Composition for forming resist underlayer film

Abstract

Disclosed is a composition for forming a resist underlayer film, the composition containing a resin (A) that has a hydroxy group bonded to an aromatic ring and at least one of a bromo group and an iodo group, and a solvent (B), wherein the resin (A) has a structural unit that is represented by formula (A-1). (In formula (A-1), R1 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R2 represents an optionally substituted alkyl group having 1 to 3 carbon atoms, an optionally substituted alkoxy group having 1 to 3 carbon atoms, a fluorine atom, or a chlorine atom, X represents a bromine atom or an iodine atom, and Ar1 represents a benzene ring or a naphthalene ring. p represents an integer of 0-4, q represents an integer of 1-4, and r represents an integer of 0-4.)

Description

Composition for forming a resist underlayer film

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

[0002] Conventionally, microfabrication using lithography with resist compositions has been performed in the manufacturing of semiconductor devices. This microfabrication method involves forming a thin film of a photoresist composition on a semiconductor substrate such as a silicon wafer, irradiating it with an active light such as ultraviolet light through a mask pattern on which the device pattern is drawn, developing the film, and then etching the substrate using the resulting photoresist pattern as a protective film, thereby forming fine irregularities on the substrate surface corresponding to the photoresist pattern. In recent years, with the increasing integration density of semiconductor devices, the active light used has also evolved. In addition to the conventionally used i-line (wavelength 365 nm), KrF excimer laser (wavelength 248 nm), and ArF excimer laser (wavelength 193 nm), the practical application of EUV light (wavelength 13.5 nm) or EB (electron beam) is being considered for cutting-edge microfabrication. Consequently, poor resist pattern formation due to influence from the semiconductor substrate has become a major problem. Therefore, in order to solve this problem, methods of providing a resist underlayer film between the resist and the semiconductor substrate are being widely investigated.

[0003] Patent Document 1 discloses a lithography underlayer film forming composition containing a naphthalene ring having a halogen atom. Patent Document 2 discloses a halogenated anti-reflective film. Patent Document 3 discloses a resist underlayer film forming composition.

[0004] International Publication No. 2006 / 003850, JP 2005-526270, International Publication No. 2020 / 111068

[0005] The properties required of a resist underlayer include, for example, that it does not intermix with the resist film formed on top (i.e., it is insoluble in the resist solvent), that it can form resist patterns with high sensitivity, and that it has a fast etching rate. The present invention has been made in view of the above circumstances, and aims to provide a resist underlayer film formation composition that can form a resist underlayer film that can form resist patterns with high sensitivity and has a fast etching rate, as well as a method for manufacturing a resist underlayer film, a laminate, a semiconductor device, and a pattern formation method using the resist underlayer film formation composition.

[0006] The inventors of the present invention conducted diligent research to solve the above problems and, as a result, found that they could solve the above problems, and completed the present invention having the following gist.

[0007] In other words, the present invention encompasses the following aspects: [1] A resist underlayer film forming composition comprising a resin (A) having a hydroxyl group bonded to an aromatic ring and at least one of a bromo group and an iodine group, and a solvent (B), wherein the resin (A) is a resin having a structural unit represented by the following formula (A-1). (In formula (A-1), R １ R represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. ２ represents an optionally substituted alkyl group having 1 to 3 carbon atoms, an optionally substituted alkoxy group having 1 to 3 carbon atoms, a fluorine atom, or a chlorine atom, X represents a bromine atom or an iodine atom, and Ar １(where p represents a benzene ring or a naphthalene ring, p represents an integer from 0 to 4, q represents an integer from 1 to 4, and r represents an integer from 0 to 4.) [2] The resist underlayer film forming composition according to [1], wherein the resin (A) is a polymer of an aromatic compound having a vinyl group. [3] The resist underlayer film forming composition according to [1] or [2], wherein the solvent (B) comprises at least one selected from the group consisting of a carboxylic acid having a hydroxyl group, a linear or cyclic alkyl ketone, a cyclic lactone, an alkylene glycol monoalkyl ether, a monocarboxylic acid ester of an alkylene glycol monoalkyl ether, and an alkoxycarboxylic acid ester of an alkylene glycol monoalkyl ether. [4] The resist underlayer film forming composition according to any one of [1] to [3], further comprising a crosslinking agent (C). [5] The resist underlayer film forming composition according to [4], wherein the crosslinking agent (C) is at least one selected from the group consisting of an aminoplast crosslinking agent and a phenoplast crosslinking agent. [6] A resist underlayer film forming composition according to any one of [1] to [5], further comprising a curing catalyst (D). [7] A resist underlayer film forming composition according to any one of [1] to [6], used in an EUV (extreme ultraviolet) exposure process. [8] A resist underlayer film, which is a cured product of the resist underlayer film forming composition according to any one of [1] to [7]. [9] A laminate comprising a semiconductor substrate and the resist underlayer film according to [8].

[10] A method for manufacturing a semiconductor device, comprising the steps of: forming a resist underlayer film on a semiconductor substrate using the resist underlayer film forming composition according to any one of [1] to [7]; and forming a resist film on the resist underlayer film.

[11] A pattern formation method comprising: forming a resist underlayer film on a semiconductor substrate using a resist underlayer film forming composition according to any one of [1] to [7]; forming a resist film on the resist underlayer film; irradiating the resist film with light or an electron beam, then developing the resist film to obtain a resist pattern; and etching the resist underlayer film using the resist pattern as a mask.

[0008] According to the present invention, there can be provided a composition for forming a resist underlayer film capable of forming a resist pattern with high sensitivity and forming a resist underlayer film having a high etching rate, and a method for manufacturing a resist underlayer film, a laminate, a semiconductor element, and a pattern forming method using the composition for forming a resist underlayer film.

[0009] (Composition for forming a resist underlayer film) The composition for forming a resist underlayer film of the present invention contains a resin (A) and a solvent (B). The composition for forming a resist underlayer film may contain a crosslinking agent (C), a curing catalyst (D), and the like.

[0010] By including the resin (A) in the composition for forming a resist underlayer film, the etching rate of the resist underlayer film formed from the composition for forming a resist underlayer film can be increased.

[0011] <Resin (A)> The resin (A) has a hydroxy group bonded to an aromatic ring. The resin (A) has at least one of a bromo group and an iodo group. The resin (A) is a resin having a structural unit represented by the following formula (A-1). At least one of the bromo group and the iodo group may be included in the structural unit represented by the formula (A-1) or may be included in another structural unit.

[0012] (In the formula (A-1), R １ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ２ represents an optionally substituted alkyl group having 1 to 3 carbon atoms, an optionally substituted alkoxy group having 1 to 3 carbon atoms, a fluorine atom or a chlorine atom, X represents a bromine atom or an iodine atom, and Ar １ represents a benzene ring or a naphthalene ring. p represents an integer of 0 to 4, q represents an integer of 1 to 4, and r represents an integer of 0 to 4.)

[0013] In the formula (A-1), R １ is preferably a hydrogen atom or a methyl group. In the formula (A-1), R ２ is preferably an alkoxy group having 1 to 3 carbon atoms, more preferably a methoxy group or an ethoxy group. In the formula (A-1), X is preferably an iodine atom. In the formula (A-1), Ar １A benzene ring is preferred. In formula (A-1), p is preferably 1 to 2. In formula (A-1), q is preferably 1 to 2. In formula (A-1), r is preferably 0 to 1.

[0014] In formula (A-1), R ２ In this context, "may be substituted" means that at least one hydrogen atom of an alkyl group having 1 to 3 carbon atoms or an alkoxy group having 1 to 3 carbon atoms may be substituted by a substituent. Examples of such substituents include halogen atoms, nitro groups, cyano groups, amino groups, hydroxyl groups, and carboxyl groups. Here, examples of halogen atoms include fluorine atoms, chlorine atoms, and bromine atoms.

[0015] Examples of structural units represented by formula (A-1) include the structural unit represented by the following formula (A-1-1) and the structural unit represented by the following formula (A-1-2). The resin (A) may be a resin having both or either of the structural units represented by the following formula (A-1-1) and the structural unit represented by the following formula (A-1-2). (In formula (A-1-1) to formula (A-1-2), R １ R represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. ２ represents an optionally substituted alkyl group having 1 to 3 carbon atoms, an optionally substituted alkoxy group having 1 to 3 carbon atoms, a fluorine atom, or a chlorine atom, X represents a bromine atom or an iodine atom, and Ar １ (where p represents a benzene ring or a naphthalene ring, q represents an integer from 1 to 4, and r represents an integer from 0 to 4.)

[0016] In formulas (A-1-1) to (A-1-2), R １ A hydrogen atom or a methyl group is preferred. In formulas (A-1-1) to (A-1-2), R ２ The group is preferably an alkoxy group having 1 to 3 carbon atoms, and more preferably a methoxy group or an ethoxy group. In formula (A-1-1), X is preferably an iodine atom. In formulas (A-1-1) to (A-1-2), Ar １A benzene ring is preferred. In formula (A-1-1), p is preferably 1 to 2. In formulas (A-1-1) to (A-1-2), q is preferably 1 to 2. In formulas (A-1-1) to (A-1-2), r is preferably 0 to 1.

[0017] Resin (A) may be a homopolymer having one type of structural unit, or a copolymer having two or more types of structural units. Resin (A) may be a polymer having only the structural unit represented by formula (A-1). Resin (A) may be a polymer having only the structural unit represented by formula (A-1-1), or a polymer having the structural unit represented by formula (A-1-1) and the structural unit represented by formula (A-1-2). If resin (A) does not have the structural unit represented by formula (A-1-1), then resin (A) has the structural unit represented by formula (A-1-2). In this case, resin (A) is a copolymer having the structural unit represented by formula (A-1-2) and other structural units, and the copolymer has at least one of a bromo group and an iodine group at any position of the other structural units.

[0018] The following are specific examples of structural units represented by formula (A-1-1), but are not limited to these.

[0019] Specific examples of structural units represented by formula (A-1-2) are given, but are not limited to these.

[0020] Resin (A) is obtained, for example, by radical polymerization of a monomer containing an aromatic compound having a vinyl group (aromatic monomer) that gives a structural unit represented by formula (A-1). In this case, it is preferable to protect the hydroxyl group of the aromatic monomer with a protecting group such as an acetoxy group. After radical polymerization, a polymer in which a hydroxyl group is bonded to the aromatic ring is obtained by deprotecting the protecting group with an alkali such as sodium hydroxide. Thus, it is preferable that resin (A) is a polymer of an aromatic compound having a vinyl group.

[0021] The proportion of structural units represented by formula (A-1) in resin (A) is not particularly limited, but the molar ratio of structural units represented by formula (A-1) to the total structural units of resin (A) may be, for example, 5 mol% or more and 100 mol% or less, or 5 mol% or more and less than 100 mol%.

[0022] The proportion of structural units represented by formula (A-1-1) in resin (A) is not particularly limited, but the molar ratio of structural units represented by formula (A-1-1) to the total structural units of resin (A) may be, for example, 5 mol% or more and 100 mol% or less, or 5 mol% or more and less than 100 mol%.

[0023] The total ratio of structural units represented by formula (A-1-1) and structural units represented by formula (A-1-2) in resin (A) is not particularly limited, however, the molar ratio of the total structural units represented by formula (A-1-1) and structural units represented by formula (A-1-2) to the total structural units of resin (A) may be, for example, 5 mol% or more and 100 mol% or less, or 5 mol% or more and less than 100 mol%.

[0024] In the case where resin (A) is a copolymer of structural units represented by formula (A-1-1) and structural units represented by formula (A-1-2), the molar ratio ((A-1-1m):(A-1-2m)) of monomer (A-1-1m) that gives structural units represented by formula (A-1-1) and monomer (A-1-2m) that gives structural units represented by formula (A-1-2) is preferably 20:80 to 80:20, and more preferably 40:60 to 60:40, from the viewpoint of suitably obtaining the effects of the present invention.

[0025] The resin (A) may contain structural units other than the structural unit represented by formula (A-1). In that case, the molar ratio of the other structural units to the total structural units of the resin (A) is preferably, for example, greater than 0 mol% and 90 mol% or less, greater than 0 mol% and 80 mol% or less, greater than 0 mol% and 70 mol% or less, greater than 0 mol% and 60 mol% or less, greater than 0 mol% and 50 mol% or less, greater than 0 mol% and 40 mol% or less, greater than 0 mol% and 30 mol% or less, greater than 0 mol% and 20 mol% or less, greater than 0 mol% and 10 mol% or less, greater than 0 mol% and 5 mol% or less, or greater than 0 mol% and 1 mol% or less.

[0026] The molecular weight of resin (A) is not particularly limited. The lower limit of the weight-average molecular weight (Mw) of resin (A) is, for example, 500, 1,000, 2,000, or 3,000. The upper limit of the weight-average molecular weight of resin (A) is, for example, 100,000, 50,000, 30,000, 20,000, or 10,000. In this specification, the weight-average molecular weight (Mw) is the polystyrene equivalent value measured by gel permeation chromatography (GPC).

[0027] The degree of dispersion of resin (A) is not particularly limited. The degree of dispersion (Mw / Mn) of resin (A) is preferably 1.0 to 10, more preferably 1.1 to 6.0, and even more preferably 1.2 to 4.0. The degree of dispersion of resin (A) can be determined, for example, by GPC.

[0028] The content of resin (A) in the resist underlayer film forming composition is not particularly limited, but from the viewpoint of suitably obtaining the effects of the present invention, it is preferably 40% to 99% by mass, more preferably 45% to 95% by mass, and particularly preferably 50% to 90% by mass, relative to the film constituent components. In this invention, film constituent components refer to components other than the solvent contained in the composition.

[0029] <Solvent (B)> Examples of solvent (B) include carboxylic acids having a hydroxyl group, linear or cyclic alkyl ketones, cyclic lactones, alkylene glycol alkyl ethers, alkylene glycol monoalkyl ether carboxylic acid esters (monocarboxylic acid esters of alkylene glycol monoalkyl ethers, and alkoxycarboxylic acid esters of alkylene glycol monoalkyl ethers). These solvents (B) can be used alone or in combination of two or more.

[0030] Examples of carboxylic acids having a hydroxyl group include ethyl lactate, propyl lactate, isopropyl lactate, butyl lactate, isobutyl lactate, ethyl hydroxyethyl acetate, ethyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxypropionate, and methyl 2-hydroxy-3-methylbutyrate.

[0031] An example of a cyclic lactone is γ-butyrolactone.

[0032] Examples of alkylene glycol alkyl ethers include alkylene glycol monoalkyl ethers and alkylene glycol dialkyl ethers. Examples of alkylene glycol monoalkyl ethers include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether (1-methoxy-2-propanol), propylene glycol monoethyl ether (1-ethoxy-2-propanol), methyl isobutylcarbinol, and propylene glycol monobutyl ether. Examples of alkylene glycol dialkyl ethers include diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dipropyl ether, and propylene glycol dibutyl ether.

[0033] Examples of alkylene glycol monoalkyl ether carboxylic acid esters include monocarboxylic acid esters of alkylene glycol monoalkyl ethers and alkoxycarboxylic acid esters of alkylene glycol monoalkyl ethers. Examples of monocarboxylic acid esters of alkylene glycol monoalkyl ethers include alkylene glycol monoalkyl ether acetates. Examples of alkylene glycol monoalkyl ether acetates include methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate (1-methoxy-2-propanol monoacetate), propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, and ethylene glycol monobutyl ether acetate. Examples of alkoxycarboxylic acid esters of alkylene glycol monoalkyl ethers include 2-methoxyethyl methyl carbonate, 2-ethoxyethyl methyl carbonate, 2-ethoxyethyl ethyl carbonate, and 2-propoxyethyl methyl carbonate.

[0034] The content of solvent (B) in the resist underlayer film forming composition is not particularly limited, but is preferably 50% to 99.99% by mass, more preferably 75% to 99.95% by mass, and particularly preferably 90% to 99.9% by mass.

[0035] <Crosslinking agent (C)> There are no particular restrictions on the crosslinking agent (C). The crosslinking agent (C) has a different structure from the resin (A).

[0036] As the crosslinking agent (C), aminoplast crosslinking agents and phenoplast crosslinking agents are preferred. Aminoplast crosslinking agents are addition condensates of a compound having an amino group, such as melamine or guanamine, and formaldehyde. Phenoplast crosslinking agents are addition condensates of a compound having a phenolic hydroxyl group and formaldehyde.

[0037] Examples of crosslinking agents (C) include compounds having two or more of the following structures. (In the structure, R １０１ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxyalkyl group having 2 to 6 carbon atoms. * represents a bond. The bond is, for example, attached to a nitrogen atom or a carbon atom constituting an aromatic hydrocarbon ring.

[0038] R １０１ Preferably, the group is a hydrogen atom, a methyl group, an ethyl group, or a group represented by the following structure. (In the structure, R １０２ represents a hydrogen atom, a methyl group, or an ethyl group. * represents a bonding bond.

[0039] Preferred crosslinking agents (C) include melamine compounds, guanamine compounds, glycoluryl compounds, urea compounds, and compounds having a phenolic hydroxyl group. These can be used individually or in combination of two or more.

[0040] Examples of melamine compounds include hexamethylmelamine, hexamethoxymethylmelamine, compounds in which 1 to 6 methylol groups of hexamethylmelamine are methoxymethylated or mixtures thereof, hexamethoxyethylmelamine, hexaacyloxymethylmelamine, compounds in which 1 to 6 methylol groups of hexamethylmelamine are acyloxymethylated or mixtures thereof.

[0041] Examples of guanamine compounds include tetramethylolguanamine, tetramethoxymethylguanamine, compounds in which one to four methylol groups of tetramethylolguanamine are methoxymethylated or mixtures thereof, tetramethoxyethylguanamine, tetraacyloxyguanamine, compounds in which one to four methylol groups of tetramethylolguanamine are acyloxymethylated or mixtures thereof.

[0042] Examples of glycoluryl compounds include tetramethylol glycoluryl, tetramethoxy glycoluryl, tetramethoxymethyl glycoluryl, compounds in which 1 to 4 methylol groups of tetramethylol glycoluryl are methoxymethylated or mixtures thereof, and compounds in which 1 to 4 methylol groups of tetramethylol glycoluryl are acyloxymethylated or mixtures thereof.

[0043] Furthermore, the glycoluryl compound may also be, for example, a glycoluryl derivative represented by the following formula (1E). (In equation (1E), four R １ Each of these independently represents either a methyl group or an ethyl group, R ２ and R ３ Each of these independently represents a hydrogen atom, an alkyl group with 1 to 4 carbon atoms, or a phenyl group.

[0044] Examples of glycoluryl derivatives represented by formula (1E) include compounds represented by the following formulas (1E-1) to (1E-6).

[0045] A glycoluryl derivative represented by formula (1E) can be obtained, for example, by reacting a glycoluryl derivative represented by the following formula (2E) with at least one compound represented by the following formula (3d).

[0046] (In formula (2E), R ２ and R ３ Each of these independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group, R ４ Each of these independently represents an alkyl group having 1 to 4 carbon atoms.

[0047] (In formula (3d), R １ (This represents a methyl group or an ethyl group.)

[0048] Examples of glycoluryl derivatives represented by formula (2E) include the compounds represented by formulas (2E-1) to (2E-4) below. Furthermore, examples of compounds represented by formula (3d) include the compounds represented by formulas (3d-1) and (3d-2) below.

[0049] Examples of urea compounds include tetramethylolurea, tetramethoxymethylurea, compounds in which one to four methylol groups of tetramethylolurea are methoxymethylated or mixtures thereof, and tetramethoxyethylurea.

[0050] Examples of compounds having a phenolic hydroxyl group include compounds represented by the following formulas (G-1) or (G-2). (In equations (G-1) and (G-2), Q １ R indicates a single bond or an m1-valent organic group. １ and R ４ Each of these represents an alkyl group having 2 to 10 carbon atoms, or an alkyl group having 2 to 10 carbon atoms and an alkoxy group having 1 to 10 carbon atoms. ２ and R ５ Each represents either a hydrogen atom or a methyl group. ３ and R ６ Each of these represents an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 40 carbon atoms. １ is 1 ≤ n １ n is an integer ≤ 3. ２ is 2 ≤ n ２ An integer n ≤ 5 ３ is 0 ≤ n ３ n is an integer ≤ 3. ４ is 0 ≤ n ４ integers ≤ 3, 3 ≤ (n １ +n ２ +n ３ +n ４ This shows integers n ≤ 6. ５ is 1 ≤ n ５n is an integer ≤ 3. ６ is 1 ≤ n ６ An integer n ≤ 4 ７ is 0 ≤ n ７ n is an integer ≤ 3. ８ is 0 ≤ n ８ integers ≤ 3, 2 ≤ (n ５ +n ６ +n ７ +n ８ (This represents an integer between 5 and 2. m1 represents an integer between 2 and 10.)

[0051] Furthermore, examples of compounds having a phenolic hydroxyl group include compounds represented by the following formulas (G-3) or (G-4). Compounds represented by formulas (G-1) or (G-2) may be obtained by reacting a compound represented by the following formula (G-3) or (G-4) with a hydroxyl group-containing ether compound or an alcohol having 2 to 10 carbon atoms. (In equations (G-3) and (G-4), Q ２ R indicates a single bond or an m2 valent organic group. ８ , R ９ , R １１ and R １２ Each represents either a hydrogen atom or a methyl group. ７ and R １０ Each of these represents an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 40 carbon atoms. ９ is 1 ≤ n ９ n is an integer ≤ 3. １０ is 2 ≤ n １０ An integer n ≤ 5 １１ is 0 ≤ n １１ n is an integer ≤ 3. １２ is 0 ≤ n １２ integers ≤ 3, 3 ≤ (n ９ +n １０ +n １１ +n １２ This shows integers n ≤ 6. １３ is 1 ≤ n １３ n is an integer ≤ 3. １４ is 1 ≤ n １４ An integer n ≤ 4 １５ is 0 ≤ n １５ n is an integer ≤ 3. １６ is 0 ≤ n １６ integers ≤ 3, 2 ≤ (n１３ +n １４ +n １５ +n １６ ) indicates an integer ≤ 5. m² indicates an integer from 2 to 10. ) Q ２ Examples of m2 valent organic groups in this context include m2 valent organic groups having 1 to 15 carbon atoms.

[0052] Examples of compounds represented by formula (G-1) or formula (G-2) include the following compounds.

[0053] Examples of compounds represented by formula (G-3) or formula (G-4) include the following compounds. Me represents a methyl group.

[0054] The above compounds can be obtained as products from Asahi Organic Chemicals Co., Ltd. and Honshu Chemical Industry Co., Ltd. Examples of such products include TMOM-BP and HMOM-TPPA, both trade names of Asahi Organic Chemicals Co., Ltd.

[0055] Among these, glycoluryl compounds are preferred, specifically tetramethylol glycoluryl, tetramethoxy glycoluryl, tetramethoxymethyl glycoluryl, compounds in which 1 to 4 methylol groups of tetramethylol glycoluryl are methoxymethylated or mixtures thereof, compounds in which 1 to 4 methylol groups of tetramethylol glycoluryl are acyloxymethylated or mixtures thereof, and tetramethoxymethyl glycoluryl is more preferred.

[0056] The molecular weight of the crosslinking agent (C) is not particularly limited, but it is preferably 1,000 or less.

[0057] The content of the crosslinking agent (C) in the resist underlayer film forming composition is not particularly limited, but is, for example, 1% to 70% by mass relative to the polymer, and preferably 5% to 60% by mass.

[0058] <Curing Catalyst (D)> The curing catalyst (D) included as an optional component in the resist underlayer film formation composition can be either a thermal acid generator or a photoacid generator, but it is preferable to use a thermal acid generator. Examples of thermal acid generating agents include sulfonic acid compounds and carboxylic acid compounds such as p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium-p-toluenesulfonate (pyridinium-p-toluenesulfonic acid), pyridinium phenolsulfonic acid, pyridinium-p-hydroxybenzenesulfonic acid (pyridinium salt of p-phenolsulfonic acid), pyridinium-trifluoromethanesulfonic acid, salicylic acid, camphorsulfonic acid, 5-sulfosalicylic acid, 4-chlorobenzenesulfonic acid, 4-hydroxybenzenesulfonic acid, benzenedisulfonic acid, 1-naphthalenesulfonic acid, citric acid, benzoic acid, hydroxybenzoic acid, N-methylmorpholine-p-toluenesulfonic acid, N-methylmorpholine-p-hydroxybenzenesulfonic acid, and N-methylmorpholine-5-sulfosalicylic acid.

[0059] Examples of photoacid generators include onium salt compounds, sulfonimide compounds, and disulfonyldiazomethane compounds.

[0060] Examples of iodonium salt compounds include iodonium salt compounds such as diphenyliodonium hexafluorophosphate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoron-butanesulfonate, diphenyliodonium perfluoron-octanesulfonate, diphenyliodonium camphorsulfonate, bis(4-tert-butylphenyl)iodonium camphorsulfonate and bis(4-tert-butylphenyl)iodonium trifluoromethanesulfonate, and sulfonium salt compounds such as triphenylsulfonium hexafluoroantimonate, triphenylsulfonium nonafluoron-butanesulfonate, triphenylsulfonium camphorsulfonate and triphenylsulfonium trifluoromethanesulfonate.

[0061] Examples of sulfonimide compounds include N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoron-butanesulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, and N-(trifluoromethanesulfonyloxy)naphthalimide.

[0062] Examples of disulfonyl diazomethane compounds include bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(2,4-dimethylbenzenesulfonyl)diazomethane, and methylsulfonyl-p-toluenesulfonyldiazomethane.

[0063] Only one type of curing catalyst (D) may be used, or two or more types may be used in combination.

[0064] When a curing catalyst (D) is used, the content of the curing catalyst (D) is, for example, 0.1% to 50% by mass, preferably 1% to 30% by mass, relative to the crosslinking agent (C).

[0065] <Other components> The resist underlayer film forming composition does not produce pinholes or striations, and surfactants can be added to further improve the coatability against surface unevenness.

[0066] Examples of surfactants include linear or branched alkylbenzenesulfonic acids (e.g., dodecylbenzenesulfonic acid), polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oleyl ether, polyoxyethylene alkylaryl ethers such as polyoxyethylene octylphenol ether and polyoxyethylene nonylphenol ether, polyoxyethylene / polyoxypropylene block copolymers, sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, and sorbitan tristearate, polyoxyethylene sorbitan monolaurate, and poly Nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters including oxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate, F-Top EF301, EF303, EF352 (manufactured by Tochem Products Co., Ltd., product names), Megafac F171, F173, Examples of fluorine-based surfactants include R-30, R-30N (manufactured by DIC Corporation, trade name), Florard FC430, FC431 (manufactured by Sumitomo 3M Co., Ltd., trade name), Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by AGC Inc., trade name), and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.). The amount of these surfactants added 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. These surfactants may be added individually or in combination of two or more types.

[0067] The solid content of the resist underlayer film forming composition of the present invention, i.e., the components excluding the solvent (B), is, for example, 0.01% to 10% by mass.

[0068] The resist underlayer film formation composition of this embodiment is preferable for use in EUV (extreme ultraviolet) exposure processes because it can form resist patterns with higher sensitivity.

[0069] (Resist Underlayer Film) The resist underlayer of the present invention is a cured product of the resist underlayer film forming composition described above. The resist underlayer film can be manufactured, for example, by coating the resist underlayer film forming composition described above onto a semiconductor substrate and firing it.

[0070] Examples of semiconductor substrates to which the resist underlayer film formation composition is applied include silicon wafers, germanium wafers, and compound semiconductor wafers such as gallium arsenide, indium phosphide, gallium nitride, indium nitride, and aluminum nitride.

[0071] When a semiconductor substrate with an inorganic film formed on its surface is used, the inorganic film is formed by, for example, ALD (atomic layer deposition), CVD (chemical vapor deposition), reactive sputtering, ion plating, vacuum deposition, or spin coating (spin-on-glass: SOG). Examples of the inorganic film include polysilicon films, silicon oxide films, silicon nitride films, BPSG (Boro-Phosphoric Acid Glass) films, titanium nitride films, titanium oxide nitride films, tungsten films, gallium nitride films, and gallium arsenide films.

[0072] The resist underlayer film forming composition of the present invention is applied to such a semiconductor substrate by an appropriate coating method such as a spinner or coater. Subsequently, the resist underlayer film is formed by baking using a heating means such as a hot plate. The baking conditions are appropriately selected from a bake temperature of 100°C to 400°C and a bake time of 0.3 minutes to 60 minutes. Preferably, the bake temperature is 120°C to 350°C and the bake time is 0.5 minutes to 30 minutes, and more preferably, the bake temperature is 150°C to 300°C and the bake time is 0.8 minutes to 10 minutes.

[0073] The thickness of the resist underlayer film can be, 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 (3 nm) to 0.05 μm (50 nm), 0.004 μm (4 nm) to 0.05 μm (50 nm), 0.005 μm (5 nm) to 0.05 μm (5 These are 0 nm), 0.003 μm (3 nm) to 0.03 μm (30 nm), 0.003 μm (3 nm) to 0.02 μm (20 nm), 0.005 μm (5 nm) to 0.02 μm (20 nm), 0.005 μm (5 nm) to 0.02 μm (20 nm), 0.003 μm (3 nm) to 0.01 μm (10 nm), 0.005 μm (5 nm) to 0.01 μm (10 nm), 0.003 μm (3 nm) to 0.006 μm (6 nm), or 0.005 μm (5 nm).

[0074] The method for measuring the film thickness of the resist underlayer in this specification is as follows: • Measurement device name: Ellipsometer-type film thickness measuring device RE-3100 (SCREEN Corporation) • SWE (single-wavelength ellipsometer) mode • Arithmetic mean of 8 points (for example, 8 points measured at 1 cm intervals in the wafer X direction)

[0075] (Laminate) The laminate of the present invention comprises a semiconductor substrate and a resist underlayer film of the present invention. Examples of the semiconductor substrate include the semiconductor substrate described above. The resist underlayer film is disposed on top of the semiconductor substrate, for example.

[0076] (Method for manufacturing semiconductor devices, method for forming patterns) The method for manufacturing semiconductor devices of the present invention includes at least the following steps: - A step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film forming composition of the present invention; and - A step of forming a resist film on the resist underlayer film.

[0077] The pattern formation method of the present invention includes at least the following steps: • A step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film formation composition of the present invention; • A step of forming a resist film on the resist underlayer film; • A step of irradiating the resist film with light or an electron beam, then developing the resist film to obtain a resist pattern; and • A step of etching the resist underlayer film using the resist pattern as a mask.

[0078] Typically, a resist layer is formed on top of a resist underlayer. The thickness of the resist layer can be, for example, 3,000 nm or less, 2,000 nm or less, 1,800 nm or less, 1,500 nm or less, or 1,000 nm or less. The lower limits are 100 nm, 80 nm, 50 nm, 30 nm, 20 nm, and 10 nm.

[0079] The resist film formed on the resist underlayer by a known method (e.g., coating and firing of a resist composition) is not particularly limited as long as it responds to light or electron beam (EB) used for irradiation. Both negative-type and positive-type photoresists can be used. In this specification, resists that respond to EB are also referred to as photoresists. Examples of photoresists include positive-type photoresists consisting of a novolac resin and 1,2-naphthoquinone diazide sulfonic acid ester, chemically amplified photoresists consisting of a binder having a group that decomposes with acid to increase the alkali dissolution rate and a photoacid generator, chemically amplified photoresists consisting of a low-molecular-weight compound that decomposes with acid to increase the alkali dissolution rate of the photoresist, an alkali-soluble binder and a photoacid generator, and chemically amplified photoresists consisting of a binder having a group that decomposes with acid to increase the alkali dissolution rate and a low-molecular-weight compound that decomposes with acid to increase the alkali dissolution rate of the photoresist and a photoacid generator, and resists containing metal elements. Examples include V146G (manufactured by JSR Corporation), APEX-E (manufactured by Cyprey Corporation), PAR710 (manufactured by Sumitomo Chemical Co., Ltd.), and AR2772 and SEPR430 (manufactured by Shin-Etsu Chemical Co., Ltd.). Additionally, examples include fluorine-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).

[0080] Also, WO2019 / 188595, WO2019 / 187881, WO2019 / 187803, WO2019 / 167737, WO2019 / 167725, WO2019 / 187445, WO2019 / 167419, WO2019 / 123842, WO2019 / 054282, WO2019 / 058945, WO2019 / 058890, WO2019 / 039290, WO2019 / 044259, WO2019 / 044231, WO2019 / 026549, WO2018 / 193954, WO201 9 / 172054, WO2019 / 021975, WO2018 / 230334, WO2018 / 194123, JP 2018-180525, WO2018 / 190088, JP 2018-070596, JP 2018-028090, JP 2016-153409, JP 2016-130240, JP 2016-108325, JP 2016-047920, JP 2016-035570, JP 2016-035567, JP 2016-035565, JP 2019-101417, JP 2019-117373, JP 2019-052294, JP 2019-008280, JP 2019-008279, JP 2019-003176, JP 2019-003175, JP 2018-197853, JP 2019-191298, JP 2019-061217, JP 2018-045152, JP 2018-022039, JP 2016-090441, JP 2015-10878, JP 2012-168279, JP 2012-022261, JP 2012-022258, JP 2011-043749, JP 2010-18 While so-called resist compositions and metal-containing resist compositions such as resist compositions, radiation-sensitive resin compositions, and high-resolution patterning compositions based on organometallic solutions described in JP 1857, JP 2010-128369, WO2018 / 031896, JP 2019-113855, WO2017 / 156388, WO2017 / 066319, JP 2018-41099, WO2016 / 065120, WO2015 / 026482, JP 2016-29498, JP 2011-253185, etc., can be used, they are not limited to these.

[0081] Examples of resist compositions include the following compositions.

[0082] A resin A having a repeating unit with an acid-decomposable group in which a polar group is protected by a protecting group that is eliminated by the action of an acid, and a photoactive or radiation-sensitive resin composition containing a compound represented by the following general formula (121).

[0083] In the general formula (121), m represents an integer of 1 to 6. R １ and R ２ each independently represents a fluorine atom or a perfluoroalkyl group. L １ represents -O-, -S-, -COO-, -SO ２ -, or -SO ３ -. L ２ represents an alkylene group which may have a substituent or a single bond. W １ represents a cyclic organic group which may have a substituent. M ＋ represents a cation.

[0084] A metal-containing film-forming composition for extreme ultraviolet or electron beam lithography, which contains a compound having a metal-oxygen covalent bond and a solvent, and the metal element constituting the above compound belongs to the 3rd to 7th periods of Groups 3 to 15 of the periodic table.

[0085] A radiation-sensitive resin composition containing a polymer having a first structural unit represented by the following formula (31) and a second structural unit containing an acid dissociable group represented by the following formula (32), and an acid generator.

[0086] (In the formula (31), Ar is a group obtained by removing (n + 1) hydrogen atoms from an arene having 6 to 20 carbon atoms. R １ is a hydroxy group, a sulfanyl group or a monovalent organic group having 1 to 20 carbon atoms. n is an integer of 0 to 11. When n is 2 or more, a plurality of R １ are the same or different. R ２ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. In the formula (32), R ３ is a monovalent group having 1 to 20 carbon atoms containing the above acid dissociable group. Z is a single bond, an oxygen atom or a sulfur atom. R ４(These are a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.)

[0087] A resist composition containing a resin (A1) comprising structural units having a cyclic carbonate ester structure, structural units represented by the following formula, and structural units having an acid-unstable group, and an acid generator.

[0088] [In the formula, R ２ X represents an alkyl group having 1 to 6 carbon atoms, a hydrogen atom, or a halogen atom, which may have a halogen atom. １ These are single bonds, -CO-O-* or -CO-NR ４ - represents *, where * represents a bond with -Ar, R ４ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and Ar represents an aromatic hydrocarbon group having 6 to 20 carbon atoms, which may have one or more groups selected from the group consisting of hydroxyl groups and carboxyl groups.

[0089] Examples of resist films include the following:

[0090] A resist film comprising a base resin containing repeating units represented by the following formula (a1) and / or repeating units represented by the following formula (a2), and repeating units that generate acid bonded to the polymer main chain upon exposure.

[0091] (In equations (a1) and (a2), R Ａ Each of these is independently either a hydrogen atom or a methyl group. １ and R ２ These are each independently tertiary alkyl groups having 4 to 6 carbon atoms. ３ Each of these is independently either a fluorine atom or a methyl group. m is an integer from 0 to 4. １ X is a linking group having 1 to 12 carbon atoms, containing a single bond, a phenylene group or a naphthylene group, or at least one selected from an ester bond, a lactone ring, a phenylene group, and a naphthylene group. ２ (These are single bonds, ester bonds, or amide bonds.)

[0092] Examples of resist materials include the following:

[0093] A resist material comprising a polymer having repeating units represented by the following formula (b1) or formula (b2).

[0094] (In equations (b1) and (b2), R Ａ X is a hydrogen atom or a methyl group. １ X is a single bond or an ester group. ２ X is a linear, branched, or cyclic alkylene group having 1 to 12 carbon atoms or an arylene group having 6 to 10 carbon atoms, and a portion of the methylene groups constituting the alkylene group may be substituted with an ether group, an ester group, or a lactone ring-containing group, and X ２ At least one hydrogen atom in is replaced by a bromine atom. ３ Rf is a single bond, an ether group, an ester group, or a linear, branched, or cyclic alkylene group having 1 to 12 carbon atoms, and some of the methylene groups constituting the alkylene group may be substituted with an ether group or an ester group. １ ~Rf ４ Each of these is independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one is a fluorine atom or a trifluoromethyl group. Also, Rf １ and Rf ２ They may combine to form a carbonyl group. １ ~R ５ Each of these is independently a linear, branched, or cyclic alkyl group having 1 to 12 carbon atoms, a linear, branched, or cyclic alkenyl group having 2 to 12 carbon atoms, an alkynyl group having 2 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or an aryloxyalkyl group having 7 to 12 carbon atoms, and some or all of the hydrogen atoms of these groups may be substituted with a hydroxyl group, a carboxyl group, a halogen atom, an oxo group, a cyano group, an amide group, a nitro group, a sultone group, a sulfone group, or a sulfonium salt-containing group, and some of the methylene groups constituting these groups may be substituted with an ether group, an ester group, a carbonyl group, a carbonate group, or a sulfonic acid ester group. １ and R ２These may combine to form a ring with the sulfur atom to which they are bonded.

[0095] A resist material comprising a base resin containing a polymer having repeating units represented by the following formula (a).

[0096] (In formula (a), R Ａ R is a hydrogen atom or a methyl group. １ R is a hydrogen atom or an acid-unstable group. ２ This is a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms, or a halogen atom other than bromine. １ This is a linear, branched, or cyclic alkylene group having 1 to 12 carbon atoms, which may contain a single bond or a phenylene group, or an ester group or a lactone ring. ２ is -O-, -O-CH ２ It is - or -NH-. m is an integer from 1 to 4. u is an integer from 0 to 3. However, m + u is an integer from 1 to 4.

[0097] A resist composition that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid, comprising a base component whose solubility in a developer changes due to the action of the acid and a fluorine additive component (F) that exhibits decomposition in an alkaline developer, wherein the fluorine additive component (F) comprises a fluororesin component (F1) having a constituent unit (f1) containing a base-dissociable group and a constituent unit (f2) containing a group represented by the following general formula (f2-r-1).

[0098] [In formula (f2-r-1), Rf ２１ Each of these is independently a hydrogen atom, an alkyl group, an alkoxy group, a hydroxyl group, a hydroxyalkyl group, or a cyano group. n'' is an integer from 0 to 2. * represents a bond.

[0099] The aforementioned constituent unit (f1) includes a constituent unit represented by the following general formula (f1-1) or a constituent unit represented by the following general formula (f1-2).

[0100] [In formulas (f1-1) and (f1-2), R is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. X is a divalent linking group that does not have an acid-dissociable site. A ａｒｙｌ X is a divalent aromatic cyclic group which may have substituents. ０１ R is a single bond or a divalent linking group. ２ These are, independently, organic groups that contain a fluorine atom.

[0101] The resist composition may be a metal-containing resist. Metal-containing resists are also called metal oxide resists (MORs), and a typical example is a tin oxide-based resist. Examples of materials for metal oxide resists include coating compositions containing a metal oxo-hydroxo network having organic ligands via metal-carbon bonds and / or metal-carboxylate bonds, as described in Japanese Patent Application Publication No. 2019-113855. An example of a metal-containing resist uses a peroxo ligand as a radiosensitizing stabilizing ligand. Details of peroxo-based metal oxo-hydroxo compounds are described in, for example, the patent document described in paragraph

[0011] of Publication No. 2019-532489. Examples of relevant patent documents include U.S. Patent No. 9,176,377B2, U.S. Patent Publication No. 2013 / 0224652A1, U.S. Patent No. 9,310,684B2, U.S. Patent Publication No. 2016 / 0116839A1, and U.S. Patent Publication No. 15 / 291738. Examples of materials for metal oxide resists include the compositions and solutions described below.

[0102] A coating comprising a metal oxo-hydroxo network having organic ligands via metal-carbon bonds and / or metal-carboxylate bonds.

[0103] Inorganic oxo / hydroxo-based compositions.

[0104] A coating solution comprising an organic solvent; a first organometallic composition comprising formula R ｚ SnO （２－（ｚ／２）－（ｘ／２）） (OH) ｘ(Here, 0 < z ≤ 2 and 0 < (z + x) ≤ 4), equation R' ｎ SnX ４－ｎ A first organometallic composition represented by (where n = 1 or 2), or a mixture thereof, where R and R' are independently hydrocarbyl groups having 1 to 31 carbon atoms, and X is a ligand or a combination thereof having a hydrolyzable bond to Sn; and a hydrolyzable metal compound of the formula MX' ｖ A coating solution comprising a hydrolyzable metal compound represented by (where M is a metal selected from groups 2 to 16 of the periodic table, v is a number from 2 to 6, and X' is a ligand or combination thereof having a hydrolyzable M-X bond).

[0105] Organic solvent and formula RSnO （３／２－ｘ／２） (OH) ｘ A coating solution comprising a first organometallic compound represented by the formula (wherein 0 < x < 3), wherein the solution contains about 0.0025 M to about 1.5 M of tin, and R is an alkyl group or cycloalkyl group having 3 to 31 carbon atoms, wherein the alkyl group or cycloalkyl group is bonded to tin at a secondary or tertiary carbon atom.

[0106] An aqueous solution of an inorganic pattern-forming precursor comprising a mixture of water, a metal suboxide cation, a polyatomic inorganic anion, and a radiation-sensitive ligand containing a peroxide group.

[0107] Other examples of metal-containing resists include the compositions described in Japanese Patent Publication No. 2011-253185, WO2015 / 026482, WO2016 / 065120, WO2017 / 066319, WO2017 / 156388, WO2018 / 031896, Japanese Patent Publication No. 2020-122959, Japanese Patent Publication No. 2020-122960, WO2019 / 099981, WO2019 / 199467, WO2019 / 195522, WO2019 / 195522, WO2020 / 210660, WO2021 / 011367, and WO2021 / 016229. These contents are incorporated into this specification to the same extent as if they were all explicitly stated.

[0108] The method for forming a metal-containing resist film from a metal-containing resist is not particularly limited, and includes a method of applying a coating-type resist material (a composition for forming a metal-containing resist film), which is a metal-containing resist, and firing it.

[0109] Furthermore, the metal-containing resist film may be formed by vapor deposition. An example of a method for forming a metal-containing resist film by vapor deposition is the method described in Japanese Patent Application Publication No. 2017-116923. The contents of Japanese Patent Application Publication No. 2017-116923 are incorporated herein to the same extent as if they were fully disclosed. In Japanese Patent Application Publication No. 2017-116923, the metal-containing resist film in the present invention is referred to as a metal oxide-containing film.

[0110] Irradiation with light or an electron beam is performed, for example, through a mask (reticle) for forming a predetermined pattern. For example, i-rays, KrF excimer lasers, ArF excimer lasers, EUV (extreme ultraviolet) or EB (electron beams) are used. The resist underlayer film forming composition of the present invention is preferably applied for EB (electron beam) or EUV (extreme ultraviolet: 13.5 nm) irradiation, and more preferably for EUV (extreme ultraviolet) exposure. The electron beam irradiation energy and the amount of light exposure are not particularly limited.

[0111] A bake (PEB: Post Exposure Bake) may be performed after irradiation with light or electron beam and before development. The bake temperature is not particularly limited, but is preferably 60°C to 150°C, more preferably 70°C to 120°C, and particularly preferably 75°C to 110°C. The bake time is not particularly limited, but is preferably 1 second to 10 minutes, more preferably 10 seconds to 5 minutes, and particularly preferably 30 seconds to 3 minutes.

[0112] For development, for example, alkaline developers and organic solvents are used. The development temperature can be, for example, 5°C to 50°C. The development time can be, for example, 10 seconds to 300 seconds. As alkaline developers, aqueous solutions of the following alkalis can be used: inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia; primary amines such as ethylamine and n-propylamine; secondary amines such as diethylamine and di-n-butylamine; tertiary amines such as triethylamine and methyldiethylamine; alcohol amines such as dimethylethanolamine and triethanolamine; quaternary ammonium salts such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline; and cyclic amines such as pyrrole and piperidine. Furthermore, appropriate amounts of alcohols such as isopropyl alcohol and nonionic surfactants can be added to the aqueous solutions of the above alkalis. Among these, preferred developers are aqueous solutions of quaternary ammonium salts, and more preferably aqueous solutions of tetramethylammonium hydroxide and choline. Furthermore, surfactants can also be added to these developers. Alternatively, instead of using an alkaline developer, development can be performed with an organic solvent such as butyl acetate, and the areas of the photoresist where the alkaline dissolution rate has not improved can be developed.

[0113] Organic solvents can be used as the developer for metal-containing resists, and development is performed with the developer (solvent) after irradiation with light or electron beam. As a result, for example, when a negative-type metal-containing resist film is used, the unexposed areas of the metal-containing resist film are removed, and a pattern of the metal-containing resist film is formed. Examples of developers (organic solvents) include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyethyl acetate, ethoxyethyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3 - Methoxybutyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3 - Methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate,Examples include propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl-3-methoxypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, and propyl-3-methoxypropionate. Furthermore, surfactants can be added to these developers.

[0114] Next, the resist underlayer film is etched using the formed resist pattern as a mask. The etching may be dry etching or wet etching, but dry etching is preferred. If the inorganic film is formed on the surface of the semiconductor substrate used, the surface of the inorganic film is exposed; if the inorganic film is not formed on the surface of the semiconductor substrate used, the surface of the semiconductor substrate is exposed. After that, the semiconductor substrate is processed by a known method (such as dry etching) to manufacture a semiconductor device.

[0115] The present invention will now be specifically described with reference to examples, but the present invention is not limited to these examples.

[0116] The weight-average molecular weight and dispersion of the resins shown in Synthesis Examples 1-3 and Comparative Synthesis Example 1 in this specification were obtained by gel permeation chromatography (hereinafter abbreviated as GPC). A GPC instrument manufactured by Tosoh Corporation was used for the measurement, and the measurement conditions were as follows: • GPC column: TSKgel Super-MultiporeHZ-N (2 columns) • Column temperature: 40°C • Solvent: Tetrahydrofuran (THF) • Flow rate: 0.35 ml / min • Standard sample: Polystyrene (manufactured by Tosoh Corporation)

[0117] <Synthesis Example 1> 6.00 g of 4-vinylphenyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.), 15.3 g of 4-acetoxy-3,5-diiodostyrene (manufactured by Mitsubishi Gas Chemical Corporation) (molar ratio 50 / 50 (mol%)), and 0.49 g of azobisisobutyronitrile (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to 52.32 g of propylene glycol monomethyl ether acetate and dissolved to prepare a monomer solution. 34.89 g of propylene glycol monomethyl ether acetate was placed in an empty reaction vessel, and after purging the reaction vessel with nitrogen, it was heated to 80°C while stirring. Next, the monomer solution was added dropwise to the reaction vessel over 1 hour, and the polymerization reaction was carried out for a total of 6 hours, with the start of the dropwise addition of the monomer solution being taken as the start time of the polymerization reaction, to obtain a polymerization solution. After the polymerization reaction was completed, the polymerization solution was cooled to room temperature. 25 g of the cooled polymerization solution was taken, and 16.97 g of 20% sodium hydroxide aqueous solution and 41.97 g of tetrahydrofuran were added. Hydrolysis was carried out at 40°C for 4 hours with stirring. After the hydrolysis reaction was complete, the solution was added dropwise to 168 g of 2 mol / L hydrochloric acid and stirred for 2 hours. The stirred solution was extracted with 250 g of ethyl acetate to recover the organic layer consisting of ethyl acetate. Then, the organic layer was further recovered by liquid-liquid separation with 250 g of water. The remaining solvent was removed by distillation, and the solution was dissolved in propylene glycol monomethyl ether acetate to obtain a resin solution. GPC analysis revealed that the resin in the obtained solution had a weight-average molecular weight (Mw) of 13000 and a dispersion degree (Mw / Mn) of 2.3 on a standard polystyrene basis. The resin obtained in this synthesis example has structural units represented by the following formulas (1) and (2).

[0118]

[0119] <Synthesis Example 2> 6.00 g of 4-vinylphenyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.), 11.8 g of 4-acetoxy-3-iodo-5-methoxystyrene (manufactured by Mitsubishi Gas Chemical Corporation) (molar ratio 50 / 50 (mol%)), and 0.49 g of azobisisobutyronitrile (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to 43.81 g of propylene glycol monomethyl ether acetate and dissolved to prepare a monomer solution. 29.21 g of propylene glycol monomethyl ether acetate was placed in an empty reaction vessel, and after purging the reaction vessel with nitrogen, it was heated to 80°C while stirring. Next, the monomer solution was added dropwise to the reaction vessel over 1 hour, and the polymerization reaction was carried out for a total of 6 hours, with the start of the dropwise addition of the monomer solution being taken as the start time of the polymerization reaction, to obtain a polymerization solution. After the polymerization reaction was completed, the polymerization solution was cooled to room temperature. 25 g of the cooled polymerization solution was taken, and 20.27 g of 20% sodium hydroxide aqueous solution and 45.27 g of tetrahydrofuran were added. Hydrolysis was carried out at 40°C for 4 hours with stirring. After the hydrolysis reaction was complete, the solution was added dropwise to 168 g of 2 mol / L hydrochloric acid and stirred for 2 hours. The stirred solution was extracted with 250 g of ethyl acetate to recover the organic layer consisting of ethyl acetate. Then, the organic layer was further recovered by liquid-liquid separation with 250 g of water. The remaining solvent was removed by distillation, and the solution was dissolved in propylene glycol monomethyl ether acetate to obtain a resin solution. GPC analysis revealed that the resin in the obtained solution had a weight-average molecular weight of 11800 on a standard polystyrene basis and a dispersion degree of 2.5. The resin obtained in this synthesis example has structural units represented by the following formulas (1) and (3).

[0120]

[0121] <Synthesis Example 3> 6.0 g of 4-acetoxy-3-iodo-5-methoxystyrene (manufactured by Mitsubishi Gas Chemical Co., Ltd.) and 0.095 g of azobisisobutyronitrile (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to 14.63 g of propylene glycol monomethyl ether acetate and dissolved to prepare a monomer solution. 9.75 g of propylene glycol monomethyl ether acetate was placed in an empty reaction vessel, the vessel was purged with nitrogen, and the mixture was heated to 80°C while stirring. Next, the monomer solution was added dropwise to the reaction vessel over 1 hour, and the polymerization reaction was carried out for a total of 6 hours, with the start of the dropwise addition of the monomer solution being taken as the start time of the polymerization reaction, to obtain a polymerization solution. After the polymerization reaction was completed, the polymerization solution was cooled to room temperature. 25 g of the cooled polymerization solution was taken, and 11.89 g of 20% sodium hydroxide aqueous solution and 36.89 g of tetrahydrofuran were added, and a hydrolysis reaction was carried out at 40°C for 4 hours while stirring. After the hydrolysis reaction was complete, the solution was added dropwise to 148 g of 2 mol / L hydrochloric acid and stirred for 2 hours. The stirred solution was extracted with 220 g of ethyl acetate to recover the organic layer consisting of ethyl acetate. Then, the organic layer was further recovered by liquid-liquid separation with 220 g of water. The remaining solvent was removed by distillation, and the solution was dissolved in propylene glycol monomethyl ether acetate to obtain a resin solution. GPC analysis revealed that the resin in the obtained solution had a weight-average molecular weight of 14100 on a standard polystyrene basis and a dispersion degree of 4.6. The resin obtained in this synthesis example has a structural unit represented by the following formula (3).

[0122]

[0123] <Comparative Synthesis Example 1> 100.00 g of monoallyl diglycidyl isocyanuric acid (manufactured by Shikoku Chemicals, Inc.), 66.4 g of 5,5-diethylbarbituric acid, and 4.1 g of benzyltriethylammonium chloride were added to 682.00 g of propylene glycol monomethyl ether in a reaction vessel and dissolved. After purging the reaction vessel with nitrogen, the reaction was carried out at 130°C for 24 hours to obtain a resin solution. GPC analysis revealed that the resin in the obtained solution had a weight-average molecular weight of 6,800 on a standard polystyrene basis and a dispersion degree of 4.8. The resin obtained in this synthesis example has structural units represented by the following formula.

[0124]

[0125] <Preparation of Resist Underlayer Film> (Examples 1-3, Comparative Examples 1-2) The resins obtained in Synthesis Examples 1-3 and Comparative Synthesis Example 1, along with the following resins, crosslinking agents, curing catalysts, and solvents, were mixed in the proportions shown in Table 1 and filtered through a 0.1 μm fluororesin filter to prepare compositions for forming resist underlayer films. The following resins were used. Abbreviations in Table 1 are also shown.・VP-8000: Polyp-hydroxystyrene (product name: VP-8000, manufactured by Nippon Soda Co., Ltd.) ・PL-LI: Tetramethoxymethyl glycol uryl (crosslinking agent) ・PGME-PL: Imidazo[4,5-d]imidazole-2,5(1H,3H)-dione,tetrahydro-1,3,4,6-tetrakis[(2-methoxy-1-methylethoxy)methyl]- (crosslinking agent) ・Py-PSA: Pyridinium-p-hydroxybenzenesulfonic acid (curing catalyst) ・R-30N: Surfactant ・PGMEA: Propylene glycol monomethyl ether acetate ・PGME: Propylene glycol monomethyl ether The amount of each additive is shown in parts by mass, and the solvent is shown in composition ratio (mass ratio). In the table, "-" indicates that the ingredient is not included.

[0126]

[0127] (Elution Test in Photoresist Solvent) Each of the resist underlayer film formation compositions of Examples 1 to 3 and Comparative Examples 1 to 2 was coated onto a silicon wafer using a spinner. 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. These resist underlayer films were immersed for 1 minute in a mixed solution of propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate = 70 / 30 (mass ratio), which is the solvent used for the photoresist. A film thickness change of 5 Å or less was classified as "good," and a change greater than 5 Å was classified as "poor." The results are shown in Table 2.

[0128]

[0129] (Etching Rate Test) Solutions of the resist underlayer formation compositions prepared in Examples 1-3 and Comparative Example 2 were applied to silicon wafers using a spinner. The silicon wafers were baked on a hot plate at 205°C for 60 seconds to obtain resist underlayer films. The etching rate (decrease in film thickness per unit time) of these resist underlayer films was then measured using a Samco RIE-200NL dry etching gas with CF ４ Measurements were taken under the conditions used. The results are shown in Table 3. In Table 3, the etching rate is the etching rate of each resist underlayer when the etching rate of Comparative Example 2 is set to 1.00.

[0130]

[0131] (Formation of resist patterns using electron beam lithography) The resist underlayer formation compositions of Examples 1-3 and Comparative Example 1 were applied to silicon wafers using a spinner. The silicon wafers were baked on a hot plate at 205°C for 60 seconds to obtain a resist underlayer with a thickness of 5 nm. An EUV positive-type resist solution (containing methacrylic polymer) was spin-coated onto the resist underlayer and heated at 110°C for 60 seconds to form an EUV resist film. The resist film was exposed to electron beam lithography (ELS-G130) under predetermined conditions. After exposure, baking (PEB) was performed at 90°C for 60 seconds, the film was cooled to room temperature on a cooling plate, and developed with an alkaline developer (2.38% by mass TMAH) to form a resist pattern with a 23 nm hole pattern. A scanning electron microscope (Hitachi High-Technologies Corporation, CG4100) was used to measure the length of the resist pattern. In forming the resist pattern described above, Table 4 indicates "Good" if a hole pattern with a CD size of 23 nm was formed, and "Poor" if poor resolution of the hole pattern was observed. Furthermore, the optimal irradiation energy was set to the charge amount required to form the 23 nm hole pattern, and the irradiation energy (μC / cm²) was set to 1.00 for Comparative Example 1. ２ ) are also shown in Table 4.

[0132]

[0133] Table 4 shows that when a resist underlayer was formed using the resist underlayer formation compositions of Examples 1 to 3, a reduction in optimal irradiation energy was observed compared to when a resist underlayer was formed using the resist underlayer formation composition of Comparative Example 1.

Claims

1. A resist underlayer film forming composition comprising a resin (A) having a hydroxyl group bonded to an aromatic ring and at least one of a bromo group and an iodine group, and a solvent (B), wherein the resin (A) is a resin having a structural unit represented by the following formula (A-1). (In formula (A-1), R １ R represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. ２ represents an optionally substituted alkyl group having 1 to 3 carbon atoms, an optionally substituted alkoxy group having 1 to 3 carbon atoms, a fluorine atom, or a chlorine atom, X represents a bromine atom or an iodine atom, and Ar １ (where p represents a benzene ring or a naphthalene ring, q represents an integer from 0 to 4, r represents an integer from 0 to 4.) 2. The resist underlayer film forming composition according to claim 1, wherein the resin (A) is a polymer of an aromatic compound having a vinyl group.

3. The resist underlayer film forming composition according to claim 1, wherein the solvent (B) comprises at least one selected from the group consisting of a carboxylic acid having a hydroxyl group, a linear or cyclic alkyl ketone, a cyclic lactone, an alkylene glycol monoalkyl ether, a monocarboxylic acid ester of an alkylene glycol monoalkyl ether, and an alkoxycarboxylic acid ester of an alkylene glycol monoalkyl ether.

4. The resist underlayer film forming composition according to claim 1, further comprising a crosslinking agent (C).

5. The resist underlayer film forming composition according to claim 4, wherein the crosslinking agent (C) is at least one selected from the group consisting of aminoplast crosslinking agents and phenoplast crosslinking agents.

6. The resist underlayer film forming composition according to claim 1, further comprising a curing catalyst (D).

7. The resist underlayer film formation composition according to claim 1, used in an EUV (extreme ultraviolet) exposure process.

8. A resist underlayer film, which is a cured product of a resist underlayer film forming composition according to any one of claims 1 to 7.

9. A laminate comprising a semiconductor substrate and a resist underlayer film according to claim 8.

10. A method for manufacturing a semiconductor device, comprising the steps of: forming a resist underlayer film on a semiconductor substrate using a resist underlayer film forming composition according to any one of claims 1 to 7; and forming a resist film on the resist underlayer film.

11. A pattern formation method comprising: forming a resist underlayer film on a semiconductor substrate using a resist underlayer film forming composition according to any one of claims 1 to 7; forming a resist film on the resist underlayer film; irradiating the resist film with light or an electron beam, then developing the resist film to obtain a resist pattern; and etching the resist underlayer film using the resist pattern as a mask.

Images