Resist underlayer film-forming composition

Abstract

Provided are: a resist underlayer film-forming composition that can form a resist underlayer film capable of forming, with high sensitivity, a fine resist pattern; and a resist underlayer film, a laminate, a method for producing a semiconductor element, and a pattern formation method, in all of which the resist underlayer film-forming composition is used.　This resist underlayer film-forming composition contains a solvent and a polymer (A) having, in a sidechain, an aromatic hydrocarbon ring and one or more polymerizable multiple bonds selected from the group consisting of a carbon-carbon double bond, a carbon-carbon triple bond, a carbon-nitrogen double bond, and a carbon-nitrogen triple bond.

Description

Composition for forming 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 producing a semiconductor element, and a method for forming a pattern.

[0002] In the manufacture of semiconductor devices, microfabrication by lithography using a resist composition has traditionally been performed. This microfabrication process involves forming a thin film of a photoresist composition on a semiconductor substrate, such as a silicon wafer, irradiating the substrate with active light such as ultraviolet light through a mask pattern bearing a device pattern, developing the film, and 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, the integration density of semiconductor devices has increased, and 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 use of EUV light (wavelength 13.5 nm) or EB (electron beam) is being considered for cutting-edge microfabrication. As a result, poor resist pattern formation due to influences from the semiconductor substrate, etc., has become a major problem. To address this issue, methods of providing a resist underlayer film between the resist and the semiconductor substrate have been widely investigated.

[0003] Patent Document 1 discloses a composition for forming an underlayer film for lithography, which contains a naphthalene ring having a halogen atom. Patent Document 2 discloses a halogenated antireflective film. Patent Document 3 discloses a composition for forming a resist underlayer film.

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

[0005]

[0010] The present invention has been made in view of the above circumstances, and aims to provide a composition for forming a resist underlayer film capable of forming a resist underlayer film capable of sensitively forming a fine resist pattern, as well as a method for manufacturing a resist underlayer film, a laminate, and a semiconductor device, and a method for forming a pattern, using the composition for forming a resist underlayer film.

[0006] The present inventors have conducted extensive research to solve the above problems, and as a result have found that the above problems can be solved, and have completed the present invention having the following gist.

[0007] That is, the present invention encompasses the following aspects: [1] A composition for forming a resist underlayer film, comprising: a polymer (A) having, in a side chain, one or more polymerizable multiple bonds selected from the group consisting of a carbon-carbon double bond, a carbon-carbon triple bond, a carbon-nitrogen double bond, and a carbon-nitrogen triple bond, and an aromatic hydrocarbon ring; and a solvent. [2] The composition for forming a resist underlayer film according to [1], wherein the polymer (A) has a group represented by the following formula (A): (In formula (A), L １ represents a single bond or a linking group. ２ represents the divalent group having an aromatic hydrocarbon ring. ３ represents a monovalent group having a polymerizable multiple bond. * represents a bond. [3] In the group represented by formula (A), ２ The composition for forming a resist underlayer film according to [2], wherein the compound is represented by the following formula (b): (In formula (b), W １ , W ２ , and W ３ each independently represents a single bond, —O—, —C(═O)—O—, —O—C(═O)—, or —O—C(═O)—CH ２ -, -C(=O)-N(R')- or -N(R')-C(=O)-. W ２ When the number of is 2 or more, each W ２may be the same or different. R' represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Q represents a single bond, an alkylene group having 1 to 10 carbon atoms, or an alkenylene group having 2 to 10 carbon atoms. Some or all of the hydrogen atoms of the alkylene group or alkenylene group may be substituted with halogen atoms. L ｂ is a single bond, an alkylene group having 1 to 12 carbon atoms, or —CH ２ represents a divalent linking group in which one or more - groups that are not adjacent to each other are substituted with -O-, -S-, -C(=O)-O-, or O-C(=O)-, and some or all of the hydrogen atoms of the alkylene group may be substituted with halogen atoms. １ represents a single bond, a phenylene group, a naphthylene group, or a divalent alicyclic hydrocarbon group having 5 to 8 carbon atoms, and some or all of the hydrogen atoms of the phenylene group and naphthylene group may be substituted with a cyano group, a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkylcarbonyl group having 2 to 6 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms. １ When the number of is 2 or more, each Q １ may be the same or different. ｂ is an alkyl group having 1 to 6 carbon atoms, a haloalkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a haloalkoxy group having 1 to 6 carbon atoms, a cyano group, or a nitro group. p is 0, 1, 2, 3, or 4. m is 0 or 1. n1 is 0, 1, 2, or 3. *a and *b represent bonds, and *a is a bond that is bonded to L. １ *b is bonded to L ３ [4] The L ２ In the divalent group represented by the formula (b), W ３ As a combination of and Q, W ３ is a single bond and Q is a single bond, W ３ is a single bond, Q is an alkylene group having 1 to 10 carbon atoms, and W ３ is a single bond, and Q is an alkenylene group having 2 to 10 carbon atoms.２ In the divalent group represented by the formula (b), Q １ and W ２ As a combination of １ is a single bond and W ２ is a single bond, and when n1 is 1, Q １ is a phenylene group and W ２ is —C(═O)—O—. [6] The composition for forming a resist underlayer film according to [3] or [4], ２ In the divalent group represented by the formula (b), L ｂ and W １ As a combination of ｂ is a single bond and W １ is a single bond, L ｂ is an alkylene group having 1 to 10 carbon atoms, and W １ is -O-C(=O)-CH ２ - and L ｂ is an alkylene group having 1 to 10 carbon atoms, and W １ [7] The composition for forming a resist underlayer film according to any one of [3] to [5], wherein in the group represented by formula (A), the L １ The composition for forming a resist underlayer film according to any one of [2] to [6], wherein the linking group has a structural moiety represented by the following formula (t1) or the following formula (t2): (wherein *1 represents L in formula (A) ２ *2 represents the bond on the opposite side to the bond to L in formula (A). ２ [8] In the group represented by formula (A), the L ３ The composition for forming a resist underlayer film according to any one of [2] to [7], wherein the monovalent group having a polymerizable multiple bond has a structural moiety represented by the following formula (u1) or the following formula (u2): (wherein * represents L in formula (A) ２ represents a bond bonded to the group represented by the formula (1): [9] The composition for forming a resist underlayer film according to the above [1], wherein the polymer (A) has a structural unit represented by the formula (1): (In formula (1), R １represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. １１ represents a single bond or a linking group. １２ represents the divalent group having an aromatic hydrocarbon ring. １３ represents the monovalent group having a polymerizable multiple bond.

[10] In the structural unit represented by formula (1), １１ The composition for forming a resist underlayer film according to [9], wherein the linking group is represented by the following formula (L1-1) or the following formula (L1-2): (wherein *1 represents R in formula (1) １ *2 represents a bond bonded to a carbon atom bonded to L in formula (1). １２

[11] The composition for forming a resist underlayer film according to [1], wherein the polymer (A) has a structural unit represented by the following formula (2): (In formula (2), R ａ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. Ar represents a benzene ring, a naphthalene ring, or an anthracene ring. L Ｘ represents a single bond or a divalent group which may have a substituent. ２１ represents a single bond or a linking group. ２２ represents the divalent group having an aromatic hydrocarbon ring. ２３ represents the monovalent group having a polymerizable multiple bond, and n1 is an integer of 0 to 3.

[12] In the structural unit represented by formula (2), ２１ The composition for forming a resist underlayer film according to

[11] , wherein the linking group is represented by the following formula (L1-12): (In the formula, *1 represents a bond bonded to Ar in formula (2). *2 represents a bond bonded to L in formula (1). ２２

[13] The composition for forming a resist underlayer film according to [1], wherein the polymer (A) has a structural unit represented by the following formula (3): (In formula (3), L ３１ represents a single bond or a linking group. ３２ represents the divalent group having an aromatic hydrocarbon ring. ３３represents the monovalent group having a polymerizable multiple bond.

[14] In the structural unit represented by formula (3), ３１ The composition for forming a resist underlayer film according to

[13] , wherein the linking group is represented by the following formula (L1-13): (In the formula, *1 represents a bond bonded to the alicyclic hydrocarbon in formula (3). *2 represents a bond bonded to L in formula (3). ３２ represents a bond bonding to the.)

[15] The composition for forming a resist underlayer film according to any one of [1] to

[15] , further comprising a crosslinking agent.

[16] A resist underlayer film that is a cured product of the composition for forming a resist underlayer film according to any one of [1] to

[15] .

[17] A laminate comprising: a semiconductor substrate; and the resist underlayer film according to

[16] .

[18] A method for manufacturing a semiconductor device, comprising: forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film according to any one of [1] to

[15] ; and forming a resist film on the resist underlayer film.

[19] A pattern forming method comprising: forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film according to any one of [1] to

[15] ; forming a resist film on the resist underlayer film; irradiating the resist film with light or an electron beam and 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, it is possible to provide a composition for forming a resist underlayer film that can form a resist underlayer film that can form a fine resist pattern with high sensitivity, as well as methods for producing a resist underlayer film, a laminate, and a semiconductor element, and a pattern forming method, all of which use the composition for forming a resist underlayer film.

[0009] FIG. 2 is a photograph showing an observation of a resist pattern formed in Example 1.

[0010] (Composition for forming a resist underlayer film) The composition for forming a resist underlayer film of the present invention contains a polymer (A) and a solvent. The composition for forming a resist underlayer film may also contain a crosslinking agent, a curing catalyst, a thermal radical polymerization initiator, etc. A resist pattern with excellent sensitivity can be formed on a resist underlayer film formed from the composition for forming a resist underlayer film containing the polymer (A) and a solvent.

[0011] <Polymer (A)> Polymer (A) has a polymerizable multiple bond and an aromatic hydrocarbon ring in a side chain. The polymerizable multiple bond and the aromatic hydrocarbon ring are preferably present in the same side chain. The polymerizable multiple bond is one or more types of polymerizable multiple bonds selected from the group consisting of a carbon-carbon double bond, a carbon-carbon triple bond, a carbon-nitrogen double bond, and a carbon-nitrogen triple bond.

[0012] The polymer (A) is an organic polymer. The polymer (A) may be a homopolymer or a copolymer.

[0013] The polymer (A) has, in its side chain, a group having a polymerizable multiple bond, such as a (meth)acryloyl group, a vinylaryl group (for example, a styryl group), a vinyloxy group, or an allyl group.

[0014] The polymer (A) preferably has a group represented by the following formula (A).

[0015] (In formula (A), L １ represents a single bond or a linking group. ２ represents the divalent group having an aromatic hydrocarbon ring. ３ represents a monovalent group having a polymerizable multiple bond. * represents a bond.

[0016] In the group represented by formula (A), L ２ is preferably represented by the following formula (b):

[0017] (In formula (b), W １ , W ２ , and W ３each independently represents a single bond, —O—, —C(═O)—O—, —O—C(═O)—, or —O—C(═O)—CH ２ -, -C(=O)-N(R')- or -N(R')-C(=O)-. W ２ When the number of is 2 or more, each W ２ may be the same or different. R' represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Q represents a single bond, an alkylene group having 1 to 10 carbon atoms, or an alkenylene group having 2 to 10 carbon atoms. Some or all of the hydrogen atoms of the alkylene group or alkenylene group may be substituted with halogen atoms. L ｂ is a single bond, an alkylene group having 1 to 12 carbon atoms, or —CH ２ represents a divalent linking group in which one or more - groups that are not adjacent to each other are substituted with -O-, -S-, -C(=O)-O-, or O-C(=O)-, and some or all of the hydrogen atoms of the alkylene group may be substituted with halogen atoms. １ represents a single bond, a phenylene group, a naphthylene group, or a divalent alicyclic hydrocarbon group having 5 to 8 carbon atoms, and some or all of the hydrogen atoms of the phenylene group and naphthylene group may be substituted with a cyano group, a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkylcarbonyl group having 2 to 6 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms. １ When the number of is 2 or more, each Q １ may be the same or different. ｂ is an alkyl group having 1 to 6 carbon atoms, a haloalkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a haloalkoxy group having 1 to 6 carbon atoms, a cyano group, or a nitro group. p is 0, 1, 2, 3, or 4. m is 0 or 1. n1 is 0, 1, 2, or 3. *a and *b represent bonds, and *a is a bond that is bonded to L. １ and *b is L ３ Binds to

[0018] Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, a cyclopropyl group, an n-butyl group, an i-butyl group, an s-butyl group, a t-butyl group, a cyclobutyl group, a 1-methyl-cyclopropyl group, a 2-methyl-cyclopropyl group, an n-pentyl group, a 1-methyl-n-butyl group, a 2-methyl-n-butyl group, a 3-methyl-n-butyl group, a 1,1-dimethyl-n-propyl group, a 1,2-dimethyl-n-propyl group, a 2,2-dimethyl-n-propyl group, and a 1-ethyl-n-propyl group. cyclopentyl, 1-methylcyclobutyl, 2-methylcyclobutyl, 3-methylcyclobutyl, 1,2-dimethylcyclopropyl, 2,3-dimethylcyclopropyl, 1-ethylcyclopropyl, 2-ethylcyclopropyl, 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 group, 2,3-dimethyl-n-butyl group, 3,3-dimethyl-n-butyl group, 1-ethyl-n-butyl group, 2-ethyl-n-butyl group, 1,1,2-trimethyl-n-propyl group, 1,2,2-trimethyl-n-propyl group, 1-ethyl-1-methyl-n-propyl group, 1-ethyl-2-methyl-n-propyl group, cyclohexyl group, 1-methyl-cyclopentyl group, 2-methyl-cyclopentyl group, 3-methyl-cyclopentyl group, 1-ethyl-cyclobutyl group, 2-ethyl-cyclobutyl group, 3-ethyl-cyclobutyl group, 1,2-dimethyl-cyclobutyl group, 1,3-dimethyl-cyclobutyl group, 2,2-dimethyl-cyclobutyl group, 2,3-dimethyl-cyclobutyl group, 2,4-dimethyl-cyclobutyl group, 3,3-dimethyl-cyclobutyl group, 1-n-propyl-cyclopropyl group, 2-n-propyl-cyclopropyl group, 1-i-propyl-cyclopropyl group, 2-i-propyl-cyclopropyl group, 1,2,2-trimethyl-cyclopropyl group, 1,2,3-trimethyl-cyclopropyl group, 2,2,Examples include a 3-trimethylcyclopropyl group, a 1-ethyl-2-methylcyclopropyl group, a 2-ethyl-1-methylcyclopropyl group, a 2-ethyl-2-methylcyclopropyl group, a 2-ethyl-3-methylcyclopropyl group, an n-heptyl group, a cycloheptyl group, a norbornyl group, an n-octyl group, a cyclooctyl group, an n-nonyl group, an isobornyl group, a tricyclononyl group, an n-decyl group, an adamantyl group, and a tricyclodecyl group. Of these, a methyl group is preferred.

[0019] The alkenylene group may be linear or branched and may contain at least one double bond in the chain. Examples of alkenylene groups having 2 to 10 carbon atoms include vinylene, 1-propenylene, 2-propenylene, 1-butenylene, 2-butenylene, 1-pentenylene, 2-pentenylene, 1-hexenylene, and 2-hexenylene.

[0020] L in formula (A) １ When L is a linking group, the number of carbon atoms in the linking group is not particularly limited, but may be, for example, 1 to 10. １ When is a linking group, examples of the linking group include a linking group having a structure obtained by reacting an epoxy group with a nucleophilic functional group. Here, examples of the nucleophilic functional group include one or more selected from the group consisting of a carboxy group, a hydroxy group, an amino group, and a thiol group. The hydroxy group may or may not be a phenolic hydroxy group.

[0021] L １ The linking group preferably has a structural moiety represented by the following formula (t1) or (t2).

[0022] (wherein *1 represents L in formula (A) ２ *2 represents the bond on the opposite side to the bond to L in formula (A). ２ represents a bond bonded to

[0023] L １Examples of the linking groups include the following linking groups (L1-1) to (L1-11).

[0024]

[0025]

[0026] (wherein *1 represents L in formula (A) ２ *2 represents the bond on the opposite side to the bond to L in formula (A). ２ represents a bond bonded to

[0027] L ２ is a divalent group having an aromatic hydrocarbon ring, and is preferably a divalent group represented by the above formula (b). Preferred embodiments of the divalent group represented by formula (b) include the following. In the divalent group represented by formula (b), W ３ As a combination of and Q, W ３ is a single bond and Q is a single bond, W ３ is a single bond, Q is an alkylene group having 1 to 10 carbon atoms, and W ３ is a single bond and Q is an alkenylene group having 2 to 10 carbon atoms. １ and W ２ As a combination of １ is a single bond and W ２ is a single bond, and when n1 is 1, Q １ is a phenylene group and W ２ In the divalent group represented by formula (b), L is preferably any combination of ｂ and W １ As a combination of ｂ is a single bond and W １ is a single bond, L ｂ is an alkylene group having 1 to 10 carbon atoms, and W １ is -O-C(=O)-CH ２ - and L ｂ is an alkylene group having 1 to 10 carbon atoms, and W １is —O—.

[0028] L ２ Examples of the group include the following divalent groups (L2-1) to (L2-5).

[0029]

[0030] (wherein *a represents L in formula (A) １ *b represents a bond bonded to L in formula (A). ３ represents a bond bonded to

[0031] L ３ is a monovalent group having a polymerizable multiple bond. The monovalent group may be the polymerizable multiple bond itself. The number of carbon atoms in the monovalent group is not particularly limited, but may be, for example, 1 to 20 or 1 to 10.

[0032] L ３ The monovalent group having a polymerizable multiple bond preferably has a structural moiety represented by the following formula (u1) or (u2).

[0033] (wherein * represents L in formula (A) ２ represents a bond bonded to

[0034] L ３ Examples of the group include the following monovalent groups (L3-1) to (L3-81).

[0035]

[0036]

[0037]

[0038]

[0039]

[0040]

[0041]

[0042] (In the formula, * represents a bond.)

[0043] The polymer (A) having a group represented by formula (A) can be obtained, for example, by reacting a resin containing an epoxy group with a resin containing a nucleophilic functional group. Examples of the nucleophilic functional group include one or more selected from the group consisting of a carboxy group, a hydroxy group, an amino group, and a thiol group. The hydroxy group may or may not be a phenolic hydroxy group. For example, when an epoxy group reacts with a carboxy group, the following reaction occurs, forming the following structure (S1):

[0044] (In the formula, * represents a bond.)

[0045] Preferred embodiments of the polymer (A) according to the present invention include, for example, the polymers described in the following first to third embodiments.

[0046] <<First Embodiment>> An example of the polymer (A) of the first embodiment is a polymer having a structural unit represented by the following formula (1).

[0047] (In formula (1), R １ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. １１ represents a single bond or a linking group. １２ represents the divalent group having an aromatic hydrocarbon ring. １３ represents the monovalent group having a polymerizable multiple bond.

[0048] L １１ is L in formula (A). １ It shows the same as L. １２ is L in formula (A). ２ It shows the same as L. １３ is L in formula (A). ３ and the same thing.

[0049] In the present invention, in formula (1), L １１ The linking group is preferably a group represented by the following formula (L1-1) or (L1-2).

[0050] (wherein *1 represents R in formula (1) １ *2 represents a bond bonded to a carbon atom bonded to L in formula (1). １２ represents a bond bonded to

[0051] The polymer (A) of the first embodiment can be obtained, for example, by reacting a glycidyl (meth)acrylate polymer (E1) with a compound (C1) having a polymerizable multiple bond, an aromatic hydrocarbon ring, and a carboxy group, as shown below. The glycidyl (meth)acrylate polymer may be a homopolymer or a copolymer. Examples of copolymers include a copolymer of glycidyl (meth)acrylate and 2-hydroxyethyl (meth)acrylate, and a copolymer of glycidyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate.

[0052] (In the formula, R １ is R in formula (1). １ It is synonymous with L. ２ is L in formula (1) １２ It is synonymous with L. ３ is L in formula (1) １３ is synonymous with

[0053] The reaction can be carried out in the presence of a catalyst such as tetrabutylphosphonium bromide.

[0054] <<Second Embodiment>> An example of the polymer (A) of the second embodiment is a polymer having a structural unit represented by the following formula (2).

[0055] (In formula (2), R ａ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. Ar represents a benzene ring, a naphthalene ring, or an anthracene ring. L Ｘ represents a single bond or a divalent group which may have a substituent. ２１ represents a single bond or a linking group. ２２ represents the divalent group having an aromatic hydrocarbon ring. ２３represents the monovalent group having a polymerizable multiple bond, and n1 is an integer of 0 to 3.

[0056] L ２１ is L in formula (A). １ It shows the same as L. ２２ is L in formula (A). ２ It shows the same as L. ２３ is L in formula (A). ３ and the same thing.

[0057] In the present invention, in formula (2), L ２１ The linking group is preferably a group represented by the following formula (L1-12).

[0058] (In the formula, *1 represents a bond bonded to Ar in formula (2). *2 represents a bond bonded to L in formula (1). ２２ represents a bond bonded to

[0059] L Ｘ The divalent group represents, for example, an alkylene group having 1 to 10 carbon atoms, an aromatic hydrocarbon group having 6 to 25 carbon atoms, or a group in which two or more of these groups are combined.

[0060] L Ｘ The alkylene group in L may be a linear, branched, or cyclic alkylene group. Ｘ The aromatic hydrocarbon group may be a monocyclic or condensed ring aromatic hydrocarbon group, and may be a linked ring in which these aromatic hydrocarbon groups are linked.

[0061] L Ｘ Examples of the substituent that may be substituted on the divalent group include a group containing a (meth)acryloyloxy group and an alkoxy group.

[0062] The polymer (A) of the second embodiment can be obtained, for example, by reacting a polymer having a structural unit represented by the following formula (2-1′) with a compound having a polymerizable multiple bond, an aromatic hydrocarbon ring, and a carboxy group.

[0063] (In formula (2-1'), Ar, R ａ , n1, L Ｘrepresents Ar and R in formula (2). ａ , n1, L Ｘ These are synonyms. １ represents a single bond or an alkylene group having 1 to 10 carbon atoms which may be interrupted by an ether bond, an ester bond or an amide bond. E represents a group having an epoxy group.

[0064] The polymer (A) of the second embodiment can be obtained, for example, by reacting the following polymer (E2) having an epoxy group with a compound (C1) having a polymerizable multiple bond, an aromatic hydrocarbon ring, and a carboxy group.

[0065] (In the formula, L ２ is L in formula (2) ２２ It is synonymous with L. ３ is L in formula (2) ２３ is synonymous with

[0066] Examples of polymers having a structural unit represented by formula (2-1') include those having the following structural units.

[0067]

[0068]

[0069] <<Third Embodiment>> An example of the polymer (A) of the third embodiment is a polymer having a structural unit represented by the following formula (3).

[0070] (In formula (3), L ３１ represents a single bond or a linking group. ３２ represents the divalent group having an aromatic hydrocarbon ring. ３３ represents the monovalent group having a polymerizable multiple bond.

[0071] L ３１ is L in formula (A). １ It shows the same as L. ３２ is L in formula (A). ２ It shows the same as L. ３３ is L in formula (A). ３ and the same thing.

[0072] In the present invention, in formula (3), L ３１ The linking group is preferably a group represented by the following formula (L1-13).

[0073] (In the formula, *1 represents a bond bonded to the alicyclic hydrocarbon in formula (3). *2 represents a bond bonded to L in formula (3). ３２ represents a bond bonded to

[0074] The polymer (A) of the third embodiment can be obtained, for example, by reacting a polymer having a structural unit represented by the following formula (3-1') with a compound having a polymerizable multiple bond, an aromatic hydrocarbon ring, and a carboxy group.

[0075] (In formula (3-1′), E is a group having an epoxy group.)

[0076] The polymer (A) of the third embodiment can be obtained, for example, by reacting the following polymer (E3) having an epoxy group with a compound (C1) having a polymerizable multiple bond, an aromatic hydrocarbon ring, and a carboxy group.

[0077] (In the formula, L ２ is L in formula (3) ３２ It is synonymous with L. ３ is L in formula (3) ３３ is synonymous with

[0078] Examples of polymers having the structural unit represented by formula (3-1') include those having the following structural units.

[0079]

[0080] Preferred embodiments of the polymer (A) include, for example, polymers having the following structural units:

[0081]

[0082]

[0083] The polymer (A) may have a structural unit other than the structural unit represented by formula (1). Examples of such a structural unit include a structural unit represented by the following formula (4), a structural unit represented by the following formula (5), and a structural unit represented by the following formula (6).

[0084] (In formula (4), R ２ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; L ３０ represents a monovalent group having 1 to 20 carbon atoms. ２ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, Ar represents a benzene ring or a naphthalene ring, L ４０ is a hydroxy group, a cyano group, a nitro group, or an amino group (-NH ２ ) represents. ５０ represents a halogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. m1 represents an integer of 0 to 3. m2 represents an integer of 0 to 5, provided that the sum of m1 and m2 is 0 to 5. When m1 is 2 or 3, multiple L ４０ may be the same or different. When m2 is 2 to 5, multiple L ５０ may be the same or different. ２ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; L ６０ represents a monovalent organic group selected from an alkyl group having 1 to 10 carbon atoms and an aryl group having 6 to 40 carbon atoms, and at least one hydrogen atom of the alkyl group and the aryl group may be substituted with a hydroxy group or an alkoxy group having 1 to 6 carbon atoms.

[0085] L in formula (4) ３０ The monovalent group having 1 to 20 carbon atoms represents, for example, a monovalent organic group selected from an alkyl group having 1 to 10 carbon atoms and an aryl group having 6 to 40 carbon atoms, and at least one hydrogen atom of the alkyl group and the aryl group may be substituted with a hydroxy group. In addition, the alkyl group may have an oxygen atom inserted between carbon atoms. In addition, L ３０Examples of the monovalent group having 1 to 20 carbon atoms include groups represented by the following formula (4-1).

[0086] (In formula (4-1), L ３ａ represents an optionally substituted alkyl group having 1 to 6 carbon atoms, or an optionally substituted aromatic hydrocarbon group. ３ａ Examples of the aromatic hydrocarbon group in L include a phenyl group and a naphthyl group. ３ａ Examples of the substituent in the optionally substituted alkyl group having 1 to 6 carbon atoms include a halogen atom and a hydroxy group. The number of substituents may be one or more. When there are more than one substituent, the multiple substituents may be the same or different. ３ａ Examples of the substituent in the optionally substituted aromatic hydrocarbon group include a halogen atom, a hydroxy group, and an alkyl group having 1 to 3 carbon atoms which may be substituted with a halogen atom. The number of substituents may be one or more. When there are multiple substituents, the multiple substituents may be the same or different.

[0087] R ２ an alkyl group having 1 to 10 carbon atoms represented by the formula: ３０ and L ６０ Specific examples of the alkyl group having 1 to 10 carbon atoms represented by are as described above. ５０ Examples of the halogen atom in L include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. ５０ Examples of the alkyl group having 1 to 6 carbon atoms in the formula (L) include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, a cyclopropyl group, an n-butyl group, and an i-butyl group. ５０Examples of the alkoxy group having 1 to 6 carbon atoms in the formula (I) include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. m1 represents an integer of 0 to 3 and may be 0, 1, 2, or 3. m2 represents an integer of 0 to 5 and may be 0, 1, 2, 3, 4, or 5.

[0088] L ３０ and L ６０ Examples of the aryl group having 6 to 40 carbon atoms represented by L include a phenyl group, an o-methylphenyl group, an m-methylphenyl group, a p-methylphenyl group, an o-chlorophenyl group, an m-chlorophenyl group, a p-chlorophenyl group, an o-fluorophenyl group, a p-fluorophenyl group, an o-methoxyphenyl group, a p-methoxyphenyl group, a p-nitrophenyl group, a p-cyanophenyl group, an α-naphthyl group, a β-naphthyl group, an o-biphenylyl group, an m-biphenylyl group, a p-biphenylyl group, a 1-anthryl group, a 2-anthryl group, a 9-anthryl group, a 1-phenanthryl group, a 2-phenanthryl group, a 3-phenanthryl group, a 4-phenanthryl group, and a 9-phenanthryl group. ６０ Examples of the alkoxy group having 1 to 6 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.

[0089] The proportion of the structural units represented by at least one of formulas (1) to (3) in polymer (A) is not particularly limited, but the molar ratio of the structural units represented by any one of formulas (1) to (3) to all structural units of polymer (A) may be, for example, 20 mol% to 100 mol%, or 20 mol% or more but less than 100 mol%. The proportion of the structural units represented by formula (4) in polymer (A) is not particularly limited, but the molar ratio of the structural units represented by formula (4) to all structural units of polymer (A) may be, for example, 0 mol% to 80 mol%, or more than 0 mol% but 80 mol% or less.

[0090] The polymer (A) may contain structural units other than the structural units represented by any one of formulas (1) to (3) and the structural unit represented by formula (4). In this case, the molar ratio of the other structural units to all structural units of the polymer (A) is, for example, more than 0 mol % and not more than 20 mol %.

[0091] The polymer (A) is not, for example, a polysiloxane. The polymer (A) is not, for example, a hydrolysis condensate of a hydrolyzable silane. The polymer (A) is not, for example, a reaction product of a tetracarboxylic dianhydride and a diepoxy compound having two epoxy groups. The polymer (A) is not, for example, a reaction product of a tetracarboxylic dianhydride, a diepoxy compound having two epoxy groups, and a monohydroxy compound having one hydroxy group. The polymer (A) does not, for example, have an isocyanuric acid skeleton having an alkenyl group. Examples of the alkenyl group include alkenyl groups having 3 to 6 carbon atoms. Examples of the alkenyl group having 3 to 6 carbon atoms include allyl groups.

[0092] The molecular weight of the polymer (A) is not particularly limited. The lower limit of the weight average molecular weight of the polymer (A) is, for example, 500, 1,000, 2,000, or 3,000. The upper limit of the weight average molecular weight of the polymer (A) is, for example, 100,000, 50,000, 30,000, 20,000, or 10,000.

[0093] <Solvent> The solvent is not particularly limited and may be water or an organic solvent. Examples of the organic solvent include alkylene glycol monoalkyl ether and monocarboxylic acid ester of alkylene glycol monoalkyl ether.

[0094] Examples of the alkylene group of the alkylene glycol monoalkyl ether include alkylene groups having 2 to 4 carbon atoms. Examples of the alkyl group of the alkylene glycol monoalkyl ether include alkyl groups having 1 to 4 carbon atoms. Examples of the number of carbon atoms of the alkylene glycol monoalkyl ether include 3 to 8. Examples of the alkylene glycol monoalkyl ether include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether.

[0095] Examples of the alkylene group of the monocarboxylic acid ester of alkylene glycol monoalkyl ether include alkylene groups having 2 to 4 carbon atoms. Examples of the alkyl group of the monocarboxylic acid ester of alkylene glycol monoalkyl ether include alkyl groups having 1 to 4 carbon atoms. Examples of the monocarboxylic acid of the monocarboxylic acid ester of alkylene glycol monoalkyl ether include saturated monocarboxylic acids having 2 to 4 carbon atoms. Examples of saturated monocarboxylic acids having 2 to 4 carbon atoms include acetic acid, propionic acid, and butyric acid. Examples of the number of carbon atoms of the monocarboxylic acid ester of alkylene glycol monoalkyl ether include those having 5 to 10 carbon atoms. Examples of the monocarboxylic acid ester of alkylene glycol monoalkyl ether include methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, and propylene glycol propyl ether acetate.

[0096] Other organic solvents include, for example, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, cycloheptanone, 4-methyl-2-pentanol, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, ethyl ethoxyacetate, 2-hydroxyethyl acetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, 2-heptanone, methoxycyclopentane, anisole, γ-butyrolactone, N-methylpyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide.

[0097] Among these solvents, alkylene glycol monoalkyl ethers and monocarboxylic acid esters of alkylene glycol monoalkyl ethers are preferred.

[0098] These solvents may be used alone or in combination of two or more.

[0099] The mass proportion of the organic solvent in the solvent is not particularly limited, but is preferably 50 mass % to 100 mass %.

[0100] The content of the solvent in the composition for forming a resist underlayer film is not particularly limited, but is preferably 50% by mass to 99.99% by mass, more preferably 75% by mass to 99.95% by mass, and particularly preferably 90% by mass to 99.9% by mass.

[0101] <Crosslinking Agent> The crosslinking agent is not particularly limited and has a structure different from that of the polymer (A).

[0102] Preferred crosslinking agents are aminoplast crosslinking agents and phenoplast crosslinking agents. Aminoplast crosslinking agents are addition condensation products of a compound having an amino group, such as melamine or guanamine, with formaldehyde. Phenoplast crosslinking agents are addition condensation products of a compound having a phenolic hydroxy group with formaldehyde.

[0103] Examples of the crosslinking agent include compounds having two or more of the following structures:

[0104] (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 bonded to, for example, a nitrogen atom or a carbon atom constituting an aromatic hydrocarbon ring.

[0105] R １０１ is preferably a hydrogen atom, a methyl group, an ethyl group or a group represented by the following structure.

[0106] (In the structure, R １０２ represents a hydrogen atom, a methyl group, or an ethyl group. * represents a bond.

[0107] As the crosslinking agent, a melamine compound, a guanamine compound, a glycoluril compound, a urea compound, or a compound having a phenolic hydroxy group is preferred. These may be used alone or in combination of two or more.

[0108] Examples of the melamine compound include hexamethylol melamine, hexamethoxymethyl melamine, a compound in which 1 to 6 methylol groups of hexamethylol melamine have been methoxymethylated, or a mixture thereof, hexamethoxyethyl melamine, hexaacyloxymethyl melamine, a compound in which 1 to 6 methylol groups of hexamethylol melamine have been acyloxymethylated, or a mixture thereof.

[0109] Examples of the guanamine compound include tetramethylolguanamine, tetramethoxymethylguanamine, a compound in which one to four methylol groups of tetramethylolguanamine are methoxymethylated, or a mixture thereof; tetramethoxyethylguanamine, tetraacyloxyguanamine, a compound in which one to four methylol groups of tetramethylolguanamine are acyloxymethylated, or a mixture thereof; and the like.

[0110] Examples of glycoluril compounds include tetramethylol glycoluril, tetramethoxy glycoluril, tetramethoxymethyl glycoluril, compounds in which one to four methylol groups of tetramethylol glycoluril are methoxymethylated or mixtures thereof, and compounds in which one to four methylol groups of tetramethylol glycoluril are acyloxymethylated or mixtures thereof.

[0111] The glycoluril compound may be, for example, a glycoluril derivative represented by the following formula (1E).

[0112] (In formula (1E), four R １ each independently represents a methyl group or an ethyl group, R ２ and R ３ each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group.

[0113] Examples of the glycoluril derivative represented by the formula (1E) include compounds represented by the following formulas (1E-1) to (1E-6).

[0114]

[0115] The glycoluril derivative represented by formula (1E) can be obtained, for example, by reacting a glycoluril derivative represented by the following formula (2E) with at least one compound represented by the following formula (3d).

[0116] (In formula (2E), R ２ and R ３ each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group; R４ each independently represents an alkyl group having 1 to 4 carbon atoms.

[0117] (In formula (3d), R １ represents a methyl group or an ethyl group.)

[0118] Examples of glycoluril derivatives represented by formula (2E) include compounds represented by formulas (2E-1) to (2E-4) below. Furthermore, examples of compounds represented by formula (3d) include compounds represented by formulas (3d-1) and (3d-2) below.

[0119]

[0120]

[0121] Examples of the urea compound include tetramethylol urea, tetramethoxymethyl urea, tetramethylol urea compounds in which one to four methylol groups are methoxymethylated, or mixtures thereof, and tetramethoxyethyl urea.

[0122] Examples of the compound having a phenolic hydroxy group include compounds represented by the following formula (G-1) or (G-2).

[0123] (In formula (G-1) and formula (G-2), Q １ represents a single bond or a monovalent organic group. １ and R ４ R 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 R represents a hydrogen atom or a methyl group. ３ and R ６ n 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 an integer ≦3, n ２ is 2≦n ２ n is an integer ≦5 ３ is 0≦n ３ an integer ≦3, n４ is 0≦n ４ an integer ≦3, 3≦(n １ +n ２ +n ３ +n ４ ) represents an integer ≦6. ５ is 1≦n ５ an integer ≦3, n ６ is 1≦n ６ n is an integer ≦4 ７ is 0≦n ７ an integer ≦3, n ８ is 0≦n ８ an integer ≦3, 2≦(n ５ +n ６ +n ７ +n ８ ) represents an integer of ≦5. m1 represents an integer of 2 to 10.

[0124] Examples of compounds having a phenolic hydroxy group include compounds represented by the following formula (G-3) or formula (G-4): The compound represented by formula (G-1) or formula (G-2) may be obtained by reacting a compound represented by the following formula (G-3) or formula (G-4) with a hydroxyl group-containing ether compound or an alcohol having 2 to 10 carbon atoms.

[0125] (In formula (G-3) and formula (G-4), Q ２ represents a single bond or a divalent organic group. ８ , R ９ , R １１ and R １２ R represents a hydrogen atom or a methyl group. ７ and R １０ n 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 an integer ≦3, n １０ is 2≦n １０ n is an integer ≦5 １１ is 0≦n １１ an integer ≦3, n １２ is 0≦n １２ an integer ≦3, 3≦(n ９ +n １０ +n １１ +n １２) represents an integer ≦6. １３ is 1≦n １３ an integer ≦3, n １４ is 1≦n １４ n is an integer ≦4 １５ is 0≦n １５ an integer ≦3, n １６ is 0≦n １６ an integer ≦3, 2≦(n １３ +n １４ +n １５ +n １６ ) represents an integer of ≦5. m2 represents an integer of 2 to 10. ２ In the above, the m2-valent organic group includes, for example, an m2-valent organic group having 1 to 4 carbon atoms.

[0126] Examples of the compound represented by formula (G-1) or formula (G-2) include the following compounds:

[0127]

[0128]

[0129]

[0130]

[0131]

[0132] Examples of the compound represented by formula (G-3) or formula (G-4) include the following compounds:

[0133]

[0134] The above compound is available as a product of Asahi Organic Chemicals Co., Ltd. and Honshu Chemical Industry Co., Ltd. An example of the product is TMOM-BP, a product name of Asahi Organic Chemicals Co., Ltd.

[0135] Among these, glycoluril compounds are preferred, specifically tetramethylol glycoluril, tetramethoxy glycoluril, tetramethoxymethyl glycoluril, tetramethylol glycoluril compounds in which one to four methylol groups are methoxymethylated or mixtures thereof, and tetramethylol glycoluril compounds in which one to four methylol groups are acyloxymethylated or mixtures thereof, with tetramethoxymethyl glycoluril being preferred.

[0136] The molecular weight of the crosslinking agent is not particularly limited, but is preferably 500 or less.

[0137] The content of the crosslinking agent in the composition for forming a resist underlayer film is not particularly limited, but is, for example, 1% by mass to 50% by mass, and preferably 5% by mass to 40% by mass, relative to the polymer (A).

[0138] <Curing Catalyst> The curing catalyst contained as an optional component in the composition for forming a resist underlayer film may be either a thermal acid generator or a photoacid generator, but it is preferable to use a thermal acid generator. Examples of the thermal acid generator include sulfonic acid compounds and carboxylic acid compounds such as p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium-p-toluenesulfonate (pyridinium-p-toluenesulfonic acid), pyridinium phenolsulfonic acid, pyridinium-p-hydroxybenzenesulfonic acid (pyridinium p-phenolsulfonate salt), 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.

[0139] Examples of the photoacid generator include an onium salt compound, a sulfonimide compound, and a disulfonyldiazomethane compound.

[0140] Examples of the onium salt compound include iodonium salt compounds such as diphenyliodonium hexafluorophosphate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-normal butanesulfonate, diphenyliodonium perfluoro-normal 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 nonafluoro-normal butanesulfonate, triphenylsulfonium camphorsulfonate, and triphenylsulfonium trifluoromethanesulfonate.

[0141] Examples of the sulfonimide compound include N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoronormalbutanesulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, and N-(trifluoromethanesulfonyloxy)naphthalimide.

[0142] Examples of the disulfonyldiazomethane compound include bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(2,4-dimethylbenzenesulfonyl)diazomethane, and methylsulfonyl-p-toluenesulfonyldiazomethane.

[0143] The curing catalyst may be used alone or in combination of two or more.

[0144] When a curing catalyst is used, the content of the curing catalyst is, for example, 0.1% by mass to 50% by mass, and preferably 1% by mass to 30% by mass, relative to the crosslinking agent.

[0145] <Other Components> A surfactant may be further added to the composition for forming a resist underlayer film in order to prevent pinholes, striations, and the like from occurring and to further improve the coatability against surface irregularities.

[0146] Examples of surfactants include linear or branched alkylbenzenesulfonic acids (e.g., dodecylbenzenesulfonic acid, etc.), 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, and polyoxyethylene sorbitan monolaurate. nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters, such as polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate; fluorine-based surfactants such as Eftop EF301, EF303, and EF352 (trade names, manufactured by Tochem Products Co., Ltd.), Megafac F171, F173, and R-30 (trade names, manufactured by DIC Corporation), Fluorad FC430 and FC431 (trade names, manufactured by Sumitomo 3M Limited), Asahiguard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, and SC106 (trade names, manufactured by AGC Inc.); and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.). The amount of these surfactants to be added is usually 2.0 mass % or less, and preferably 1.0 mass % or less, based on the total solid content of the composition for forming a resist underlayer film. These surfactants may be added alone or in combination of two or more.

[0147] The composition for forming a resist underlayer film may contain a polymerization inhibitor (radical trapping agent) as necessary. Examples of the polymerization inhibitor include 2,6-diisobutylphenol, 3,5-di-tert-butylphenol, 3,5-di-tert-butylcresol, hydroquinone, hydroquinone monomethyl ether, pyrogallol, tert-butylcatechol, and 4-methoxy-1-naphthol. The content of the polymerization inhibitor in the composition for forming a resist underlayer film is not particularly limited, but is preferably 1 mass % or less based on the solid content.

[0148] The solid content of the composition for forming a resist underlayer film of the present invention, that is, the content of components excluding the solvent, is, for example, 0.01% by mass to 10% by mass.

[0149] The composition for forming a resist underlayer film is preferably used for EUV lithography.The composition for forming a resist underlayer film is preferably used for forming an underlayer film of a metal-containing resist.

[0150] (Resist Underlayer Film) The resist underlayer film of the present invention is a cured product of the composition for forming a resist underlayer film described above. The resist underlayer film can be produced, for example, by applying the composition for forming a resist underlayer film described above onto a semiconductor substrate and baking the applied composition.

[0151] Examples of semiconductor substrates onto which the resist underlayer film-forming composition can be applied include silicon wafers, germanium wafers, and wafers of compound semiconductors such as gallium arsenide, indium phosphide, gallium nitride, indium nitride, and aluminum nitride.

[0152] When a semiconductor substrate having an inorganic film formed on its surface is used, the inorganic film can be 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 a polysilicon film, a silicon oxide film, a silicon nitride film, a BPSG (Boro-Phospho Silicate Glass) film, a titanium nitride film, a titanium nitride oxide film, a tungsten film, a gallium nitride film, and a gallium arsenide film.

[0153] The resist underlayer film-forming composition of the present invention is applied to such a semiconductor substrate by a suitable application method such as a spinner or coater. The composition is then baked using a heating means such as a hot plate to form a resist underlayer film. The baking conditions are appropriately selected from a baking temperature of 100°C to 400°C and a baking time of 0.3 to 60 minutes. A baking temperature of 120°C to 350°C and a baking time of 0.5 to 30 minutes are preferred, and a baking temperature of 150°C to 300°C and a baking time of 0.8 to 10 minutes are more preferred.

[0154] The thickness of the resist underlayer film may 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 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).

[0155] The method for measuring the film thickness of the resist underlayer film in this specification is as follows: Name of measuring device: Ellipso film thickness measuring device RE-3100 (SCREEN Corporation) SWE (single wavelength ellipsometer) mode Arithmetic mean of 8 points (for example, measuring 8 points at 1 cm intervals in the X direction of the wafer)

[0156] (Laminate) The laminate of the present invention includes a semiconductor substrate and the resist underlayer film of the present invention. Examples of the semiconductor substrate include the semiconductor substrates described above. The resist underlayer film is disposed on the semiconductor substrate, for example.

[0157] (Method for manufacturing a semiconductor element, method for forming a pattern) The method for manufacturing a semiconductor element of the present invention includes at least the following steps: forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film of the present invention, and forming a resist film on the resist underlayer film.

[0158] The pattern forming method of the present invention includes at least the following steps: forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film of the present invention, forming a resist film on the resist underlayer film, irradiating the resist film with light or an electron beam and then developing the resist film to obtain a resist pattern, and etching the resist underlayer film using the resist pattern as a mask.

[0159] Typically, a resist layer is formed on the resist underlayer film. The film thickness of the resist layer is, 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 limit is 100 nm, 80 nm, 50 nm, 30 nm, 20 nm, or 10 nm.

[0160] The resist film formed on the resist underlayer film by a known method (e.g., coating and baking a resist composition) is not particularly limited as long as it is responsive to light or electron beam (EB) irradiation. Both negative and positive photoresists can be used. In this specification, resists responsive to EB are also referred to as photoresists. Examples of photoresists include positive photoresists composed of a novolak resin and a 1,2-naphthoquinone diazide sulfonic acid ester; chemically amplified photoresists composed of a binder having a group that decomposes in the presence of an acid to increase the alkaline dissolution rate and a photoacid generator; chemically amplified photoresists composed of a low-molecular-weight compound that decomposes in the presence of an acid to increase the alkaline dissolution rate of the photoresist, an alkali-soluble binder, and a photoacid generator; chemically amplified photoresists composed of a binder having a group that decomposes in the presence of an acid to increase the alkaline dissolution rate, a low-molecular-weight compound that decomposes in the presence of an acid to increase the alkaline dissolution rate of the photoresist, and a photoacid generator; and resists containing metal elements. Examples of such photoresists include V146G (trade name) manufactured by JSR Corporation, APEX-E (trade name) manufactured by Shipley Co., Ltd., PAR710 (trade name) manufactured by Sumitomo Chemical Co., Ltd., and AR2772 and SEPR430 (trade names) manufactured by Shin-Etsu Chemical Co., Ltd. Further 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).

[0161] 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 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., radiation-sensitive resin compositions, so-called resist compositions such as high-resolution patterning compositions based on organometallic solutions, and metal-containing resist compositions can be used, but are not limited to these.

[0162] Examples of the resist composition include the following compositions.

[0163] An actinic ray-sensitive or radiation-sensitive resin composition comprising: Resin A having a repeating unit having an acid-decomposable group in which a polar group is protected with a protecting group that is cleaved by the action of an acid; and a compound represented by the following general formula (121):

[0164] In the general formula (121), m represents an integer of 1 to 6. １ and R ２ each independently represents a fluorine atom or a perfluoroalkyl group. １ is -O-, -S-, -COO-, -SO ２ - or -SO ３ - represents. ２ represents an alkylene group which may have a substituent or a single bond. １ represents a cyclic organic group which may have a substituent. ＋ represents a cation.

[0165] A metal-containing film-forming composition for extreme ultraviolet or electron beam lithography, comprising a compound having a metal-oxygen covalent bond and a solvent, wherein the metal element constituting the compound belongs to Periods 3 to 7 of Groups 3 to 15 of the periodic table.

[0166] A radiation-sensitive resin composition comprising: a polymer having a first structural unit represented by the following formula (31) and a second structural unit represented by the following formula (32) containing an acid-dissociable group; and an acid generator.

[0167] In formula (31), Ar is a group obtained by removing (n+1) hydrogen atoms from an arene having 6 to 20 carbon atoms. 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, multiple R １ are the same or different. ２ is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 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 ４is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0168] A resist composition comprising: a resin (A1) containing a structural unit having a cyclic carbonate structure, a structural unit represented by the following formula, and a structural unit having an acid labile group; and an acid generator.

[0169] [In the formula, R ２ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom; X １ represents a single bond, —CO—O—*, or —CO—NR ４ -*, * represents a bond to -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 a hydroxy group and a carboxyl group.]

[0170] Examples of the resist film include the following.

[0171] A resist film comprising a base resin comprising a repeating unit represented by the following formula (a1) and / or a repeating unit represented by the following formula (a2), and a repeating unit that generates an acid bonded to a polymer main chain upon exposure:

[0172] (In formula (a1) and formula (a2), R Ａ are each independently a hydrogen atom or a methyl group. １ and R ２ are each independently a tertiary alkyl group having 4 to 6 carbon atoms. ３ are each independently a fluorine atom or a methyl group, and m is an integer of 0 to 4. １ X is a single bond, a phenylene group, or a naphthylene group, or a linking group having 1 to 12 carbon atoms and containing at least one selected from an ester bond, a lactone ring, a phenylene group, and a naphthylene group. ２ is a single bond, an ester bond, or an amide bond.

[0173] Examples of resist materials include the following:

[0174] A resist material comprising a polymer having a repeating unit represented by the following formula (b1) or (b2):

[0175] (In formula (b1) and formula (b2), R Ａ is a hydrogen atom or a methyl group. １ is a single bond or an ester group. ２ 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 some 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 contained in X is substituted with 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 are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one is a fluorine atom or a trifluoromethyl group. １ and Rf ２ may combine to form a carbonyl group. １ ~R ５ are each 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, in which some or all of the hydrogen atoms may be substituted with a hydroxy group, a carboxy 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 in which 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 sulfonate ester group. １ and R ２may be bonded to form a ring together with the sulfur atom to which they are attached.

[0176] A resist material comprising a base resin containing a polymer containing a repeating unit represented by the following formula (a):

[0177] (In formula (a), R Ａ is a hydrogen atom or a methyl group. １ is a hydrogen atom or an acid labile group. ２ is a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, or a halogen atom other than bromine. １ X is a single bond, a phenylene group, or a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms which may contain an ester group or a lactone ring. ２ is -O-, -O-CH ２ - or -NH-. m is an integer of 1 to 4. u is an integer of 0 to 3. However, m+u is an integer of 1 to 4.

[0178] A resist composition that generates an acid upon exposure, and whose solubility in a developer changes due to the action of the acid, comprising: a base component (A) 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) that has a structural unit (f1) that includes a base dissociable group, and a structural unit (f2) that includes a group represented by the following general formula (f2-r-1):

[0179] [In formula (f2-r-1), Rf ２１ are each independently a hydrogen atom, an alkyl group, an alkoxy group, a hydroxy group, a hydroxyalkyl group, or a cyano group. n" is an integer of 0 to 2. * is a bond.

[0180] The structural unit (f1) includes a structural unit represented by the following general formula (f1-1) or a structural unit represented by the following general formula (f1-2).

[0181] [In formulas (f1-1) and (f1-2), each 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 represents a divalent aromatic cyclic group which may have a substituent. ０１ is a single bond or a divalent linking group. ２ are each independently an organic group having a fluorine atom.

[0182] The resist composition may be a metal-containing resist. Metal-containing resists are also called metal oxide resists (MOR), and a representative example is a tin oxide-based resist. Examples of metal oxide resist materials include coating compositions containing metal oxo-hydroxo networks having organic ligands via metal-carbon bonds and / or metal carboxylate bonds, as described in JP-A-2019-113855. One example of a metal-containing resist uses a peroxo ligand as a radiation-sensitive stabilizing ligand. Details of peroxo-based metal oxo-hydroxo compounds are described, for example, in the patent document described in paragraph

[0011] of JP-A-2019-532489. Examples of such patent documents include U.S. Pat. No. 9,176,377 B2, U.S. Patent Application Publication No. 2013 / 0224652 A1, U.S. Pat. No. 9,310,684 B2, U.S. Patent Application Publication No. 2016 / 0116839 A1, and U.S. Patent Application Publication No. 15 / 291738.

[0183] A coating comprising a metal oxo-hydroxo network having organic ligands with metal carbon and / or metal carboxylate bonds.

[0184] Inorganic oxo / hydroxo-based compositions.

[0185] a coating solution comprising an organic solvent; a first organometallic composition having the formula R ｚ SnO （２－（ｚ／２）－（ｘ／２）） (OH) ｘ (where 0<z≦2 and 0<(z+x)≦4), formula R′ｎ SnX ４－ｎ wherein n=1 or 2, or mixtures thereof, where R and R′ are independently hydrocarbyl groups having 1 to 31 carbon atoms, and X is a ligand having a hydrolyzable bond to Sn, or a combination thereof; and a hydrolyzable metal compound having the formula MX′ ｖ wherein M is a metal selected from groups 2 to 16 of the periodic table of the elements, v is a number from 2 to 6, and X' is a ligand having a hydrolyzable M-X bond or a combination thereof.

[0186] an organic solvent and a solution of the formula RSnO （３／２－ｘ／２） (OH) ｘ and a first organometallic compound of the formula: wherein 0<x<3, wherein the solution contains from about 0.0025M to about 1.5M tin, and R is an alkyl or cycloalkyl group having from 3 to 31 carbon atoms, the alkyl or cycloalkyl group being bonded to the tin at a secondary or tertiary carbon atom.

[0187] An aqueous inorganic patterning precursor solution comprising a mixture of water, metal suboxide cations, polyatomic inorganic anions, and radiation-sensitive ligands comprising peroxide groups.

[0188] Other examples of metal-containing resists include those described in JP 2011-253185 A, WO 2015 / 026482, WO 2016 / 065120, WO 2017 / 066319, WO 2017 / 156388, WO 2018 / 031896, JP 2020-122959 A, JP 2020-122960 A, WO 2019 / 099981, WO 2019 / 199467, WO 2019 / 195522, WO 2019 / 195522, WO 2020 / 210660, WO 2021 / 011367, and WO 2021 / 016229. The contents of these are incorporated herein in their entirety to the same extent as if set forth in full.

[0189] The method for forming a metal-containing resist film from a metal-containing resist is not particularly limited, and examples include a method in which a coating-type resist material (a composition for forming a metal-containing resist film) that is a metal-containing resist is coated and baked.

[0190] The metal-containing resist film may also be formed by vapor deposition. Examples of methods for forming a metal-containing resist film by vapor deposition include the method described in JP 2017-116923 A. The contents of JP 2017-116923 A are incorporated herein by reference to the same extent as if fully set forth herein. In JP 2017-116923 A, the metal-containing resist film of the present invention is referred to as a metal oxide-containing film.

[0191] Irradiation with light or electron beams is carried out, for example, through a mask (reticle) for forming a predetermined pattern. For example, i-line, KrF excimer laser, ArF excimer laser, EUV (extreme ultraviolet), or EB (electron beam) can be used. The composition for forming a resist underlayer film of the present invention is preferably applied for EB (electron beam) or EUV (extreme ultraviolet: 13.5 nm) irradiation, more preferably for EUV (extreme ultraviolet) exposure. The irradiation energy of the electron beam and the exposure dose of light are not particularly limited.

[0192] After irradiation with light or electron beams and before development, baking (PEB: Post Exposure Bake) may be performed. The baking temperature is not particularly limited, but is preferably 60° C. to 260° C., more preferably 70° C. to 180° C., and particularly preferably 75° C. to 110° C. The baking 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.

[0193] For example, an alkaline developer or an organic solvent is used for development. The development temperature is, for example, 5°C to 50°C. The development time is, for example, 10 seconds to 300 seconds. Examples of alkaline developers that can be used include aqueous solutions of alkalis such as inorganic alkalis (e.g., sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia); primary amines (e.g., ethylamine and n-propylamine); secondary amines (e.g., diethylamine and di-n-butylamine); tertiary amines (e.g., triethylamine and methyldiethylamine); alcohol amines (e.g., dimethylethanolamine and triethanolamine); quaternary ammonium salts (e.g., tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline); and cyclic amines (e.g., pyrrole and piperidine). Furthermore, the aqueous solutions of the alkalis may be used by adding an appropriate amount of alcohols (e.g., isopropyl alcohol) or a nonionic surfactant. Among these, preferred developers are aqueous solutions of quaternary ammonium salts, more preferably aqueous solutions of tetramethylammonium hydroxide and choline. Furthermore, surfactants and the like may also be added to these developers. Alternatively, development may be carried out with an organic solvent such as butyl acetate instead of an alkaline developer, and the portions of the photoresist where the alkaline dissolution rate is not improved may be developed.

[0194] An organic solvent can be used as a developer for the metal-containing resist, and development is carried out with the developer (solvent) after irradiation with light or electron beams. As a result, for example, when a negative metal-containing resist film is used, the metal-containing resist film in the unexposed areas is removed, and a pattern of the metal-containing resist film is formed. Examples of the developer (organic solvent) include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methyl ... -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 of the developer 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 and the like can also be added to these developers.

[0195] 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. Thereafter, the semiconductor substrate is processed by a known method (e.g., dry etching), thereby manufacturing a semiconductor device.

[0196] The present invention will now be described in detail with reference to examples, but the present invention is not limited to these examples.

[0197] The weight average molecular weight (Mw) of the polymers shown in the following synthesis examples is the result of measurement by gel permeation chromatography (GPC). A GPC device manufactured by Tosoh Corporation was used for the measurement, and the measurement conditions are as follows: Measurement device: HLC-8020GPC (trade name) (manufactured by Tosoh Corporation) GPC column: TSKgel G2000HXL; 2 columns, G3000HXL; 1 column, G4000HXL; 1 column (trade name) (all manufactured by Tosoh Corporation) Column temperature: 40°C Solvent: tetrahydrofuran (THF) Flow rate: 1.0 mL / min Standard sample: polystyrene (manufactured by Tosoh Corporation)

[0198] Synthesis Example 1 63.64 g of glycidyl methacrylate and 6.36 g of 2,2'-azobisisobutyronitrile were dissolved in 130.00 g of propylene glycol monomethyl ether acetate. After replacing the atmosphere in the reaction vessel with nitrogen, the solution was heated and stirred at 100°C for approximately 24 hours. The reaction solution was added dropwise to isopropyl alcohol, and the precipitate was recovered by suction filtration and then dried under reduced pressure at 40°C to recover polymer 1. The weight average molecular weight Mw measured by GPC in terms of polystyrene was 3700. The polymer obtained in this synthesis example has a structural unit represented by the following formula (1'):

[0199]

[0200] Synthesis Example 2 1.71 g of polyglycidyl methacrylate synthesized in Synthesis Example 1, 4.17 g of 4-((6-(methacryloyloxy)hexyl)oxy)cinnamic acid, 0.006 g of hydroquinone, and 0.12 g of tetrabutylphosphonium bromide were added to 20 g of propylene glycol monomethyl ether acetate and 20 g of propylene glycol monomethyl ether in a reaction vessel and dissolved. The reaction vessel was then purged with nitrogen, and the mixture was reacted at 90°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and had good solubility in the propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent. GPC analysis revealed that the polymer in the obtained solution had a weight-average molecular weight of 12,000 in terms of standard polystyrene. The polymer obtained in this Synthesis Example has a structural unit represented by the following formula (1a):

[0201]

[0202] Synthesis Example 3: 1.81 g of polyglycidyl methacrylate synthesized in Synthesis Example 1, 4.06 g of 4-{[6-(methacryloyloxy)hexyl]oxy}benzenecarboxylic acid, 0.007 g of hydroquinone, and 0.12 g of tetrabutylphosphonium bromide were added to 20 g of propylene glycol monomethyl ether acetate and 20 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 90°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and exhibited good solubility in a propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent. Analysis by GPC revealed that the polymer in the obtained solution had a weight-average molecular weight of 10,600 in terms of standard polystyrene. The polymer obtained in this Synthesis Example had a structural unit represented by the following formula (1b):

[0203]

[0204] Synthesis Example 4 1.39 g of polyglycidyl methacrylate synthesized in Synthesis Example 1, 4.51 g of 4-[[4-[[6-[(1-oxo-2-propenyl)oxy]hexyl]oxy]benzoyl]oxy]benzenepropanoic acid, 0.005 g of hydroquinone, and 0.09 g of tetrabutylphosphonium bromide were added to 20 g of propylene glycol monomethyl ether acetate and 20 g of propylene glycol monomethyl ether in a reaction vessel and dissolved. The reaction vessel was then purged with nitrogen, and the mixture was reacted at 90°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and exhibited good solubility in a propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent. Analysis by GPC revealed that the polymer in the obtained solution had a weight-average molecular weight of 11,700 in terms of standard polystyrene. The polymer obtained in this Synthesis Example had a structural unit represented by the following formula (1c):

[0205]

[0206] Synthesis Example 5 2.52 g of polyglycidyl methacrylate synthesized in Synthesis Example 1, 3.29 g of 4-hydroxyphenyl methacrylate, 0.009 g of hydroquinone, and 0.17 g of tetrabutylphosphonium bromide were added to 20 g of propylene glycol monomethyl ether acetate and 20 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 90°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and exhibited good solubility in a propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent. Analysis by GPC revealed that the polymer in the obtained solution had a weight-average molecular weight of 18,400 in terms of standard polystyrene. The polymer obtained in this Synthesis Example had a structural unit represented by the following formula (1d):

[0207]

[0208] Synthesis Example 6 1.09 g of cresol novolac epoxy resin EOCN-104S (manufactured by Nippon Kayaku Co., Ltd.), 1.85 g of 4-((6-(methacryloyloxy)hexyl)oxy)cinnamic acid, 0.01 g of hydroquinone, and 0.05 g of tetrabutylphosphonium bromide were added to 23.67 g of propylene glycol monomethyl ether in a reaction vessel and dissolved. The atmosphere in the reaction vessel was replaced with nitrogen, and the reaction was carried out at 105°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and the solubility in the propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent was good. Analysis by GPC revealed that the weight average molecular weight of the polymer in the obtained solution was 6,000 in terms of standard polystyrene. The polymer obtained in this Synthesis Example has a structural unit represented by the following formula (1e):

[0209]

[0210] Synthesis Example 7 1.00 g of alicyclic epoxy resin NER-HM (manufactured by Finechem Co., Ltd.), 5.50 g of 4-{[6-(methacryloyloxy)hexyl]oxy}benzenecarboxylic acid, 0.05 g of hydroquinone, and 0.19 g of tetrabutylphosphonium bromide were added to 37.02 g of propylene glycol monomethyl ether in a reaction vessel and dissolved. The atmosphere in the reaction vessel was replaced with nitrogen, and the reaction was carried out at 105°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and exhibited good solubility in a propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent. Analysis by GPC revealed that the weight-average molecular weight of the polymer in the resulting solution was 7,180 in terms of standard polystyrene. The polymer obtained in this synthesis example has a structural unit represented by the following formula (1f):

[0211]

[0212] Synthesis Example 8 1.00 g of alicyclic epoxy resin NER-HM (manufactured by Finechem Co., Ltd.), 7.91 g of 4-[[4-[[6-[(1-oxo-2-propenyl)oxy]hexyl]oxy]benzoyl]oxy]benzenepropanoic acid, 0.05 g of hydroquinone, and 0.19 g of tetrabutylphosphonium bromide were added to 46.65 g of propylene glycol monomethyl ether in a reaction vessel and dissolved. The atmosphere in the reaction vessel was replaced with nitrogen, and the reaction was carried out at 105°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and exhibited good solubility in a propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent. Analysis by GPC revealed that the weight-average molecular weight of the polymer in the obtained solution was 8,240 in terms of standard polystyrene. The polymer obtained in this Synthesis Example has a structural unit represented by the following formula (1g):

[0213]

[0214] Synthesis Example 9 3.00 g of polyglycidyl methacrylate synthesized in Synthesis Example 1, 2.38 g of propionic acid, and 0.21 g of tetrabutylphosphonium bromide were added to 32 g of propylene glycol monomethyl ether acetate and 32 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 80°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and exhibited good solubility in a propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent. Analysis by GPC revealed that the polymer in the obtained solution had a weight-average molecular weight of 10,426 in terms of standard polystyrene. The polymer obtained in this Synthesis Example had a structural unit represented by the following formula (2a):

[0215]

[0216] (Preparation of composition 1 for forming resist underlayer film) 0.43 g of a 5 mass % propylene glycol monomethyl ether solution of tetramethoxymethyl glycoluril, 0.22 g of a 1 mass % propylene glycol monomethyl ether solution of pyridinium phenolsulfonic acid, 33 g of propylene glycol monomethyl ether, and 15 g of propylene glycol monomethyl ether acetate were added to and dissolved in 0.66 g of the polymer solution (solid content 13.1 mass %) obtained in Synthesis Example 2. The mixture was then filtered using a polyethylene microfilter with a pore size of 0.05 μm to obtain composition 1 for forming a resist underlayer film for lithography.

[0217] (Preparation of composition 2 for forming resist underlayer film) 0.43 g of a 5 mass % propylene glycol monomethyl ether solution of tetramethoxymethyl glycoluril, 0.22 g of a 1 mass % propylene glycol monomethyl ether solution of pyridinium phenolsulfonic acid, 33 g of propylene glycol monomethyl ether, and 15 g of propylene glycol monomethyl ether acetate were added to and dissolved in 0.66 g of the polymer solution (solid content 13.0 mass %) obtained in Synthesis Example 3. The mixture was then filtered using a polyethylene microfilter having a pore size of 0.05 μm to obtain composition 2 for forming a resist underlayer film for lithography.

[0218] (Preparation of resist underlayer film-forming composition 3) 0.43 g of a 5 mass % propylene glycol monomethyl ether solution of tetramethoxymethyl glycoluril, 0.22 g of a 1 mass % propylene glycol monomethyl ether solution of pyridinium phenolsulfonic acid, 33 g of propylene glycol monomethyl ether, and 15 g of propylene glycol monomethyl ether acetate were added to and dissolved in 0.66 g of the polymer solution (solid content 13.0 mass %) obtained in Synthesis Example 4. The mixture was then filtered using a polyethylene microfilter having a pore size of 0.05 μm to obtain resist underlayer film-forming composition 3 for lithography.

[0219] (Preparation of Resist Underlayer Film-Forming Composition 4) 0.37 g of a 5 mass % propylene glycol monomethyl ether solution of tetramethoxymethyl glycoluril, 0.19 g of a 1 mass % propylene glycol monomethyl ether solution of pyridinium phenolsulfonic acid, 34 g of propylene glycol monomethyl ether, and 14 g of propylene glycol monomethyl ether acetate were added to and dissolved in 0.74 g of the polymer solution (solid content 10.05 mass %) obtained in Synthesis Example 5. The mixture was then filtered using a polyethylene microfilter having a pore size of 0.05 μm to obtain Resist Underlayer Film-Forming Composition 4.

[0220] (Preparation of composition for forming resist underlayer film 5) 0.37 g of a 5 mass % propylene glycol monomethyl ether solution of tetramethoxymethyl glycoluril, 0.19 g of a 1 mass % propylene glycol monomethyl ether solution of pyridinium phenolsulfonic acid, 34 g of propylene glycol monomethyl ether, and 14 g of propylene glycol monomethyl ether acetate were added to 0.74 g of the polymer solution (solid content 10.38 mass %) obtained in Synthesis Example 6 and dissolved. The mixture was then filtered using a polyethylene microfilter with a pore size of 0.05 μm to obtain composition for forming resist underlayer film for lithography 5.

[0221] (Preparation of Resist Underlayer Film Forming Composition 6) 0.37 g of a 5 mass % propylene glycol monomethyl ether solution of tetramethoxymethyl glycoluril (manufactured by Nippon Cytec Industries Co., Ltd.), 0.18 g of a 1 mass % propylene glycol monomethyl ether solution of pyridinium phenolsulfonic acid, 34 g of propylene glycol monomethyl ether, and 14 g of propylene glycol monomethyl ether acetate were added to 0.43 g of the polymer solution (solid content 17.0 mass %) obtained in Synthesis Example 7 and dissolved. The mixture was then filtered using a polyethylene microfilter having a pore size of 0.05 μm to obtain Resist Underlayer Film Forming Composition 6 for lithography.

[0222] (Preparation of Resist Underlayer Film Forming Composition 7) 0.37 g of a 5 mass % propylene glycol monomethyl ether solution of tetramethoxymethylglycoluril (manufactured by Nippon Cytec Industries Co., Ltd.), 0.19 g of a 1 mass % propylene glycol monomethyl ether solution of pyridinium phenolsulfonic acid, 34 g of propylene glycol monomethyl ether, and 15 g of propylene glycol monomethyl ether acetate were added to 0.46 g of the polymer solution (solid content 16.3 mass %) obtained in Synthesis Example 8 and dissolved. The mixture was then filtered using a polyethylene microfilter with a pore size of 0.05 μm to obtain Resist Underlayer Film Forming Composition 7 for lithography.

[0223] (Preparation of Resist Underlayer Film Forming Composition 8) 0.38 g of a 5 mass % propylene glycol monomethyl ether solution of tetramethoxymethyl glycoluril (manufactured by Nippon Cytec Industries Co., Ltd.), 0.19 g of a 1 mass % propylene glycol monomethyl ether solution of pyridinium phenolsulfonic acid, 33 g of propylene glycol monomethyl ether, and 15 g of propylene glycol monomethyl ether acetate were added to 0.41 g of the polymer solution (solid content 18.5 mass %) obtained in Synthesis Example 9 and dissolved. The mixture was then filtered using a polyethylene microfilter having a pore size of 0.05 μm to obtain Resist Underlayer Film Forming Composition 8 for lithography.

[0224] <Metal Oxide Resist Preparation Example> (Preparation of Metal Oxide Resist Composition) 0.16 g of monobutyltin oxide (manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved in 9.84 g of 4-methyl-2-pentanol, and then filtered using a polyethylene microfilter with a pore size of 0.05 μm to obtain Metal Oxide Resist Composition 1.

[0225] Example 1 (Resist Patterning Evaluation) [Formation of Metal Oxide Resist Pattern Using Electron Beam Lithography Apparatus] Resist underlayer film forming composition 1 was applied to a silicon wafer using a spinner. The silicon wafer was baked on a hot plate at 215°C for 60 seconds to obtain a resist underlayer film with a thickness of 5 nm. Metal oxide resist composition 1 prepared in the Metal Oxide Resist Preparation Example was spin-coated onto the resist underlayer film and heated at 100°C for 60 seconds to form a metal oxide resist film with a thickness of 26 nm. Subsequently, to form a target pattern, the resist was exposed under specified conditions using an electron beam lithography apparatus (ELS-G130). After exposure, the resist was baked at 260°C for 60 seconds (PEB) and developed with a developer (a 5% by weight solution of acetic acid in propylene glycol monomethyl ether acetate) to form a line and space pattern with a CD size of 22 nm and a pitch of 44 nm. The resist pattern was measured using a scanning electron microscope (CG4100, manufactured by Hitachi High-Technologies Corporation). An observation photograph of the resist pattern formed in Example 1 is shown in FIG.

[0226] Examples 2 to 7 Line and space patterns with a CD size of 22 nm and a pitch of 44 nm were formed in the same manner as in Example 1, except that compositions 2 to 7 for forming a resist underlayer film were used instead of composition 1 for forming a resist underlayer film.

[0227] Comparative Example 1 A line and space pattern with a CD size of 22 nm and a pitch of 44 nm was formed in the same manner as in Example 1, except that composition 8 for forming a resist underlayer film was used instead of composition 1 for forming a resist underlayer film.

[0228] The photoresist patterns obtained in Examples 1 to 7 and Comparative Example 1 were observed from above the patterns, and the amount of charge forming 22 nm lines / 44 nm pitch (line and space (L / S=1 / 1)) was defined as the optimal irradiation energy. The irradiation energy (mC / cm ２ The results are shown in Table 1.

[0229]

[0230] As can be seen from Table 1, in Examples 1 to 7, it is possible to reduce the irradiation energy required for pattern formation compared to Comparative Example 1, and the sensitivity of the resist is increased, so that when this process is applied, the underlayer film-forming composition is useful for resist pattern formation.

Claims

1. A composition for forming a resist underlayer film, comprising: a polymer (A) having, in its side chain, one or more polymerizable multiple bonds selected from the group consisting of a carbon-carbon double bond, a carbon-carbon triple bond, a carbon-nitrogen double bond, and a carbon-nitrogen triple bond, and an aromatic hydrocarbon ring; and a solvent.

2. The composition for forming a resist underlayer film according to claim 1, wherein the polymer (A) has a group represented by the following formula (A): (In formula (A), L １ represents a single bond or a linking group. ２ represents the divalent group having an aromatic hydrocarbon ring. ３ represents a monovalent group having a polymerizable multiple bond. * represents a bond.

3. In the group represented by formula (A), ２ The composition for forming a resist underlayer film according to claim 2 , wherein is represented by the following formula (b): (In formula (b), W １ , W ２ , and W ３ each independently represents a single bond, —O—, —C(═O)—O—, —O—C(═O)—, or —O—C(═O)—CH ２ -, -C(=O)-N(R')- or -N(R')-C(=O)-. W ２ When the number of is 2 or more, each W ２ may be the same or different. R' represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Q represents a single bond, an alkylene group having 1 to 10 carbon atoms, or an alkenylene group having 2 to 10 carbon atoms. Some or all of the hydrogen atoms of the alkylene group or alkenylene group may be substituted with halogen atoms. L ｂ is a single bond, an alkylene group having 1 to 12 carbon atoms, or —CH ２ represents a divalent linking group in which one or more - groups that are not adjacent to each other are substituted with -O-, -S-, -C(=O)-O-, or O-C(=O)-, and some or all of the hydrogen atoms of the alkylene group may be substituted with halogen atoms. １ represents a single bond, a phenylene group, a naphthylene group, or a divalent alicyclic hydrocarbon group having 5 to 8 carbon atoms, and some or all of the hydrogen atoms of the phenylene group and naphthylene group may be substituted with a cyano group, a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkylcarbonyl group having 2 to 6 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms. １ When the number of is 2 or more, each Q １ may be the same or different. ｂ is an alkyl group having 1 to 6 carbon atoms, a haloalkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a haloalkoxy group having 1 to 6 carbon atoms, a cyano group, or a nitro group. p is 0, 1, 2, 3, or 4. m is 0 or 1. n1 is 0, 1, 2, or 3. *a and *b represent bonds, and *a is a bond that is bonded to L. １ and *b is L ３ Binds to 4. Said L ２ In the divalent group represented by the formula (b), W ３ As a combination of and Q, W ３ is a single bond and Q is a single bond, W ３ is a single bond, Q is an alkylene group having 1 to 10 carbon atoms, and W ３ and Q is an alkenylene group having 2 to 10 carbon atoms.

5. Said L ２ In the divalent group represented by the formula (b), Q １ and W ２ As a combination of １ is a single bond and W ２ is a single bond, and when n1 is 1, Q １ is a phenylene group and W ２ and -C(=O)-O-.

6. Said L ２ In the divalent group represented by the formula (b), L ｂ and W １ As a combination of ｂ is a single bond and W １ is a single bond, L ｂ is an alkylene group having 1 to 10 carbon atoms, and W １ is -O-C(=O)-CH ２ - and L ｂ is an alkylene group having 1 to 10 carbon atoms, and W １ and wherein is —O—.

7. In the group represented by formula (A), １ The composition for forming a resist underlayer film according to claim 2 , wherein the linking group has a structural moiety represented by the following formula (t1) or the following formula (t2): (wherein *1 represents L in formula (A) ２ *2 represents the bond on the opposite side to the bond to L in formula (A). ２ represents a bond bonded to 8. In the group represented by formula (A), ３ The composition for forming a resist underlayer film according to claim 2 , wherein the monovalent group having a polymerizable multiple bond has a structural moiety represented by the following formula (u1) or the following formula (u2): (wherein * represents L in formula (A) ２ represents a bond bonded to 9. The composition for forming a resist underlayer film according to claim 1, wherein the polymer (A) has a structural unit represented by the following formula (1): (In formula (1), R １ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. １１ represents a single bond or a linking group. １２ represents the divalent group having an aromatic hydrocarbon ring. １３ represents the monovalent group having a polymerizable multiple bond.

10. In the structural unit represented by the formula (1), １１ The composition for forming a resist underlayer film according to claim 9, wherein the linking group is represented by the following formula (L1-1) or the following formula (L1-2): (wherein *1 represents R in formula (1) １ *2 represents a bond bonded to the carbon atom bonded to L in formula (1). １２ represents a bond bonded to 11. The composition for forming a resist underlayer film according to claim 1, wherein the polymer (A) has a structural unit represented by the following formula (2): (In formula (2), R ａ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. Ar represents a benzene ring, a naphthalene ring, or an anthracene ring. L Ｘ represents a single bond or a divalent group which may have a substituent. ２１ represents a single bond or a linking group. ２２ represents the divalent group having an aromatic hydrocarbon ring. ２３ represents the monovalent group having a polymerizable multiple bond, and n1 is an integer of 0 to 3.

12. In the structural unit represented by the formula (2), ２１ The composition for forming a resist underlayer film according to claim 11, wherein the linking group is represented by the following formula (L1-12): (In the formula, *1 represents a bond bonded to Ar in formula (2). *2 represents a bond bonded to L in formula (1). ２２ represents a bond bonded to 13. The composition for forming a resist underlayer film according to claim 1, wherein the polymer (A) has a structural unit represented by the following formula (3): (In formula (3), L ３１ represents a single bond or a linking group. ３２ represents the divalent group having an aromatic hydrocarbon ring. ３３ represents the monovalent group having a polymerizable multiple bond.

14. In the structural unit represented by the formula (3), ３１ The composition for forming a resist underlayer film according to claim 13, wherein the linking group is represented by the following formula (L1-13): (In the formula, *1 represents a bond bonded to the alicyclic hydrocarbon in formula (3). *2 represents a bond bonded to L in formula (3). ３２ represents a bond bonded to 15. The composition for forming a resist underlayer film according to claim 1, further comprising a crosslinking agent.

16. A resist underlayer film, which is a cured product of the composition for forming a resist underlayer film according to any one of claims 1 to 15.

17. A laminate comprising: a semiconductor substrate; and the resist underlayer film according to claim 16.

18. A method for manufacturing a semiconductor device, comprising: a step of forming a resist underlayer film on a semiconductor substrate using a composition for forming a resist underlayer film according to any one of claims 1 to 15; and a step of forming a resist film on the resist underlayer film.

19. A pattern formation method comprising: a step of forming a resist underlayer film on a semiconductor substrate using a composition for forming a resist underlayer film according to any one of claims 1 to 15; 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 and 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.

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