (L1-3) and (L2-4) · The combination of (L1-4) and (L2-7) · The combination of (L1-5) and (L2-1) · The combination of (L1-5) and (L2-2) · The combination of (L1-6) and (L2-1) · The combination of (L1-6) and (L2-2) · The combination of (L1-7) and (L2-5) · The combination of (L1-7) and (L2-6) · The combination of (L1-8) and (L2-7) · The combination of (L1-9) and (L2-7) Note that the combination of (L1-1) and (L2-1) is synonymous with the combination of (L1-2) and (L2-3). The combination of (L1-1) and (L2-2) is synonymous with the combination of (L1-2) and (L2-4).

[0076] Also, L in the structural unit represented by formula (Z) 1 -L 2 preferably has a structure represented by the following formula (Za), (Zb) or (Zc).

Chemical formula

[0077] Examples of the structural unit represented by formula (Z) include the following structural units.

Chemical formula

Chemical formula

Chemical formula

Chemical formula

[0078] An example of the polymer (B) containing the structural unit represented by the formula (Z) can be obtained, for example, by reacting a glycidyl (meth)acrylate-based polymer with a compound (M1) having a polymerizable multiple bond and a carboxy group as follows. The glycidyl (meth)acrylate-based polymer may be a homopolymer or a copolymer. Examples of the copolymer include a copolymer of glycidyl (meth)acrylate and 2-hydroxyethyl (meth)acrylate and a copolymer of glycidyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate.

[0079] [Chemical formula] (In the formula, R 1 , and L 2 are synonymous with R 1 , and L 2 in the formula (Z), respectively.)

[0080] The reaction can be carried out, for example, in the presence of a catalyst such as tetrabutylphosphonium bromide.

[0081] Examples of the compound (M1) having a polymerizable multiple bond and a carboxy group include acrylic acid, methacrylic acid, 4-vinylbenzoic acid, sorbic acid, tetrol acid, tiglic acid, 1-cyclohexene-1-carboxylic acid, 2-benzylacrylic acid, trans-cinnamic acid, trans-4-methoxycinnamic acid, α-phenylcinnamic acid, monomethyl fumarate, α-cyanocinnamic acid, 4-nitrocinnamic acid, 3-nitrocinnamic acid, and the like.

[0082] Another example of the polymer (B) containing the structural unit represented by the formula (Z) can be obtained, for example, by reacting a (meth)acrylate-based polymer having a hydroxy group with a compound (M2) having a polymerizable multiple bond and an isocyanate group as follows. The (meth)acrylate-based polymer having a hydroxy group may be a homopolymer or a copolymer. [Chemical formula] (In the formula, R 1 , and L 2 are respectively synonymous with R 1 , and L 2 in formula (Z). R 11 represents a divalent organic group. R 12 represents a single bond or a divalent organic group.) R 11 is, for example, an alkylene group having 1 to 4 carbon atoms. R 12 is, for example, a single bond or an alkylene group having 1 to 4 carbon atoms.

[0083] Another example of the polymer (B) containing the structural unit represented by formula (Z) can be obtained, for example, by reacting a styrene polymer having a hydroxy group or an amino group with a compound (M2) having a polymerizable multiple bond and an isocyanate group as follows. The styrene polymer having a hydroxy group or an amino group may be a homopolymer or a copolymer.

Chemical formula

[0084] Examples of the compound (M2) having a polymerizable multiple bond and an isocyanate group include the following compounds.

Chemical formula

[0085] Polymer (B) may have structural units other than the structural unit represented by formula (Z). Examples of such structural units include a structural unit represented by the following formula (Z2), a structural unit represented by the following formula (Z3), and the like. [Chemical Formula] (In formula (Z2), R 2 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and L 3 represents a monovalent group having 1 to 20 carbon atoms. In formula (Z3), R 2 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, Ar represents a benzene ring or a naphthalene ring, and L 4 represents a hydroxy group, a cyano group, a nitro group, or an amino group (-NH2). L 5 represents a halogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. m1 represents an integer of 0 to 3. m2 represents an integer of 0 to 5. However, the sum of m1 and m2 is 0 to 5. When m1 is 2 or 3, the plurality of Ls 4 may be the same or different. When m2 is 2 to 5, the plurality of Ls 5 may be the same or different. In formula (Z4), R 2 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and L 6 represents a monovalent organic group selected from an alkyl group having 1 to 10 carbon atoms and an aryl group having 6 to 40 carbon atoms, and at least one hydrogen atom of the alkyl group and the aryl group may be substituted with a hydroxy group or an alkoxy group having 1 to 6 carbon atoms.

[0086] The monovalent group having 1 to 20 carbon atoms of L in formula (Z2) 3 represents, for example, a monovalent organic group selected from an alkyl group having 1 to 10 carbon atoms and an aryl group having 6 to 40 carbon atoms, and at least one hydrogen atom of the alkyl group and the aryl group may be substituted with a hydroxy group. Further, the alkyl group may have an oxygen atom inserted between carbon atoms. In addition, examples of the monovalent group having 1 to 20 carbon atoms for L 3 include, for example, a group represented by the following formula (Z2-1). [Chemical formula] (In formula (Z2-1), L 3a represents an optionally substituted alkyl group having 1 to 6 carbon atoms or an optionally substituted aromatic hydrocarbon group.) Examples of the aromatic hydrocarbon group for L 3a include, for example, a phenyl group and a naphthyl group. Examples of the substituent in the optionally substituted alkyl group having 1 to 6 carbon atoms for L 3a include, for example, a halogen atom, a hydroxy group, etc. The substituent may be one or plural. When there are plural substituents, the plural substituents may be the same or different. Examples of the substituent in the optionally substituted aromatic hydrocarbon group for L 3a include, for example, a halogen atom, a hydroxy group, an alkyl group having 1 to 3 carbon atoms which may be substituted with a halogen atom, etc. The substituent may be one or plural. When there are plural substituents, the plural substituents may be the same or different.

[0087] Examples of the alkyl group having 1 to 10 carbon atoms represented by R 2 , and the alkyl groups having 1 to 10 carbon atoms represented by L 3 and L 6 are as described above. Examples of the halogen atom for L 5 include, for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. Examples of the alkyl group having 1 to 6 carbon atoms for L 5 include, for example, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, a cyclopropyl group, an n-butyl group, an i-butyl group, etc. Examples of the alkyl group having 1 to 6 carbon atoms for L 5Examples of the alkoxy group having 1 to 6 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a butoxy group and the like. m1 represents an integer of 0 to 3, and may be 0, may be 1, may be 2, or may be 3. m2 represents an integer of 0 to 5, and may be 0, may be 1, may be 2, may be 3, may be 4, or may be 5.

[0088] L 3 and L 6 Examples of the aryl group having 6 to 40 carbon atoms represented by include a phenyl group, an o-methylphenyl group, an m-methylphenyl group, a p-methylphenyl group, an o-chlorophenyl group, an m-chlorophenyl group, a p-chlorophenyl group, an o-fluorophenyl group, a p-fluorophenyl group, an o-methoxyphenyl group, a p-methoxyphenyl group, a p-nitrophenyl group, a p-cyanophenyl group, an α-naphthyl group, a β-naphthyl group, an o-biphenylyl group, an m-biphenylyl group, a p-biphenylyl group, a 1-anthryl group, a 2-anthryl group, a 9-anthryl group, a 1-phenanthryl group, a 2-phenanthryl group, a 3-phenanthryl group, a 4-phenanthryl group and a 9-phenanthryl group and the like. L 6 Examples of the alkoxy group having 1 to 6 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a butoxy group and the like.

[0089] Examples of the monomer used for deriving the formula (Z2) include the following compounds.

Chemical formula

Chemical formula

Chemical formula

Chemical formula

[0090] Examples of the monomers used for deriving formula (Z3) include, for example, the following compounds. [Chemistry] [Chemistry] [Chemistry] Me represents a methyl group.

[0091] Examples of the monomers used for deriving formula (Z4) include, for example, the following compounds. [Chemistry] [Chemistry]

[0092] The proportion of the structural unit represented by formula (Z) in polymer (B) is not particularly limited, but the molar ratio of the structural unit represented by formula (Z) to all the structural units of polymer (B) may be, for example, 20 mol% to 100 mol%, or may be 20 mol% or more and less than 100 mol%. The proportion of the structural unit represented by formula (Z2) in polymer (B) is not particularly limited, but the molar ratio of the structural unit represented by formula (Z2) to all the structural units of polymer (B) may be, for example, 0 mol% to 80 mol%, or may be more than 0 mol% and 80 mol% or less.

[0093] Polymer (B) may contain structural units other than the structural unit represented by formula (Z) and the structural unit represented by formula (Z2). In that case, the molar ratio of the other structural units in all the structural units of polymer (B) is, for example, more than 0 mol% and 20 mol% or less.

[0094] Polymer (B) is not, for example, a polysiloxane. Polymer (B) is not, for example, a hydrolysis condensate of a hydrolyzable silane. Polymer (B) is not, for example, a reaction product of a tetracarboxylic dianhydride and a diepoxy compound having two epoxy groups. Polymer (B) is not, for example, a reaction product of a tetracarboxylic dianhydride, a diepoxy compound having two epoxy groups, and a monohydroxy compound having one hydroxy group. Polymer (B) does not have, for example, an isocyanuric acid skeleton having an alkenyl group. Examples of the alkenyl group include alkenyl groups having 3 to 6 carbon atoms. Examples of the alkenyl group having 3 to 6 carbon atoms include an allyl group.

[0095] Examples of polymer (B) include the polymers described in International Publication No. 2015 / 178235 pamphlet. The content of International Publication No. 2015 / 178235 pamphlet is incorporated herein to the same extent as if fully set forth.

[0096] The molecular weight of polymer (B) is not particularly limited. The lower limit of the weight average molecular weight of polymer (B) is, for example, 500, 1,000, 2,000, or 3,000. The upper limit of the weight average molecular weight of polymer (B) is, for example, 100,000, 50,000, 30,000, 20,000, or 10,000.

[0097] <<Polymer (C)>> As described above, polymer (C) has a polycyclic aromatic hydrocarbon structure in its side chain. Note that polymer (C) is a polymer having a structure different from those of polymer (A), polymer (B), and polymer (D). Hereinafter, the unit structure (C1) having a polycyclic aromatic hydrocarbon structure possessed by polymer (C) will be described.

[0098] <<Unit Structure (C1)>> As described above, unit structure (C1) is a unit structure having a polycyclic aromatic hydrocarbon structure. The polycyclic aromatic hydrocarbon structure preferably contains at least one structure selected from the group consisting of naphthalene, anthracene, phenanthrene, carbazole, pyrene, triphenylene, chrysene, naphthacene, biphenylene, and fluorene.

[0099] In this specification, the polycyclic aromatic hydrocarbon structure is an aromatic structure having a hydrocarbon composed of two or more aromatic rings exhibiting aromaticity, and includes a condensed polycyclic aromatic hydrocarbon structure having a condensed ring and a hydrocarbon ring assembly structure in which a plurality of aromatic rings are directly bonded by single bonds. Note that in this specification, the polycyclic aromatic hydrocarbon structure also includes a heterocyclic structure in which some carbons of the aromatic ring are substituted with nitrogen.

[0100] The condensed polycyclic aromatic hydrocarbon structure is not particularly limited, and examples thereof include a naphthalene structure, an anthracene structure, a phenanthrene structure, carbazole, a pyrene structure, a triphenylene structure, a chrysene structure, a naphthacene structure, a biphenylene structure, and a fluorene structure.

[0101] The hydrocarbon ring assembly structure is not particularly limited, and examples thereof include a carbazole structure, a biphenyl structure, a terphenyl structure, a quaterphenyl structure, a binaphthalene structure, a phenylnaphthalene structure, a phenylfluorene structure, and a diphenylfluorene structure.

[0102] The polycyclic aromatic hydrocarbon structure may be substituted by a substituent. The substituent that may be present is not particularly limited, and examples thereof include an alkyl group, a hydroxy group, a carboxy group, and a halogen group (e.g., a fluorine group, a chlorine group, a bromine group, an iodine group). Examples of the above alkyl group include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, an s-butyl group, a t-butyl group, an n-pentyl group, a 1-methyl-n-butyl group, a 2-methyl-n-butyl group, a 3-methyl-n-butyl group, a 1,1-dimethyl-n-propyl group, a 1,2-dimethyl-n-propyl group, a 2,2-dimethyl-n-propyl group, a 1-ethyl-n-propyl group, an n-hexyl group, a 1-methyl-n-pentyl group, a 2-methyl-n-pentyl group, a 3-methyl-n-pentyl group, a 4-methyl-n-pentyl group, a 1,1-dimethyl-n-butyl group, a 1,2-dimethyl-n-butyl group, a 1,3-dimethyl-n-butyl group, a 2,2-dimethyl-n-butyl group, a 2,3-dimethyl-n-butyl group, a 3,3-dimethyl-n-butyl group, a 1-ethyl-n-butyl group, a 2-ethyl-n-butyl group, a 1,1,2-trimethyl-n-propyl group, a 1,2,2-trimethyl-n-propyl group, a 1-ethyl-1-methyl-n-propyl group, and a 1-ethyl-2-methyl-n-propyl group, etc.In addition, a cyclic alkyl group can also be used as the above alkyl group. For example, as the cyclic alkyl group having 1 to 10 carbon atoms, cyclopropyl group, cyclobutyl group, 1-methyl-cyclopropyl group, 2-methyl-cyclopropyl 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, 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 group, and 2-ethyl-3-methyl-cyclopropyl group, etc. can be mentioned.

[0103] From the viewpoint of preferably obtaining the effects of the present invention, the polycyclic aromatic hydrocarbon structure is preferably a naphthalene structure, anthracene structure, phenanthrene structure, pyrene structure, triphenylene structure, chrysene structure, naphthacene structure, biphenylene structure, fluorene structure, or carbazole structure, more preferably a naphthalene structure, anthracene structure, phenanthrene structure, pyrene structure, or carbazole structure, and even more preferably a naphretane structure or carbazole structure. The polycyclic aromatic hydrocarbon structure may be one kind or two or more kinds, but is preferably 1 kind or 2 kinds.

[0104] As the unit structure (C1), specifically, although not particularly limited, the unit structure represented by the following formula (C1-1) can be preferably used. [Chemical formula] (In formula (C1-1), R 1 represents a hydrogen atom or a methyl group. X represents an ester group or an amide group. Y represents an alkylene group having 1 to 6 carbon atoms. p and q each independently represent 0 or 1. Ar represents a monovalent group obtained by removing a hydrogen atom from naphthalene, anthracene, phenanthrene, pyrene, triphenylene, chrysene, naphthacene, biphenylene, fluorene, or carbazole, which may be substituted.)

[0105] Also, as the unit structure (C1), although not particularly limited, the unit structure represented by the following formula (C1-2) can be preferably used. [Chemical formula] (In formula (C1-2), R 1 represents a hydrogen atom or a methyl group, Z represents a halogen atom, a hydroxyl group, an alkyl group, an alkoxy group, a thiol group, a cyano group, a carboxy group, an amino group, an amide group, an alkoxycarbonyl group, or a thioalkyl group substituted on the naphthalene ring, and n represents an integer from 0 to 7. When n is 2 or more, two or more Z's may be the same or different.)

[0106] In Z, as the halogen atom, a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom can be used. As the alkyl group, for example, it is a linear or branched alkyl group having 1 to 6 carbon atoms, and these may be substituted with a halogen atom or the like. For example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butoxy group, a t-butoxy group, an n-hexyl group, a chloromethyl group, etc. may be mentioned. As the alkoxy group, for example, it is an alkoxy group having 1 to 6 carbon atoms, and for example, a methoxy group, an ethoxy group, an isopropoxy group, etc. may be mentioned. As the amide group, for example, it is an amide group having 1 to 12 carbon atoms, and for example, a formamide group, an acetamide group, a propionamide group, an isobutyramide group, a benzamide group, a naphthylamide group, an acrylamide group, etc. may be mentioned. As the alkoxycarbonyl group, for example, it is an alkoxycarbonyl group having 1 to 12 carbon atoms, and for example, a methoxycarbonyl group, an ethoxycarbonyl group, a benzyloxycarbonyl group, etc. may be mentioned. As the thioalkyl group, for example, it is a thioalkyl group having 1 to 6 carbon atoms, and for example, a methylthio group, an ethylthio group, a butylthio group, a hexylthio group, etc. may be mentioned.

[0107] Specific examples of the unit structure (C1) represented by the formula (C1-2) include the following.

Chemical formula

Chemical formula

[0108] Furthermore, as the unit structure (C1), although not particularly limited, the unit structure represented by the following formula (C1-3) can be preferably used.

Chemical formula

[0109] Examples of the aromatic ring having 6 to 40 carbon atoms include benzene, naphthalene, anthracene, acenaphthene, fluorene, triphenylene, phenalene, phenanthrene, indene, indane, indacene, pyrene, chrysene, perylene, naphthacene, pentacene, coronene, heptacene, benzo[a]anthracene, dibenzophenanthrene, and dibenzo[a,j]anthracene, etc.)

[0110] Examples of the divalent linking group in Q include an ether group, an ester group, and an imino group, etc., and an imino group is preferred.)

[0111] The unit structure (C1) may be one type or two or more types, but preferably one or two types.)

[0112] When the polymer contains the unit structure (C1), the molar ratio of the unit structure (C1) is preferably 10 to 90 mol%, more preferably 30 to 85 mol%, and even more preferably 40 to 80 mol% based on all the unit structures of the polymer from the viewpoint of suitably obtaining the effects of the present invention.)

[0113] Examples of the polymer (C) include the polymers described in International Publication No. 2023 / 106364 pamphlet. The contents of International Publication No. 2023 / 106364 pamphlet are incorporated herein to the same extent as if they were all expressly stated.)

[0114] The molecular weight of the polymer (C) is not particularly limited. The weight average molecular weight by gel permeation chromatography (hereinafter sometimes abbreviated as GPC) is preferably 1,500 to 100,000, and more preferably 2,000 to 50,000.)

[0115] <<Polymer (D)>> Polymer (D) has, as described above, an aromatic hydrocarbon structure having 6 to 40 carbon atoms in the main chain. Note that Polymer (D) is a polymer having a structure different from that of Polymer (A), Polymer (B), and Polymer (D).

[0116] Polymer (D) has the following formula (Q):

Chemical formula

[0117] Examples of the aromatic ring having 6 to 40 carbon atoms include benzene, naphthalene, anthracene, acenaphthene, fluorene, triphenylene, phenalene, phenanthrene, indene, indan, indacene, pyrene, chrysene, perylene, naphthacene, pentacene, coronene, heptacene, benzo[a]anthracene, dibenzophenanthrene, dibenzo[a,j]anthracene, or derivatives thereof. Among these, benzene, naphthalene, or anthracene is preferable.

[0118] Examples of the alkylene group having 1 to 10 carbon atoms include methylene group, ethylene group, n-propylene group, isopropylene group, cyclopropylene group, n-butylene group, isobutylene group, s-butylene group, t-butylene group, cyclobutylene group, 1-methyl-cyclopropylene group, 2-methyl-cyclopropylene group, n-pentylene group, 1-methyl-n-butylene group, 2-methyl-n-butylene group, 3-methyl-n-butylene group, 1,1-dimethyl-n-propylene group, 1,2-dimethyl-n-propylene group, 2,2-dimethyl-n-propylene, 1-ethyl-n-propylene group, cyclopentylene group, 1-methyl-cyclobutylene group, 2-methyl-cyclobutylene group, 3-methyl-cyclobutylene group, 1,2-dimethyl-cyclopropylene group, 2,3-dimethyl-cyclopropylene group, 1-ethyl-cyclopropylene group, 2-ethyl-cyclopropylene group, n-hexylene group, 1-methyl-n-pentylene group, 2-methyl-n-pentylene group, 3-methyl-n-pentylene group, 4-methyl-n-pentylene group, 1,1-dimethyl-n-butylene group, 1,2-dimethyl-n-butylene group, 1,3-dimethyl-n-butylene group, 2,2-dimethyl-n-butylene group, 2,3-dimethyl-n-butylene group, 3,3-dimethyl-n-butylene group, 1-ethyl-n-butylene group, 2-ethyl-n-butylene group, 1,1,2-trimethyl-n-propylene group, 1,2,2-trimethyl-n-propylene group, 1-ethyl-1-methyl-n-propylene group, 1-ethyl-2-methyl-n-propylene group, cyclohexylene group, 1-methyl-cyclopentylene group, 2-methyl-cyclopentylene group, 3-methyl-cyclopentylene group, 1-ethyl-cyclobutylene group, 2-ethyl-cyclobutylene group, 3-ethyl-cyclobutylene group, 1,2-dimethyl-cyclobutylene group, 1,3-dimethyl-cyclobutylene group, 2,2-dimethyl-cyclobutylene group, 2,3-dimethyl-cyclobutylene group, 2,4-dimethyl-cyclobutylene group, 3,3-dimethyl-cyclobutylene group, 1-n-propyl-cyclopropylene group, 2-n-propyl-cyclopropylene group, 1-isopropyl-cyclopropylene group, 2-isopropyl-cyclopropylene group, 1,2,2-trimethyl-cyclopropylene group, 1,2,3-trimethyl-cyclopropylene group, 2,2,Examples thereof include a 3-trimethyl-cyclopropylene group, a 1-ethyl-2-methyl-cyclopropylene group, a 2-ethyl-1-methyl-cyclopropylene group, a 2-ethyl-2-methyl-cyclopropylene group, a 2-ethyl-3-methyl-cyclopropylene group, an n-heptylene group, an n-octylene group, an n-nonylene group or an n-decanylene group.

[0119] Examples of the alkenylene group having 2 to 10 carbon atoms include groups having at least one double bond formed by removing hydrogen atoms from adjacent carbon atoms among the alkylene groups having 2 to 10 carbon atoms. Among the alkenylene groups having 2 to 10 carbon atoms, a vinylene group is preferred.

[0120] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

[0121] The term "optionally substituted" means that some or all of the hydrogen atoms present in the aromatic ring having 6 to 40 carbon atoms, the alkylene group having 1 to 10 carbon atoms or the alkenylene group having 2 to 10 carbon atoms may be substituted with, for example, a hydroxy group, a halogen atom, a carboxy group, a nitro group, a cyano group, a methylenedioxy group, an acetoxy group, a methylthio group, an amino group, an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms.

[0122] Polymer (D) preferably contains a structure represented by the following formula (Q-1) at its terminal:

Chemical formula

[0123] Examples of the structure represented by the above formula (Q-1) include the following. (In the following examples, the structure shown as a compound due to substitution of a hydrogen atom or the like for a bond * is shown.)

Chemical formula

Chemical formula

[0124] Polymer (D) is preferably a reaction product of the above-exemplified compound and an epoxy group-containing compound. It is also preferable that the reaction product with the epoxy group-containing compound has a repeating unit. Examples of the epoxy group-containing compound include the following.

[0125]

Chemical formula

Chemical formula

Chemical formula

[0126] Examples of Polymer (D) include the polymers described in International Publication No. WO2022 / 196662 pamphlet. Polymer (D) may be a polymer containing at least one structure selected from resist underlayer film-forming compositions A, B, and C described in International Publication No. WO2022 / 196662 pamphlet. For example, examples of Polymer (D) include the polymers described as Examples A1 to A19 in International Publication No. WO2022 / 196662 pamphlet. The content of International Publication No. WO2022 / 196662 pamphlet is incorporated herein to the same extent as if fully set forth.

[0127] The molecular weight of the polymer (D) is not particularly limited, but the weight average molecular weight by gel permeation chromatography (hereinafter sometimes abbreviated as GPC) is preferably 1,000 to 30,000, and more preferably 2,000 to 20,000.

[0128] As described above, the composition for forming a resist underlayer film of the present invention preferably contains at least one polymer selected from the group consisting of the polymers (A), (B), (C), and (D) described above. The molecular weight of this polymer is not particularly limited. The weight average molecular weight by gel permeation chromatography (hereinafter sometimes abbreviated as GPC) is preferably 500 to 100,000, more preferably 1,000 to 50,000, and even more preferably 2,000 to 20,000.

[0129] The content of the polymer described above in the composition for forming a resist underlayer film is not particularly limited, but from the viewpoint of solubility, it is preferably 0.1% by mass to 50% by mass, and more preferably 0.1% by mass to 10% by mass with respect to the entire composition for forming a resist underlayer film.

[0130] <Crosslinking agent> The crosslinking agent contained as an optional component in the composition for forming a resist underlayer film may be a nitrogen-containing compound having 2 to 6 substituents represented by the following formula (1d) bonded to a nitrogen atom, as described in International Publication No. 2017 / 187969.

[0131]

Chemical formula

[0132] The nitrogen-containing compound having 2 to 6 substituents represented by the above formula (1d) in one molecule may be a glycoluril derivative represented by the following formula (1E).

[0133] [Chemical formula] (In formula (1E), the four R1s each independently represent a methyl group or an ethyl group, and R2 and R3 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group.)

[0134] Examples of the glycoluril derivative represented by the above formula (1E) include compounds represented by the following formulas (1E-1) to (1E-6).

[0135] [Chemical formula]

[0136] The nitrogen-containing compound having 2 to 6 substituents represented by the above formula (1d) in one molecule is obtained by reacting a nitrogen-containing compound having 2 to 6 substituents represented by the following formula (2d) bonded to a nitrogen atom in one molecule with at least one compound represented by the following formula (3d).

[0137] [Chemical formula] (In formulas (2d) and (3d), R1 represents a methyl group or an ethyl group, R4 represents an alkyl group having 1 to 4 carbon atoms. * represents a bond bonded to a nitrogen atom.)

[0138] The glycoluril derivative represented by the above formula (1E) is obtained by reacting a glycoluril derivative represented by the following formula (2E) with at least one compound represented by the above formula (3d).

[0139] The nitrogen-containing compound having 2 to 6 substituents represented by the above formula (2d) in one molecule is, for example, a glycoluril derivative represented by the following formula (2E).

[0140] [Chemical formula] (In formula (2E), R2 and R3 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group, and R4 each independently represents an alkyl group having 1 to 4 carbon atoms.)

[0141] Examples of the glycoluril derivative represented by the above formula (2E) include compounds represented by the following formulas (2E-1) to (2E-4). Further, examples of the compound represented by the above formula (3d) include compounds represented by the following formulas (3d-1) and (3d-2).

[0142] [Chemical formula] [Chemical formula]

[0143] Regarding the content related to the nitrogen-containing compound having 2 to 6 substituents represented by formula (1d) bonded to the above nitrogen atom in one molecule, the entire disclosure of WO2017 / 187969 is incorporated herein by reference.

[0144] Further, the crosslinking agent may be a compound represented by the following formula (21). [Chemical formula] (In formula (21), R 1 each independently represents an alkylene group having 1 to 6 carbon atoms, R 2 each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxyalkyl group having a total of 2 to 10 carbon atoms, and R 3 each independently represents an alkyl group having 1 to 6 carbon atoms. m1 and m2 each independently represent an integer of 1 to 2. When m1 and m2 are 1, Q 1 represents a single bond, an oxygen atom, or a divalent organic group having 1 to 20 carbon atoms, and in other cases, Q 1 represents a (m1 + m2)-valent organic group having 1 to 20 carbon atoms.)

[0145] Q1 Examples of the (m1 + m2)-valent organic group having 1 to 20 carbon atoms in 1 include groups represented by any of the following formulas (21-1) to (21-5).

[0146]

Chemical formula

[0147] Examples of Ar include divalent residues of compounds selected from benzene, biphenyl, naphthalene, and anthracene.

[0148] The group represented by formula (21-1) is a divalent group. The group represented by formula (21-2) is a tetravalent group. The group represented by formula (21-3) is a trivalent group. The group represented by formula (21-4) is a divalent group. The group represented by formula (21-5) is a trivalent group.

[0149] When the above crosslinking agent is used, the content ratio of the crosslinking agent is, for example, 1% by mass to 50% by mass, preferably 5% by mass to 30% by mass, based on the polymer having at least one of the unit structures (A) and (B).

[0150] <<Curing catalyst>> As the curing catalyst contained as an optional component in the resist underlayer film-forming composition, either a thermal acid generator or a photoacid generator can be used, but it is preferable to use a thermal acid generator.

[0151] Examples of the thermal acid generator include sulfonic acid compounds and carboxylic acid compounds such as p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium p-toluenesulfonate (pyridinium p-toluenesulfonic acid), pyridinium phenolsulfonate, pyridinium p-hydroxybenzenesulfonic acid (p-phenolsulfonic acid pyridinium salt), pyridinium trifluoromethanesulfonate, salicylic acid, camphorsulfonic acid, 5-sulfosalicylic acid, 4-chlorobenzenesulfonic acid, 4-hydroxybenzenesulfonic acid, benzenedisulfonic acid, 1-naphthalenesulfonic acid, citric acid, benzoic acid, and hydroxybenzoic acid.

[0152] Examples of the photoacid generator include onium salt compounds, sulfonimide compounds, and disulfonyldiazomethane compounds.

[0153] Examples of the onium salt compounds include iodonium salt compounds such as diphenyliodonium hexafluorophosphate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoronormalbutanesulfonate, diphenyliodonium perfluoronormaloctanesulfonate, diphenyliodonium camphorsulfonate, bis(4-tert-butylphenyl)iodonium camphorsulfonate, and bis(4-tert-butylphenyl)iodonium trifluoromethanesulfonate, and sulfonium salt compounds such as triphenylsulfonium hexafluoroantimonate, triphenylsulfonium nonafluoronormalbutanesulfonate, triphenylsulfonium camphorsulfonate, and triphenylsulfonium trifluoromethanesulfonate.

[0154] Examples of the sulfonimide compounds include N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoronormalbutanesulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, and N-(trifluoromethanesulfonyloxy)naphthalimide.

[0155] Examples of the disulfonyldiazomethane compound include bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(2,4-dimethylbenzenesulfonyl)diazomethane, methylsulfonyl-p-toluenesulfonyldiazomethane, and the like.

[0156] Only one kind of the curing catalyst can be used, or two or more kinds can be used in combination.

[0157] When the curing catalyst is used, the content ratio of the curing catalyst is, for example, 0.1% by mass to 50% by mass, preferably 1% by mass to 30% by mass, based on the crosslinking agent.

[0158] <<Other components>> In the composition for forming a resist underlayer film, a surfactant can be further added in order to prevent the occurrence of pinholes, striations, etc. and further improve the coatability with respect to surface unevenness.

[0159] Examples of the surfactant include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oleyl ether; polyoxyethylene alkyl aryl ethers such as polyoxyethylene octylphenol ether and polyoxyethylene nonylphenol ether; polyoxyethylene-polyoxypropylene block copolymers; sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, and sorbitan tristearate; polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate; nonionic surfactants; fluorosurfactants such as F-Top EF301, EF303, and EF352 (trade names, manufactured by Tocem Products Co., Ltd.), Megafac F171, F173, and R-30 (trade names, manufactured by DIC Corporation), Fluorad FC430 and FC431 (trade names, manufactured by Sumitomo 3M Limited), Asahi Guard AG710, and Surflon S-382, SC101, SC102, SC103, SC104, SC105, and SC106 (trade names, manufactured by Asahi Glass Co., Ltd.); and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.). The compounding amount of these surfactants is not particularly limited, but is usually 2.0% by mass or less, preferably 1.0% by mass or less, based on the resist underlayer film-forming composition. These surfactants may be added alone or in combination of two or more.

[0160] <Solvent> As the solvent, an organic solvent generally used in chemical solutions for semiconductor lithography processes is preferred. Specifically, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, propylene glycol propyl ether acetate, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, cycloheptanone, 4-methyl-2-pentanol, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, ethyl ethoxyacetate, 2-hydroxyethyl acetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, 2-heptanone, methoxycyclopentane, anisole, γ-butyrolactone, N-methylpyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide may be mentioned. These solvents can be used alone or in combination of two or more.

[0161] Among these solvents, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl lactate, butyl lactate, and cyclohexanone are preferred. In particular, propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate are preferred.

[0162] The composition for forming a resist underlayer film is preferably used as a composition for forming a resist underlayer film for EB or EUV lithography. Further, the composition for forming a resist underlayer film for EB or EUV lithography is preferably used for forming a resist underlayer film for EB or EUV lithography having a film thickness of less than 10 nm.

[0163] (Resist underlayer film) The resist underlayer film of the present invention is a fired film of a coating film of the composition for forming a resist underlayer film described above.

[0164] The film thickness of the resist underlayer film of the present invention is less than 10 nm. Usually, when the film thickness of the resist underlayer film is made thin, it becomes difficult to obtain a flat film surface. If the surface is not flat, the film thickness variation of the resist layer formed on the underlayer film becomes large, and as a result, the LWR becomes large. By containing the polymer described above, the resist underlayer film of the present invention tends to have excellent adhesion to the substrate and film-forming properties. Therefore, even if the film thickness of the resist underlayer film is less than 10 nm, it is presumed that a flat film surface can be formed and the LWR of the resist pattern can be improved. Particularly remarkable effects are achieved when using EUV or EB.

[0165] When a resist underlayer film with a film thickness of 20 nm or more is used during EUV or EB exposure, in the dry etching process after resist pattern formation, since the resist film thickness is thin, the resist pattern is damaged during the process of etching the underlayer film, resulting in shape defects such as a decrease in resist film thickness or a top-rounded shape, making it difficult to form a pattern with the desired line width during actual substrate processing.

[0166] The resist underlayer film of the present invention can be produced by applying a composition for forming a resist underlayer film on a semiconductor substrate and baking it.

[0167] Examples of the semiconductor substrate on which the composition for forming a resist underlayer film of the present invention is applied include silicon wafers, germanium wafers, and compound semiconductor wafers such as gallium arsenide, indium phosphide, gallium nitride, indium nitride, and aluminum nitride.

[0168] When using a semiconductor substrate with an inorganic film formed on its surface, the inorganic film is formed by, for example, the ALD (Atomic Layer Deposition) method, CVD (Chemical Vapor Deposition) method, reactive sputtering method, ion plating method, vacuum evaporation method, spin coating method (spin on glass: SOG). Examples of the inorganic film include a polysilicon film, a silicon oxide film, a silicon nitride film, a BPSG (Boro-Phospho Silicate Glass) film, a titanium nitride film, a titanium oxynitride film, a tungsten film, a gallium nitride film, and a gallium arsenide film.

[0169] On such a semiconductor substrate, the composition for forming a resist underlayer film of the present invention is applied by an appropriate coating method such as a spinner or a coater. Then, a resist underlayer film is formed by baking using a heating means such as a hot plate. As the baking conditions, they are appropriately selected from a baking temperature of 100°C to 400°C and a baking time of 0.3 minutes to 60 minutes. Preferably, the baking temperature is 120°C to 350°C and the baking time is 0.5 minutes to 30 minutes, and more preferably, the baking temperature is 150°C to 300°C and the baking time is 0.8 minutes to 10 minutes.

[0170] The film thickness of the resist underlayer film is less than 10 nm, preferably 9 nm or less, more preferably 8 nm or less, and even more preferably 7 nm or less. Also, the film thickness of the resist underlayer film may be 1 nm or more, or 2 nm or more, or 3 nm or more.

[0171] The method for measuring the film thickness of the resist underlayer film in this specification is as follows. · Measuring device name: Ellipsometric film thickness measuring device RE-3100 (SCREEN Co., Ltd.) · SWE (Single Wavelength Ellipsometer) mode · Arithmetic mean of 8 points (for example, measuring 8 points at 1 cm intervals in the X direction of the wafer)

[0172] The resist underlayer film is preferably used as a resist underlayer film for EB or EUV lithography.

Example

[0173] Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[0174] The weight average molecular weight (Mw) of the polymer shown in the following Synthesis Examples is the measurement result by the Gel Permeation Chromatography (GPC) method. A GPC apparatus manufactured by Tosoh Corporation was used for the measurement, and the measurement conditions are as follows. Measuring device: HLC-8020GPC [trade name] (manufactured by Tosoh Corporation) GPC column: TSKgel G2000HXL; 2 pieces, G3000HXL: 1 piece, G4000HXL; 1 piece [trade name] (all manufactured by Tosoh Corporation) Column temperature: 40 °C Solvent: Tetrahydrofuran (THF) Flow rate: 1.0 ml / min Standard sample: Polystyrene (manufactured by Tosoh Corporation)

[0175] <Synthesis Example 1> 8.00 g of monoallyl diglycidyl isocyanurate, 5.45 of barbital, and 0.48 g of tetrabutylphosphonium bromide were added to 56.00 g of propylene glycol monomethyl ether in a reaction vessel and dissolved. After replacing the reaction vessel with nitrogen, the mixture was reacted by reflux heating for 24 hours to obtain a Polymer 1 solution. When GPC analysis was performed, the polymer in the obtained solution had a weight average molecular weight of 10,000 in terms of standard polystyrene.

[0176] <Synthesis Example 2> 6.00 g of polyglycidyl methacrylate (manufactured by Maruzen Petrochemical Co., Ltd.), 4.88 g of sorbic acid, 0.02 g of hydroquinone, and 0.46 g of tetrabutylphosphonium bromide were added to 16.7 g of propylene glycol monomethyl ether acetate and 16.7 g of propylene glycol monomethyl ether in a reaction vessel and dissolved. After the reaction vessel was purged with nitrogen, it was reacted at 100 °C for 24 hours to obtain a polymer 2 solution. The polymer solution did not become cloudy or the like even when cooled to room temperature, and had good solubility in the propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent. After the polymer solution was cooled to room temperature, the propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent was added to make a 10 mass% solution. When analyzed by GPC, the polymer in the obtained solution had a weight average molecular weight of 24,300 in terms of standard polystyrene.

[0177] (Preparation of Composition 1 for Forming Resist Underlayer Film) To 0.41 g of the polymer solution (solid content: 18.45 mass%) obtained in Synthesis Example 1, 0.38 g of a 5 mass% propylene glycol monomethyl ether solution of tetramethoxymethyl glycoluril, 0.19 g of a 1 mass% propylene glycol monomethyl ether solution of pyridinium phenol sulfonate, 33 g of propylene glycol monomethyl ether, and 15 g of propylene glycol monomethyl ether acetate were added and dissolved. Then, it was filtered using a polyethylene microfilter with a pore size of 0.05 μm to obtain Composition 1 for forming a resist underlayer film.

[0178] (Preparation of Composition 2 for Forming Resist Underlayer Film) To 1.54 g of the polymer solution (solid content: 10% by mass) obtained in Synthesis Example 2, 0.85 g of a 5% by mass propylene glycol monomethyl ether solution of tetramethoxymethyl glycoluril, 0.38 g of a 1% by mass propylene glycol monomethyl ether solution of pyridinium phenolsulfonate, 87.9 g of propylene glycol monomethyl ether, and 9.3 g of propylene glycol monomethyl ether acetate were added and dissolved. Then, it was filtered using a polyethylene microfilter with a pore size of 0.05 μm to obtain a composition for forming a resist underlayer film 2.

[0179] <Preparation Example of Metal Oxide Resist> (Preparation of Metal Oxide Resist Composition) 0.10 g of monobutyltin oxide (manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved in 9.90 g of propylene glycol monomethyl ether. Then, it was filtered using a polyethylene microfilter with a pore size of 0.05 μm to obtain a metal oxide resist composition 1.

[0180] <Example 1> (Resist Patterning Evaluation) [Formation of Metal Oxide Resist Pattern by Electron Beam Lithography Apparatus] The composition for forming a resist underlayer film 1 was respectively applied onto a silicon wafer using a spinner. The silicon wafer was baked on a hot plate at 215 °C for 60 seconds to obtain a resist underlayer film with a film thickness of 5 nm. On the resist underlayer film, the metal oxide resist composition 1 prepared in the preparation example of the metal oxide resist was spin-coated and heated at 100 °C for 60 seconds to form a metal oxide resist film with a film thickness of 26 nm. The entire surface of the wafer coated with this resist film was irradiated with light having a wavelength of 172 nm at 5 mJ / cm² in a nitrogen atmosphere using a 172 nm light irradiation apparatus SUS867 manufactured by USHIO INC. 2It was irradiated with the energy of . After that, an electron beam lithography apparatus (ELS-G130) was used to form a target pattern and exposed under predetermined conditions. After exposure, baking (PEB) was performed at 180 °C for 60 seconds, developed with a developer (5 mass% acetic acid propylene glycol monomethyl ether acetate solution), and then baking (hard bake) was carried out at 250 °C for 60 seconds to form a line-and-space pattern with a CD size of 22 nm and a pitch of 44 nm. A scanning electron microscope (manufactured by Hitachi High-Technologies Corporation, CG4100) was used to measure the length of the resist pattern. An observation photograph of the resist pattern formed in Example 1 is shown in FIG. 1.

[0181] <Example 2> A line-and-space pattern with a CD size of 22 nm and a pitch of 44 nm was formed in the same manner as in Example 1, except that the composition 2 for forming a resist underlayer film was used instead of the composition 1 for forming a resist underlayer film.

[0182] <Comparative Example 1> Using a 172 nm light irradiation device SUS867 manufactured by USHIO INC., in a nitrogen atmosphere, light with a wavelength of 172 nm was irradiated at 5 mJ / cm 2 A line-and-space pattern with a CD size of 22 nm and a pitch of 44 nm was formed in the same manner as in Example 1, except for the step of irradiating with light.

[0183] <Comparative Example 2> A line-and-space pattern with a CD size of 22 nm and a pitch of 44 nm was formed in the same manner as in Example 1, except for the step of applying the composition 1 for forming a resist underlayer film. An observation photograph of the resist pattern formed in Comparative Example 2 is shown in FIG. 2.

[0184] Regarding the photoresist patterns obtained in Examples 1 and 2 and Comparative Examples 1 and 2, observations were made from the top of the pattern, and the charge amount for forming a 22 nm line / 44 nm pitch (line and space (L / S = 1 / 1)) was defined as the optimum irradiation energy, and the irradiation energy (mC / cm 2 ) at that time was confirmed. The results are shown in Table 1.

[0185]

Table 1

[0186] From Table 1, in Examples 1 and 2, it is possible to significantly reduce the irradiation energy required for pattern formation as compared with Comparative Example 1. Further, from Table 1 and FIGS. 1 and 2, since pattern collapse can be prevented as compared with Comparative Example 2 where the composition for forming the lower layer film is not applied, the composition for forming the lower layer film is useful for resist pattern formation when this process is applied.

Claims

1. A step of forming a resist underlayer film on a semiconductor substrate using a composition for forming a resist underlayer film for EB or EUV lithography; A step of forming a resist film for EB or EUV lithography on the resist underlayer film; A step of irradiating the resist film with UV; A step of selectively irradiating the resist film irradiated with UV with EB or EUV, and then developing the resist film to obtain a resist pattern; A pattern forming method comprising the above steps.

2. The UV irradiation step is performed at 1 mJ / cm ２ ~100mJ / cm ２ The pattern forming method according to claim 1 , wherein the UV irradiation is performed at a wavelength of 100 nm or more.

3. The pattern forming method according to claim 1, wherein baking is performed in the step of obtaining the resist pattern.

4. The pattern forming method according to claim 1, wherein the composition for forming the resist underlayer film contains at least one polymer selected from the group consisting of a polymer (A) having a ring structure in which at least one is a heterocycle in the main chain, a polymer (B) having one or more polymerizable multiple bonds selected from the group consisting of a carbon-carbon double bond, a carbon-carbon triple bond, a carbon-nitrogen double bond, and a carbon-nitrogen triple bond in the side chain, a polymer (C) having a polycyclic aromatic hydrocarbon structure in the side chain, and a polymer (D) having an aromatic hydrocarbon structure having 6 to 40 carbon atoms in the main chain.

5. The pattern forming method according to claim 4, wherein the polymer (A) is a polymer (Y) having a repeating unit represented by the following formula (Y). 【Chemical 1】 (In formula (X), A １ , A ２ , A ３ , A ４ , A ５ , and A ６ each represent a hydrogen atom, a methyl group, or an ethyl group. X １ represents the following formula (Y2), the following formula (Y3), the following formula (Y4), or the following formula (Y0). Q represents the following formula (Y5) or the following formula (Y6). [Chemical Formula 2] (In formula (Y2), formula (Y3), formula (Y4) and formula (Y0), R １ and R ２ each represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 3 to 6 carbon atoms, a benzyl group or a phenyl group, and the alkyl group having 1 to 6 carbon atoms, the alkenyl group having 3 to 6 carbon atoms, the benzyl group and the phenyl group may be substituted with a group selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, a halogen atom, an alkoxy group having 1 to 6 carbon atoms, a nitro group, a cyano group, a hydroxy group, a carboxy group and an alkylthio group having 1 to 6 carbon atoms. Further, R １ and R ２ may be bonded to each other to form a ring having 3 to 6 carbon atoms.) R ３ represents a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 3 to 6 carbon atoms, a benzyl group or a phenyl group, and the phenyl group may be substituted with a group selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, a halogen atom, an alkoxy group having 1 to 6 carbon atoms, a nitro group, a cyano group, a hydroxy group, and an alkylthio group having 1 to 6 carbon atoms. * represents a bond. *1 represents a bond that binds to a carbon atom. *2 represents a bond that binds to a nitrogen atom. 【Chemical 3】 (In formula (Y5) and formula (Y6), Q １ represents an alkylene group having 1 to 10 carbon atoms, a phenylene group, a naphthylene group, or an anthrylene group, and the alkylene group, the phenylene group, the naphthylene group, and the anthrylene group are each an alkyl group having 1 to 6 carbon atoms, a carbonyloxyalkyl group having 2 to 7 carbon atoms, a halogen atom, an alkoxy group having 1 to 6 carbon atoms, a phenyl group, a nitro group, a cyano group, a hydroxy group, an alkylthio group having 1 to 6 carbon atoms, a group having a disulfide group, a carboxy group, or a group substituted with a combination thereof. n １ and n ２ each represents 0 or 1. X ２ represents the formula (Y2), the formula (Y3), the formula (Y4), or the formula (Y0). * represents a bond.

6. The pattern forming method according to claim 5, wherein the polymer (Y) is a polymer produced by reacting a compound represented by the following formula (Y7) with a compound represented by the following formula (Y8). 【Chemical Formula 4】 (In formula (Y7), X １ represents the formula (Y2), the formula (Y3), the formula (Y4), or the formula (Y0). In formula (8), Q represents the formula (Y5) or the formula (Y6). A １ 、 A ２ 、 A ３ 、 A ４ 、 A ５ 、 and A ６ each represent a hydrogen atom, a methyl group, or an ethyl group.)

7. In the polymer (B), The polymerizable multiple bond is bonded to the main chain of the polymer (B) via a linking group having a structure obtained by reacting with one or more nucleophilic functional groups selected from the group consisting of an epoxy group and a carboxy group, a hydroxy group, an amino group, and a thiol group, or The polymer (B) is bonded to the main chain of the polymer (B) via a linking group having a structure obtained by reacting the polymerizable multiple bond with a nucleophilic functional group selected from the group consisting of an isocyanate group and one or more selected from the group consisting of a hydroxy group, an amino group, and a thiol group. , the pattern forming method according to claim 4.

8. The polymer (B) has a structural unit represented by the following formula (Z), L in the structural unit represented by the formula (Z) above １ -L ２ The pattern forming method according to claim 7, wherein has a structure represented by the following formula (Za), (Zb) or (Zc). [Chemical Formula 5] (In formula (Z), R １ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. L １ represents a single bond or a linking group. L ２ represents a monovalent group having the polymerizable multiple bond.) 【Chemical Formula 6】 (In formulas (Za) to (Zc), R ２ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. *a and *b represent bonds, *a is on the main chain side of polymer (B), and *b is on the terminal side of the side chain of polymer (B).)

9. The polycyclic aromatic hydrocarbon structure in the polymer (C) contains at least one structure selected from the group consisting of naphthalene, anthracene, phenanthrene, carbazole, pyrene, triphenylene, chrysene, naphthacene, biphenylene, and fluorene. The pattern forming method according to claim 4.

10. The polymer (D) has the following formula (Q): 【Chemical Formula 7】 (In formula (Q), Ar represents an optionally substituted aromatic ring group having 6 to 40 carbon atoms, L ０ represents a single bond, an ester bond, an ether bond, an optionally substituted alkylene group having 1 to 10 carbon atoms or an optionally substituted alkenylene group having 2 to 10 carbon atoms, T ０ represents a single bond, an ester bond, an ether bond, an optionally substituted alkylene group having 1 to 10 carbon atoms, or an optionally substituted alkenylene group having 2 to 10 carbon atoms, However, L ０ and T ０ are different from n Rs ０ each independently represents a hydroxy group, a halogen atom, a nitro group, a cyano group, an amino group, or a monovalent organic group, n represents an integer of 0 to 5, ＊ represents a bonding hand.) The pattern forming method according to claim 4, comprising a structure represented by

11. The polymer (D) has the following formula (Q-1): [Chemical Formula 8] (In formula (Q-1), Ar represents an optionally substituted aromatic ring having 6 to 40 carbon atoms, and L １ represents a single bond, an ester bond, an ether bond, an alkylene group having 1 to 10 carbon atoms, or an alkenylene group having 2 to 10 carbon atoms, n represents an integer of 1 to 3, ＊ represents a bond.) The pattern forming method according to claim 10, comprising a structure represented by the formula at the terminal.

12. A composition for forming a resist underlayer film used in the pattern forming method according to any one of claims 1 to 11.

13. A resist underlayer film which is a fired product of a coating film of the composition for forming a resist underlayer film according to claim 12.

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