Resist underlayer film-forming composition containing alicyclic compound-terminated polymer

Abstract

Provided are a composition for forming a resist underlayer film capable of forming a desired resist pattern, a resist pattern manufacturing method using the resist underlayer film forming composition, and a semiconductor device manufacturing method. A resist underlayer film forming composition, comprising a polymer containing an aliphatic ring at the end, and further comprising an organic solvent, wherein the carbon-carbon bond of the aliphatic ring can be interrupted by a heteroatom and the aliphatic ring can be substituted by a substituent. The aliphatic ring is a monocyclic or polycyclic aliphatic ring having 3 to 10 carbon atoms. The polycyclic aliphatic ring is a bicyclic or tricyclic ring.

Description

Technical Field

[0001] The present invention relates to a composition that can be used in a photolithography process in semiconductor manufacturing, particularly in the most advanced photolithography processes (ArF, EUV, EB, etc.), and also relates to a method for manufacturing a substrate with a resist pattern to which the resist underlayer film is applied, and a method for manufacturing a semiconductor device. Background Art

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

[0003] Patent Document 1 discloses a resist underlayer film-forming composition used in a photolithography process for manufacturing a semiconductor device, comprising a polymer having a repeating unit structure having a polycyclic aliphatic ring in its main chain. Patent Document 2 discloses a resist underlayer film-forming composition for lithography, comprising a polymer having a specific structure at its terminal.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2009-093162

[0007] Patent Document 2: International Publication No. 2013 / 141015 Summary of the invention

[0008] Problems to be solved by the invention

[0009] 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.

[0010] 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., making it difficult to form a uniform film without defects.

[0011] On the other hand, when the resist pattern is formed, in the developing process, a method is sometimes adopted in which the unexposed portion of the resist film is removed using a solvent capable of dissolving the resist film, usually an organic solvent, and the exposed portion of the resist film is left as the resist pattern. In such a negative developing process, the improvement of the adhesion of the resist pattern becomes a major issue.

[0012] Furthermore, it is required to suppress deterioration of LWR (Line Width Roughness) during resist pattern formation, form a resist pattern having a good rectangular shape, and improve resist sensitivity.

[0013] An object of the present invention is to 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, which solves the above-mentioned problems.

[0014] Means for solving problems

[0015] The present invention includes the following aspects.

[0016] [1] A resist underlayer film-forming composition comprising a polymer having an aliphatic ring at a terminal, wherein the carbon-carbon bond of the aliphatic ring may be interrupted by a heteroatom and the aliphatic ring may be substituted by a substituent, and further comprising an organic solvent.

[0017] [2] The resist underlayer film forming composition according to [1], wherein the aliphatic ring is a monocyclic or polycyclic aliphatic ring having 3 to 10 carbon atoms.

[0018] [3] The resist underlayer film forming composition according to [2], wherein the polycyclic aliphatic ring is a bicyclic or tricyclic ring.

[0019] [4] The resist underlayer film forming composition according to any one of [1] to [3], wherein the aliphatic ring has at least one unsaturated bond.

[0020] [5] According to any one of [1] to [4], the above-mentioned substituent is selected from a hydroxyl group, a linear or branched alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an acyloxy group having 1 to 10 carbon atoms and a carboxyl group.

[0021] [6] The resist underlayer film-forming composition according to any one of [1] to [5], wherein the polymer has at least one structural unit represented by the following formula (3) in the main chain.

[0022]

[0023] (In formula (3), A1, A2, A3, A4, A5 and A6 each independently represent a hydrogen atom, a methyl group or an ethyl group, Q1 represents a divalent organic group, and m1 and m2 each independently represent 0 or 1.)

[0024] [7] The resist underlayer film forming composition according to [6], wherein in the above formula (3), Q1 represents a divalent organic group represented by the following formula (5).

[0025]

[0026] (In the formula, Y represents a divalent group represented by the following formula (6) or formula (7).)

[0027]

[0028] (In the formula, R6 and R7 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 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 and an alkylthio group having 1 to 6 carbon atoms, or R6 and R7 may be bonded to each other to form a ring having 3 to 6 carbon atoms together with the carbon atom to which R6 and R7 are bonded.)

[0029] [8] The resist underlayer film-forming composition according to any one of [1] to [7], wherein the polymer further contains a disulfide bond in the main chain.

[0030] [9] The resist underlayer film forming composition according to any one of [1] to [8], further comprising a curing catalyst.

[0031]

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

[0032]

[11] 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] .

[0033]

[12] 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 [1] to

[10] on a semiconductor substrate and baking the coating to form a resist underlayer film; a step of coating a resist on the resist underlayer film and baking the coating 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.

[0034]

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

[0035] 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;

[0036] forming a resist film on the resist underlayer film;

[0037] A process of forming a resist pattern by irradiating the resist film with light or electron beams and then developing the resist film;

[0038] a step of etching the resist underlayer film through the formed resist pattern to form a patterned resist underlayer film; and

[0039] A step of processing a semiconductor substrate using the patterned resist underlayer film.

[0040] Effects of the Invention

[0041] The composition for forming a resist underlayer film for lithography of the present invention is characterized in that the terminal of the polymer (or also referred to as a polymer) contained in the composition for forming a resist underlayer film is terminated by an aliphatic ring whose carbon-carbon bond can be interrupted by a heteroatom, or an aliphatic ring that can be substituted by a substituent, and contains such a polymer and an organic solvent, preferably further containing a crosslinking agent and / or a compound that promotes a crosslinking reaction (curing catalyst). The composition for forming a resist underlayer film for lithography of the present application can achieve the formation of a resist pattern with a good rectangular shape (no pattern collapse), the suppression of LWR deterioration during the formation of the resist pattern, and the improvement of sensitivity by having such a structure. DETAILED DESCRIPTION

[0042] 《Explanation of Terminology》

[0043] The terms used in the present invention have the following definitions unless otherwise specified.

[0044] Examples of the “alkyl group having 1 to 10 carbon atoms” include methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclobutyl, 1-methyl-cyclopropyl, 2-methyl-cyclopropyl, n-pentyl, 1-methyl-n-butyl, 2-methyl-n-butyl, 3-methyl-n-butyl, 1,1-dimethyl-n-propyl, 1,2-dimethyl-n-propyl, 2,2-dimethyl-n-propyl, 1-ethyl-n-propyl, cyclopentyl, 1-methyl-cyclobutyl, 2-methyl-cyclobutyl, 3-methyl-n-butyl, 1 ,2-dimethyl-cyclopropyl, 2,3-dimethyl-cyclopropyl, 1-ethyl-cyclopropyl, 2-ethyl-cyclopropyl, n-hexyl, 1-methyl-n-pentyl, 2-methyl-n-pentyl, 3-methyl-n-pentyl, 4-methyl-n-pentyl, 1,1-dimethyl-n-butyl, 1,2-dimethyl-n-butyl, 1,3-dimethyl-n-butyl, 2,2-dimethyl-n-butyl, 2,3-dimethyl-n-butyl, 3,3-dimethyl-n-butyl, 1-ethyl-n-butyl, 2-ethyl-n-butyl, 1,1,2-trimethyl-n-butyl 1,2,2-trimethyl-n-propyl, 1-ethyl-1-methyl-n-propyl, 1-ethyl-2-methyl-n-propyl, cyclohexyl, 1-methyl-cyclopentyl, 2-methyl-cyclopentyl, 3-methyl-cyclopentyl, 1-ethyl-cyclobutyl, 2-ethyl-cyclobutyl, 3-ethyl-cyclobutyl, 1,2-dimethyl-cyclobutyl, 1,3-dimethyl-cyclobutyl, 2,2-dimethyl-cyclobutyl, 2,3-dimethyl-cyclobutyl, 2,4-dimethyl-cyclobutyl, 3,3-dimethyl-cyclobutyl, 1-n-propyl-cyclopropyl , 2-n-propyl-cyclopropyl, 1-isopropyl-cyclopropyl, 2-isopropyl-cyclopropyl, 1,2,2-trimethyl-cyclopropyl, 1,2,3-trimethyl-cyclopropyl, 2,2,3-trimethyl-cyclopropyl, 1-ethyl-2-methyl-cyclopropyl, 2-ethyl-1-methyl-cyclopropyl, 2-ethyl-2-methyl-cyclopropyl, 2-ethyl-3-methyl-cyclopropyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, etc.

[0045] Examples of the “alkoxy group having 1 to 20 carbon atoms” include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentyloxy, 1-methyl-n-butoxy, 2-methyl-n-butoxy, 3-methyl-n-butoxy, 1,1-dimethyl-n-propoxy, 1,2-dimethyl-n-propoxy, 2,2-dimethyl-n-propoxy, 1-ethyl-n-propoxy, n-hexyloxy, 1-methyl-n-pentyloxy, 2-methyl-n-pentyloxy, 3-methyl-n-pentyloxy, 4-methyl-n-pentyloxy, 1,1-dimethyl-n-butoxy , 1,2-dimethyl-n-butoxy, 1,3-dimethyl-n-butoxy, 2,2-dimethyl-n-butoxy, 2,3-dimethyl-n-butoxy, 3,3-dimethyl-n-butoxy, 1-ethyl-n-butoxy, 2-ethyl-n-butoxy, 1,1,2-trimethyl-n-propoxy, 1,2,2-trimethyl-n-propoxy, 1-ethyl-1-methyl-n-propoxy, and 1-ethyl-2-methyl-n-propoxy, cyclopentyloxy, cyclohexyloxy, norbornyloxy, adamantyloxy, adamantylmethyloxy, adamantylethyloxy, tetracyclodecanyloxy, tricyclodecanyloxy, and the like.

[0046] The "acyloxy group having 1 to 10 carbon atoms" refers to a group represented by the following formula (20).

[0047] Z-COO-* Formula (20)

[0048] (In formula (20), Z represents a hydrogen atom or the "alkyl group having 1 to 9 carbon atoms" in the above-mentioned "alkyl group having 1 to 10 carbon atoms", and * represents a bonding portion with the above-mentioned "aliphatic ring".)

[0049] Examples of the “alkenyl group having 3 to 6 carbon atoms” include 1-propenyl, 2-propenyl, 1-methyl-1-vinyl, 1-butenyl, 2-butenyl, 3-butenyl, 2-methyl-1-propenyl, 2-methyl-2-propenyl, 1-ethylvinyl, 1-methyl-1-propenyl, 1-methyl-2-propenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-n-propylvinyl, 1-methyl-1-butenyl, 1-methyl-2-butenyl, 1-methyl-3-butenyl, 2-ethyl-2-propenyl, 2-methyl-1-butenyl, 2-methyl-2-butenyl, 2-methyl-3-butenyl, 3-methyl-1-butenyl, 3-methyl-2-butenyl, 3-methyl-3-butenyl, 1,1-dimethyl-2-propenyl, 1-isopropylvinyl, 1,2-dimethyl-1-propenyl, 1,2-dimethyl-2-propenyl, 1-cyclopentenyl, 2-cyclopentenyl, 3-cyclopentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, 5-hexenyl, 1-methyl-1-pentenyl, 1-methyl-2-pentenyl, 1-methyl-3-pentenyl, 1-methyl-4-pentenyl, 1-n-butylvinyl, 2-methyl-1-pentenyl, 2-methyl-2-pentenyl, 2-methyl-3-pentenyl, 2 4-Methyl-2-pentenyl, 2-n-propyl-2-propenyl, 3-methyl-1-pentenyl, 3-methyl-2-pentenyl, 3-methyl-3-pentenyl, 3-methyl-4-pentenyl, 3-ethyl-3-butenyl, 4-methyl-1-pentenyl, 4-methyl-2-pentenyl, 4-methyl-3-pentenyl, 4-methyl-4-pentenyl, 1,1-dimethyl-2-butenyl, 1,1-dimethyl-3-butenyl, 1,2-dimethyl-1-butenyl, 1,2-dimethyl-2-butenyl, 1,2-dimethyl-3-butenyl, 1-methyl-2-ethyl-2-propenyl, 1-sec-butylvinyl, 1,3-dimethyl- methyl-1-butenyl, 1,3-dimethyl-2-butenyl, 1,3-dimethyl-3-butenyl, 1-isobutylvinyl, 2,2-dimethyl-3-butenyl, 2,3-dimethyl-1-butenyl, 2,3-dimethyl-2-butenyl, 2,3-dimethyl-3-butenyl, 2-isopropyl-2-propenyl, 3,3-dimethyl-1-butenyl, 1-ethyl-1-butenyl, 1-ethyl-2-butenyl, 1-ethyl-3-butenyl, 1-n-propyl-1-propenyl, 1-n-propyl-2-propenyl, 2-ethyl-1-butenyl, 2-ethyl-2-butenyl, 2-ethyl-3-butenyl, 1,1,2-Trimethyl-2-propenyl, 1-tert-butylvinyl, 1-methyl-1-ethyl-2-propenyl, 1-ethyl-2-methyl-1-propenyl, 1-ethyl-2-methyl-2-propenyl, 1-isopropyl-1-propenyl, 1-isopropyl-2-propenyl, 1-methyl-2-cyclopentenyl, 1-methyl-3-cyclopentenyl, 2-methyl-1-cyclopentenyl, 2-methyl-2-cyclopentenyl cyclopentenyl, 2-methyl-3-cyclopentenyl, 2-methyl-4-cyclopentenyl, 2-methyl-5-cyclopentenyl, 2-methylene-cyclopentyl, 3-methyl-1-cyclopentenyl, 3-methyl-2-cyclopentenyl, 3-methyl-3-cyclopentenyl, 3-methyl-4-cyclopentenyl, 3-methyl-5-cyclopentenyl, 3-methylene-cyclopentyl, 1-cyclohexenyl, 2-cyclohexenyl and 3-cyclohexenyl, etc.

[0050] Examples of the "alkylthio group having 1 to 6 carbon atoms" include methylthio, ethylthio, propylthio, butylthio, pentylthio and hexylthio.

[0051] Examples of the "halogen atom" include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

[0052] Examples of the “arylene group having 6 to 40 carbon atoms” include phenylene, o-methylphenylene, m-methylphenylene, p-methylphenylene, o-chlorophenylene, m-chlorophenylene, p-chlorophenylene, o-fluorophenylene, p-fluorophenylene, o-methoxyphenylene, p-methoxyphenylene, p-nitrophenylene, p-cyanophenylene, α-naphthylene, β-naphthylene, o-biphenylene, m-biphenylene, p-biphenylene, 1-anthrylene, 2-anthrylene, 9-anthrylene, 1-phenanthrylene, 2-phenanthrylene, 3-phenanthrylene, 4-phenanthrylene and 9-phenanthrylene.

[0053] <Resist underlayer film forming composition>

[0054] The resist underlayer film-forming composition of the present application contains an aliphatic ring whose carbon-carbon bond may be interrupted by a heteroatom at the terminal of a polymer contained in the resist underlayer film-forming composition, and further contains an organic solvent.

[0055] The carbon-carbon bond may be interrupted by a heteroatom, which means that the carbon-carbon bonds of the aliphatic ring in the present application include -O- and -S- bonds.

[0056] The aliphatic ring which may be substituted with a substituent means that all or part of the hydrogen atoms of the aliphatic ring of the present application are substituted with, for example, a hydroxyl group, a linear or branched alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an acyloxy group having 1 to 10 carbon atoms, and a carboxyl group.

[0057] The aliphatic ring is preferably a monocyclic or polycyclic aliphatic ring having 3 to 10 carbon atoms.

[0058] Examples of the "monocyclic or polycyclic aliphatic ring having 3 to 10 carbon atoms" include cyclopropane, cyclobutane, cyclopentane, cyclohexane, cyclohexene, cycloheptane, cyclooctane, cyclononane, cyclodecane, spirobicyclopentane, bicyclo[2.1.0]pentane, bicyclo[3.2.1]octane, tricyclo[3.2.1.0] 2,7 ]octane, spiro[3,4]octane, norbornene, norbornene, tricyclo[3.3.1.1 3,7 ]Decane (adamantane), etc.

[0059] The polycyclic aliphatic ring is preferably bicyclic or tricyclic.

[0060] Among them, examples of the bicyclic ring include norbornane, norbornene, spirobicyclopentane, bicyclo[2.1.0]pentane, bicyclo[3.2.1]octane, and spiro[3,4]octane.

[0061] Among them, as a tricyclic ring, there can be mentioned a tricyclic ring [3.2.1.0 2,7 ]Octane, tricyclic [3.3.1.1 3,7 ]Decane (adamantane).

[0062] The aliphatic ring preferably has at least one unsaturated bond (eg, double bond, triple bond). The aliphatic ring preferably has 1 to 3 unsaturated bonds. The aliphatic ring preferably has 1 or 2 unsaturated bonds. The unsaturated bond is preferably a double bond.

[0063] Specific examples of the "aliphatic ring whose carbon-carbon bond may be interrupted by a heteroatom and which may be substituted by a substituent" include those derived by reacting the following compounds with the terminal of the polymer by a method known per se.

[0064]

[0065]

[0066] The above polymer preferably has at least one structural unit represented by the following formula (3) in the main chain.

[0067]

[0068] (In formula (3), A1, A2, A3, A4, A5 and A6 each independently represent a hydrogen atom, a methyl group or an ethyl group, Q1 represents a divalent organic group, and m1 and m2 each independently represent 0 or 1.)

[0069] In the above formula (3), Q1 preferably represents a divalent organic group represented by the following formula (5).

[0070]

[0071] (In the formula, Y represents a divalent group represented by the following formula (6) or formula (7).)

[0072]

[0073] (In the formula, R6 and R7 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 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 and an alkylthio group having 1 to 6 carbon atoms, or R6 and R7 may be bonded to each other to form a ring having 3 to 6 carbon atoms together with the carbon atom to which R6 and R7 are bonded.)

[0074] Examples of the "ring having 3 to 6 carbon atoms" include cyclopropane, cyclobutane, cyclopentane, cyclopentadiene and cyclohexane.

[0075] The above polymer preferably further contains a disulfide bond in the main chain.

[0076] The polymer preferably includes an arylene group having 6 to 40 carbon atoms which may be substituted with a substituent. The substituent has the same meaning as described above.

[0077] The weight average molecular weight of the polymer is, for example, 2,000 to 50,000.

[0078] Examples of monomers that form the structural unit represented by the above formula (3) in which m1 and m2 are 1 include compounds having two epoxy groups represented by the following formulas (10-a) to (10-k):

[0079]

[0080] That is, 1,4-terephthalic acid diglycidyl ester, 2,6-naphthalene diglycidyl ester, 1,6-dihydroxynaphthalene diglycidyl ester, 1,2-cyclohexane dicarboxylic acid diglycidyl ester, 2,2-bis(4-hydroxyphenyl)propane diglycidyl ester, 2,2-bis(4-hydroxycyclohexane)propane diglycidyl ester, 1,4-butanediol diglycidyl ester, monoallyl isocyanuric acid diglycidyl ester, monomethyl isocyanuric acid diglycidyl ester, 5,5-diethylbarbituric acid diglycidyl ester, 5,5-dimethylhydantoin diglycidyl ester, but the present invention is not limited to these examples.

[0081] Examples of monomers that form the structural unit represented by the above formula (3) in which m1 and m2 are represented by 0 include compounds having two carboxyl groups, hydroxyphenyl groups or imide groups, and acid dianhydrides represented by the following formulas (11-a) to (11-s):

[0082]

[0083] That is, isophthalic acid, 5-hydroxyisophthalic acid, 2,4-dihydroxybenzoic acid, 2,2-bis(4-hydroxyphenyl)sulfone, succinic acid, fumaric acid, tartaric acid, 3,3'-dithiodipropionic acid, 1,4-cyclohexanedicarboxylic acid, cyclobutane dianhydride, cyclopentane dianhydride, monoallyl isocyanuric acid, 5,5-diethylbarbituric acid, diglycolic acid, acetone dicarboxylic acid, 2,2'-thiodiglycolic acid, 4-hydroxyphenyl 4-hydroxybenzoate, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxyphenyl)hexafluoropropane, 1,3-bis(carboxymethyl)-5-methyl isocyanurate, and 1,3-bis(carboxymethyl)-5-allyl isocyanurate.

[0084] The copolymerization ratio (charge weight ratio) of the monomer (difunctional) forming the structural unit represented by the above formula (3) and in which m1 and m2 are 1, and the monomer (difunctional) forming the structural unit represented by the above formula (3) and in which m1 and m2 are 0 is, for example, 1:2 to 2:1.

[0085] The weight ratio of the monomer for deriving the aliphatic ring bonded to the terminal of the polymer of the present application (the site mainly reacting with the polymer is monofunctional) and the total of the above monomers is, for example, 20:1 to 5:1.

[0086] The term "functionality" is a concept that focuses on the chemical properties and chemical reactivity of a substance. When a functional group is referred to, inherent physical properties and chemical reactivity are assumed, respectively. However, in the present application, it refers to a reactive substituent that can bind to other compounds.

[0087] The number of repetitions of the structural unit represented by the above formula (3) is, for example, in the range of 5 or more and 10,000 or less.

[0088] Examples of the organic solvent contained in the resist underlayer film-forming composition of the present invention 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 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-pentanone, and the like. alcohol, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, ethyl ethoxylate, 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. These solvents can be used alone or in combination of two or more.

[0089] Among these solvents, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl lactate, butyl lactate, and cyclohexanone are preferred. Propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate are particularly preferred.

[0090] Furthermore, the ratio of the organic solvent to the resist underlayer film-forming composition of the present invention is, for example, 50 mass % or more and 99.9 mass % or less.

[0091] The polymer contained in the resist underlayer film-forming composition of the present invention is, for example, 0.1% by mass to 50% by mass based on the resist underlayer film-forming composition.

[0092] The resist underlayer film forming composition of the present invention may further include a crosslinking agent and a crosslinking catalyst (curing catalyst) as a compound that promotes a crosslinking reaction in addition to a polymer and an organic solvent. If the component after removing the organic solvent from the resist underlayer film forming composition of the present invention is defined as a solid component, the solid component includes a polymer and additives such as a crosslinking agent and a crosslinking catalyst added as needed. The proportion of the additive is, for example, 0.1% to 50% by mass, preferably 1% to 30% by mass, relative to the solid component of the resist underlayer film forming composition of the present invention.

[0093] Examples of the crosslinking agent included as an optional component in the resist underlayer film-forming composition of the present invention include hexamethoxymethylmelamine, tetramethoxymethylbenzoguanamine, 1,3,4,6-tetrakis(methoxymethyl)glycoluril (tetramethoxymethylglycoluril) (POWDERLINK [registered trademark] 1174), 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, 1,1,3,3-tetrakis(methoxymethyl)urea, and 3,3',5,5'-tetrakis(methoxymethyl)4,4'-biphenol. When the crosslinking agent is used, the content ratio of the crosslinking agent is, for example, 1% to 50% by mass, preferably 5% to 30% by mass, relative to the polymer.

[0094] Examples of the curing catalyst (crosslinking catalyst) that may be optionally contained in the resist underlayer film-forming composition of the present invention include p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridine - p-Toluenesulfonate (pyridine -p-Toluenesulfonic acid), pyridine -p-Hydroxybenzenesulfonic acid, pyridine - sulfonic acid compounds and carboxylic acid compounds such as trifluoromethanesulfonic acid, cyclohexyl p-toluenesulfonate, morpholine, p-toluenesulfonic acid ester, salicylic acid, camphorsulfonic acid, 5-sulfosalicylic acid, 4-chlorobenzenesulfonic acid, 4-hydroxybenzenesulfonic acid, benzene disulfonic acid, 1-naphthalenesulfonic acid, citric acid, benzoic acid, and hydroxybenzoic acid. When the crosslinking catalyst is used, the content ratio of the crosslinking catalyst relative to the crosslinking agent is, for example, 0.1% to 50% by mass, preferably 1% to 30% by mass.

[0095] The resist underlayer film-forming composition of the present invention may further contain a surfactant in order to prevent the occurrence of pinholes, streaks, etc. and to further improve the coating properties on uneven surfaces. 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 allyl ethers such as polyoxyethylene octylphenol ether and polyoxyethylene nonylphenol ether, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, and sorbitan tristearate, and sorbitan fatty acid esters such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate. Nonionic surfactants such as polyoxyethylene sorbitan tristearate and other polyoxyethylene sorbitan fatty acid esters, Efthot EF301, EF303, EF352 (Co., Ltd.)ーケムプロダクツ, brand name), メガファック F171, F173, R-30 (made by Dainippon Technology Co., Ltd., brand name), フロラード FC430, F Fluorine-based surfactants such as C431 (manufactured by Sumitomo Soft Arm (Strain), Asahigard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass (Strain), trade name), and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.). The blending amount of these surfactants is usually 2.0% by mass or less, preferably 1.0% by mass or less, relative to the total solid content of the resist underlayer film-forming composition of the present invention. These surfactants may be added alone or in combination of two or more.

[0096] <Resist underlayer film>

[0097] 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.

[0098] 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.

[0099] 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 polysilicon 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.

[0100] On such a semiconductor substrate, the resist underlayer film forming composition of the present invention is applied by a suitable coating method such as a spin coater or a coater. Then, the resist underlayer film is formed by baking using a heating means such as a hot plate. 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.

[0101] The thickness of the resist underlayer film to be formed is, for example, 0.001 μm (1 nm) to 10 μm, 0.002 μm (2 nm) to 1 μm, 0.005 μm (5 nm) to 0.5 μm (500 nm), 0.001 μm (1 nm) to 0.05 μm (50 nm), 0.002 μm (2 nm) to 0.05 μm (50 nm), 0.003 μm (1 nm) ~0.05μm (50nm), 0.004μm (4nm)~0.05μm (50nm), 0.005μm (5nm)~0.05μm (50nm), 0.003μm (3nm)~0.03μm (30nm), 0.003μm (3nm)~0.02μm (20nm), 0.005μm (5nm)~0.02μm (20nm). 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.

[0102] <Method for manufacturing patterned substrate and method for manufacturing semiconductor device>

[0103] 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 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's product name PAR710, and Shin-Etsu Chemical'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.

[0104] Exposure is performed through a mask (photomask) for forming a prescribed pattern, using, for example, i-rays, KrF excimer lasers, ArF excimer lasers, EUV (extreme ultraviolet rays) or EB (electron beams), but the resist underlayer film forming composition of the present application is preferably used for EUV (extreme ultraviolet rays) exposure. An alkaline developer is used for development, and the development temperature is 5°C to 50°C, and the development time is 10 seconds to 300 seconds. As an alkaline developer, for example, an aqueous solution of an inorganic base such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia water, primary amines such as ethylamine, n-propylamine, secondary amines such as diethylamine, di-n-butylamine, tertiary amines such as triethylamine, methyldiethylamine, alcohol amines such as dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, quaternary ammonium salts such as choline, cyclic amines such as pyrrole and piperidine can be used. Furthermore, it is also possible to add an appropriate amount of surfactants such as alcohols such as isopropyl alcohol and nonionic systems to the aqueous solution of the above-mentioned alkalis and use them. Among them, preferred developers are quaternary ammonium salts, and more preferably tetramethylammonium hydroxide and choline. Further, surfactants and the like can also be added to these developers. It is also possible to use a method in which an organic solvent such as butyl acetate is used instead of an alkaline developer to develop the portion where the alkali dissolution rate of the photoresist is not improved. Through the above-mentioned steps, a substrate in which the above-mentioned resist has been patterned can be manufactured.

[0105] 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.

[0106] Example

[0107] Next, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

[0108] The weight average molecular weights of the polymers shown in Synthesis Examples 1 to 8 and Comparative Synthesis Examples 1 and 2 in this specification are the results of measurements obtained by gel permeation chromatography (hereinafter referred to as GPC). The measurement was performed using a GPC apparatus manufactured by Tosoh Corporation, and the measurement conditions and the like are as follows.

[0109] GPC columns: Shodex KF803L, Shodex KF802, Shodex KF801〔Registered trademark〕(Showa Denko K.K.)

[0110] Column temperature: 40°C

[0111] Solvent: Tetrahydrofuran (THF)

[0112] Flow rate: 1.0ml / min

[0113] Standard sample: Polystyrene (manufactured by Tosoh Corporation)

[0114] <Synthesis example 1>

[0115] Regarding polymer 1, 7.88 g of N,N-diglycidyl-5,5-dimethylhydantoin (manufactured by Shikoku Chemical Industry Co., Ltd.), 5.03 g of monoallyl isocyanuric acid (manufactured by Shikoku Chemical Industry Co., Ltd.), 1.45 g of 5-norbornene-2-carboxylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and ethyltriphenylphosphine bromide were mixed. 0.65 g of (Tokyo Chemical Industry Co., Ltd.) was added to 66.60 g of propylene glycol monomethyl ether for dissolution. After nitrogen substitution in the reaction vessel, the reaction was carried out at 110° C. for 24 hours to obtain a polymer solution. GPC analysis was performed, and the result showed that the obtained polymer had a weight average molecular weight of 3000 in terms of standard polystyrene and a dispersity of 2.8. The structure present in polymer 1 is shown in the following formula.

[0116]

[0117] <Synthesis example 2>

[0118] Regarding polymer 2, 7.88 g of N,N-diglycidyl-5,5-dimethylhydantoin (manufactured by Shikoku Chemical Industry Co., Ltd.), 5.07 g of monoallyl isocyanuric acid (manufactured by Shikoku Chemical Industry Co., Ltd.), 1.34 g of 3-cyclohexene-1-carboxylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and ethyltriphenylphosphine bromide were mixed. 0.66 g of (Tokyo Chemical Industry Co., Ltd.) was added to 66.60 g of propylene glycol monomethyl ether for dissolution. After nitrogen substitution in the reaction vessel, the reaction was carried out at 110° C. for 24 hours to obtain a polymer solution. GPC analysis was performed, and the result showed that the obtained polymer had a weight average molecular weight of 2500 in terms of standard polystyrene and a dispersity of 2.2. The structure present in polymer 2 is shown in the following formula.

[0119]

[0120] <Synthesis example 3>

[0121] Regarding polymer 3, 7.95 g of N,N-diglycidyl-5,5-dimethylhydantoin (manufactured by Shikoku Chemical Industry Co., Ltd.), 5.07 g of monoallyl isocyanuric acid (manufactured by Shikoku Chemical Industry Co., Ltd.), 1.74 g of 5-norbornene-2,3-dicarboxylic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.), and ethyltriphenylphosphine bromide were mixed. 0.66 g of (Tokyo Chemical Industry Co., Ltd.) was added to 66.60 g of propylene glycol monomethyl ether for dissolution. After nitrogen substitution in the reaction vessel, the reaction was carried out at 110° C. for 24 hours to obtain a polymer solution. GPC analysis was performed, and the result showed that the obtained polymer had a weight average molecular weight of 2500 in terms of standard polystyrene and a dispersity of 2.2. The structure present in polymer 3 is shown in the following formula.

[0122]

[0123] <Synthesis example 4>

[0124] Regarding polymer 4, 7.88 g of N,N-diglycidyl-5,5-dimethylhydantoin (manufactured by Shikoku Chemical Industry Co., Ltd.), 5.07 g of monoallyl isocyanuric acid (manufactured by Shikoku Chemical Industry Co., Ltd.), 1.73 g of cyclohexane-1-carboxylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and ethyltriphenylphosphine bromide were mixed. 0.63 g of (Tokyo Chemical Industry Co., Ltd.) was added to 66.60 g of propylene glycol monomethyl ether for dissolution. After nitrogen substitution in the reaction vessel, the reaction was carried out at 110° C. for 24 hours to obtain a polymer solution. GPC analysis was performed, and the result showed that the obtained polymer had a weight average molecular weight of 2500 in terms of standard polystyrene and a dispersity of 2.2. The structure present in polymer 4 is shown in the following formula.

[0125]

[0126] <Synthesis example 5>

[0127] Regarding polymer 5, 7.73 g of N,N-diglycidyl-5,5-dimethylhydantoin (manufactured by Shikoku Chemical Industry Co., Ltd.), 4.94 g of monoallyl isocyanuric acid (manufactured by Shikoku Chemical Industry Co., Ltd.), 1.71 g of 7-oxabicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.), and ethyltriphenylphosphine bromide were mixed. 0.64 g of (Tokyo Chemical Industry Co., Ltd.) was added to 66.60 g of propylene glycol monomethyl ether for dissolution. After nitrogen substitution in the reaction vessel, the reaction was carried out at 110° C. for 24 hours to obtain a polymer solution. GPC analysis was performed, and the result showed that the obtained polymer had a weight average molecular weight of 2500 in terms of standard polystyrene and a dispersity of 2.0. The structure present in polymer 5 is shown in the following formula.

[0128]

[0129] <Synthesis example 6>

[0130] Regarding polymer 6, 7.20 g of N,N-diglycidyl-5,5-dimethylhydantoin (manufactured by Shikoku Chemical Industry Co., Ltd.), 4.95 g of 5-hydroxyisophthalic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 1.33 g of 5-norbornene-2-carboxylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and ethyltriphenylphosphine bromide were mixed. 0.54 g of propylene glycol monomethyl ether (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to 39.19 g of propylene glycol monomethyl ether and dissolved. After replacing the reaction container with nitrogen, the reaction was carried out at 110°C for 24 hours to obtain a polymer solution. GPC analysis was performed, and the result showed that the obtained polymer had a weight average molecular weight of 2500 in terms of standard polystyrene and a dispersion degree of 2.2.

[0131] The structure present in the polymer 6 is shown in the following formula.

[0132]

[0133] <Synthesis Example 7>

[0134] Regarding polymer 7, 25.00 g of monoallyl diglycidyl isocyanuric acid (manufactured by Shikoku Chemical Industry Co., Ltd.), 14.72 g of diethylbarbituric acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 2.91 g of 5-norbornene-2,3-dicarboxylic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) and ethyltriphenylphosphine bromide were mixed. 1.64 g of (Tokyo Chemical Industry Co., Ltd.) was added to 89.73 g of propylene glycol monomethyl ether for dissolution. After nitrogen substitution in the reaction vessel, the reaction was carried out at 110° C. for 24 hours to obtain a polymer solution. GPC analysis was performed, and the result showed that the obtained polymer had a weight average molecular weight of 3000 in terms of standard polystyrene and a dispersity of 2.3. The structure present in polymer 7 is shown in the following formula.

[0135]

[0136] <Synthesis example 8>

[0137] Regarding polymer 8, 25.00 g of monoallyl diglycidyl isocyanuric acid (manufactured by Shikoku Chemical Industry Co., Ltd.), 15.86 g of dithiodipropionic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 4.80 g of adamantane carboxylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) and tetrabutyl bromide were mixed. 1.13 g of (Tokyo Chemical Industry Co., Ltd.) was added to 57.12 g of propylene glycol monomethyl ether for dissolution. After nitrogen substitution in the reaction vessel, the reaction was carried out at 110° C. for 24 hours to obtain a polymer solution. GPC analysis was performed, and the result showed that the obtained polymer had a weight average molecular weight of 5000 in terms of standard polystyrene and a dispersity of 2.3. The structure present in polymer 8 is shown in the following formula.

[0138]

[0139] <Synthesis Example 9>

[0140] Regarding polymer 9, 25.00 g of monoallyl diglycidyl isocyanuric acid (manufactured by Shikoku Chemical Industry Co., Ltd.), 15.86 g of dithiodipropionic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 3.68 g of 5-norbornene-2-carboxylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) and tetrabutyl bromide were mixed. 1.13 g of propylene glycol monomethyl ether (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to 57.12 g of propylene glycol monomethyl ether and dissolved. After replacing the reaction container with nitrogen, the reaction was carried out at 110°C for 24 hours to obtain a polymer solution. GPC analysis was performed, and the result showed that the obtained polymer had a weight average molecular weight of 5000 in terms of standard polystyrene and a dispersion degree of 2.5.

[0141] The structure present in the polymer 9 is shown in the following formula.

[0142]

[0143] <Comparative Synthesis Example 1>

[0144] Regarding polymer 10, 21.90 g of monoallyl diglycidyl isocyanuric acid (manufactured by Shikoku Chemical Industry Co., Ltd.), 12.17 g of diethylbarbituric acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 4.67 g of lauric acid (manufactured by Tokyo Chemical Industry Co., Ltd.) and ethyltriphenylphosphine bromide were mixed. (Tokyo Chemical Industry Co., Ltd.) 0.56 g was added to 89.73 g of propylene glycol monomethyl ether for dissolution. After nitrogen substitution in the reaction vessel, the reaction was carried out at 110°C for 24 hours to obtain a polymer solution. GPC analysis was performed, and the result showed that the obtained polymer had a weight average molecular weight of 3000 in terms of standard polystyrene and a dispersity of 2.2. The structure present in polymer 10 is shown in the following formula.

[0145]

[0146] <Comparative Synthesis Example 2>

[0147] Regarding polymer 11, 25.00 g of monoallyl diglycidyl isocyanuric acid (manufactured by Shikoku Chemical Industry Co., Ltd.), 15.86 g of dithiodipropionic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and tetrabutyl bromide were mixed. 1.13 g of (Tokyo Chemical Industry Co., Ltd.) was added to 57.12 g of propylene glycol monomethyl ether for dissolution. After nitrogen substitution in the reaction vessel, the reaction was carried out at 110° C. for 24 hours to obtain a polymer solution. GPC analysis was performed, and the result showed that the obtained polymer had a weight average molecular weight of 5000 in terms of standard polystyrene and a dispersity of 4.3. The structure present in polymer 11 is shown in the following formula.

[0148]

[0149] (Preparation of Resist Underlayer Film)

[0150] (Example 1)

[0151] The above-mentioned Synthesis Examples 1 to 9, Comparative Synthesis Examples 1 to 2, polymers, crosslinking agents, curing catalysts, and solvents were mixed in the ratios shown in Table 1 and filtered through a 0.1 μm fluororesin filter to prepare solutions of resist underlayer film-forming compositions.

[0152] In Table 1, tetramethoxymethyl glycoluril (manufactured by Nippon Science Instruments Co., Ltd.) is abbreviated as PL-LI, and pyridine -PyPTS is abbreviated as p-toluenesulfonic acid. -PyPSA is abbreviated to p-hydroxybenzenesulfonic acid, PGMEA is abbreviated to propylene glycol monomethyl ether acetate, and PGME is abbreviated to propylene glycol monomethyl ether. The amounts added are expressed in parts by mass.

[0153] [Table 1]

[0154] Table 1

[0155]

[0156] [Table 2]

[0157] Table 2

[0158]

[0159] (Dissolution test into photoresist solvent)

[0160] The resist underlayer film-forming compositions of Examples 1 to 11, Comparative Examples 1 and 2 were applied to 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 5 nm. The resist underlayer films were immersed in a mixed solution of propylene glycol monomethyl ether / propylene glycol monomethyl ether = 70 / 30 as a solvent used for photoresists. The following cases are set to good. The above cases were regarded as failures, and the results are shown in Table 3. Only Comparative Example 1 was failure.

[0161] (Measurement of water contact angle)

[0162] The resist underlayer film-forming compositions of Examples 1 to 11, Comparative Examples 1 and 2 were applied to 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 5 nm. The contact angle of water was measured using a fully automatic contact angle meter DM-701 (manufactured by Kyowa Interface Science Co., Ltd.) using a droplet method.

[0163] [Table 3]

[0164] Table 3

[0165]

[0166] (Resist Pattern Formation Evaluation)

[0167] [Formation of resist pattern using KrF exposure]

[0168] DUV-30J (manufactured by Nissan Chemical Co., Ltd.) was applied as an anti-reflective 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 underlayer film of Examples 1 to 6, Example 8, and Comparative Examples 1 to 2 were respectively applied on the silicon wafer using a spin coater. The silicon wafer was baked on a hot plate at 205°C for 60 seconds to obtain an underlayer film of resist with a thickness of 5 nm. SEPR-430 (manufactured by Shin-Etsu Chemical Co., Ltd.), a positive resist solution for KrF excimer laser, was spin-coated on the underlayer film of resist (manufactured by Nikon Co., Ltd., NSR S205C), and a KrF resist film was formed. The resist film was exposed under specified conditions using an exposure device for KrF excimer laser (manufactured by Nikon Co., Ltd., NSR S205C). After exposure, post-exposure heating was performed at 110° C. for 60 seconds, and then paddle development was performed for 60 seconds using a 2.38% tetramethylammonium hydroxide aqueous solution (manufactured by Tokyo Ohka Kogyo Co., Ltd., trade name NMD-3) as a photoresist developer. The obtained photoresist pattern was evaluated as good if no significant pattern peeling occurred.

[0169] [Table 4]

[0170] Table 4

[0171]

[0172] 〔EUV exposure test〕

[0173] The resist underlayer film forming composition of Example 9, Example 10 and Comparative Example 2 of the present invention was spin-coated on a silicon wafer and heated at 215°C for 1 minute to form a resist underlayer film (film thickness 5 nm). An EUV resist solution (methacrylate resin resist) 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 (manufactured by ASML, NXE3300). After exposure, post-exposure heating (PEB, 100°C for 60 seconds) was performed, and the film was cooled to room temperature on a cooling plate, and alkali development and rinsing were performed to form a resist pattern on the silicon wafer. Evaluation was performed by whether a 16nm line and space (L / S) could be formed. In all cases of Example 9, Example 10 and Comparative Example 2, 16nm L / S pattern formation was confirmed. In addition, the exposure amount for forming 16nm line / 32nm spacing (line and space (L / S=1 / 1) is set as the optimal exposure amount, and the exposure amount (EOP) at this time is shown. The roughness of the line width (LWR) at this time is further shown in Table 5. Compared with Comparative Example 2, an improvement in LWR was observed in Examples 9 and 10.

[0174] [Table 5]

[0175] Table 5

[0176]

[0177] 〔EUV exposure test〕

[0178] The resist underlayer film-forming composition of Example 1 of the present invention was spin-coated on a silicon wafer and heated at 215° C. for 1 minute to form a resist underlayer film (film thickness 5 nm). Further, an EUV resist solution (methacrylate resin resist) was spin-coated thereon and heated at 130° C. for 1 minute to form an EUV resist film, and an EUV exposure device (NXE3300B) manufactured by ASML was used to expose the film under the conditions of NA=0.33, Dipole. After exposure, post-exposure heating (PEB, 110° C. for 1 minute) was performed, and the film was cooled to room temperature on a cooling plate, developed for 60 seconds using an organic solvent developer (butyl acetate), and rinsed to form a resist pattern.

[0179] In the same procedure, the compositions obtained in Examples 3, 6 to 8, and Comparative Example 2 were used to form resist patterns.

[0180] Regarding the evaluation, the pattern shape was confirmed by pattern cross-section observation to evaluate whether a line and space with a pitch of 44 nm and a length of 22 nm could be formed.

[0181] In the observation of the pattern shape, the shape between the footing and the undercut and the state without significant residue in the gap portion was evaluated as "good", the undesirable state that the resist pattern peeled off and collapsed was evaluated as "collapse", and the undesirable state that the upper or lower parts of the resist pattern contacted each other was evaluated as "bridge". The obtained results are shown in Table 6.

[0182] [Table 6]

[0183] Table 6

[0184]

[0185] Industrial Availability

[0186] 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 method for producing a substrate with a resist pattern and a method for producing a semiconductor device using the resist underlayer film forming composition.

Claims

1. A composition for forming a resist underlayer film, comprising a polymer having an aliphatic ring at a terminal, wherein the carbon-carbon bond of the aliphatic ring may be interrupted by a heteroatom and the aliphatic ring may be substituted by a substituent, and further comprising an organic solvent, The polymer has at least one structural unit represented by the following formula (3) in the main chain, In formula (3), A1, A2, A3, A4, A5 and A6 each independently represent a hydrogen atom, a methyl group or an ethyl group, Q1 represents a divalent organic group, m1 and m2 each independently represent 0 or 1, The weight ratio of the total of the monomers forming the structural unit represented by the above formula (3) in which m1 and m2 are 1 and the monomers forming the structural unit represented by the above formula (3) in which m1 and m2 are 0 to the monomer for deriving the aliphatic ring is 20:1 to 5:1, The monomer used to derive the aliphatic ring bonded to the terminal of the polymer is selected from the compounds of the following formula:

2. The resist underlayer film forming composition according to claim 1, wherein in the formula (3), Q1 represents a divalent organic group represented by the following formula (5), In the formula, Y represents a divalent group represented by the following formula (6) or formula (7); In the formula, R6 and R7 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 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 and an alkylthio group having 1 to 6 carbon atoms, or R6 and R7 may be combined with each other to form a ring having 3 to 6 carbon atoms together with the carbon atoms to which R6 and R7 are combined. 3 . The resist underlayer film-forming composition according to claim 1 , wherein the polymer further contains a disulfide bond in a main chain. The resist underlayer film-forming composition according to claim 1 , further comprising a curing catalyst. The resist underlayer film-forming composition according to claim 1 , further comprising a cross-linking agent.

6. 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 5.

7. A method for manufacturing a patterned substrate, comprising the following steps: a step of coating a resist underlayer film-forming composition as described in any one of claims 1 to 5 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.

8. 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 5 on a semiconductor substrate; forming a resist film on the resist underlayer film; A process of forming a resist pattern by irradiating the resist film with light or electron beams and then developing the resist film; a step of etching the resist underlayer film through the formed resist pattern to form a patterned resist underlayer film; and A step of processing a semiconductor substrate using the patterned resist underlayer film.

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