Composition for resist underlayer film formation, method for producing semiconductor substrate, and method for producing aromatic-ring-containing compound

Abstract

The present invention provides: a composition for resist underlayer film formation which makes it possible to form a resist underlayer film having excellent embedding properties and bending resistance; a method for producing a semiconductor substrate; and a method for producing an aromatic-ring-containing compound. Provided is a composition for resist underlayer film formation, said composition comprising an aromatic-ring-containing compound and a solvent, wherein the aromatic-ring-containing compound is a polymer having a repeating unit represented by formula (A4) or formula (A5) or a compound represented by formula (A1), formula (A2), or formula (A3). (In formulae (A1) to (A5), each X is independent and is -C(=O)- or -S(=O)2-.)

Description

Composition for forming a resist underlayer film, method for manufacturing a semiconductor substrate, and method for manufacturing an aromatic ring-containing compound.

[0001] This invention relates to a composition for forming a resist underlayer film, a method for manufacturing a semiconductor substrate, and a method for manufacturing an aromatic ring-containing compound.

[0002] In the manufacturing of semiconductor devices, for example, a multilayer resist process is used to form a resist pattern by exposing and developing a resist film that has been laminated on a substrate via a resist underlayer film such as an organic underlayer film or a silicon-containing film. In this process, the resist pattern is used as a mask to etch the resist underlayer film, and the substrate is further etched using the resulting resist underlayer film pattern as a mask, thereby forming a desired pattern on the semiconductor substrate.

[0003] Various studies have been conducted on materials used in such resist underlayer formation compositions (International Publication No. 2011 / 108365).

[0004] International Publication No. 2011 / 108365

[0005] Recently, substrates with patterns such as trenches and holes have been increasingly used, and the resist underlayer film formation composition is required to have sufficient embedding properties to be embedded in the substrate pattern. Furthermore, regardless of whether or not there is a pattern, the resist underlayer film is required to have bending resistance.

[0006] The present invention has been made based on the circumstances described above, and its purpose is to provide a resist underlayer film forming composition capable of forming a resist underlayer film with excellent embedding properties and bending resistance, a method for manufacturing a semiconductor substrate, and a method for manufacturing an aromatic ring-containing compound.

[0007] In one embodiment, the present invention relates to a composition for forming a resist underlayer film, which contains an aromatic ring-containing compound (hereinafter also referred to as "[A] compound") and a solvent (hereinafter also referred to as "[B] solvent"), and the aromatic ring-containing compound is a compound represented by the following formula (A1), formula (A2) or formula (A3) (hereinafter also referred to as "[A1] compound", etc., respectively), or a polymer having a repeating unit represented by the following formula (A4) or formula (A5) (hereinafter also referred to as "[A4] polymer", etc., respectively). (In formula (A1) to formula (A5), X is independently -C(=O)- or -S(=O)2- respectively. Ar ０ is independently a substituted or unsubstituted aromatic ring having 3 to 40 carbon atoms. Ar １ and Ar ２ are independently monovalent groups containing a substituted or unsubstituted aromatic ring having 3 to 40 carbon atoms. W １ is an s-valent organic group having 1 to 40 carbon atoms. s is an integer of 1 to 4. When s is 2 or more, a plurality of X, Ar ０ and Ar １ are the same as or different from each other. t is an integer of 1 to 4. When t is 2 or more, a plurality of X, Ar ０ , Ar １ and Ar ２ are the same as or different from each other respectively. W ２ is a t-valent organic group having 1 to 40 carbon atoms when t is 1, 3 or 4, and is a divalent organic group having 1 to 40 carbon atoms, a single bond or a divalent heteroatom-containing linking group when t is 2. Cy is a substituted or unsubstituted ring structure having 6 to 40 carbon atoms. u1 and u2 are independently integers of 0 to 4. However, u1 + u2 is 1 or more. A plurality of X, Ar ０ , Ar １ and Ar ２ are the same as or different from each other respectively. W ３１ is a divalent group containing an aromatic ring having 3 to 40 carbon atoms. W ３２ is a divalent organic group having 1 to 40 carbon atoms, a single bond or a divalent heteroatom-containing linking group. W ３３Ar is a divalent organic group having 1 to 40 carbon atoms. ５ (This is a divalent group containing a substituted or unsubstituted aromatic ring with 3 to 40 carbon atoms.)

[0008] The resist underlayer film formation composition in question can form a resist underlayer film with excellent embedding properties and bending resistance. Although the reason for this is not entirely clear, it is presumed to be as follows: [A] In the heterocycle having a lactone or sultone structure in the compound, the heteroatoms are densely arranged (short interatomic distance), which allows for excellent elastic modulus after film formation. Furthermore, the cardo structure of the heterocycle allows for good solubility. It is presumed that the combined effects of these factors enable the resist underlayer film formation composition to form a resist underlayer film with excellent embedding properties and bending resistance.

[0009] In other embodiments, the present invention relates to a method for manufacturing a semiconductor substrate, comprising the steps of: coating a resist underlayer film forming composition directly or indirectly onto a substrate; directly or indirectly forming a resist pattern on the resist underlayer film formed by the coating step; and etching using the resist pattern as a mask, wherein the resist underlayer film forming composition contains an aromatic ring-containing compound and a solvent, and the aromatic ring-containing compound is a compound represented by the following formula (A1), formula (A2), or formula (A3), or a polymer having repeating units represented by the following formula (A4) or formula (A5). (In equations (A1) to (A5), X is independently either -C(=O)- or -S(=O)²-.) ０ Each of these is independently a substituted or unsubstituted aromatic ring with 3 to 40 carbon atoms. １ and Ar ２ Each of these is independently a monovalent group containing a substituted or unsubstituted monovalent aromatic ring having 3 to 40 carbon atoms. １ is an s-valent organic group with 1 to 40 carbon atoms. s is an integer from 1 to 4. If s is 2 or greater, multiple X, Ar ０ and Ar １They are either identical or different from each other. t is an integer from 1 to 4. If t is 2 or greater, there are multiple X, Ar ０ Ar １ and Ar ２ These are either identical or different from each other. ２ When t is 1, 3, or 4, it is a t-valent organic group having 1 to 40 carbon atoms, and when t is 2, it is a divalent organic group having 1 to 40 carbon atoms, a single bond, or a divalent heteroatom-containing linking group. Cy is a substituted or unsubstituted ring structure having 6 to 40 carbon atoms. u1 and u2 are each independently integers from 0 to 4, except that u1 + u2 is 1 or greater. Multiple X, Ar ０ Ar １ and Ar ２ These are either identical or different from each other. ３１ This is a divalent group containing an aromatic ring with 3 to 40 carbon atoms. ３２ This refers to a divalent organic group having 1 to 40 carbon atoms, a single bond, or a linking group containing a divalent heteroatom. ３３ Ar is a divalent organic group having 1 to 40 carbon atoms. ５ (This is a divalent group containing a substituted or unsubstituted aromatic ring with 3 to 40 carbon atoms.)

[0010] According to the semiconductor substrate manufacturing method, by using a predetermined resist underlayer film formation composition in the coating step, a resist underlayer film with excellent embedding properties and bending resistance can be formed, making it possible to manufacture a semiconductor substrate with a good pattern shape.

[0011] In yet another embodiment, the present invention relates to a method for producing an aromatic ring-containing compound, comprising the step of reacting a compound represented by the following formula (a1), the following formula (a2), or the following formula (a3) ​​(hereinafter also referred to as "[a] compound") with a compound represented by the following formula (b) (hereinafter also referred to as "[b] compound"). (In equations (a1) to (a3), of the two X atoms in the five-membered ring, one is -C(=O)- and the other is -C(=O)- or -S(=O)2-.) ０Each is independently a substituted or unsubstituted aromatic ring with 3 to 40 carbon atoms. t is an integer from 1 to 4. If t is 2 or greater, multiple X and Ar ０ These are either identical or different from each other. ２ When t is 1, 3, or 4, it is a t-valent organic group having 1 to 40 carbon atoms, and when t is 2, it is a divalent organic group having 1 to 40 carbon atoms, a single bond, or a divalent heteroatom-containing linking group. Cy is a substituted or unsubstituted ring structure having 6 to 40 carbon atoms. u1 and u2 are each an integer from 0 to 4, where u1 + u2 is 1 or greater. Multiple Xs are either identical or different from each other. In formula (b), Ar is a monovalent group containing a substituted or unsubstituted aromatic ring having 3 to 40 carbon atoms. v is an integer from 1 to 4. W ０ When v is 3 or 4, it is a v-valent organic group having 1 to 40 carbon atoms; when v is 1, it is a monovalent organic group having 1 to 40 carbon atoms or a hydrogen atom; and when v is 2, it is a divalent organic group having 1 to 40 carbon atoms, a single bond, or a linking group containing a divalent heteroatom.

[0012] In this specification, "fused ring" refers to a polycyclic structure formed by adjacent rings sharing one edge (two adjacent atoms). "Organic group" refers to a group containing at least one carbon atom.

[0013] The resist underlayer film formation composition allows for the formation of a film with excellent embedding properties and bending resistance. The semiconductor substrate manufacturing method allows for the formation of a resist underlayer film with excellent embedding properties and bending resistance, thereby enabling the production of a semiconductor substrate with a good pattern shape. The aromatic ring-containing compound manufacturing method efficiently produces aromatic ring-containing compounds suitable as components of the resist underlayer film formation composition. Therefore, these can be suitably used in the manufacture of semiconductor devices, where further miniaturization is expected in the future.

[0014] This is a schematic plan view illustrating the method for evaluating bending resistance.

[0015] The following describes in detail the resist underlayer film formation compositions, semiconductor substrate manufacturing methods, and aromatic ring-containing compound manufacturing methods according to each embodiment of the present invention. Preferred combinations of embodiments are also preferred.

[0016] <Composition for forming a resist underlayer film> The resist underlayer film formation composition contains compound [A] and solvent [B]. The resist underlayer film formation composition may contain optional components as long as they do not impair the effects of the present invention. The components contained in the resist underlayer film formation composition will be described below.

[0017] <[A] Compound> The [A] compound is a compound represented by the following formula (A1), formula (A2), or formula (A3), or a polymer having repeating units represented by the following formula (A4) or formula (A5). The resist underlayer film forming composition may contain one or more [A] compounds. The [A4] polymer may have one or more repeating units represented by the following formula (A4). The [A5] polymer may have one or more repeating units represented by the following formula (A5). In the following formula, Ar ０ Alternatively, Cy has a five-membered ring structure containing -O-X- and Ar ０ Alternatively, two adjacent carbon atoms that form Cy share a fused ring structure. The same applies to other general formulas. (In equations (A1) to (A5), X is independently either -C(=O)- or -S(=O)²-.) ０ Each of these is independently a substituted or unsubstituted aromatic ring with 3 to 40 carbon atoms. １ and Ar ２ Each of these is independently a monovalent group containing a substituted or unsubstituted aromatic ring with 3 to 40 carbon atoms. １ is an s-valent organic group with 1 to 40 carbon atoms. s is an integer from 1 to 4. If s is 2 or greater, multiple X, Ar ０ and Ar １ They are either identical or different from each other. t is an integer from 1 to 4. If t is 2 or greater, there are multiple X, Ar ０ Ar １ and Ar ２These are either identical or different from each other. ２ When t is 1, 3, or 4, it is a t-valent organic group having 1 to 40 carbon atoms, and when t is 2, it is a divalent organic group having 1 to 40 carbon atoms, a single bond, or a divalent heteroatom-containing linking group. Cy is a substituted or unsubstituted ring structure having 6 to 40 carbon atoms. u1 and u2 are each independently integers from 0 to 4, except that u1 + u2 is 1 or greater. Multiple X, Ar ０ Ar １ and Ar ２ These are either identical or different from each other. ３１ This is a divalent group containing an aromatic ring with 3 to 40 carbon atoms. ３２ This refers to a divalent organic group having 1 to 40 carbon atoms, a single bond, or a linking group containing a divalent heteroatom. ３３ Ar is a divalent organic group having 1 to 40 carbon atoms. ５ (This is a divalent group containing a substituted or unsubstituted aromatic ring with 3 to 40 carbon atoms.)

[0018] In the above formulas (A1) to (A2) and formulas (A4) to (A5), Ar ０ Examples of aromatic rings having 3 to 40 carbon atoms in this context include aromatic hydrocarbon rings having 6 to 40 carbon atoms such as benzene rings, naphthalene rings, anthracene rings, phenalene rings, phenanthrene rings, pyrene rings, fluorene rings, perylene rings, coronene rings, and biphenyl rings; aromatic heterocyclic rings having 3 to 40 carbon atoms such as triazole rings, imidazole rings, furan rings, pyrrole rings, thiophene rings, phosphole rings, pyrazole rings, oxazole rings, isoxazole rings, thiazole rings, pyridine rings, pyridine rings, pyridazine rings, triazine rings, and indole rings; or combinations thereof. These combinations of rings may be fused rings, aggregated rings (structures in which two rings are joined by a single bond), or spirostructures.

[0019] Ar ０When the aromatic ring in a compound has substituents, examples of substituents include halogen atoms such as fluorine, chlorine, bromine, and iodine; hydroxyl groups; carboxyl groups; cyano groups; nitro groups; amino groups; alkyl groups; alkoxy groups; alkoxycarbonyl groups; alkoxycarbonyloxy groups; acyl groups; acyloxy groups; alkenyl groups; substituted or unsubstituted alkynyl groups; alkynyloxy groups; groups combining these; or groups in which the hydrogen atoms of these groups are substituted with halogen atoms; oxo groups (=O), etc. An example of an alkenyl group is the ethenyl group (vinyl group). Examples of substituted or unsubstituted alkyl groups include the ethynyl group, 1-propynyl group, and phenylethynyl group. An example of an alkynyloxy group is the propargyloxy group.

[0020] Ar １ and Ar ２ As for the aromatic ring with 3 to 40 carbon atoms in the above Ar ０ The aromatic ring in this can be suitably adopted.

[0021] Ar ０ Ar １ and Ar ２ The aromatic rings in are preferably, independently, a benzene ring, a naphthalene ring, an anthracene ring, a pyrene ring, or a biphenyl ring, with a benzene ring, a naphthalene ring, or a biphenyl ring being more preferred.

[0022] Ar １ and Ar ２ If the aromatic ring in has substituents, the substituents are the above Ar ０ The substituents that the aromatic ring in the Ar can have can be suitably adopted. １ and Ar ２ Preferred substituents that the aromatic ring may have are halogen atoms, hydroxyl groups, vinyl groups, ethynyl groups, acetyl groups, or combinations thereof.

[0023] Ar １ and Ar ２ Examples of monovalent groups containing an aromatic ring having 3 to 40 carbon atoms, as represented by , include groups obtained by removing one hydrogen atom from the above aromatic ring with or without a substituent.

[0024] In the above formula (A1), W １ As the s-valent organic group having 1 to 40 carbon atoms represented by , a group obtained by removing s-1 hydrogen atoms from a monovalent organic group having 1 to 40 carbon atoms can be suitably adopted.

[0025] Examples of the monovalent organic groups having 1 to 40 carbon atoms include monovalent hydrocarbon groups having 1 to 40 carbon atoms, groups having a divalent heteroatom-containing linking group between carbon atoms or at the terminal end of the hydrocarbon group (hereinafter also referred to as "group (x)"), groups in which some or all of the hydrogen atoms of the hydrocarbon group or group (x) are replaced with monovalent heteroatom-containing substituents, or groups that combine these.

[0026] Examples of monovalent hydrocarbon groups having 1 to 40 carbon atoms include monovalent linear hydrocarbon groups having 1 to 40 carbon atoms, monovalent alicyclic hydrocarbon groups having 3 to 40 carbon atoms, monovalent aromatic hydrocarbon groups having 6 to 40 carbon atoms, or groups combining these.

[0027] Examples of monovalent chain hydrocarbon groups having 1 to 40 carbon atoms include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, s-butyl, and t-butyl groups; alkenyl groups such as ethenyl, propenyl, and butenyl groups; and alkynyl groups such as ethynyl, propynyl, and butynyl groups.

[0028] Examples of monovalent alicyclic hydrocarbon groups having 3 to 40 carbon atoms include cycloalkyl groups such as cyclopentyl and cyclohexyl groups; cycloalkenyl groups such as cyclopropenyl, cyclopentenyl, and cyclohexenyl groups; bridged ring saturated hydrocarbon groups such as norbornyl, adamantyl, and tricyclodecyl groups; and bridged ring unsaturated hydrocarbon groups such as norbornyl and tricyclodecenyl groups.

[0029] Examples of monovalent aromatic hydrocarbon groups having 6 to 40 carbon atoms include aryl groups such as phenyl, tolyl, xyl, naphthyl, anthracenyl, pyrenyl, and fluorenyl groups; and aralkyl groups such as benzyl and phenethyl groups.

[0030] Examples of heteroatoms that constitute a divalent heteroatom-containing linking group or a monovalent heteroatom-containing substituent include oxygen, nitrogen, sulfur, phosphorus, silicon, and halogen atoms. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms.

[0031] Examples of divalent heteroatom-containing linking groups include -CO-, -CS-, -NR'-, -O-, -S-, and -SO ２ - and combinations thereof are examples. R' is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms.

[0032] Examples of monovalent heteroatom-containing substituents include hydroxyl groups, sulfanyl groups, cyano groups, nitro groups, amino groups, and halogen atoms.

[0033] In the above formula (A1), W １ The organic group with 1 to 40 carbon atoms represented by is preferably an s-valent group containing a substituted or unsubstituted aromatic ring with 3 to 40 carbon atoms. The group is Ar １ and Ar ２ A monovalent group containing an aromatic ring with 3 to 40 carbon atoms, represented by [the formula shown], can be suitably used, with s-1 hydrogen atoms removed from it.

[0034] s is preferably an integer between 1 and 3, more preferably 1 or 2, and even more preferably 1.

[0035] In the above formula (A2), W ２ As an organic group with 1 to 40 carbon atoms represented by W １ A group obtained by removing t-1 hydrogen atoms from a monovalent organic group having 1 to 40 carbon atoms, as shown in the above, can be suitably adopted.

[0036] W ２ It is preferable that the hydrocarbon group is a substituted or unsubstituted t-valent hydrocarbon group having 1 to 40 carbon atoms, or a group having a divalent heteroatom-containing linking group between carbon atoms or at the terminal end of the hydrocarbon group. ２ As for t-valent hydrocarbon groups with 1 to 40 carbon atoms in W, １A group obtained by removing t hydrogen atoms from a hydrocarbon corresponding to the monovalent hydrocarbon group having 1 to 40 carbon atoms shown in can be preferably employed. As the hydrocarbon having 1 to 40 carbon atoms, W １ a hydrocarbon corresponding to the monovalent chain hydrocarbon group having 1 to 40 carbon atoms shown in , an aromatic hydrocarbon corresponding to the monovalent aromatic hydrocarbon group having 6 to 40 carbon atoms, or a combination thereof is preferable, a chain saturated hydrocarbon corresponding to the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, an aromatic hydrocarbon corresponding to the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, or a combination thereof is more preferable, methane, ethane, propane, butane, benzene, naphthalene, fluorene, or a combination thereof is even more preferable. W ２ As the divalent heteroatom-containing linking group in , W １ the divalent heteroatom-containing linking group shown in can be preferably employed.

[0037] W ２ When the t-valent hydrocarbon group having 1 to 40 carbon atoms in has a substituent, as the substituent, Ar ０ a substituent that the aromatic ring of may have can be preferably employed.

[0038] t is preferably an integer of 1 to 3, and more preferably 2 or 3.

[0039] When t is 2, as the divalent heteroatom-containing linking group represented by W ２ in , W １ the divalent heteroatom-containing linking group shown in can be preferably employed.

[0040] In the above formula (A3), examples of the ring structure having 6 to 40 carbon atoms represented by Cy include an aromatic ring structure having 6 to 40 carbon atoms, an alicyclic ring structure having 6 to 40 carbon atoms, or a combination thereof. The combination of these rings may be any of a condensed ring, a ring assembly (a structure in which two rings are bonded by a single bond), and a spiro structure.

[0041] As the aromatic ring structure having 6 to 40 carbon atoms, a structure corresponding to 6 to 40 carbon atoms among the aromatic rings having 3 to 40 carbon atoms in Ar ０ in can be preferably employed.

[0042] Examples of the above-mentioned alicyclic structures include alicyclic hydrocarbon structures or aliphatic heterocyclic structures having 3 to 40 carbon atoms.

[0043] As for the above alicyclic hydrocarbon structure with 3 to 40 carbon atoms, W １ Structures corresponding to monovalent alicyclic hydrocarbon groups having 3 to 40 carbon atoms, as shown in [reference], can be suitably adopted.

[0044] Examples of the above-mentioned aliphatic heterocyclic structures include: oxygen atom-containing aliphatic heterocyclic structures such as oxiran, oxetane, tetrahydrofuran, tetrahydropyran, dioxolane, dioxane, and dioxepane; nitrogen atom-containing aliphatic heterocyclic structures such as aziridine, pyrrolidine, piperidine, and piperazine; sulfur atom-containing aliphatic heterocyclic structures such as thiethane, thiolane, and thian; aliphatic heterocyclic structures containing multiple heteroatoms such as morpholine, 1,2-oxathiolane, and 1,3-oxathiolane; lactone structures, cyclic carbonate structures, sultone structures, cyclic acetals, or combinations thereof.

[0045] If Cy has substituents, the substituents are Ar ０ The substituents that the aromatic ring may have can be suitably adopted.

[0046] Cy is preferably a substituted or unsubstituted aromatic ring having 3 to 40 carbon atoms. Cy is preferably an aromatic hydrocarbon ring having 6 to 20 carbon atoms, more preferably an aromatic hydrocarbon ring having 6 to 10 carbon atoms, and even more preferably a benzene ring.

[0047] In the above formula (A3), u1 and u2 are each preferably integers between 0 and 3, more preferably integers between 0 and 2, and more preferably 0 or 1. It is particularly preferable that both u1 and u2 are 1.

[0048] In the above formula (A4), W ３１ As a divalent group containing an aromatic ring with 3 to 40 carbon atoms, represented by Ar １ and Ar ２ A monovalent group containing an aromatic ring with 3 to 40 carbon atoms, represented by [the formula shown], can be suitably used, with one hydrogen atom removed from it.

[0049] W ３１ is preferably a divalent group represented by the following formula (W-31). (In formula (W-31), Ar ３ and Ar ４ are each independently a substituted or unsubstituted divalent aromatic ring having 3 to 40 carbon atoms. When there are a plurality of Ar ４ s, the plurality of Ar ４ s are the same as or different from each other. g is an integer of 0 to 4. When g is 1, R １ and R ２ are each independently a monovalent organic group having 1 to 40 carbon atoms, or R １ and R ２ are combined with each other to form a ring structure together with the carbon atom to which they are attached. When g is 2 or more, R １ and R ２ are each independently a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms, or R １ and R ２ are combined with each other to form a ring structure together with the carbon atom to which they are attached. When there are a plurality of R １ s and R ２ s, the plurality of R １ s and R ２ s are the same as or different from each other. * is a bond with a partial structure other than W ３１ in the above formula (A4).)

[0050] As the divalent aromatic ring having 3 to 40 carbon atoms represented by Ar ３ and Ar ４ , a group obtained by removing two hydrogen atoms from the aromatic ring having 3 to 40 carbon atoms shown in Ar ０ can be preferably adopted. As the aromatic rings in Ar ３ and Ar ４ , benzene ring, naphthalene ring, anthracene ring, pyrene ring, biphenyl ring or a combination thereof are each independently preferable.

[0051] g is preferably an integer of 0 to 3, more preferably an integer of 0 to 2, and even more preferably 0 or 1.

[0052] If g is 1 or 2, R １ and R ２ As a monovalent organic group having 1 to 40 carbon atoms, represented by W １ The monovalent organic groups having 1 to 40 carbon atoms shown in the above can be suitably used. １ and R ２ The monovalent organic group having 1 to 40 carbon atoms represented by is preferably a monovalent linear hydrocarbon group having 1 to 40 carbon atoms, the above monovalent aromatic hydrocarbon group having 6 to 40 carbon atoms, or a combination thereof; more preferably a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, or a combination thereof; and even more preferably a methyl group, ethyl group, propyl group, isopropyl group, phenyl group, naphthyl group, fluorenyl group, or a combination thereof.

[0053] R １ and R ２ If it has substituents, the substituents are Ar ０ The substituents that the aromatic ring may have can be suitably adopted.

[0054] R １ and R ２ As the ring structure formed when these elements are combined with each other and bonded together with carbon atoms, a structure that extends the C6-C40 ring structure represented by Cy to C3-C40 can be suitably adopted. The above ring structure is preferably an aromatic ring structure with C6-C20 or an alicyclic structure with C3-C20, more preferably an aromatic ring structure with C6-C20, and even more preferably a fluorene ring structure.

[0055] In the above formula (A5), W ３２ and W ３３ As a divalent organic group having 1 to 40 carbon atoms, represented by W, １ A group obtained by removing one hydrogen atom from a monovalent organic group having 1 to 40 carbon atoms, as shown above, can be suitably adopted.

[0056] W ３２ and W ３３ Each of these is preferably a divalent organic group containing a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 20 carbon atoms.

[0057] W３２ and W ３３ In this context, the divalent aromatic hydrocarbon group having 6 to 20 carbon atoms is W １ Examples include groups obtained by removing one hydrogen atom from the groups corresponding to C6-C20 among the monovalent aromatic hydrocarbon groups having C6-C40 shown above. Preferred aromatic hydrocarbon groups are benzene rings, naphthalene rings, pyrene rings, fluorene rings, biphenyl rings, or combinations thereof, with benzene rings and fluorene rings being more preferred.

[0058] W ３２ and W ３３ In the case where a divalent aromatic hydrocarbon group having 6 to 20 carbon atoms has substituents, the substituents are Ar ０ The substituents that the aromatic ring may have can be suitably adopted.

[0059] W ３２ and W ３３ The divalent organic group represented above is preferably a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 20 carbon atoms, a substituted or unsubstituted monovalent chain hydrocarbon group having 1 to 20 carbon atoms, or a combination thereof. Preferably, it is a substituted or unsubstituted divalent benzenediyl group, fluoranyl group, methylene group, ethylene group, propylene group, or a combination thereof. A hydroxyl group is preferred as a substituent for these groups.

[0060] W ３２ and W ３３ As a divalent heteroatom-containing linking group represented by , W １ The divalent heteroatom-containing linking group shown can be suitably adopted.

[0061] Ar ５ As a divalent group containing a substituted or unsubstituted aromatic ring with 3 to 40 carbon atoms, represented by Ar ０ Ar can suitably be used as a group obtained by removing two hydrogen atoms from a substituted or unsubstituted aromatic ring having 3 to 40 carbon atoms. ５ The aromatic rings in this compound are preferably benzene rings, naphthalene rings, anthracene rings, pyrene rings, biphenyl rings, or combinations thereof.

[0062] [A1] Specific examples of compounds include, but are not limited to, the following formulas (A1-1) to (A1-4).

[0063]

[0064] [A2] Specific examples of compounds include, but are not limited to, the following formulas (A2-1) to (A2-14).

[0065]

[0066]

[0067]

[0068] [A3] Specific examples of compounds include, but are not limited to, the following formulas (A3-1) to (A3-6).

[0069]

[0070] [A4] Specific examples of polymers include, but are not limited to, polymers having repeating units represented by the following formulas (A4-1) to (A4-18).

[0071]

[0072]

[0073]

[0074] [A5] Specific examples of polymers include, but are not limited to, polymers having repeating units represented by the following formulas (A5-1) to (A5-2).

[0075]

[0076] The molecular weight of compound [A] is preferably 500 or more, regardless of whether compound [A] is compound [A1] to compound [A3] or polymer [A4] to polymer [A5]. When compound [A] is compound [A1] to compound [A3], the lower limit of the molecular weight is more preferably 600, and even more preferably 700. The upper limit of the molecular weight of compound [A1] to compound [A3] is preferably 1800, and even more preferably 1500. When compound [A] is polymer [A4] to polymer [A5], the lower limit of the molecular weight is more preferably 2000, and even more preferably 2500. The upper limit of the molecular weight of polymer [A4] to polymer [A5] is preferably 8000, and even more preferably 7000. The molecular weight of compound [A1] is the value obtained from the structural formula. The molecular weight of polymer [A4] to polymer [A5] is the weight-average molecular weight measured by gel permeation chromatography using monodisperse polystyrene as the standard.

[0077] The content of compound [A] in the components other than the solvent in the above resist underlayer film forming composition is preferably 1% by mass or more. The above content of compound [A] may be 5% by mass or more, 10% by mass or more, 20% by mass or more, 30% by mass or more, 40% by mass or more, 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, or 100% by mass.

[0078] <Method for producing compound [A]> The method for producing compound [A] includes a step of reacting compound [a] with compound [b]. In this method, compound [A] can be produced simply and efficiently by an acid addition condensation reaction of compound [b] as a phenol to compound [a] as a carboxylic acid anhydride.

[0079] ([a] compound) A [a] compound is a compound represented by the following formula (a1), formula (a2), or formula (a3) ​​(hereinafter also referred to as "[a1] compound," etc.). In the following formula, Ar０ Alternatively, Cy has a five-membered ring structure containing -X-O-X- and Ar ０ Alternatively, two adjacent carbon atoms that form Cy share a fused ring structure. The same applies to other general formulas.

[0080] (In equations (a1) to (a3), of the two X atoms in the five-membered ring, one is -C(=O)- and the other is -C(=O)- or -S(=O)2-.) ０ Each is independently a substituted or unsubstituted aromatic ring with 3 to 40 carbon atoms. t is an integer from 1 to 4. If t is 2 or greater, multiple X and Ar ０ These are either identical or different from each other. ２ When t is 1, 3, or 4, it is a t-valent organic group having 1 to 40 carbon atoms; when t is 2, it is a divalent organic group having 1 to 40 carbon atoms, a single bond, or a divalent heteroatom-containing linking group. Cy is a substituted or unsubstituted ring structure having 6 to 40 carbon atoms. u1 and u2 are each an integer from 0 to 4, independently of each other, except that u1 + u2 is 1 or greater. Multiple Xs are either identical or different from each other.

[0081] In the above formulas (a1) to (a3), Ar ０ , W ２ For t, Cy, u1, and u2, the corresponding structures in formulas (A1) to (A5) can be suitably adopted.

[0082] [a1] Specific examples of compounds, though not limited to them, include the following formulas (a1-1) to (a1-7).

[0083]

[0084] [a2] Specific examples of compounds include, but are not limited to, the following formulas (a2-1) to (a2-8).

[0085]

[0086]

[0087] [a3] Specific examples of compounds, though not limited to them, include the following formulas (a3-1) to (a3-4).

[0088]

[0089] ([b] compound) The [b] compound is a compound represented by the following formula (b). (In formula (b), Ar is a monovalent group containing a substituted or unsubstituted aromatic ring having 3 to 40 carbon atoms. v is an integer from 1 to 4. W) ０ When v is 3 or 4, it is a v-valent organic group having 1 to 40 carbon atoms; when v is 1, it is a v-valent organic group having 1 to 40 carbon atoms or a hydrogen atom; and when v is 2, it is a divalent organic group having 1 to 40 carbon atoms, a single bond, or a linking group containing a divalent heteroatom.

[0090] As a monovalent group containing a substituted or unsubstituted aromatic ring having 3 to 40 carbon atoms represented by Ar in formula (b) above, Ar such as in formula (A1) above. １ and Ar ２ A monovalent group containing a substituted or unsubstituted aromatic ring having 3 to 40 carbon atoms, represented by the formula (A1), can be suitably used. When Ar has substituents, the substituents may be Ar such as the above formula (A1). ０ The substituents that the aromatic ring may have can be suitably adopted.

[0091] W ０ For the v-valent organic group having 1 to 40 carbon atoms, a group obtained by removing v-1 hydrogen atoms from a monovalent organic group having 1 to 40 carbon atoms can be suitably adopted. The above monovalent organic group having 1 to 40 carbon atoms is the W of formula (A1) above. １ The monovalent organic groups having 1 to 40 carbon atoms shown in the above can be suitably used. ０ The divalent heteroatom-containing linking group represented by is W in the above formula (A1). １ The divalent heteroatom-containing linking group shown can be suitably adopted.

[0092] v is preferably an integer between 1 and 3, and more preferably 1 or 2.

[0093] [b] Specific examples of compounds include, but are not limited to, formulas (b-1) to (b-21) below.

[0094]

[0095]

[0096]

[0097] The reaction between compound [a] and compound [b] can be carried out according to known methods, preferably in a reaction solvent under an inert gas atmosphere such as a nitrogen gas atmosphere. Typically, the reaction can be carried out by mixing compound [a] and compound [b] and heating them. More specifically, compound [A] can be produced by an acid addition condensation reaction of compound [b] to the carboxylic acid anhydride structure (carbonyl group) of compound [a].

[0098] The molar ratio of the reaction between compound [a] and compound [b] can be appropriately set considering the number of carboxylic acid anhydride structures in compound [a], the number of moles of compound [b], the number of OH groups in compound [b], etc.

[0099] As an acid catalyst for acid addition condensation, ZnCl ２ AlCl ３ TiCl ４ Examples include Lewis acids such as sulfuric acid, Brønsted acids such as sulfuric acid, and organic acids such as trifluoromethanesulfonic acid.

[0100] The lower limit of the reaction temperature during acid addition condensation is preferably 80°C, and more preferably 100°C. The upper limit of the reaction temperature is preferably 180°C, and more preferably 160°C. The reaction may also be carried out at a temperature that produces reflux. The lower limit of the reaction time during acid addition condensation is preferably 2 hours, and more preferably 4 hours. The upper limit of the reaction time is preferably 20 hours, and more preferably 15 hours.

[0101] After the reaction, compound [A] can be obtained by separation, purification, drying, etc. Solvent [B], described later, can be suitably used as the reaction solvent.

[0102] <[B] Solvent> The [B] solvent is not particularly limited as long as it can dissolve or disperse the [A] compound and any optional components contained therein as needed.

[0103] [B] Examples of solvents include hydrocarbon solvents, ester solvents, alcohol solvents, ketone solvents, ether solvents, and nitrogen-containing solvents. [B] Solvents can be used individually or in combination of two or more.

[0104] Examples of hydrocarbon solvents include aliphatic hydrocarbon solvents such as n-pentane, n-hexane, and cyclohexane, and aromatic hydrocarbon solvents such as benzene, toluene, and xylene.

[0105] Examples of ester solvents include carbonate solvents such as diethyl carbonate, acetic acid monoester solvents such as methyl acetate and ethyl acetate, lactone solvents such as γ-butyrolactone, polyhydric alcohol partial ether carboxylate solvents such as diethylene glycol acetate monomethyl ether and propylene glycol acetate monomethyl ether, and lactate ester solvents such as methyl lactate and ethyl lactate.

[0106] Examples of alcohol-based solvents include monoalcohol solvents such as methanol, ethanol, n-propanol, and 1-butanol, and polyhydric alcohol solvents such as ethylene glycol and 1,2-propylene glycol.

[0107] Examples of ketone solvents include linear ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, and cyclic ketone solvents such as cyclohexanone.

[0108] Examples of ether-based solvents include linear ether solvents such as n-butyl ether, cyclic ether solvents such as tetrahydrofuran and dioxane, polyhydric alcohol ether solvents such as ethylene glycol dimethyl ether, and polyhydric alcohol partial ether solvents such as diethylene glycol monomethyl ether.

[0109] Examples of nitrogen-containing solvents include linear nitrogen-containing solvents such as N,N-dimethylacetamide and N,N-dimethylformamide, and cyclic nitrogen-containing solvents such as N-methylpyrrolidone.

[0110] [B] As the solvent, ester solvents or ketone solvents are preferred, polyhydric alcohol partial ether carboxylate solvents or cyclic ketone solvents are more preferred, and propylene glycol acetate monomethyl ether or cyclohexanone is even more preferred.

[0111] The lower limit of the content of solvent [B] in the resist underlayer film forming composition is preferably 50% by mass, more preferably 60% by mass, and still more preferably 70% by mass. The upper limit of the above content is preferably 99.9% by mass, more preferably 99% by mass, and still more preferably 98% by mass.

[0112] [Optional Components] The resist underlayer film forming composition may contain optional components as long as they do not impair the effects of the present invention. Examples of optional components include acid generators, base generators, crosslinking agents, surfactants, defoaming agents, etc. Specific examples of base generators include, for example, "U-CAT (registered trademark) SA1", "U-CAT (registered trademark) SA102", "U-CAT (registered trademark) SA102-50", "U-CAT (registered trademark) SA106", "U-CAT (registered trademark) SA112", "U-CAT (registered trademark) SA506", "U-CAT (registered trademark) SA603", "U-CAT (registered trademark) 1000", "U-CAT (registered trademark) 1102", "U-CAT (registered trademark) 2000", "U-CAT (registered trademark) Examples include "U-CAT 2024", "U-CAT 2026", "U-CAT 2030", "U-CAT 2110", "U-CAT 2313", "U-CAT 651M", "U-CAT 660M", "U-CAT 18X", "TMED", "U-CAT 201G", "U-CAT 202", "U-CAT 420A", "U-CAT 130", "U-CAT 891", "POLYCAT 8", "POLYCAT 9", "POLYCAT 12", and "POLYCAT 41" (all trade names, manufactured by Sunapro Co., Ltd.). These compounds may be used individually or in combination of two or more. As the defoaming agent, known defoaming agents can be used, including alcohol defoaming agents, phosphate ester defoaming agents, fatty acid ester defoaming agents, polyether defoaming agents, and silicone defoaming agents. Examples of fatty acid ester defoaming agents include methyl laurate, methyl palmitate, methyl stearate, propyl butyrate, butyl butyrate, ethyl isovalerate, and isobutyl propionate, with propyl butyrate and butyl butyrate being preferred. Ketone solvents such as 2-heptanone may also be used as the defoaming agent. The optional components can be used individually or in combination of two or more. The content ratio of the optional components in the resist underlayer film forming composition can be appropriately determined depending on the type of optional component.

[0113] [Method for preparing the composition] The resist underlayer film forming composition can be prepared by mixing [A] compound, [B] solvent, and optionally any other components in a predetermined ratio, and preferably by filtering the resulting mixture through a membrane filter with a pore size of 0.5 μm or less.

[0114] 《Method for Manufacturing Semiconductor Substrates》 The method for manufacturing the semiconductor substrate includes a step of directly or indirectly coating a resist underlayer film formation composition onto a substrate (hereinafter also referred to as the "coating step"), a step of directly or indirectly forming a resist pattern onto the resist underlayer film formed by the coating step (hereinafter also referred to as the "resist pattern formation step"), and a step of performing etching using the resist pattern as a mask (hereinafter also referred to as the "etching step").

[0115] The method for manufacturing the semiconductor substrate may, if necessary, further include a step of heating the resist underlayer film formed by the coating step before the resist pattern formation step (hereinafter also referred to as the "heating step").

[0116] The method for manufacturing the semiconductor substrate may further include, if necessary, a step of forming a silicon-containing film directly or indirectly on the resist underlayer film before forming the resist pattern (hereinafter also referred to as the "silicon-containing film formation step").

[0117] The following describes the resist underlayer film formation composition and each step used in the manufacturing method of the semiconductor substrate.

[0118] [Coating Process] In this process, the resist underlayer film formation composition is coated onto the substrate either directly or indirectly. In this process, the resist underlayer film formation composition described above is used.

[0119] The coating method for the resist underlayer film formation composition is not particularly limited and can be carried out by any suitable method, such as rotary coating, casting coating, or roll coating. A coating film is formed thereafter, and the resist underlayer film is formed by the volatilization of solvent [B].

[0120] Examples of substrates include metal or metalloid substrates such as silicon substrates, aluminum substrates, nickel substrates, chromium substrates, molybdenum substrates, tungsten substrates, copper substrates, tantalum substrates, and titanium substrates, with silicon substrates being preferred among these. The above substrates may also be substrates on which silicon nitride films, alumina films, silicon dioxide films, tantalum nitride films, titanium nitride films, etc., are formed.

[0121] The substrate may have patterns. The resist underlayer film forming composition has excellent embedding properties, so even if the substrate has patterns, it can form a good film while filling the gaps between patterns. Examples of the pattern shapes include trench patterns, line-and-space patterns, hole patterns, and pillar patterns. Examples of trench patterns and line-and-space patterns include patterns containing recesses with a width of 5 nm to 100 nm and patterns containing recesses with a depth of 5 nm to 500 nm. Examples of hole patterns include patterns containing holes with a diameter of 5 nm to 100 nm and patterns containing holes with a depth of 5 nm to 500 nm. Examples of pillar patterns include patterns containing pillars with a width of 5 nm to 100 nm and patterns containing pillars with a height of 5 nm to 500 nm.

[0122] Examples of indirectly coating a substrate with a resist underlayer film formation composition include coating a low-dielectric insulating film or an organic underlayer film formed on the substrate with the resist underlayer film formation composition.

[0123] [Heating Process] In this process, the coated film formed by the above coating process is heated. Heating the coated film promotes the formation of the resist underlayer film. More specifically, heating the coated film promotes the volatilization of solvent [B], etc.

[0124] The above-mentioned coating film may be heated in an atmospheric environment or in a nitrogen atmosphere. The lower limit of the heating temperature is preferably 200°C, more preferably 250°C, and even more preferably 300°C. The upper limit of the heating temperature is preferably 600°C, and more preferably 500°C. The lower limit of the heating time is preferably 15 seconds, and more preferably 30 seconds. The upper limit of the heating time is preferably 1,200 seconds, and more preferably 600 seconds.

[0125] Furthermore, the resist underlayer may be exposed after the above coating process. The resist underlayer may be exposed to plasma after the above coating process. Ion implantation may be performed on the resist underlayer after the above coating process. Exposure of the resist underlayer improves the etching resistance of the resist underlayer. Exposure of the resist underlayer improves the etching resistance of the resist underlayer. Ion implantation of the resist underlayer improves the etching resistance of the resist underlayer.

[0126] The radiation used for exposure of the resist underlayer film is appropriately selected from electromagnetic waves such as visible light, ultraviolet light, far ultraviolet light, X-rays, and gamma rays; and particle beams such as electron beams, molecular beams, and ion beams.

[0127] Methods for exposing the resist underlayer film to plasma include, for example, a direct method in which the substrate is placed in a gas atmosphere and plasma discharge is performed. The conditions for plasma exposure are typically a gas flow rate of 50 cc / min to 100 cc / min and a power supply of 100 W to 1,500 W.

[0128] The lower limit of the plasma exposure time is preferably 10 seconds, more preferably 30 seconds, and even more preferably 1 minute. The upper limit of the above time is preferably 10 minutes, more preferably 5 minutes, and even more preferably 2 minutes.

[0129] Plasma is, for example, H ２ Plasma is generated in an atmosphere of a mixed gas of gas and Ar gas. Also, H ２ In addition to gas and Ar gas, CF ４ Gas and CH ４ It is also possible to introduce carbon-containing gases such as gases. ２Instead of either or both of gas and Ar gas, CF ４ Gas, NF ３ Gas, CHF ３ Gas, CO ２ Gas, CH ２ F ２ Gas, CH ４ Gas and C ４ F ８ At least one of the gases may be introduced.

[0130] Ion implantation into the resist underlayer involves implanting dopants into the resist underlayer. Dopants can be selected from a group consisting of boron, carbon, nitrogen, phosphorus, arsenic, aluminum, and tungsten. The implantation energy used to apply voltage to the dopant ranges from approximately 0.5 keV to 60 keV, depending on the type of dopant used and the desired implantation depth.

[0131] The lower limit of the average thickness of the resist underlayer film formed is preferably 30 nm, more preferably 50 nm, and even more preferably 100 nm. The upper limit of the average thickness is preferably 3,000 nm, more preferably 2,000 nm, and even more preferably 500 nm. The method for measuring the average thickness is as described in the examples.

[0132] [Silicon-containing film formation process] In this process, a silicon-containing film is formed directly or indirectly on the resist underlayer film formed by the coating process or the heating process described above. An example of indirect formation of a silicon-containing film on the resist underlayer film is when a surface modification film of the resist underlayer film is formed on the resist underlayer film. The surface modification film of the resist underlayer film is, for example, a film whose contact angle with water is different from that of the resist underlayer film.

[0133] Silicon-containing films can be formed by coating with a silicon-containing film-forming composition, chemical vapor deposition (CVD), atomic layer deposition (ALD), etc. A method for forming a silicon-containing film by coating with a silicon-containing film-forming composition includes, for example, directly or indirectly coating the resist underlayer with the silicon-containing film-forming composition, and then curing the resulting coated film by exposure and / or heating. Commercially available silicon-containing film-forming compositions include, for example, "NFC SOG01," "NFC SOG04," and "NFC SOG080" (all manufactured by JSR Corporation). Silicon oxide films, silicon nitride films, silicon oxidnitride films, and amorphous silicon films can be formed by chemical vapor deposition (CVD) or atomic layer deposition (ALD).

[0134] Examples of radiation used in the above exposure include electromagnetic waves such as visible light, ultraviolet rays, far ultraviolet rays, X-rays, and gamma rays, as well as particle beams such as electron beams, molecular beams, and ion beams.

[0135] The lower limit of the temperature when heating the coating film is preferably 90°C, more preferably 150°C, and even more preferably 180°C. The upper limit of the above temperature is preferably 550°C, more preferably 450°C, and even more preferably 350°C. Heating may be carried out by gradually increasing or decreasing the heating temperature.

[0136] The lower limit of the average thickness of the silicon-containing film is preferably 1 nm, more preferably 10 nm, and even more preferably 20 nm. The upper limit is preferably 20,000 nm, more preferably 1,000 nm, and even more preferably 100 nm. The average thickness of the silicon-containing film is the value measured using the spectroscopic ellipsometer, similar to the average thickness of the resist underlayer film.

[0137] [Resist Pattern Formation Process] In this process, a resist pattern is formed directly or indirectly on the resist underlayer film. Methods for performing this process include, for example, using a resist composition, using a nanoimprint method, or using a self-assembled composition. An example of indirectly forming a resist pattern on the resist underlayer film is forming a resist pattern on the silicon-containing film.

[0138] Examples of the above-mentioned resist compositions include positive or negative type chemically amplified resist compositions containing a radiation-sensitive acid generator, positive type resist compositions containing an alkali-soluble resin and a quinone diazide-based photosensitive agent, negative type resist compositions containing an alkali-soluble resin and a crosslinking agent, and metal-containing resist compositions containing metals such as tin, zirconium, and hafnium.

[0139] Examples of coating methods for the resist composition include rotary coating. The pre-baking temperature and time can be appropriately adjusted depending on the type of resist composition used.

[0140] Next, the resist film formed above is exposed by selective radiation irradiation. The radiation used for exposure can be appropriately selected depending on the type of radiation-sensitive acid generator used in the resist composition, and examples include electromagnetic waves such as visible light, ultraviolet light, far ultraviolet light, X-rays, and gamma rays, as well as particle beams such as electron beams, molecular beams, and ion beams. Among these, far ultraviolet light is preferred, and KrF excimer laser light (wavelength 248 nm), ArF excimer laser light (wavelength 193 nm), F ２ Excimer laser light (wavelength 157 nm), Kr ２ Excimer laser light (wavelength 147 nm), ArKr excimer laser light (wavelength 134 nm), or extreme ultraviolet light (wavelength 13.5 nm, etc., hereinafter also referred to as "EUV") is more preferred, and KrF excimer laser light, ArF excimer laser light, or EUV is even more preferred.

[0141] After the exposure described above, post-baking can be performed to improve resolution, pattern profile, developability, etc. The temperature and time of this post-baking can be appropriately determined depending on the type of resist composition used, etc.

[0142] Next, the exposed resist film is developed with a developer to form a resist pattern. This development may be alkaline development or organic solvent development. Examples of developers for alkaline development include basic aqueous solutions such as ammonia, triethanolamine, tetramethylammonium hydroxide (TMAH), and tetraethylammonium hydroxide. These basic aqueous solutions may also have appropriate amounts of water-soluble organic solvents such as methanol and ethanol, or surfactants added to them. For organic solvent development, examples of developers include the various organic solvents exemplified as solvent [B] in the resist underlayer film forming composition described above.

[0143] After development with the above-mentioned developer, the resist pattern is formed by washing and drying.

[0144] [Etching Process] In this process, etching is performed using the resist pattern described above as a mask. The etching may be performed once or multiple times, i.e., sequentially using the pattern obtained by etching as a mask. From the viewpoint of obtaining a pattern with a better shape, multiple etchings are preferred. When multiple etchings are performed, for example, the silicon-containing film, the resist underlayer film, and the substrate are etched sequentially. Examples of etching methods include dry etching and wet etching. From the viewpoint of obtaining a better shape for the substrate pattern, dry etching is preferred. For this dry etching, for example, a gas plasma such as oxygen plasma is used. By performing the above etching, a semiconductor substrate having a predetermined pattern is obtained.

[0145] Dry etching can be performed, for example, using a known dry etching apparatus. The etching gas used for dry etching can be appropriately selected depending on the mask pattern, the elemental composition of the film to be etched, etc., for example, CHF ３ CF ４ , C ２ F ６ , C ３ F ８ SF ６ Fluorine-based gases such as Cl ２ , BCl ３ Chlorine-based gases such as O ２ , O ３ , H ２ Oxygen-based gases such as O, H ２ CO, CO ２ ,CH ４ , C ２ H ２ , C ２ H ４ , C ２ H ６ , C ３ H ４ , C ３ H ６ , C ３ H ８ , HF, HI, HBr, HCl, NO, NH ３ , BCl ３ Reducing gases such as He, N ２ Examples include inert gases such as Ar. These gases can also be used in mixtures. When etching a substrate using the pattern of the resist underlayer as a mask, fluorine-based gases are usually used.

[0146] 《Method for producing aromatic ring-containing compounds》 The method for producing the aromatic ring-containing compounds includes a step of reacting compound [a] with compound [b]. The method for producing compound [A] in the above-mentioned resist underlayer film forming composition can be suitably adopted as the method for producing the aromatic ring-containing compounds.

[0147] The present invention will be described in detail below based on examples, but the present invention is not limited to these examples.

[0148] [Weight-average molecular weight (Mw)] The Mw of the polymer was measured by gel permeation chromatography (detector: differential refractometer) using monodisperse polystyrene as the standard, under analytical conditions of flow rate: 1.0 mL / min, elution solvent: tetrahydrofuran, column temperature: 40°C, using GPC columns from Tosoh Corporation (two "G2000HXL" columns and one "G3000HXL" column).

[0149] [Average film thickness] The average film thickness was determined by measuring the film thickness at nine arbitrary points at 5 cm intervals, including the center of the resist underlayer film formed on a silicon wafer (substrate), using a spectroscopic ellipsometer (J.A. WOOLLAM's "M2000D"). The average of these film thicknesses was then calculated.

[0150] <[A] Compound Raw Materials> For the synthesis of compound [A], compounds (a-1) to (a-17) represented by the following formulas (a-1) to (a-15) were used as compound [a], and compounds (b-1) to (b-19) represented by the following formulas (b-1) to (b-19) were used as compound [b].

[0151]

[0152]

[0153]

[0154]

[0155]

[0156] <Synthesis of Compound [A]> Using the above raw materials, compounds (A-1) to (A-33) were synthesized as Compound [A] represented by the following formulas according to the procedure shown below.

[0157]

[0158]

[0159]

[0160]

[0161]

[0162]

[0163]

[0164] Furthermore, if compound [A] is produced using compound [a] (a-6) as compound [a] and compound [b] (b-6) as compound [b], in addition to the isomer structures shown in (1) and (2) below, it is possible that there are other isomer structures with different naphthol introduction positions. Therefore, in the above structural formulas, for compounds derived from the same starting material, one type of isomer structure is represented as the representative structure.

[0165]

[0166] [Example 1-1] (Synthesis of compound (A-1)) In a reaction vessel, under a nitrogen atmosphere, 20.0 g of compound (a-1), 20.6 g of compound (b-1), 100 g of diethylene glycol dimethyl ether, and 5.0 g of trifluoromethanesulfonic acid were added and reacted under reflux for 12 hours. After the reaction was complete, the reaction solution was transferred to a separatory funnel and the organic phase was washed with 400 g of methyl isobutyl ketone and 400 g of 1% aqueous oxalic acid. After separating the aqueous phase, the obtained organic phase was washed several times with water. Then, it was concentrated in an evaporator, and the residue was added dropwise to 600 g of heptane to obtain a precipitate. The precipitate was collected by suction filtration and washed several times with 300 g of heptane. Then, compound (A-1) was obtained by drying in a vacuum dryer at 60°C for 12 hours. The Mw of (A-1) was 895.

[0167] [Examples 1-2 to 1-33] (Synthesis of compounds (A-2) to (A-33)) Compounds (A-2) to (A-33) were obtained as products under the same reaction conditions as in Example 1-1, except that the starting compounds shown in Tables 1-1 and 1-2 were used. The Mw of the obtained compounds is shown in Tables 1-1 and 1-2.

[0168] [Comparative Synthesis Example 1-1] (Synthesis of Polymer (x-1)) In a reaction vessel, under a nitrogen atmosphere, 250.0 g of m-cresol, 125.0 g of 37% by mass formalin, and 2 g of oxalic anhydride were added. The mixture was reacted at 100°C for 3 hours and then at 180°C for 1 hour. After that, unreacted monomers were removed under reduced pressure to obtain polymer (x-1) represented by the following formula (x-1). The Mw of the obtained polymer (x-1) was 11,000.

[0169]

[0170]

[0171]

[0172] <Preparation of composition for forming a resist underlayer film> The following describes the [A] compound, [B] solvent, [C] acid generator, [D] crosslinking agent and other components used in the preparation of the composition for forming a resist underlayer film (hereinafter also referred to as "the composition").

[0173] [[A] Compounds] A-1 to A-33: Compounds synthesized above (A-1) to (A-33)

[0174] [B Solvent] B-1: Propylene glycol monomethyl ether acetate B-2: Cyclohexanone

[0175] [C] Acid Generator: C-1: Compound represented by the following formula (C-1)

[0176] [D] Crosslinking agent: D-1: Compound represented by the following formula (D-1) D-2: Compound represented by the following formula (D-2)

[0177] (Other components) x-1: The polymer synthesized above (x-1) E-1: The compound represented by the following formula (E-1) E-2: The compound represented by the following formula (E-2) E-3: The compound represented by the following formula (E-3) E-4: The compound represented by the following formula (E-4)

[0178]

[0179] [Example 2-1] [A] 3 parts by mass of (A-1) as compound was dissolved in [B] 97 parts by mass of (B-1) as solvent. The resulting solution was filtered through a polytetrafluoroethylene (PTFE) membrane filter with a pore size of 0.45 μm to prepare composition (J-1).

[0180] [Examples 2-2 to 2-41 and Comparative Example 2-1] Compositions (J-2) to (J-41) and (CJ-1) were prepared in the same manner as in Example 2-1, except that the types and amounts of each component shown in Table 2 below were used. A "-" in Table 2 indicates that the corresponding component was not used.

[0181]

[0182] <Evaluation> [Examples 3-1 to 3-41 and Comparative Example 3-1] The embedding properties and bending resistance were evaluated using the above-prepared resist underlayer film forming compositions by the following method. The evaluation results are shown in Table 3 below.

[0183] [Embedding Properties] The above resist underlayer film formation composition was applied to a substrate on which trench patterns with a depth of 65 nm and widths of 20 nm and 30 nm were formed, using a spin coater (LITHIUS Pro Z from Tokyo Electron Limited) by rotary coating. The rotation conditions of the spin coater were set to obtain a film-coated substrate with an average thickness of 100 nm. Next, the substrate was heated at 400°C for 90 seconds in an air atmosphere, and then cooled at 23°C for 60 seconds. The cross-sectional shape of the substrate was observed (200,000x magnification) using a scanning electron microscope (S-4800 from Hitachi High-Technologies Corporation) to evaluate its embedding properties. The embedding performance was evaluated as follows: "A" (good) if the resist underlayer film was embedded to the bottom of the 20 nm wide trench pattern on the substrate; "B" (fairly good) if it was not embedded to the bottom of the 20 nm wide trench pattern but was embedded to the bottom of the 30 nm wide trench pattern; and "C" (poor) if it was not embedded to the bottom of the 30 nm wide trench pattern.

[0184] [Bending Resistance] The above-prepared composition was coated onto a silicon substrate on which a silicon dioxide film with an average thickness of 500 nm had been formed, using a spin coater (CLEAN TRACK ACT12 from Tokyo Electron Limited) by rotary coating. Next, the substrate was heated at 350°C for 60 seconds in an air atmosphere, and then cooled at 23°C for 60 seconds to obtain a film-coated substrate on which a resist underlayer film with an average thickness of 200 nm had been formed. On the above-prepared film-coated substrate, a silicon-containing film-forming composition (NFC SOG080 from JSR Corporation) was coated by rotary coating, and then heated at 200°C for 60 seconds in an air atmosphere, and further heated at 300°C for 60 seconds to form a silicon-containing film with an average thickness of 50 nm. An ArF resist composition (AR1682J from JSR Corporation) was coated onto the silicon-containing film using a rotary coating method, and the resist film was heated (fired) at 130°C for 60 seconds in an air atmosphere to form a resist film with an average thickness of 200 nm. The resist film was exposed using an ArF excimer laser exposure apparatus (lens numerical aperture 0.78, exposure wavelength 193 nm) through a 1:1 line-and-space mask pattern with a target size of 100 nm, with varying exposure levels. After exposure, the resist film was heated (fired) at 130°C for 60 seconds in an air atmosphere, developed at 25°C for 1 minute using a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (TMAH), washed with water, and dried to obtain a substrate on which a line-and-space resist pattern with a 200 nm pitch and line widths ranging from 30 nm to 100 nm was formed.

[0185] Using the above resist pattern as a mask, the above etching apparatus is used to CF ４ Under the conditions of =200 sccm, PRESS. =85 mT, HF RF (high-frequency power for plasma generation) =500 W, LF RF (high-frequency power for bias) =0 W, DCS = -150 V, and RDC (gas center flow rate ratio) =50%, a silicon-containing film was etched to obtain a substrate with a pattern formed on the silicon-containing film. Next, using the silicon-containing film pattern as a mask, the etching apparatus was used to etch O ２Under the conditions of =400 sccm, PRESS. =25 mT, HF RF (high-frequency power for plasma generation) =400 W, LF RF (high-frequency power for bias) =0 W, DCS =0 V, and RDC (gas center flow rate ratio) =50%, the resist underlayer film was etched to obtain a substrate with a pattern formed on the resist underlayer film. Using the above resist underlayer film pattern as a mask, the above etching apparatus was used to CF ４ Under the conditions of 180 sccm, Ar = 360 sccm, PRESS. = 150 mT, HF RF (high-frequency power for plasma generation) = 1,000 W, LF RF (high-frequency power for bias) = ​​1,000 W, DCS = -150 V, RDC (gas center flow rate ratio) = 50%, and 60 seconds, a silicon dioxide film was etched to obtain a substrate with a pattern formed on the silicon dioxide film.

[0186] Subsequently, for the substrate on which the silicon dioxide film pattern was formed, images of the shape of the resist underlayer film pattern for each line width were obtained by magnifying 250,000 times using a scanning electron microscope (Hitachi High-Technologies Corporation's "CG-4000"). By processing these images, as shown in Figure 1, the LER (line edge roughness) was defined as the standard deviation of 3 times the average position Xa calculated from the position Xn (n=1 to 10) in the line width direction, which was measured at 10 locations at 100 nm intervals on the lateral surface 3a of the resist underlayer film pattern 3 (line pattern) with a length of 1,000 nm, and the average position Xa of these positions in the line width direction. The LER, which indicates the degree of curvature of the resist underlayer film pattern, increases as the line width of the resist underlayer film pattern becomes narrower. Bending resistance was evaluated as follows: "A" (good) if the line width of the film pattern with a LER of 5.5 nm was less than 40.0 nm; "B" (fairly good) if it was between 40.0 nm and 45.0 nm; and "C" (poor) if it was 45.0 nm or more. Note that the degree of bending of the film pattern shown in Figure 1 is exaggerated compared to the actual degree.

[0187]

[0188] As can be seen from the results in Table 3, the compositions of the examples and the resist underlayer films formed from these compositions exhibited superior embedding properties and bending resistance compared to the comparative examples.

[0189] The resist underlayer film formation composition of the present invention makes it possible to form a resist underlayer film with excellent embedding properties and bending resistance. The semiconductor substrate manufacturing method of the present invention makes it possible to form a resist underlayer film that not only has sufficient embedding properties to adequately embed the substrate pattern, but also has excellent bending resistance after embedding. The aromatic ring-containing compound manufacturing method of the present invention can efficiently produce aromatic ring-containing compounds suitable as components of the resist underlayer film formation composition for forming a resist underlayer film. Therefore, these can be suitably used in the manufacture of semiconductor devices, for which further miniaturization is expected in the future.

[0190] 3. Resist underlayer pattern 3a. Side view of the resist underlayer pattern

Claims

1. A resist underlayer film-forming composition containing an aromatic ring-containing compound and a solvent, wherein the aromatic ring-containing compound is a compound represented by the following formula (A1), the following formula (A2) or the following formula (A3), or a polymer having a repeating unit represented by the following formula (A4) or the following formula (A5). (In formula (A1) to formula (A5), X is independently -C(=O)- or -S(=O)2- respectively. Ar ０ is independently a substituted or unsubstituted aromatic ring having 3 to 40 carbon atoms. Ar １ and Ar ２ are independently monovalent groups containing a substituted or unsubstituted aromatic ring having 3 to 40 carbon atoms. W １ is an s-valent organic group having 1 to 40 carbon atoms. s is an integer of 1 to 4. When s is 2 or more, a plurality of X, Ar ０ and Ar １ are the same as or different from each other. t is an integer of 1 to 4. When t is 2 or more, a plurality of X, Ar ０ , Ar １ and Ar ２ are the same as or different from each other respectively. W ２ is a t-valent organic group having 1 to 40 carbon atoms when t is 1, 3 or 4, and is a divalent organic group having 1 to 40 carbon atoms, a single bond or a divalent heteroatom-containing linking group when t is 2. Cy is a substituted or unsubstituted ring structure having 6 to 40 carbon atoms. u1 and u2 are independently integers of 0 to 4. However, u1 + u2 is 1 or more. A plurality of X, Ar ０ , Ar １ and Ar ２ are the same as or different from each other respectively. W ３１ is a divalent group containing an aromatic ring having 3 to 40 carbon atoms. W ３２ is a divalent organic group having 1 to 40 carbon atoms, a single bond or a divalent heteroatom-containing linking group. W ３３ is a divalent organic group having 1 to 40 carbon atoms. Ar ５ is a divalent group containing a substituted or unsubstituted aromatic ring having 3 to 40 carbon atoms.) 2. W ２ The resist underlayer film forming composition according to claim 1, wherein is a substituted or unsubstituted t-valent hydrocarbon group having 1 to 40 carbon atoms, or a group having a divalent heteroatom-containing linking group between carbon atoms or at the terminal end of the hydrocarbon group.

3. The resist underlayer film forming composition according to claim 1, wherein Cy is a substituted or unsubstituted aromatic ring having 3 to 40 carbon atoms.

4. W ３１ The resist underlayer film forming composition according to claim 1, wherein is a divalent group represented by the following formula (W-31). (In formula (W-31), Ar ３ and Ar ４ Each of these is independently a substituted or unsubstituted divalent aromatic ring having 3 to 40 carbon atoms. ４ If there are multiple Ar ４ They are either identical or different from each other. g is an integer from 0 to 4. If g is 1, R １ and R ２ Each of these is independently a monovalent organic group having 1 to 40 carbon atoms, or R １ and R ２ They combine with each other, forming a ring structure with the carbon atoms to which they are bonded. When g is 2 or more, R １ and R ２ Each of these is independently a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms, or R １ and R ２ These elements combine with each other, forming a ring structure with the carbon atoms to which they are bonded. １ and R ２ If multiple R １ and R ２ These are either identical or different from each other. * is W in formula (A4) above. ３１ (This is a connection to a substructure other than the main structure.) 5. Ar ０ Ar １ and Ar ２ The resist underlayer film forming composition according to claim 1, wherein the aromatic rings in are, independently, a benzene ring, a naphthalene ring, an anthracene ring, a pyrene ring, or a biphenyl ring.

6. W ３２ and W ３３ The resist underlayer film forming composition according to claim 1, wherein each of the is an independent divalent organic group comprising a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 20 carbon atoms.

7. The resist underlayer film forming composition according to any one of claims 1 to 6, wherein the molecular weight of the aromatic ring-containing compound is 500 or more.

8. The resist underlayer film forming composition according to any one of claims 1 to 6, wherein the content of the aromatic ring-containing compound in the components other than the solvent in the resist underlayer film forming composition is 1% by mass or more.

9. A method for manufacturing a semiconductor substrate, comprising the steps of: coating a substrate directly or indirectly with a resist underlayer film forming composition; directly or indirectly forming a resist pattern on the resist underlayer film formed by the coating step; and etching using the resist pattern as a mask, wherein the resist underlayer film forming composition contains an aromatic ring-containing compound and a solvent, and the aromatic ring-containing compound is a compound represented by the following formula (A1), formula (A2), or formula (A3), or a polymer having repeating units represented by the following formula (A4) or formula (A5). (In equations (A1) to (A5), X is independently either -C(=O)- or -S(=O)²-.) ０ Each of these is independently a substituted or unsubstituted aromatic ring with 3 to 40 carbon atoms. １ and Ar ２ Each of these is independently a monovalent group containing a substituted or unsubstituted monovalent aromatic ring having 3 to 40 carbon atoms. １ is an s-valent organic group with 1 to 40 carbon atoms. s is an integer from 1 to 4. If s is 2 or greater, multiple X, Ar ０ and Ar １ They are either identical or different from each other. t is an integer from 1 to 4. If t is 2 or greater, there are multiple X, Ar ０ Ar １ and Ar ２ These are either identical or different from each other. ２ When t is 1, 3, or 4, it is a t-valent organic group having 1 to 40 carbon atoms, and when t is 2, it is a divalent organic group having 1 to 40 carbon atoms, a single bond, or a divalent heteroatom-containing linking group. Cy is a substituted or unsubstituted ring structure having 6 to 40 carbon atoms. u1 and u2 are each independently integers from 0 to 4, except that u1 + u2 is 1 or greater. Multiple X, Ar ０ Ar １ and Ar ２ These are either identical or different from each other. ３１ This is a divalent group containing an aromatic ring with 3 to 40 carbon atoms. ３２ This refers to a divalent organic group having 1 to 40 carbon atoms, a single bond, or a linking group containing a divalent heteroatom. ３３ Ar is a divalent organic group having 1 to 40 carbon atoms. ５ (This is a divalent group containing a substituted or unsubstituted aromatic ring with 3 to 40 carbon atoms.) 10. The method for manufacturing a semiconductor substrate according to claim 9, further comprising the step of forming a silicon-containing film directly or indirectly on the resist underlayer film before forming the resist pattern described above.

11. A method for producing an aromatic ring-containing compound, comprising the step of reacting a compound represented by the following formula (a1), the following formula (a2), or the following formula (a3) ​​with a compound represented by the following formula (b). (In equations (a1) to (a3), of the two X atoms in the five-membered ring, one is -C(=O)- and the other is -C(=O)- or -S(=O)2-.) ０ Each is independently a substituted or unsubstituted aromatic ring with 3 to 40 carbon atoms. t is an integer from 1 to 4. If t is 2 or greater, multiple X and Ar ０ These are either identical or different from each other. ２ When t is 1, 3, or 4, it is a t-valent organic group having 1 to 40 carbon atoms, and when t is 2, it is a divalent organic group having 1 to 40 carbon atoms, a single bond, or a divalent heteroatom-containing linking group. Cy is a substituted or unsubstituted ring structure having 6 to 40 carbon atoms. u1 and u2 are each an integer from 0 to 4, where u1 + u2 is 1 or greater. Multiple Xs are either identical or different from each other. In formula (b), Ar is a monovalent group containing a substituted or unsubstituted aromatic ring having 3 to 40 carbon atoms. v is an integer from 1 to 4. W ０ When v is 3 or 4, it is a v-valent organic group having 1 to 40 carbon atoms; when v is 1, it is a monovalent organic group having 1 to 40 carbon atoms or a hydrogen atom; and when v is 2, it is a divalent organic group having 1 to 40 carbon atoms, a single bond, or a linking group containing a divalent heteroatom.

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