Composition for forming resist underlayer film and method for forming resist pattern using the same

Abstract

The present invention provides a composition for forming a resist underlayer film capable of forming a desired resist pattern, and a resist pattern forming method using the resist underlayer film forming composition. A resist underlayer film forming composition, comprising a polymer and an organic solvent, wherein the polymer has a structure represented by the following formula (1) or (2) at the end of the polymer chain. (In the above formula (1) and formula (2), X is a divalent organic group, A is an aryl group having 6 to 40 carbon atoms, R1 is a halogen atom, an alkyl group having 1 to 40 carbon atoms, or an alkoxy group having 1 to 40 carbon atoms, R2 and R3 are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be substituted, an aryl group having 6 to 40 carbon atoms, or a halogen atom, n1 and n3 are each independently integers of 1 to 12, and n2 is an integer of 0 to 11.)

Description

Technical Field

[0001] The present invention relates to a resist underlayer film forming composition for lithography, which aims to suppress the deterioration of LWR (Line Width Roughness, fluctuation of resist pattern line width) when forming a resist pattern and improve the resist sensitivity in a photolithography process during semiconductor device manufacturing, and a resist pattern forming method using the resist underlayer film forming composition. Background Art

[0002] In the manufacture of semiconductor devices, micro-machining has always been performed by photolithography using a resist composition. The above-mentioned micro-machining is a method of forming a thin film of a photoresist composition on a semiconductor substrate such as a silicon wafer, irradiating it with active light such as ultraviolet rays through a mask pattern depicting a device pattern, developing it, and etching the substrate with the obtained photoresist pattern as a protective film, thereby forming a micro-concave and convex processing method corresponding to the above-mentioned pattern on the surface of the substrate. In recent years, the high integration of semiconductor devices has progressed. In addition to the i-rays (wavelength 365nm), KrF excimer lasers (wavelength 248nm), and ArF excimer lasers (wavelength 193nm) used in the past, the practical application of EUV light (wavelength 13.5nm) has been studied in the most advanced micro-machining. Along with this, the diffuse reflection of active light from the semiconductor substrate and the influence of standing waves have become a big problem. Therefore, in order to solve this problem, a method of setting an anti-reflective film (Bottom Anti-Reflective Coating: BARC) between the resist and the semiconductor substrate has been widely studied. This antireflection film is also called a resist underlayer film. As such an antireflection film, organic antireflection films formed of polymers having light absorbing sites have been extensively studied from the viewpoint of ease of use.

[0003] Patent Document 1 discloses an antireflection film for semiconductors having a condensation polymer. Patent Document 2 discloses a resist underlayer film for lithography containing a polymer having an optionally substituted aryl ester group at the terminal. Patent Document 3 discloses a resist underlayer film-forming composition containing a polymer having a sulfonyl group introduced at the terminal.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: International Publication No. 2005 / 098542

[0007] Patent Document 2: International Publication No. 2015 / 046149

[0008] Patent Document 3: International Publication No. 2015 / 163195 Summary of the invention

[0009] Problems to be solved by the invention

[0010] Examples of the properties required of the resist underlayer film include no mixing with the resist film formed on the upper layer (insolubility in the resist solvent) and a faster dry etching rate than the resist film.

[0011] In the case of photolithography with EUV exposure, the line width of the formed resist pattern is less than 32nm, and the resist underlayer film for EUV exposure is formed and used with a thinner film thickness than before. When forming such a thin film, pinholes and agglomeration are easily generated due to the influence of the substrate surface, the polymer used, etc., and it is difficult to form a uniform film without defects.

[0012] On the other hand, when the resist pattern is formed, the following method is sometimes adopted: in the developing process, the unexposed part of the resist film is removed using a solvent that can dissolve the resist film, usually an organic solvent, and the exposed part of the resist film remains as the resist pattern. In such a negative development process, the improvement of the adhesion of the resist pattern becomes a major issue.

[0013] Furthermore, it is required to form a resist pattern having a good rectangular shape while suppressing deterioration of LWR (Line Width Roughness) during resist pattern formation, and to improve resist sensitivity.

[0014] An object of the present invention is to provide a composition for forming a resist underlayer film capable of forming a desired resist pattern, which solves the above-mentioned problems, and a resist pattern forming method using the resist underlayer film forming composition.

[0015] Means for solving problems

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

[0018] A resist underlayer film-forming composition comprises a polymer and an organic solvent, wherein the polymer has a structure represented by the following formula (1) or (2) at the end of a polymer chain.

[0019]

[0020] (In the above formulae (1) and (2), X is a divalent organic group, A is an aryl group having 6 to 40 carbon atoms, R1 is a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms, R2 and R3 are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms which may be substituted, or an aryl group having 6 to 40 carbon atoms which may be substituted, n1 and n3 are each independently an integer of 1 to 12, and n2 is an integer of 0 to 11.) [2]

[0022] The resist underlayer film forming composition according to [1], wherein in the above formula (1) and formula (2), X is an ester bond or an ether bond. [3]

[0024] The resist underlayer film forming composition according to [1], wherein in the above formula (1) and formula (2), A is a phenyl group, a naphthyl group or an anthracenyl group. [4]

[0026] The resist underlayer film forming composition according to [1], wherein in the above formula (2), R2 and R3 are hydrogen atoms. [5]

[0028] The resist underlayer film forming composition according to [1], wherein n2 is 0 in the above formula (1). [6]

[0030] The resist underlayer film-forming composition according to [1], wherein the polymer has a structural unit represented by the following formula (3).

[0031]

[0032] (In formula (3), A1, A2, A3, A4, A5 and A6 each independently represent a hydrogen atom, a methyl group or an ethyl group, Y1 represents formula (4), formula (5), formula (6) or formula (7), and Q represents formula (8) or formula (9).

[0033]

[0034] ((In formulae (4) to (7), R4 and R5 each independently represent a hydrogen 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 at least one 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 hydroxyl group, and an alkylthio group having 1 to 6 carbon atoms; further, R4 and R5 may be combined with each other to form a ring having 3 to 6 carbon atoms; R6 represents 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 at least one 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 hydroxyl group, and an alkylthio group having 1 to 6 carbon atoms)

[0035]

[0036] (In formula (8) and formula (9), Q1 represents an alkylene group having 1 to 10 carbon atoms, a phenylene group, a naphthylene group, or an anthrylene group, and each of the phenylene group, the naphthylene group, and the anthrylene group may be substituted with at least one group selected from 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 hydroxyl group, and an alkylthio group having 1 to 6 carbon atoms, n4 and n5 each independently represent an integer of 0 or 1, and Y2 represents formula (4), formula (5) or formula (7)).) [7]

[0038] The resist underlayer film forming composition according to [6], wherein the polymer having the structural unit represented by the formula (3) is a polymer obtained by reaction of a compound represented by the formula (10) and a compound represented by the formula (11).

[0039]

[0040] (In formula (10) and formula (11), A1, A2, A3, A4, A5, A6, Y1 and Q have the same meanings as defined in [6]) [8]

[0042] The resist underlayer film-forming composition according to [6], wherein the polymer having the structural unit represented by the formula (3) is a polymer obtained by reaction of a compound represented by the formula (12) and a compound represented by the formula (13).

[0043]

[0044] (In the formula, A1, A2, A3, A4, A5, A6, Y1 and Q have the same meanings as defined in [6]) [9]

[0046] The resist underlayer film forming composition according to any one of [1] to [8], further comprising a cross-linking acid catalyst.

[10]

[0048] The resist underlayer film forming composition according to any one of [1] to [9], further comprising a crosslinking agent.

[11]

[0050] A resist underlayer film characterized by being a fired product of a coating film formed from the resist underlayer film-forming composition according to any one of [1] to

[10] .

[12]

[0052] A method for manufacturing a substrate on which a pattern has been formed, comprising the following steps: a step of coating a resist underlayer film-forming composition as described in any one of [1] to

[10] on a semiconductor substrate and baking the composition to form a resist underlayer film; a step of coating a resist on the resist underlayer film and baking the composition to form a resist film; a step of exposing the semiconductor substrate coated with the resist underlayer film and the resist; and a step of developing the exposed resist film to form a pattern.

[13]

[0054] A method for manufacturing a semiconductor device, comprising the following steps:

[0055] A step of forming a resist underlayer film formed from the resist underlayer film-forming composition described in any one of [1] to

[10] on a semiconductor substrate;

[0056] forming a resist film on the resist underlayer film;

[0057] A step of forming a resist pattern by irradiating the resist film with light or electron beams and then developing the resist film;

[0058] a step of forming a patterned resist underlayer film by etching the resist underlayer film through the formed resist pattern; and

[0059] A step of processing a semiconductor substrate using the patterned resist underlayer film.

[0060] Effects of the Invention

[0061] The resist underlayer film-forming composition for lithography of the present invention is characterized in that the terminal of the polymer contained in the resist underlayer film-forming composition is capped by the structure represented by the above formula (1) or formula (2), and is a composition containing such a polymer and an organic solvent, preferably further containing a crosslinking agent and / or a compound that promotes a crosslinking reaction. The resist underlayer film-forming composition for lithography of the present application can achieve suppression of LWR deterioration and improvement of sensitivity during resist pattern formation by having such a structure. DETAILED DESCRIPTION

[0062] <Resist Underlayer Film-Forming Composition>

[0063] The resist underlayer film-forming composition of the present application contains a polymer and an organic solvent, and the polymer has a structure represented by the following formula (1) or (2) at the terminal of the polymer chain.

[0064]

[0065] (In the above formulae (1) and (2), X is a divalent organic group, A is an aryl group having 6 to 40 carbon atoms, R1 is a halogen atom, an alkyl group having 1 to 40 carbon atoms, or an alkoxy group having 1 to 40 carbon atoms, R2 and R3 are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms which may be substituted, or an aryl group having 6 to 40 carbon atoms which may be substituted, n1 and n3 are each independently an integer of 1 to 12, and n2 is an integer of 0 to 11.)

[0066] Specific examples of X include an ester bond, an ether bond, an amide bond, a urethane bond, or a urea bond. Among these, an ester bond or an ether bond is preferred.

[0067] Specific examples of A include groups derived from benzene, naphthalene, anthracene, phenanthrene or pyrene, and among these, groups derived from benzene, naphthalene or anthracene are preferred.

[0068] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

[0069] Specific examples of the alkyl group having 1 to 10 carbon atoms include methyl group, ethyl group, propyl group, butyl group, hexyl group and pentyl group, and among them, methyl group is preferred.

[0070] Specific examples of the alkoxy group having 1 to 10 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a hexyloxy group, and a pentyloxy group. Among them, a methoxy group is preferred.

[0071] The term “may be substituted” means that a part or all of the hydrogen atoms in the alkyl group having 1 to 10 carbon atoms may be substituted by, for example, a fluorine group or a hydroxyl group.

[0072] Specific examples of the alkyl group having 1 to 10 carbon atoms include methyl group, ethyl group, propyl group, butyl group, hexyl group and pentyl group, and a methyl group is preferred.

[0073] Specific examples of the aryl group having 6 to 40 carbon atoms include benzyl, naphthyl, anthryl, phenanthryl, and pyrenyl. Among them, phenyl is preferred.

[0074] n1 and n3 are each independently an integer of 1 to 12, and preferably an integer of 1 to 6.

[0075] n2 is an integer of 0 to 11, and is preferably an integer of 0 to 2.

[0076] In the above formula (2), R2 and R3 are preferably hydrogen atoms.

[0077] In the above formula (1), n2 is preferably 0.

[0078] The compound having the partial structure represented by the above formula (1) is represented by, for example, the following formula (1-1).

[0079]

[0080] (In the above formula (1-1), X is a divalent organic group, A is an aryl group having 6 to 40 carbon atoms, R1 is a halogen atom, an alkyl group having 1 to 40 carbon atoms, or an alkoxy group having 1 to 40 carbon atoms, n1 is an integer of 1 to 12, and n2 is an integer of 0 to 11.)

[0081] In the above formula (1-1), in the present invention, each preferred X, A, R1, n1 and n2 are as described above.

[0082] Specific examples of the compound represented by the above formula (1-1) are as follows.

[0083] The polymer contained in the resist underlayer film-forming composition of the present application can be produced by reacting the following compound with the terminal of the polymer by a method known per se.

[0084]

[0085]

[0086]

[0087]

[0088] The compound having the partial structure represented by the above formula (2) is represented by, for example, the following formula (2-1).

[0089]

[0090] (In the above formula (2-1), X is a divalent organic group, A is an aryl group having 6 to 40 carbon atoms, R2 and R3 are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be substituted, an aryl group having 6 to 40 carbon atoms which may be substituted, or a halogen atom, and n3 is an integer of 1 to 12.)

[0091] In the above formula (2-1), in the present invention, X, A, R2, R3 and n3 are each preferably as described above.

[0092] Specific examples of the compound represented by the above formula (2-1) are as follows.

[0093] The polymer contained in the resist underlayer film-forming composition of the present application can be produced by reacting the following compound with a polymer terminal by a method known per se.

[0094]

[0095] The polymer is not particularly limited as long as it is a known polymer used in the resist underlayer film-forming composition. Specifically, it includes vinyl polymers obtained by reacting olefins, polyamides, polyesters, polycarbonates, and polyurethanes, but preferably has a structural unit represented by the following formula (3).

[0096]

[0097] (In formula (3), A1, A2, A3, A4, A5 and A6 each independently represent a hydrogen atom, a methyl group or an ethyl group, Y1 represents formula (4), formula (5), formula (6) or formula (7), and Q represents formula (8) or formula (9).

[0098]

[0099] ((In formulae (4) to (7), R4 and R5 each independently represent a hydrogen 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 at least one 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 hydroxyl group, and an alkylthio group having 1 to 6 carbon atoms; further, R4 and R5 may be combined with each other to form a ring having 3 to 6 carbon atoms; R6 represents 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 at least one 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 hydroxyl group, and an alkylthio group having 1 to 6 carbon atoms)

[0100]

[0101] (In formula (8) and formula (9), Q1 represents an alkylene group having 1 to 10 carbon atoms, a phenylene group, a naphthylene group, or an anthrylene group, and each of the phenylene group, the naphthylene group, and the anthrylene group may be substituted with at least one group selected from 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 hydroxyl group, and an alkylthio group having 1 to 6 carbon atoms, n4 and n5 each independently represent a number of 0 or 1, and Y2 represents formula (4), formula (5), or formula (7)))

[0102] Specific examples of the alkyl group having 1 to 6 carbon atoms include methyl group, ethyl group, propyl group, butyl group, hexyl group and pentyl group, and methyl group is preferred.

[0103] Specific examples of the alkenyl group having 3 to 6 carbon atoms include groups derived from propylene, isobutylene, and pentene, and a propenyl group is preferred.

[0104] Specific examples of the alkoxy group having 1 to 6 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a hexyloxy group, and a pentyloxy group, and a methoxy group is preferred.

[0105] Specific examples of the alkylthio group having 1 to 6 carbon atoms include groups derived from dimethyl sulfide, diethyl sulfide, dimethyl disulfide, and diethyl disulfide, and preferably a group derived from diethyl disulfide.

[0106] Specific examples of the ring having 3 to 6 carbon atoms include a cyclopropane ring, a cyclobutane ring, a cyclohexane ring, and a thiophene ring.

[0107] Specific examples of the alkylene group having 1 to 10 carbon atoms include methylene, ethylene, propylene, butylene, hexylene, pentylene, heptylene, octylene, nonylene and decylene, and preferably methylene, ethylene, propylene or butylene.

[0108] The above-mentioned polymer can be used by reacting a compound of a specific structure with a polymer terminal described in Japanese Patent Application No. 2005 / 098542.

[0109] The polymer contained in the resist underlayer film-forming composition of the present application can be obtained by reacting a compound having a specific structure with a terminal of a copolymer obtained by reacting a compound represented by formula (10) with a compound represented by formula (11).

[0110] The polymer contained in the resist underlayer film forming composition of the present application may be a reaction product of a mixture of compounds including a compound represented by the following formula (10), a compound represented by the following formula (11), and a compound represented by the above formula (1-1) or formula (2-1).

[0111]

[0112] (In formula (10), A1, A2, A3, A4, A5 and A6 each independently represent a hydrogen atom, a methyl group or an ethyl group, Y1 represents formula (4), formula (5), formula (6) or formula (7), and Q represents formula (8) or formula (9).

[0113]

[0114] ((In formulae (4) to (7), R4 and R5 each independently represent a hydrogen 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 at least one 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 hydroxyl group, and an alkylthio group having 1 to 6 carbon atoms; further, R4 and R5 may be combined with each other to form a ring having 3 to 6 carbon atoms; R6 represents 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 at least one 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 hydroxyl group, and an alkylthio group having 1 to 6 carbon atoms)

[0115]

[0116] (In formula (8) and formula (9), Q1 represents an alkylene group having 1 to 10 carbon atoms, a phenylene group, a naphthylene group, or an anthrylene group, and each of the phenylene group, the naphthylene group, and the anthrylene group may be substituted with at least one group selected from 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 hydroxyl group, and an alkylthio group having 1 to 6 carbon atoms, n4 and n5 each independently represent a number of 0 or 1, and Y2 represents formula (4), formula (5), or formula (7)))

[0117] Specific examples of the alkyl group having 1 to 6 carbon atoms include methyl group, ethyl group, propyl group, butyl group, hexyl group and pentyl group, and methyl group is preferred.

[0118] Specific examples of the alkenyl group having 3 to 6 carbon atoms include groups derived from propylene, isobutylene, and pentene, and a propenyl group is preferred.

[0119] Specific examples of the alkoxy group having 1 to 6 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a hexyloxy group, and a pentyloxy group, and a methoxy group is preferred.

[0120] Specific examples of the alkylthio group having 1 to 6 carbon atoms include groups derived from dimethyl sulfide, diethyl sulfide, dimethyl disulfide, and diethyl disulfide, and preferably a group derived from diethyl disulfide.

[0121] Specific examples of the ring having 3 to 6 carbon atoms include a cyclopropane ring, a cyclobutane ring, a cyclohexane ring, and a thiophene ring.

[0122] Specific examples of the alkylene group having 1 to 10 carbon atoms include methylene, ethylene, propylene, butylene, hexylene, pentylene, heptylene, octylene, nonylene and decylene, and preferably methylene, ethylene, propylene or butylene.

[0123] The polymer contained in the resist underlayer film-forming composition of the present application can be obtained by reacting a compound having a specific structure with a terminal of a copolymer obtained by reacting a compound represented by formula (12) with a compound represented by formula (13).

[0124] The polymer contained in the resist underlayer film forming composition of the present application may be a polymer obtained by reacting a mixture of compounds including a compound represented by formula (12), a compound represented by formula (13), and a compound represented by the above formula (1-1) or formula (2-1).

[0125]

[0126] (In the formula, A1, A2, A3, A4, A5, A6, Y1 and Q have the same meanings as defined above)

[0127] The proportion of the solid content of the resist underlayer film-forming composition of the present invention as a polymer is 50% by mass or more, preferably 60% by mass or more, for example, 50 to 100% by mass, or 60 to 99% by mass, or 70 to 95% by mass. In addition, the proportion of the solid content in the resist underlayer film-forming composition of the present invention is not particularly limited as long as each component is uniformly dissolved in the solvent, but is, for example, 0.5 to 50% by mass, or 1 to 30% by mass, or 3 to 20% by mass. The so-called solid content here refers to the component after removing the solvent component from all the components of the resist underlayer film-forming composition.

[0128] The molecular weight of the polymer contained in the resist underlayer film-forming composition of the present invention is, as a weight average molecular weight, for example, 1,000 to 200,000, 1,200 to 100,000, 1,500 to 30,000, 2,000 to 20,000, or 2,000 to 4,000.

[0129] The weight average molecular weight can be determined by, for example, the gel permeation chromatography (GPC) measurement method described in Examples.

[0130] <Method for producing polymer>

[0131] As an example of a polymerization method, the polymer contained in the resist underlayer film forming composition of the present application can be synthesized by adding a polymerization catalyst to a mixture of compounds including a compound represented by the following formula (10), a compound represented by the following formula (11), and a compound represented by the above formula (1-1) or (2-1), and heating polymerization. As an example of a polymerization method, the polymer contained in the resist underlayer film forming composition of the present application can be synthesized by adding a polymerization catalyst to a mixture of compounds including a compound represented by formula (12), a compound represented by formula (13), and a compound represented by the above formula (1-1) or (2-1), and heating polymerization. The organic solvent used here can be appropriately selected from the examples described later as the preferred organic solvent contained in the resist underlayer film forming composition for lithography of the present invention. As the polymerization catalyst, for example, benzyltriethylammonium chloride, ethyltriphenylphosphine bromide, The polymerization can be carried out by heating to, for example, 50° C. to 160° C., and preferably 70° C. to 130° C. The reaction time is, for example, 1 hour to 100 hours, and preferably 2 hours to 48 hours.

[0132] <Organic Solvents>

[0133] Specific examples of the organic solvent contained in the resist underlayer film of the present application include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol propyl ether acetate, toluene, xylene, methyl ethyl ketone, cyclopentanone, cyclohexanone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutyrate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl acetate, butyl acetate, ethyl lactate, and butyl lactate. A mixed solvent of propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate is most preferred.

[0134] <Crosslinking Acid Catalyst>

[0135] The resist underlayer film-forming composition of the present application may further contain a crosslinking acid catalyst. The crosslinking acid catalyst is a thermal acid generator, and specific examples thereof include p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridine - p-Toluenesulfonate, salicylic acid, camphorsulfonic acid, 5-sulfosalicylic acid, 4-chlorobenzenesulfonic acid, 4-hydroxybenzenesulfonic acid, benzene disulfonic acid, 1-naphthalenesulfonic acid, pyridine p-phenolsulfonate Salts, citric acid, benzoic acid, hydroxybenzoic acid and other sulfonic acid compounds and carboxylic acid compounds.

[0136] The resist underlayer film-forming composition of the present application may contain a crosslinking agent. The crosslinking agent is a nitrogen-containing compound having at least two crosslinking-forming substituents (e.g., hydroxymethyl, methoxymethyl, butoxymethyl), and specific examples thereof include hexamethoxymethylmelamine, tetramethoxymethylbenzoguanamine, 1,3,4,6-tetrakis(methoxymethyl)glycoluril, 1,3,4,6-tetrakis(butoxymethyl)glycoluril, 1,3,4,6-tetrakis(hydroxymethyl)glycoluril, 1,3-bis(hydroxymethyl)urea, 1,1,3,3-tetrakis(butoxymethyl)urea, and 1,1,3,3-tetrakis(methoxymethyl)urea.

[0137] <Resist Underlayer Film>

[0138] The resist underlayer film according to the present invention can be produced by applying the resist underlayer film-forming composition on a semiconductor substrate and firing the coating.

[0139] Examples of the semiconductor substrate to which the resist underlayer film-forming composition 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.

[0140] When a semiconductor substrate having an inorganic film formed on the surface is used, the inorganic film is formed by, for example, 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 polycrystalline silicon film, silicon oxide film, silicon nitride film, BPSG (Boro-Phospho Silicate Glass) film, titanium nitride film, titanium oxide nitride film, tungsten film, gallium nitride film, and gallium arsenide film.

[0141] On such a semiconductor substrate, the resist lower film forming composition of the present invention is applied by a suitable coating method such as a spin coater or a coater. Then, a heating means such as a hot plate is used to bake to form a resist lower film. As baking conditions, it is 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.

[0142] The thickness of the resist lower film formed is, for example, 0.001 μm (1 nm) to 10 μm, preferably 0.002 μm (2 nm) to 1 μm, and more preferably 0.005 μm (5 nm) to 0.5 μm (500 nm). When the temperature during baking is lower than the above range, crosslinking sometimes becomes insufficient. On the other hand, when the temperature during baking is higher than the above range, the resist lower film sometimes decomposes due to heat.

[0143] <Method for manufacturing a patterned substrate and method for manufacturing a semiconductor device>

[0144] The method for manufacturing a patterned substrate is as follows. Usually, a photoresist layer is formed on a resist underlayer film. The photoresist formed by coating and firing on the resist underlayer film by a known method is not particularly limited as long as it is a material that is sensitive to the light used for exposure. Both negative photoresists and positive photoresists can be used. There are positive photoresists composed of novolac resin and 1,2-naphthoquinone diazosulfonic acid ester, chemically amplified photoresists composed of a binder having a group that increases the alkali dissolution rate by acid decomposition and a photoacid generator, chemically amplified photoresists composed of a low molecular weight compound that increases the alkali dissolution rate of the photoresist by acid decomposition, an alkali-soluble binder, and a photoacid generator, and chemically amplified photoresists composed of a binder having a group that increases the alkali dissolution rate by acid decomposition, a low molecular weight compound that increases the alkali dissolution rate of the photoresist by acid decomposition, and a photoacid generator, and resists containing metal elements, etc. For example, JSR Corporation's product name V146G, Shipley's product name APEX-E, Sumitomo Chemical Co., Ltd.'s product name PAR710, Shin-Etsu Chemical Co., Ltd.'s product names AR2772 and SEPR430, etc. In addition, for example, fluorine atom-containing polymer photoresists such as those 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 cited.

[0145] Exposure is performed through a mask (photomask) for forming a predetermined pattern, using, for example, i-rays, KrF excimer lasers, ArF excimer lasers, EUV (extreme ultraviolet rays) or EB (electron beams). An alkaline developer is used for development, and is appropriately selected from a development temperature of 5°C to 50°C and a development time of 10 seconds to 300 seconds. As an alkaline developer, for example, an aqueous solution of an alkali such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia water, etc., a primary amine such as ethylamine, n-propylamine, a secondary amine such as diethylamine, di-n-butylamine, a tertiary amine such as triethylamine, methyldiethylamine, etc., an alcohol amine such as dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, quaternary ammonium salts such as choline, cyclic amines such as pyrrole and piperidine, etc. can be used. Furthermore, an appropriate amount of an alcohol such as isopropyl alcohol, a nonionic surfactant, etc. can also be added to the aqueous solution of the above-mentioned alkali and used. Among them, preferred developer is quaternary ammonium salt, more preferably tetramethylammonium hydroxide and choline. Further, surfactants etc. can also be added to these developers. Alternatively, a method of developing the photoresist by using an organic solvent such as butyl acetate instead of an alkaline developer to develop the portion where the alkali dissolution rate of the photoresist is not increased can be used. Through the above steps, a substrate in which the above resist is patterned can be manufactured.

[0146] Next, the resist underlayer film is dry-etched using the formed resist pattern as a mask. At this time, if the inorganic film is formed on the surface of the semiconductor substrate used, the surface of the inorganic film is exposed, and if the inorganic film is not formed on the surface of the semiconductor substrate used, the surface of the semiconductor substrate is exposed. Then, the substrate is processed by a method known per se (dry etching method, etc.), and a semiconductor device can be manufactured.

[0147] Example

[0148] Hereinafter, the present invention will be described in detail with reference to synthesis examples and examples, but the present invention is not limited to the following descriptions at all.

[0149] The weight average molecular weight shown in the following synthesis examples 1 to 7 of this specification is the measurement result obtained by gel permeation chromatography (hereinafter referred to as GPC in this specification). The measurement was performed using a GPC apparatus manufactured by Tosoh Corporation, and the measurement conditions were as follows. In addition, the dispersion degree shown in the following synthesis examples of this specification was calculated from the measured weight average molecular weight and number average molecular weight.

[0150] GPC column: Shodex〔registered trademark〕Asahipak〔registered trademark〕(Showa Denko K.K.)

[0151] Column temperature: 40°C

[0152] Solvent: Tetrahydrofuran (THF)

[0153] Flow rate: 0.6ml / min

[0154] Standard sample: Polystyrene (manufactured by Tosoh Corporation)

[0155] Detector: RI detector (manufactured by Tosoh Corporation, RI-8020)

[0156] <Synthesis example 1>

[0157] 7.50 g of diglycidyl dimethylhydantoin (manufactured by Shikoku Chemical Industry Co., Ltd.), 4.61 g of monoallyl diglycidyl isocyanuric acid (manufactured by Shikoku Chemical Industry Co., Ltd.), 1.34 g of 3-hydroxybenzoic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) and ethyltriphenylphosphine bromide were mixed. (Produced by ACROSS) 0.60g was added to 62.30g of propylene glycol monomethyl ether to dissolve it. After the reaction container was replaced with nitrogen, the reaction was carried out at 135°C for 4 hours to obtain a polymer solution. The polymer solution did not become turbid even when cooled to room temperature, and had good solubility in propylene glycol monomethyl ether. GPC analysis was performed, and the result showed that the polymer in the obtained solution had a weight average molecular weight of 2591 and a dispersity of 1.41 based on standard polystyrene. The polymer obtained in this synthesis example has structural units represented by the following formulas (1a) and (2a), and the terminal has a structure represented by the following formula (4a).

[0158]

[0159] <Synthesis example 2>

[0160] 7.50 g of diglycidyl dimethylhydantoin (manufactured by Shikoku Chemical Industry Co., Ltd.), 4.61 g of monoallyl diglycidyl isocyanuric acid (manufactured by Shikoku Chemical Industry Co., Ltd.), 1.48 g of 3,4-dihydroxybenzoic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) and ethyltriphenylphosphine bromide were mixed. (Produced by ACROSS) 0.60g was added to 63.01g of propylene glycol monomethyl ether to dissolve it. After the reaction container was replaced with nitrogen, the reaction was carried out at 135°C for 4 hours to obtain a polymer solution. The polymer solution did not become turbid even when cooled to room temperature, and had good solubility in propylene glycol monomethyl ether. GPC analysis was performed, and the polymer in the resulting solution had a weight-average molecular weight of 2950 and a dispersity of 1.46 based on standard polystyrene. The polymer obtained in this synthesis example has structural units represented by the following formulas (1a) and (2a), and the terminal has a structure represented by the following formula (3a).

[0161]

[0162] <Synthesis example 3>

[0163] 5.40 g of diglycidyl dimethylhydantoin (manufactured by Shikoku Chemical Industry Co., Ltd.), 3.32 g of monoallyl diglycidyl isocyanuric acid (manufactured by Shikoku Chemical Industry Co., Ltd.), 1.30 g of 1-hydroxy-2-naphthoic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) and ethyltriphenylphosphine bromide were mixed. (ACROSS) 0.43g was added to 46.74g of propylene glycol monomethyl ether to dissolve it. After the reaction container was replaced with nitrogen, the reaction was carried out at 135°C for 4 hours to obtain a polymer solution. The polymer solution did not become turbid even when cooled to room temperature, and had good solubility in propylene glycol monomethyl ether. GPC analysis was performed, and the result showed that the polymer in the obtained solution had a weight average molecular weight of 2386 and a dispersity of 2.21 based on standard polystyrene. The polymer obtained in this synthesis example has structural units represented by the following formulas (1a) and (2a), and the terminal has a structure represented by the following formula (5a).

[0164]

[0165] <Synthesis example 4>

[0166] 9.00 g of diglycidyl dimethylhydantoin (manufactured by Shikoku Chemical Industry Co., Ltd.), 5.53 g of monoallyl diglycidyl isocyanuric acid (manufactured by Shikoku Chemical Industry Co., Ltd.), 1.96 g of gallic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) and ethyltriphenylphosphine bromide were mixed. (Produced by ACROSS) 0.71g was added to 47.99g of propylene glycol monomethyl ether to dissolve it. After the reaction container was replaced with nitrogen, the reaction was carried out at 135°C for 4 hours to obtain a polymer solution. The polymer solution did not become turbid even when cooled to room temperature, and had good solubility in propylene glycol monomethyl ether. GPC analysis was performed, and the result showed that the polymer in the obtained solution had a weight average molecular weight of 3402 and a dispersity of 2.23 based on standard polystyrene. The polymer obtained in this synthesis example has structural units represented by the following formulas (1a) and (2a), and the terminal has a structure represented by the following formula (6a).

[0167]

[0168] <Synthesis example 5>

[0169] 9.00 g of diglycidyl dimethylhydantoin (manufactured by Shikoku Chemical Industry Co., Ltd.), 5.53 g of monoallyl diglycidyl isocyanuric acid (manufactured by Shikoku Chemical Industry Co., Ltd.), 1.91 g of piperonol (manufactured by Tokyo Chemical Industry Co., Ltd.) and ethyltriphenylphosphine bromide were mixed. (ACROSS) 0.71g was added to 47.80g of propylene glycol monomethyl ether to dissolve it. After the reaction container was replaced with nitrogen, the reaction was carried out at 135°C for 4 hours to obtain a polymer solution. The polymer solution did not become turbid even when cooled to room temperature, and had good solubility in propylene glycol monomethyl ether. GPC analysis was performed, and the result showed that the polymer in the obtained solution had a weight average molecular weight of 3186 and a dispersity of 2.57 based on standard polystyrene. The polymer obtained in this synthesis example has structural units represented by the following formulas (1a) and (2a), and the terminal has a structure represented by the following formula (7a).

[0170]

[0171] <Comparative Synthesis Example 1>

[0172] 9.00 g of diglycidyl dimethylhydantoin (manufactured by Shikoku Chemical Industry Co., Ltd.), 5.53 g of monoallyl diglycidyl isocyanuric acid (manufactured by Shikoku Chemical Industry Co., Ltd.), 1.91 g of 4-(methylsulfonyl)benzoic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) and ethyltriphenylphosphine bromide were mixed. (Produced by ACROSS) 0.71g was added to 47.80g of propylene glycol monomethyl ether to dissolve it. After the reaction container was replaced with nitrogen, the reaction was carried out at 135°C for 4 hours to obtain a polymer solution. The polymer solution did not become turbid even when cooled to room temperature, and had good solubility in propylene glycol monomethyl ether. GPC analysis was performed, and the result showed that the polymer in the obtained solution had a weight average molecular weight of 2600 and a dispersity of 2.13 based on standard polystyrene. The polymer obtained in this synthesis example has structural units represented by the following formulas (1a) and (2a), and the terminal has a structure represented by the following formula (8a).

[0173]

[0174] <Example 1>

[0175] 0.0077 g of tetramethoxymethyl glycoluril (manufactured by Japan Science & Technology Co., Ltd.) and pyridinium p-phenolsulfonate were mixed with 0.21 g of the polymer solution containing 0.031 g of the polymer obtained in Synthesis Example 1. 0.0012 g of salt (manufactured by Tokyo Chemical Industry Co., Ltd.), 47.81 g of propylene glycol monomethyl ether and 2.00 g of propylene glycol monomethyl ether acetate were added and dissolved, and then filtered using a polyethylene microfilter with a pore size of 0.05 μm to prepare a resist underlayer film-forming composition for lithography.

[0176] <Example 2>

[0177] 0.0077 g of tetramethoxymethyl glycoluril (manufactured by Japan Science & Technology Co., Ltd., trade name: POWDERLINK [registered trademark] 1174) and pyridinium p-phenolsulfonate were mixed with 0.21 g of the polymer solution containing 0.031 g of the polymer obtained in Synthesis Example 2. 0.0012 g of salt (manufactured by Tokyo Chemical Industry Co., Ltd.), 47.81 g of propylene glycol monomethyl ether and 2.00 g of propylene glycol monomethyl ether acetate were added and dissolved, and then filtered using a polyethylene microfilter with a pore size of 0.05 μm to prepare a resist underlayer film-forming composition for lithography.

[0178] <Example 3>

[0179] 0.0077 g of tetramethoxymethyl glycoluril (manufactured by Japan Science & Technology Co., Ltd.) and pyridinium p-phenolsulfonate were mixed with 0.21 g of the polymer solution containing 0.031 g of the polymer obtained in Synthesis Example 3. 0.0012 g of salt (manufactured by Tokyo Chemical Industry Co., Ltd.), 47.81 g of propylene glycol monomethyl ether and 2.00 g of propylene glycol monomethyl ether acetate were added and dissolved, and then filtered using a polyethylene microfilter with a pore size of 0.05 μm to prepare a resist underlayer film-forming composition for lithography.

[0180] <Example 4>

[0181] 0.0077 g of tetramethoxymethyl glycoluril (manufactured by Japan Science & Technology Co., Ltd.) and pyridinium p-phenolsulfonate were mixed with 0.21 g of the polymer solution containing 0.031 g of the polymer obtained in Synthesis Example 4. 0.0012 g of salt (manufactured by Tokyo Chemical Industry Co., Ltd.), 47.81 g of propylene glycol monomethyl ether and 2.00 g of propylene glycol monomethyl ether acetate were added and dissolved, and then filtered using a polyethylene microfilter with a pore size of 0.05 μm to prepare a resist underlayer film-forming composition for lithography.

[0182] <Example 5>

[0183] 0.0077 g of tetramethoxymethyl glycoluril (manufactured by Japan Science & Technology Co., Ltd.) and pyridinium p-phenolsulfonate were mixed with 0.21 g of the polymer solution containing 0.031 g of the polymer obtained in Synthesis Example 5. 0.0012 g of salt (manufactured by Tokyo Chemical Industry Co., Ltd.), 47.81 g of propylene glycol monomethyl ether and 2.00 g of propylene glycol monomethyl ether acetate were added and dissolved, and then filtered using a polyethylene microfilter with a pore size of 0.05 μm to prepare a resist underlayer film-forming composition for lithography.

[0184] <Comparative Example 1>

[0185] 0.0077 g of tetramethoxymethyl glycoluril (manufactured by Japan Science Dustries Co., Ltd.) and pyridinium p-phenolsulfonate were mixed with 0.21 g of the polymer solution containing 0.031 g of the polymer obtained in the above-mentioned comparative synthesis example 1. 0.0012 g of salt (manufactured by Tokyo Chemical Industry Co., Ltd.), 47.81 g of propylene glycol monomethyl ether and 2.00 g of propylene glycol monomethyl ether acetate were added and dissolved, and then filtered using a polyethylene microfilter with a pore size of 0.05 μm to prepare a resist underlayer film-forming composition for lithography.

[0186] [Dissolution test into photoresist solvent]

[0187] The resist underlayer film-forming compositions of Examples 1 to 5 and Comparative Example 1 were applied to a silicon wafer as a semiconductor substrate by a spin coater. The silicon wafer was placed on a hot plate and baked at 215° C. for 1 minute to form a resist underlayer film (film thickness 5 nm). These resist underlayer films were immersed in ethyl lactate and propylene glycol monomethyl ether, which are solvents used for photoresists, and it was confirmed that they were insoluble in these solvents.

[0188] [Formation of resist pattern by KrF exposure]

[0189] DUV-30J (anti-reflection film manufactured by Nissan Chemical Co., Ltd.) was applied as an anti-reflection film on a silicon wafer using a spin coater. The silicon wafer was baked on a hot plate at 205°C for 60 seconds to obtain a film with a thickness of 18 nm. On the film, the compositions for forming an anti-etching underlayer film of Examples 1 to 5 and Comparative Example 1 were respectively applied on the silicon wafer using a spin coater. The silicon wafer was baked on a hot plate at 215°C for 60 seconds to obtain an anti-etching underlayer film with a thickness of 5 nm. A positive resist solution for KrF excimer laser was spin-coated on the resist underlayer film and heated at 110°C for 60 seconds to form a KrF resist film. The resist film was exposed under specified conditions using a KrF excimer laser exposure device (NSR S205C manufactured by Nikon Co., Ltd.). After exposure, the film was baked (PEB) at 110°C for 60 seconds, cooled to room temperature on a cooling plate, developed with butyl acetate, and rinsed with butyl acetate to form a resist pattern with 170 nm line / 340 nm pitch. The resist pattern was measured using a scanning electron microscope (manufactured by Hitachi HiTech Nologis, CG4100). In the formation of the above-mentioned resist pattern, the exposure amount that formed a 170nm line / 340nm spacing (line and space (L / S=1 / 1) was taken as the optimal exposure amount. The evaluation was carried out based on whether a 170nm line and space (L / S) could be formed, the size of the roughness (LWR) of the line width of the line pattern observed from above the formed line pattern, and the minimum pre-collapse size as the minimum line width at which the collapse of the resist pattern was not confirmed. The evaluation results are shown in Table 1. The case where a line and space were formed was set to "good". In addition, with respect to LWR, the size of the deviation (バラツキ) of the line width of the formed line pattern is represented by nm. The smaller the LWR value, the more preferred it is, so Examples 1 to 5 show good LWR compared with Comparative Example 1.

[0190] [Table 1]

[0191] LWR Can L / S be formed? Example 1 6.91nm good Example 2 6.93nm good Example 3 6.99nm good Example 4 5.88nm good Example 5 5.22nm good Comparative Example 1 7.36nm good

[0192] 〔EUV exposure test〕

[0193] The resist underlayer film forming compositions of Example 1, Example 2 and Comparative Example 1 of the present invention were spin-coated on a silicon wafer and heated at 215°C for 1 minute to form a resist underlayer film. An EUV resist solution was spin-coated on the resist underlayer film and heated, and exposed under the condition of NA=0.33 Dipole using an EUV exposure device (NXE3300B manufactured by ASML). After exposure, PEB (post-exposure heating) was performed, and the film was cooled to room temperature on a cooling plate, and then developed and rinsed to form a resist pattern on a silicon wafer. Evaluation showed whether 16nm lines and spaces (L / S) could be formed. In addition, the exposure amount that formed 16nm lines / 32nm spacing (lines and spaces (L / S=1 / 1) was taken as the optimal exposure amount, and the exposure amount (EOP) at this time was shown. Improved sensitivity was observed in Examples 1 and 2 compared with Comparative Example 1.

[0194] [Table 2]

[0195] EOP Can L / S be formed? Example 1 31.0mJ good Example 2 31.0mJ good Comparative Example 1 32.5mJ good

[0196] Industrial Availability

[0197] The resist underlayer film-forming composition according to the present invention can provide a composition for forming a resist underlayer film capable of forming a desired resist pattern, and a resist pattern forming method using the resist underlayer film-forming composition.

Claims

1. A composition for forming a resist underlayer film, comprising a polymer and an organic solvent, wherein the polymer has a structure represented by the following formula (1) or (2) at the end of the polymer chain, and the polymer has a structural unit represented by the following formula (3), In the formula (1) and the formula (2), X is a divalent organic group, A is an aryl group having 6 to 40 carbon atoms, R1 is a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms, R2 and R3 are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms which may be substituted, or an aryl group having 6 to 40 carbon atoms which may be substituted, n1 and n3 are each independently an integer of 1 to 12, and n2 is an integer of 0 to 11. In formula (3), A1, A2, A3, A4, A5 and A6 each independently represent a hydrogen atom, a methyl group or an ethyl group, Y1 represents formula (4), formula (5), formula (6) or formula (7), Q represents formula (8) or formula (9), In formulae (4) to (7), R4 and R5 each independently represent a hydrogen 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 by at least one 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 hydroxyl group, and an alkylthio group having 1 to 6 carbon atoms. In addition, R4 and R5 may be combined with each other to form a ring having 3 to 6 carbon atoms, and R6 represents 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 by at least one 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 hydroxyl group, and an alkylthio group having 1 to 6 carbon atoms. In formula (8) and formula (9), Q1 represents an alkylene group having 1 to 10 carbon atoms, a phenylene group, a naphthylene group, or an anthrylene group, and each of the phenylene group, the naphthylene group, and the anthrylene group may be substituted by at least one group selected from 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 hydroxyl group, and an alkylthio group having 1 to 6 carbon atoms, n4 and n5 each independently represent an integer of 0 or 1, and Y2 represents formula (4), formula (5) or formula (7). 2 . The resist underlayer film forming composition according to claim 1 , wherein in the formula (1) and the formula (2), X is an ester bond or an ether bond. 3 . The resist underlayer film forming composition according to claim 1 , wherein in the formula (1) and the formula (2), A is a group derived from benzene, naphthalene or anthracene. 4 . The resist underlayer film forming composition according to claim 1 , wherein in the formula (2), R 2 and R 3 are hydrogen atoms. 5 . The resist underlayer film forming composition according to claim 1 , wherein in the formula (1), n2 is 0.

6. The resist underlayer film-forming composition according to claim 1, wherein the polymer having the structural unit represented by the formula (3) is a polymer having a compound represented by the formula (10) and a compound represented by the formula (11) as comonomers, In formula (10) and formula (11), A1, A2, A3, A4, A5, A6, Y1 and Q have the same meanings as defined in claim 1.

7. The resist underlayer film-forming composition according to claim 1, wherein the polymer having the structural unit represented by the formula (3) is a polymer having a compound represented by the formula (12) and a compound represented by the formula (13) as comonomers, In the formula, A1, A2, A3, A4, A5, A6, Y1 and Q have the same meanings as defined in claim 1. 8 . The resist underlayer film-forming composition according to claim 1 , further comprising a cross-linking acid catalyst. 9 . The resist underlayer film-forming composition according to claim 1 , further comprising a crosslinking agent.

10. A resist underlayer film, characterized in that: A fired product of a coating film formed from the resist underlayer film forming composition according to any one of claims 1 to 9.

11. A method for manufacturing a substrate on which a pattern is formed, comprising the following steps: a step of coating a resist underlayer film-forming composition as described in any one of claims 1 to 9 on a semiconductor substrate and baking the composition to form a resist underlayer film; a step of coating a resist on the resist underlayer film and baking the composition to form a resist film; a step of exposing the semiconductor substrate coated with the resist underlayer film and the resist; and a step of developing the exposed resist film to form a pattern.

12. A method for manufacturing a semiconductor device, characterized in that: The process includes the following steps: A step of forming a resist underlayer film formed from the resist underlayer film-forming composition according to any one of claims 1 to 9 on a semiconductor substrate; forming a resist film on the resist underlayer film; A step of forming a resist pattern by irradiating the resist film with light or electron beams and then developing the resist film; a step of forming a patterned resist underlayer film by etching the resist underlayer film through the formed resist pattern; and A step of processing a semiconductor substrate using the patterned resist underlayer film.

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