Underlayer film-forming composition for metal-containing resist film and method for producing semiconductor substrate

Abstract

Provided are: an underlayer film-forming composition for a metal-containing resist film, with which it is possible to form a resist underlayer film that has excellent resist pattern rectangularity; and a method for producing a semiconductor substrate. This underlayer film-forming composition for a metal-containing resist film contains a polymer and a solvent, wherein the polymer has a partial structure represented by formula (a-1) or formula (a-2), and at least one monovalent group (X) selected from the group consisting of groups represented by formulas (2-1) to (2-8). (In formulas (a-1) and (a-2), R1 and R2 each represent the monovalent group (X), a C1-C20 monovalent organic group other than the monovalent group (X), a halogen atom, a hydroxy group, or a nitro group. The bond represented by the formula is a single bond or a double bond. n1 and n2 are integers of 0-4.)

Description

Metal-containing resist film base film forming composition and semiconductor substrate manufacturing method

[0001] This invention relates to a base layer forming composition for metal-containing resist films and a method for manufacturing semiconductor substrates.

[0002] In semiconductor substrate manufacturing, a multilayer resist process is used to form patterns 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. Various studies have been conducted on compositions for forming resist underlayer films (see International Publication No. 2013 / 141015).

[0003] See International Publication No. 2013 / 141015.

[0004] In recent years, semiconductor devices have become even more highly integrated, and the exposure light used is tending to be shortened from KrF excimer lasers (248 nm) and ArF excimer lasers (193 nm) to extreme ultraviolet light (13.5 nm, hereinafter also referred to as "EUV"). Furthermore, in EUV lithography, metal-containing resist films are increasingly being used instead of organic resist films.

[0005] Underlayer films for metal-containing resists require pattern rectangularity to ensure the rectangular shape of the resist pattern.

[0006] The present invention has been made based on the circumstances described above, and its objective is to provide a metal-containing resist film underlayer forming composition and a semiconductor substrate manufacturing method that can form a resist underlayer film with excellent resist pattern rectangularity.

[0007] In one embodiment, the present invention relates to an underlayer film forming composition for a metal-containing resist film, which contains a polymer (hereinafter also referred to as "[A] polymer") and a solvent (hereinafter also referred to as "[B] solvent"). The polymer has a partial structure represented by the following formula (a-1) or formula (a-2), and at least one monovalent group (X) selected from the group consisting of a group represented by the following formula (2-1), a group represented by the following formula (2-2), a group represented by the following formula (2-3), a group represented by the following formula (2-4), a group represented by the following formula (2-5), a group represented by the following formula (2-6), a group represented by the following formula (2-7), and a group represented by the following formula (2-8). (In the above formula (a-1) and formula (a-2), * is a bond with other atoms constituting the polymer. R １ and R ２ are each independently the monovalent group (X), a monovalent organic group having 1 to 20 carbon atoms other than the monovalent group (X), a halogen atom, a hydroxy group, or a nitro group. The bond represented by the following formula is a single bond or a double bond. n １ and n ２ are each independently an integer of 0 to 4. n １ or n ２ When is 2 or more, a plurality of R １ or R ２ are each the same as or different from each other.) [[ID=]21] (In the above formulas (2-1) to (2-8), R ７ are each independently a divalent organic group having 1 to 20 carbon atoms or a single bond. R ８ , R ９ , R １０ and R １３ are each independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. Cy is a ring structure having 3 to 20 ring members formed together with two carbon atoms in the formula (2-2). R １１ is a hydrogen atom, a monovalent organic group having 1 to 20 carbon atoms or a single bond. R １２ is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. ** is a bond with an atom constituting Cy. However, when R １１ is a single bond, R１１ It bonds with **. * represents the bonding site with each atom that makes up the polymer.

[0008] The metal-containing resist film underlayer forming composition (hereinafter also referred to as the "underlayer forming composition") can form a resist underlayer with excellent resist pattern rectangularity. Although the reason for this is not clear, it is presumed to be as follows: The polymer [A] of the metal-containing resist film underlayer forming composition incorporates a rigid substructure (a) derived from acenaphthylene or indene. In addition, the rigidity of the resulting film can be improved by the crosslinkable group (X). This is presumed to improve the film density and hardness of the resist underlayer, bringing it closer to the physical properties of a metal resist film, and as a result of improved adhesion at the interface between the metal resist film and the resist underlayer, the resist pattern can be made rectangular.

[0009] In other embodiments, the present invention includes the steps of: coating a substrate directly or indirectly with a metal-containing resist film underlayer composition; forming a metal-containing resist film on the resist underlayer formed by the coating step of the metal-containing resist film underlayer composition; exposing the metal-containing resist film with radiation; and developing at least the exposed metal-containing resist film, wherein the metal-containing resist film underlayer composition contains a polymer and a solvent, and the polymer has a substructure represented by the following formula (a-1) or formula (a-2) (hereinafter also referred to as "substructure (a)") and at least one monovalent group (X) selected from the group consisting of a group represented by the following formula (2-1), a group represented by the following formula (2-2), a group represented by the following formula (2-3), a group represented by the following formula (2-4), a group represented by the following formula (2-5), a group represented by the following formula (2-6), a group represented by the following formula (2-7), and a group represented by the following formula (2-8). This relates to a method for manufacturing semiconductor substrates. (In formulas (a-1) and (a-2) above, * represents a bond with another atom constituting the polymer. R １ and R ２Each of these is independently a monovalent group (X), a monovalent organic group having 1 to 20 carbon atoms other than the monovalent group (X), a halogen atom, a hydroxyl group, or a nitro group. The bond represented by the following formula is either a single bond or a double bond. n １ and n ２ Each of these is an independent integer between 0 and 4. １ or n ２ If there are two or more, multiple R １ or R ２ (These are either identical or different from each other.) (In the above equations (2-1) to (2-8), R ７ Each of these is independently a divalent organic group or single bond having 1 to 20 carbon atoms. ８ , R ９ , R １０ and R １３ Each of these is independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. Cy is a ring structure with 3 to 20 members, formed together with the two carbon atoms in formula (2-2). １１ R is a hydrogen atom, a monovalent organic group having 1 to 20 carbon atoms, or a single bond. １２ is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. ** is a bond with an atom constituting Cy. However, R １１ If it is a single bond, R １１ It bonds with **. * represents the bonding site with each atom that makes up the polymer.

[0010] The semiconductor substrate manufacturing method uses a metal-containing resist film forming composition capable of forming a resist underlayer film with excellent resist pattern rectangularity, thereby enabling the efficient production of semiconductor substrates with good patterns.

[0011] In this specification, each term and bond in a formula is defined as follows: “Organic group” means a group containing at least one carbon atom, and “number of carbon atoms” means the number of carbon atoms constituting the group. Organic groups may include ionic structures. In structural formulas, bonds represented by the following formulas mean single bonds or double bonds.

[0012] The metal-containing underlayer film forming composition can form a film with excellent resist pattern rectangularity. Furthermore, the metal-containing underlayer film forming composition can form a resist underlayer film with excellent resistance pattern peeling suppression. The semiconductor substrate manufacturing method uses a metal-containing underlayer film forming composition capable of forming an underlayer film for a metal-containing resist film with excellent resist pattern rectangularity, thus enabling efficient manufacturing of semiconductor substrates. Therefore, these can be suitably used in the manufacture of semiconductor devices and the like.

[0013] The following describes in detail the metal-containing resist film-forming compositions and semiconductor substrate manufacturing methods according to each embodiment of the present invention. Preferred combinations of embodiments are also preferred.

[0014] Composition for forming an underlayer film for metal-containing resist films The underlayer film forming composition for metal-containing resist films contains [A] a polymer and [B] a solvent. The composition may contain optional components as long as they do not impair the effects of the present invention.

[0015] The composition is suitable as a composition for forming an underlayer film of a metal-containing resist film subjected to exposure with extreme ultraviolet light. Preferably, the metal-containing resist film is formed using the metal-containing resist film forming composition. In this case, the metal-containing resist film forming composition contains a metal-containing compound and a solvent, and preferably the proportion of the metal-containing compound in the components other than the solvent in the metal-containing resist film forming composition is 50% by mass or more.

[0016] The following describes each component contained in the composition.

[0017] <[A] Polymer> The [A] polymer has a substructure (a) and a monovalent group (X). The [A] polymer may have one or more substructures (a). The [A] polymer may have one or more monovalent groups (X). The composition may contain one or more [A] polymers. In the [A] polymer, the substructure (a) may have the monovalent group (X), and parts other than the substructure (a) may have the monovalent group (X). The form of the [A] polymer is not particularly limited and may be any polymerization reaction such as an addition polymerization reaction, a polycondensation reaction, a polyaddition reaction, or an addition-condensation reaction. In accordance with the above form of the [A] polymer, the [A] polymer may contain repeating units having a substructure (a) and a monovalent group (X), or it may contain repeating units having a substructure (a) and repeating units having the monovalent group (X).

[0018] The above substructure (a) is a structure represented by the following formula (a-1) or formula (a-2). (In formulas (a-1) and (a-2) above, * represents a bond with another atom constituting the polymer. R １ and R ２ Each of these is independently a monovalent group (X), a monovalent organic group having 1 to 20 carbon atoms other than the monovalent group (X), a halogen atom, a hydroxyl group, or a nitro group. The bond represented by the following formula is either a single bond or a double bond. n １ and n ２ Each of these is an independent integer between 0 and 4. １ or n ２ If there are two or more, multiple R １ or R ２ (These are either identical or different from each other.)

[0019] R １ and R ２The monovalent group (X) described above, which may also be adopted, is at least one monovalent group selected from the group consisting of the group represented by the following formula (2-1), the group represented by the following formula (2-2), the group represented by the following formula (2-3), the group represented by the following formula (2-4), the group represented by the following formula (2-5), the group represented by the following formula (2-6), the group represented by the following formula (2-7), and the group represented by the following formula (2-8). (In the above equations (2-1) to (2-8), R ７ Each of these is independently a divalent organic group or single bond having 1 to 20 carbon atoms. ８ , R ９ , R １０ and R １３ Each of these is independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. Cy is a ring structure with 3 to 20 members, formed together with the two carbon atoms in formula (2-2). １１ R is a hydrogen atom, a monovalent organic group having 1 to 20 carbon atoms, or a single bond. １２ is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. ** is a bond with an atom constituting Cy. However, R １１ If it is a single bond, R １１ It bonds with **. * represents the bonding site with each atom that makes up the polymer.

[0020] In the above equations (2-1) to (2-8), R ７ Examples of divalent organic groups having 1 to 20 carbon atoms represented by include groups obtained by removing one hydrogen atom from a monovalent organic group having 1 to 20 carbon atoms. Examples of the monovalent organic groups having 1 to 20 carbon atoms include monovalent hydrocarbon groups having 1 to 20 carbon atoms, a group (a) having a divalent heteroatom-containing linking group between the carbon atoms of the hydrocarbon group or at the terminal end of the hydrocarbon group, a group in which some or all of the hydrogen atoms of the hydrocarbon group or group (a) are replaced with a monovalent heteroatom-containing substituent, or combinations thereof.

[0021] Examples of monovalent hydrocarbon groups having 1 to 20 carbon atoms include monovalent linear hydrocarbon groups having 1 to 20 carbon atoms, monovalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms, monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms, or combinations thereof.

[0022] Examples of monovalent chain hydrocarbon groups having 1 to 20 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.

[0023] Examples of monovalent alicyclic hydrocarbon groups having 3 to 20 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.

[0024] Examples of monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms include aryl groups such as phenyl, tolyl, xyl, naphthyl, anthracenyl, and pyrenyl groups; and aralkyl groups such as benzyl and phenethyl groups.

[0025] 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.

[0026] Examples of divalent heteroatom-containing linking groups include -CO-, -CS-, -NR'-, -O-, -S-, and -SO ２ -Or groups that combine these. R' is a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms.

[0027] Examples of monovalent heteroatom-containing substituents include hydroxyl groups, sulfanyl groups, cyano groups, nitro groups, and halogen atoms.

[0028] R ７Preferably, the combination is a divalent hydrocarbon group having 1 to 10 carbon atoms and a divalent heteroatom-containing linking group, and more preferably a combination of a methanediyl group, ethanediyl group, propanediyl group, benzenediyl group or a combination thereof, and -O-, -CO- or a combination thereof.

[0029] In the above equations (2-1) to (2-3), R ８ , R ９ , R １０ , R １１ , R １２ and R １３ (Hereinafter referred to as “R ８ ~R １３ It is also written as ). As a monovalent organic group having 1 to 20 carbon atoms, R ７ The monovalent organic groups having 1 to 20 carbon atoms shown above can be suitably adopted.

[0030] R ８ ~R １３ Preferably, all of these are hydrogen atoms.

[0031] In the above formula (2-2), the ring structure with 3 to 20 members that is formed together with the two carbon atoms in the formula represented by Cy is R ７ The ring structure corresponding to the monovalent alicyclic hydrocarbon having 3 to 20 carbon atoms shown in [reference] can be suitably adopted. As Cy, a cycloalkane ring having 5 to 10 carbon atoms is preferred, and a cyclopentane ring, cyclohexane ring, or cycloheptane ring is more preferred.

[0032] A specific example of the group represented by formula (2-1) above is the structure shown in the following formula. In the following formula, * represents a bond with an atom constituting the polymer. The same applies to specific examples of the groups represented by formulas (2-2) to (2-8).

[0033] A specific example of the group represented by the above formula (2-2) is the structure represented by the following formula.

[0034] A specific example of the group represented by the above formula (2-3) is the structure represented by the following formula.

[0035] A specific example of the group represented by the above formula (2-4) is the structure represented by the following formula.

[0036] A concrete example of the group represented by the above formula (2-5) is the structure represented by the following formula.

[0037] A specific example of the group represented by the above formula (2-6) is the structure represented by the following formula.

[0038] A specific example of the group represented by the above formula (2-7) is the structure represented by the following formula.

[0039] A specific example of the group represented by the above formula (2-8) is the structure represented by the following formula.

[0040] R １ and R ２ Other monovalent organic groups having 1 to 20 carbon atoms besides the above-mentioned monovalent group (X) include groups represented by the following formulas (a), (b), or (c).

[0041] (In formula (a), L ａ R is a single bond or a divalent linking group. ａ１ , R ａ２ and R ａ３ Each of these is independently a hydrogen atom, a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, a hydroxyl group, a cyano group or a nitro group, or R ａ１ R is a hydrogen atom, a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, a hydroxyl group, a cyano group, or a nitro group, ａ２ and R ａ３ These can be combined with each other to form a divalent alicyclic group with 3 to 20 carbon atoms, together with the carbon atoms to which they are bonded. In formula (b), L ｂ Z is a divalent linking group. ＋ is an onium cation. In formula (c), Ar １ is a substituted or unsubstituted aromatic ring having 3 to 20 carbon atoms. In formulas (a) to (c), * is R １and R ２ is a bond with an atom constituting an aromatic ring to which it is bonded.)

[0042] In the above formula (a), L ａ As the divalent linking group represented by, for example, a divalent hydrocarbon group, -COO-, -OCO-, -O-CO-O-, -CONR'-, -NR'CO-, -O-, -S-, -CO- or a group combining these can be preferably adopted. R' is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms.

[0043] 0 As the divalent hydrocarbon group in L ａ a group obtained by removing one hydrogen atom from the monovalent hydrocarbon group having 1 to 20 carbon atoms shown in R in the above formulas (2-1) to (2-8) can be preferably adopted. Among them, as the divalent hydrocarbon group in L ７ a divalent alkanediyl group is preferable, and a methanediyl group and an ethanediyl group are more preferable. ａ The above divalent hydrocarbon group may have a substituent. Examples of the substituent include a monovalent chain hydrocarbon group having 1 to 10 carbon atoms; an alkoxy group such as a methoxy group, an ethoxy group, and a propoxy group; an alkoxycarbonyl group such as a methoxycarbonyl group and an ethoxycarbonyl group; an alkoxycarbonyloxy group such as a methoxycarbonyloxy group and an ethoxycarbonyloxy group; an acyl group such as a formyl group, an acetyl group, a propionyl group, a butyryl group, and a benzoyl group; an acyloxy group such as an acetoxy group and a benzoyloxy group; a group in which some or all of the hydrogen atoms of these groups are substituted with a halogen atom; a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom; a hydroxy group; a cyano group; a nitro group; an oxo group (=O); or a group combining these groups, etc.

[0044] As the monovalent hydrocarbon group having 1 to 20 carbon atoms in R

[0045] R ａ１ R ａ２ and R ａ３ a monovalent hydrocarbon group having 1 to 20 carbon atoms shown in R in the above formulas (2-1) to (2-8) can be preferably adopted. Among them, R ７ a monovalent hydrocarbon group having 1 to 20 carbon atoms shown in R in the above formulas (2-1) to (2-8) can be preferably adopted. Among them, R ａ１ Rａ２ and R ａ３ As the monovalent hydrocarbon group having 1 to 20 carbon atoms in R, a monovalent chain hydrocarbon group having 1 to 10 carbon atoms and a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms are preferable, and a monovalent chain saturated hydrocarbon group having 1 to 6 carbon atoms and a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms are more preferable, and a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and a phenyl group are even more preferable.

[0046] R ａ１ 、R ａ２ and R ａ３ When the monovalent hydrocarbon group having 1 to 20 carbon atoms in R, R, and R has a substituent, as the substituent, the substituent that the divalent hydrocarbon group in the above L can have can be preferably adopted. ａ

[0047] R ａ２ and R ａ３ R and R together with the carbon atom to which they are attached form a divalent alicyclic group having 3 to 20 carbon atoms. As the divalent alicyclic group, a group obtained by removing one hydrogen atom from the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms shown in R in the above formulas (2-1) to (2-8) can be preferably adopted. Among them, as the divalent alicyclic group formed by R and R, a cyclopentanediy group and a cyclohexanediy group are preferable. ７ ａ２ and R ａ３

[0048] In the above formula (b), as the divalent linking group represented by L, the divalent linking group represented by L in the above formula (a) can be preferably adopted. ｂ ａ

[0049] Z ＋Examples of onium cations represented by include radiodegradable onium cations containing elements such as S, I, O, N, P, Cl, Br, F, As, Se, Sn, Sb, Te, and Bi, such as sulfonium cations, tetrahydrothiophenium cations, iodonium cations, phosphonium cations, diazonium cations, and pyridinium cations. Among these, sulfonium cations or iodonium cations are preferred, triarylsulfonium cations or diaryliodonium cations are more preferred, and triphenylsulfonium cations or diphenyliodonium cations are even more preferred. ＋ The aryl group in may have substituents. If the aryl group has substituents, the substituent may be the above L ａ The substituents that the divalent hydrocarbon group in the compound can have can be suitably adopted.

[0050] In the above formula (c), Ar １ Examples of aromatic rings having 3 to 20 carbon atoms in Ar include aromatic hydrocarbon rings such as benzene rings, naphthalene rings, anthracene rings, phenalene rings, phenanthrene rings, pyrene rings, fluorene rings, and perylene rings; heteroaromatic rings such as furan rings, pyrrole rings, thiophene rings, phosphole rings, pyrazole rings, oxazole rings, isoxazole rings, thiazole rings, pyridine rings, pyrazine rings, pyrimidine rings, pyridazine rings, and triazine rings; or combinations thereof. １ The above aromatic ring is preferably a benzene ring, a naphthalene ring, an anthracene ring, or a phenanthrene ring, with benzene rings and naphthalene rings being more preferred. If the above aromatic ring has substituents, the substituent is L. ａ The substituents that the divalent hydrocarbon group in the compound can have can be suitably adopted.

[0051] Specific examples of the group represented by formula (a) above include the structure represented by the following formula. In the following formula, * represents R １ or R ２ This is a bond with an atom constituting the aromatic ring to which it is bonded. The same applies to the specific examples of the group represented by formulas (b) and (c) above.

[0052]

[0053] Specific examples of the group represented by formula (b) above include, for example, the structure represented by the following formula.

[0054]

[0055] Specific examples of the group represented by formula (c) above include, for example, the structure represented by the following formula.

[0056]

[0057] n １ and n ２ Each of these is preferably an integer between 1 and 4, preferably an integer between 1 and 3, and more preferably 1 or 2.

[0058] The above polymer preferably has repeating units represented by the following formulas (A1-1), (A1-2), (A2-1), or (A2-2) (hereinafter also referred to as "repeating unit (A)"). (In the above formulas (A1-1), (A1-2), (A2-1), and (A2-2), W is independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. １ , R ２ , n １ and n ２ Furthermore, the combination represented by the following formula is equivalent to formulas (a-1) and (a-2) above.

[0059] As monovalent organic groups with 1 to 20 carbon atoms represented by W, the R in formulas (2-1) to (2-8) above is... ７ The monovalent organic groups having 1 to 20 carbon atoms shown in the above formula can be suitably adopted. The organic group W is preferably a monovalent group containing a substituted or unsubstituted aromatic ring having 3 to 20 carbon atoms, or an alkyl group having 1 to 10 carbon atoms. The monovalent group containing an aromatic ring having 3 to 20 carbon atoms represented by W is Ar of formula (c) above. １A group obtained by removing one hydrogen atom from an aromatic ring having 3 to 20 carbon atoms can be suitably adopted. In particular, as the organic group of W, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, an alkyl group having 1 to 8 carbon atoms, or a group in which the hydrogen atoms of these groups are substituted with substituents is preferred, and a phenyl group, naphthyl group, pyrenyl group, biphenyl group, pentyl group, hexyl group, or a group in which the hydrogen atoms of these groups are substituted with substituents is more preferred.

[0060] For W, a hydrogen atom is preferred.

[0061] A specific example of a repeating unit represented by the above formula (A1-1) that has the above monovalent group (X) is, for example, the structure represented by the following formula.

[0062]

[0063] A specific example of a repeating unit represented by the above formula (A1-1) having a group other than the monovalent group (X) is, for example, the structure represented by the following formula.

[0064]

[0065]

[0066] A specific example of a repeating unit represented by the above formula (A1-2) that has the above monovalent group (X) is, for example, the structure represented by the following formula.

[0067]

[0068] Specific examples of cases where the repeating unit represented by the above formula (A1-2) has groups other than the monovalent group (X) include, for example, the structure represented by the following formula.

[0069]

[0070] A specific example of a repeating unit represented by the above formula (A2-1) that has the above monovalent group (X) is, for example, the structure represented by the following formula.

[0071] (In the formula, the combination represented by the following formula is equivalent to formulas (a-1) and (a-2) above.)

[0072] Specific examples of cases where the repeating unit represented by the above formula (A2-1) has groups other than the monovalent group (X) include, for example, the structure represented by the following formula.

[0073]

[0074] A specific example of a repeating unit represented by the above formula (A2-2) that has the above monovalent group (X) is, for example, the structure represented by the following formula.

[0075]

[0076] A specific example of a repeating unit represented by the above formula (A2-2) having a group other than the monovalent group (X) is, for example, the structure represented by the following formula.

[0077]

[0078] [A] The proportion of repeating unit (A) in the total number of repeating units constituting the polymer can be appropriately set depending on whether or not repeating unit (A) has the monovalent group (X). If repeating unit (A) does not have the monovalent group (X), the polymer [A] includes repeating units that have a different structure from repeating unit (A) and have the monovalent group (X) (hereinafter also referred to as "repeating unit (B)," which will be described later). If repeating unit (A) has the monovalent group (X), the polymer [A] may or may not include repeating unit (B).

[0079] [A] In polymers, regardless of whether repeating unit (A), repeating unit (B), or both thereof have the monovalent group (X), the lower limit of the total content of repeating units having the monovalent group (X) is preferably 50 mol%, more preferably 60 mol%, and even more preferably 70 mol%. The upper limit of the total content of repeating units having the monovalent group (X) may be 100 mol%, 90 mol%, or 80 mol%.

[0080] If the repeating unit (A) does not have the monovalent group (X) described above, the lower limit of the content of the repeating unit (A) (or the total content if there are multiple types) is preferably 5 mol%, more preferably 10 mol%, and even more preferably 15 mol%. The upper limit of the content is preferably 40 mol%, more preferably 35 mol%, and even more preferably 30 mol%.

[0081] When the repeating unit (A) has the above-mentioned monovalent group (X), the lower limit of the above-mentioned content percentage of the repeating unit (A) (total content percentage if there are multiple types) is preferably 5 mol%, more preferably 10 mol%, and even more preferably 15 mol%. The upper limit of the above-mentioned content percentage may be 100 mol%, 90 mol%, or 80 mol%.

[0082] [A] The polymer may have repeating units represented by the following formula (B-1) or repeating units represented by the following formula (B-2) (i.e., repeating unit (B)). (In equations (B-1) and (B-2), R ３ L is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms. １ This is a single bond or 1+n ３ It is a valence linking group. Each X is independently at least one monovalent group (X) selected from the group consisting of the group represented by formula (2-1), the group represented by formula (2-2), the group represented by formula (2-3), the group represented by formula (2-4), the group represented by formula (2-5), the group represented by formula (2-6), the group represented by formula (2-7), and the group represented by formula (2-8). However, * in formulas (2-1) to (2-8) is L １ or L ２ This is a bonding bond with the constituent atoms. If there are multiple X atoms, they can be identical or different from each other. ３ Each of these is an integer between 1 and 4, independently of the others. ２ This is a substituted or unsubstituted aromatic ring with 3 to 20 carbon atoms. ２ L is a single bond or a divalent linking group. ２ If there are multiple L ２They are either identical or different from each other. ２ (This refers to a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.)

[0083] In the above formula (B-1), R ３ In this, the monovalent hydrocarbon group having 1 to 20 carbon atoms is R in the above formulas (2-1) to (2-8). ７ The monovalent hydrocarbon groups having 1 to 20 carbon atoms shown in the above can be suitably used. ３ Preferably, the element is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and more preferably a hydrogen atom, a methyl group, or an ethyl group.

[0084] In the above formula (B-1), L １ 1+n ３ As a valence linking group, L in formula (a) above is used. ａ From the divalent linking group represented by n ３ -A group with one hydrogen atom removed can be suitably adopted. The divalent linking group is preferably an alkanediyl group, an arenediyl group, -COO-, -O-, or a combination thereof, and more preferably a methanediyl group, an ethanediyl group, a benzenediyl group, -COO-, -O-, or a combination thereof.

[0085] In the above formulas (B-1) and (B-2), the monovalent group (X) represented by X is as explained above.

[0086] In the above formulas (B-1) and (B-2), n ２ It is preferably an integer between 1 and 3, and more preferably 1 or 2.

[0087] In the above formula (B-2), Ar ２ As for the aromatic ring with 3 to 20 carbon atoms in the above formula (c), Ar １ Aromatic rings having 3 to 20 carbon atoms as shown can be suitably used. If the aromatic ring has substituents, the substituents are as shown above L ａ The substituents that the divalent hydrocarbon group in the compound can have can be suitably adopted.

[0088] In the above formula (B-2), L ２ The divalent linking group represented by is L in formula (a) above. ａA divalent linking group represented by can be suitably adopted.

[0089] In the above formula (B-2), W ２ As the monovalent organic group having 1 to 20 carbon atoms represented by the above formulas (A2-1) and (A2-2), the monovalent organic group having 1 to 20 carbon atoms represented by W can be suitably adopted.

[0090] Specific examples of repeating units (B-1) include, for example, the repeating unit represented by the following formula.

[0091]

[0092] In the above formula, R ３ This is equivalent to equation (B) above.

[0093] Specific examples of repeating units (B-2) include, for example, the repeating unit represented by the following formula.

[0094]

[0095] [A] When the polymer contains repeating units (B), the lower limit of the content of repeating units (B) to the total repeating units constituting the polymer (or the total content if multiple types are included) is preferably 40 mol%, more preferably 50 mol%, and even more preferably 60 mol%. The upper limit of the above content is preferably 95 mol%, more preferably 85 mol%, and even more preferably 80 mol%.

[0096] [A] The polymer may have other repeating units (except when they correspond to repeating unit (A) or repeating unit (B)), such as an onium salt structure containing a sulfonate anion and a sulfonium cation, an onium salt structure containing a sulfonate anion and an iodonium cation, or other structures that generate acid upon exposure, a repeating unit having at least one hydroxyl group, a repeating unit having a fluorine atom, etc. When the polymer [A] contains other repeating units, the lower limit of the content of other repeating units to the total repeating units constituting the polymer [A] (the total content if there are multiple types) is preferably 2 mol%, more preferably 5 mol%, and even more preferably 8 mol%. The upper limit of the above content is preferably 35 mol%, more preferably 30 mol%, and even more preferably 25 mol%.

[0097] [A] The lower limit of the weight-average molecular weight (Mw) of the polymer is preferably 2000, more preferably 3000, and even more preferably 4000. The upper limit of the molecular weight is preferably 15000, more preferably 12000, and even more preferably 8000. The method for measuring the weight-average molecular weight is as described in the examples.

[0098] [A] The lower limit of the number-average molecular weight (Mn) of the polymer is preferably 1000, and more preferably 2000. The upper limit of the above molecular weight is preferably 6000, and more preferably 4000. The method for measuring the number-average molecular weight is as described in the examples.

[0099] The lower limit of the content of polymer [A] in the metal-containing resist film base film forming composition is preferably 0.05% by mass, more preferably 0.1% by mass, and even more preferably 0.3% by mass, based on the total mass of polymer [A] and solvent [B]. The upper limit of the above content is preferably 1.5% by mass, more preferably 1.0% by mass, and even more preferably 0.8% by mass, based on the total mass of polymer [A] and solvent [B].

[0100] The content of the polymer [A] in the components other than the solvent [B] in the underlayer film-forming composition for metal-containing resist films may be 40% by mass or more, 50% by mass, 60% by mass, 70% by mass, 80% by mass, 90% by mass, or 100% by mass.

[0101] [Method for synthesizing polymers A] Polymers A can be synthesized by radical polymerization, ionic polymerization, polycondensation, polyaddition, addition condensation, etc., depending on the type of monomer.

[0102] [A] When a polymer is synthesized by radical polymerization, the monomers that give each repeating unit can be synthesized by polymerization in a suitable solvent using a radical polymerization initiator or the like. Furthermore, the monovalent group (X) may be introduced after polymerization by an appropriate reaction.

[0103] Examples of the radical polymerization initiators mentioned above include azo-based radical initiators such as azobisisobutyronitrile (AIBN), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2-cyclopropylpropionitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl-2,2'-azobisisobutyrate, and dimethyl-2,2'-azobis(2-methylpropionate); and peroxide-based radical initiators such as benzoyl peroxide, t-butyl hydroperoxide, and cumene hydroperoxide. These radical initiators can be used individually or in combination of two or more.

[0104] The solvent used in the polymerization described above can preferably be the solvent [B] described later. These solvents used in polymerization may be used individually or in combination of two or more.

[0105] The reaction temperature in the above polymerization is usually 40°C to 180°C, preferably 60°C to 140°C. The reaction time is usually 1 hour to 48 hours, preferably 1 hour to 24 hours. Polymer [A] can be produced by acid addition condensation of an aromatic ring compound as a precursor having a phenolic hydroxyl group that gives a repeating unit represented by formula (A2-1) or formula (A2-2) with an aldehyde derivative. Furthermore, polymer [A] with the monovalent group (X) introduced as a substituent can be produced by nucleophilic substitution reaction of a halogenated hydrocarbon with a phenolic hydroxyl group corresponding to the monovalent group (X). The acid catalyst is not particularly limited, and known inorganic and organic acids can be used. After the reaction, polymer [A] can be obtained by separation, purification, drying, etc. Other structures can also be produced by appropriately changing the structure of the aromatic ring compound as a precursor, the aldehyde derivative, the substituent, etc. Solvent [B] described later can be suitably used as the reaction solvent.

[0106] <[B] Solvent> The [B] solvent is not particularly limited as long as it can dissolve or disperse the [A] polymer and any optional components contained therein as needed.

[0107] [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.

[0108] 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.

[0109] 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.

[0110] Examples of alcohol-based solvents include monoalcohol solvents such as methanol, ethanol, n-propanol, 4-methyl-2-pentanol, and 2,2-dimethyl-1-propanol, and polyhydric alcohol solvents such as ethylene glycol and 1,2-propylene glycol.

[0111] Examples of ketone solvents include linear ketone solvents such as methyl ethyl ketone, 4-methyl-2-pentanone (methyl isobutyl ketone), and 2-heptanone, as well as cyclic ketone solvents such as cyclohexanone.

[0112] Examples of ether-based solvents include linear ether solvents such as n-butyl ether, cyclic ether solvents such as tetrahydrofuran, polyhydric alcohol ether solvents such as diethylene glycol dimethyl ether, and polyhydric alcohol partial ether solvents such as diethylene glycol monomethyl ether and propylene glycol monomethyl ether.

[0113] Examples of nitrogen-containing solvents include linear nitrogen-containing solvents such as N,N-dimethylacetamide and cyclic nitrogen-containing solvents such as N-methylpyrrolidone.

[0114] [B] As the solvent, ether-based solvents or ester-based solvents are preferred, polyhydric alcohol partial ether-based solvents or polyhydric alcohol partial ether carboxylate-based solvents are more preferred, and propylene glycol monomethyl ether and propylene glycol acetate monomethyl ether are even more preferred.

[0115] [Optional Components] The metal-containing resist film base-forming composition may contain optional components as long as they do not impair the effects of the present invention. Examples of optional components include crosslinking agents, acid generators, base generators, dehydrating agents, acid diffusion control agents, surfactants, and defoaming agents. 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) 2024", "U-CAT (registered trademark) 2026", "U-CAT (registered trademark) 2030", "U-CAT (registered trademark) Examples include "Trademark 2110", "U-CAT (Registered Trademark) 2313", "U-CAT (Registered Trademark) 651M", "U-CAT (Registered Trademark) 660M", "U-CAT (Registered Trademark) 18X", "TMED", "U-CAT (Registered Trademark) 201G", "U-CAT (Registered Trademark) 202", "U-CAT (Registered Trademark) 420A", "U-CAT (Registered Trademark) 130", "U-CAT (Registered Trademark) 891", "POLYCAT (Registered Trademark) 8", "POLYCAT (Registered Trademark) 9", "POLYCAT (Registered Trademark) 12", and "POLYCAT (Registered Trademark) 41" (all are product names, manufactured by Sunapro Co., Ltd.). As for defoaming agents, 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 defoaming agents. Optional components can be used individually or in combination of two or more. The content ratio of optional components in the metal-containing resist film underlayer composition can be appropriately determined depending on the type of optional component.

[0116] [Method for preparing a base layer forming composition for metal-containing resist films] The base layer forming composition for metal-containing resist films can be prepared by mixing [A] polymer, [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 0.05 μm or more and 0.5 μm or less.

[0117] 《Method for Manufacturing a Semiconductor Substrate》 The method for manufacturing the semiconductor substrate includes a step of directly or indirectly coating a substrate with a metal-containing resist film base layer formation composition (hereinafter also referred to as the "coating step"), a step of forming a metal-containing resist film on the resist base layer formed by the coating step of the metal-containing resist film base layer formation composition (hereinafter also referred to as the "resist film formation step"), a step of exposing the metal-containing resist film with radiation (hereinafter also referred to as the "exposure step"), and a step of developing at least the exposed metal-containing resist film (hereinafter also referred to as the "development step").

[0118] The method for manufacturing the semiconductor substrate may further include, if necessary, a step of forming an organic underlayer film on the substrate directly or indirectly (hereinafter also referred to as the "organic underlayer film formation step") prior to the coating step of the resist underlayer film forming composition for metal-containing resists.

[0119] The method for manufacturing the semiconductor substrate may further include, if necessary, a step of forming a silicon-containing film on the substrate directly or indirectly (hereinafter also referred to as the "silicon-containing film formation step") prior to the coating step of the resist underlayer forming composition for metal-containing resists.

[0120] The following describes each step when the optional steps of forming an organic underlayer film and forming a silicon-containing film are included.

[0121] [Organic Underlayer Formation Process] In this process, an organic underlayer is formed directly or indirectly on the substrate before the coating process described above. This process is optional. Through this process, an organic underlayer is formed directly or indirectly on the substrate.

[0122] Examples of substrates include insulating films such as silicon oxide, silicon nitride, silicon oxynitride, and polysiloxane, as well as resin substrates. Furthermore, the substrate may be one that has been patterned with features such as wiring trenches and plug grooves (vias).

[0123] An organic underlayer can be formed by coating with an organic underlayer-forming composition. Methods for forming an organic underlayer by coating with an organic underlayer-forming composition include, for example, directly or indirectly coating a substrate with the composition and then curing the resulting coating by heating or exposure. Examples of organic underlayer-forming compositions include JSR Corporation's "HM8006". The heating and exposure conditions can be appropriately determined depending on the type of organic underlayer-forming composition used.

[0124] The lower limit of the average thickness of the organic underlayer film is preferably 20 nm, more preferably 50 nm, and even more preferably 80 nm. The upper limit is preferably 500 nm, more preferably 300 nm, and even more preferably 200 nm. The average thickness of the organic underlayer film can be measured in the same way as the average thickness of the resist underlayer film.

[0125] Examples of cases where an organic underlayer film is indirectly formed on a substrate include forming the organic underlayer film on a low-dielectric insulating film formed on the substrate.

[0126] [Silicon-containing film formation process] In this process, a silicon-containing film is formed directly or indirectly on the substrate before the coating process described above. This process is optional.

[0127] As the substrate, the substrate exemplified in the organic underlayer film formation process described above can be suitably used.

[0128] 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 a substrate with the silicon-containing film-forming composition and then curing the resulting coating by exposure and / or heating. Commercially available silicon-containing film-forming compositions include, for example, "NFC SOG01," "NFC SOG04," and "NFC SOG080" (all from JSR Corporation). Silicon oxide films, silicon nitride films, silicon oxiditride films, and amorphous silicon films can be formed by chemical vapor deposition (CVD) or atomic layer deposition (ALD).

[0129] 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.

[0130] The heating and exposure conditions can be appropriately determined depending on the type of silicon-containing film-forming composition used.

[0131] The lower limit of the average thickness of the silicon-containing film is preferably 1 nm, more preferably 10 nm, and even more preferably 15 nm. The upper limit of the average thickness is preferably 20,000 nm, more preferably 1,000 nm, and even more preferably 100 nm. The average thickness of the silicon-containing film can be measured in the same way as the average thickness of the resist underlayer film.

[0132] Examples of cases where a silicon-containing film is indirectly formed on a substrate include forming a silicon-containing film on a low-dielectric insulating film or an organic underlayer film formed on the substrate.

[0133] [Coating Process] In this process, the metal-containing resist film underlayer composition is coated onto the silicon-containing film formed on the substrate. The coating method for the metal-containing resist film underlayer 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 as a result, and the resist underlayer is formed by the volatilization of the solvent [B].

[0134] Furthermore, if the underlayer film-forming composition for metal-containing resist films is directly coated onto the substrate, the above-mentioned organic underlayer film formation step and silicon-containing film formation step may be omitted.

[0135] Next, the coating film formed by the above coating process is heated. Heating the coating film promotes the formation of the resist underlayer film. More specifically, heating the coating film promotes the volatilization of solvent [B], etc.

[0136] 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 100°C, more preferably 150°C, and even more preferably 200°C. The upper limit of the heating temperature is preferably 400°C, more preferably 350°C, and even more preferably 280°C. The lower limit of the heating time is preferably 15 seconds, more preferably 30 seconds. The upper limit of the heating time is preferably 1,200 seconds, and even more preferably 600 seconds.

[0137] The lower limit of the film thickness (average thickness) of the resist underlayer film formed is preferably 0.5 nm, more preferably 1 nm, and even more preferably 2 nm. The upper limit of the average thickness is preferably 15 nm, more preferably 12 nm, even more preferably 8 nm, and particularly preferably 5 nm. The method for measuring the average thickness is as described in the examples.

[0138] [Resist Film Formation Process] In this process, a metal-containing resist film is formed on the resist underlayer film formed by the above coating process. It is preferable that such a metal-containing resist film be formed using a metal-containing resist film forming composition. The metal-containing resist film may be either a coated film or a deposited film, but it is preferable that it be a coated film. There are no particular limitations on the coating method of the metal-containing resist film forming composition, and examples include rotary coating.

[0139] (Composition for forming metal-containing resist films) The composition for forming metal-containing resist films contains a metal-containing compound (hereinafter also referred to as "metal-containing compound (A)") and a solvent (hereinafter also referred to as "solvent (F)"), and it is preferable that the content ratio of the metal-containing compound (A) to the components other than solvent (F) in the above metal-containing resist film forming composition is 50% by mass or more. The above metal-containing resist film forming composition may further contain other components.

[0140] (Metal-containing compound (A)) Metal-containing compound (A) is a compound containing metal atoms. Metal-containing compound (A) can be used alone or in combination of two or more types. Furthermore, the metal atoms constituting metal-containing compound (A) can be used alone or in combination of two or more types. Here, "metal atom" is a concept that includes metalloids, namely boron, silicon, germanium, arsenic, antimony, and tellurium.

[0141] The metal atoms constituting the metal-containing compound (A) are not particularly limited, and examples include metal atoms from groups 3 to 16. Specific examples of the above metal atoms include, for example, group 4 metal atoms such as titanium, zirconium, and hafnium; group 5 metal atoms such as tantalum; group 6 metal atoms such as chromium and tungsten; group 8 metal atoms such as iron and ruthenium; group 9 metal atoms such as cobalt; group 10 metal atoms such as nickel; group 11 metal atoms such as copper; group 12 metal atoms such as zinc, cadmium, and mercury; group 13 metal atoms such as boron, aluminum, gallium, indium, and thallium; group 14 metal atoms such as germanium, tin, and lead; group 15 metal atoms such as antimony and bismuth; and group 16 metal atoms such as tellurium.

[0142] The metal atoms constituting the metal-containing compound (A) may include a first metal atom belonging to Group 4, Group 12, or Group 14 of the periodic table, and belonging to Period 4, Period 5, or Period 6. That is, the metal atoms may include at least one of titanium, zirconium, hafnium, zinc, cadmium, mercury, germanium, tin, and lead. In this way, the inclusion of a first metal atom in the metal-containing compound (A) promotes the emission of secondary electrons in the exposed area of ​​the resist film and the change in the solubility of the metal-containing compound (A) in the developer due to these secondary electrons. As a result, the rectangularity of the pattern can be improved. Tin or zirconium is preferred as the first metal atom.

[0143] The metal-containing compound (A) preferably further contains atoms other than metal atoms. Examples of these other atoms include carbon atoms, hydrogen atoms, oxygen atoms, nitrogen atoms, phosphorus atoms, sulfur atoms, halogen atoms, etc., with carbon atoms, hydrogen atoms, and oxygen atoms being preferred among these. The other atoms in the metal-containing compound (A) can be used individually or in combination of two or more types.

[0144] The lower limit of the content of the metal-containing compound (A) in the metal-containing resist film-forming composition, calculated on a solid content basis, is preferably 70% by mass, more preferably 90% by mass, and even more preferably 95% by mass. The above content may also be 100% by mass. Here, the solid content in the metal-containing resist film-forming composition refers to components other than the solvent (F) described later.

[0145] (Method for synthesizing metal-containing compound (A)) Metal-containing compound (A) can be obtained, for example, by performing a hydrolysis condensation reaction, ligand exchange reaction, etc., on a metal compound having a metal atom and a hydrolyzable group, a hydrolysate of this metal compound, a hydrolysis condensate of the above metal compound, or a combination thereof. The above metal compounds can be used individually or in combination of two or more.

[0146] The metal-containing compound (A) is preferably derived from a metal compound having a metal atom and a hydrolyzable group represented by the following formula (4) (hereinafter also referred to as "metal compound precursor (1)"). By using such a metal compound precursor (1), a stable metal-containing compound (A) can be obtained.

[0147] In the above formula (4), M is a metal atom. Ａ is a ligand or a monovalent organic group having 1 to 20 carbon atoms. a1 is an integer from 0 to 6. If a1 is 2 or more, multiple L Ａ Q may be the same or different. Q is a monovalent hydrolyzable group. b1 is an integer from 2 to 6. Multiple Qs may be the same or different. Note that L Ａ This is a ligand or organic group that does not correspond to Q.

[0148] The metal atom represented by M is preferably a metal atom of Group 14, and more preferably tin.

[0149] The hydrolyzable group represented by Q can be appropriately changed in accordance with the metal atom represented by M, but examples include substituted or unsubstituted ethynyl groups, halogen atoms, alkoxy groups, alkylcarbonyloxy groups, substituted or unsubstituted amino groups, etc.

[0150] The substituents in the substituted or unsubstituted ethynyl group and the substituted or unsubstituted amino group represented by Q are preferably monovalent hydrocarbon groups having 1 to 20 carbon atoms, more preferably linear hydrocarbon groups, and even more preferably alkyl groups.

[0151] Examples of halogen atoms represented by Q include fluorine, chlorine, bromine, and iodine atoms. Among these, chlorine atoms are preferred.

[0152] Examples of alkoxy groups represented by Q include methoxy, ethoxy, n-propoxy, i-propoxy, and n-butoxy groups. Among these, ethoxy, i-propoxy, and n-butoxy groups are preferred.

[0153] Examples of alkylcarbonyloxy groups represented by Q include acetoxy group, ethylcarbonyloxy group, propylcarbonyloxy group, n-butylcarbonyloxy group, t-butylcarbonyloxy group, t-amylcarbonyloxy group, n-hexylcarbonyloxy group, and n-octylcarbonyloxy group. Among these, the acetoxy group is preferred.

[0154] Examples of substituted or unsubstituted amino groups represented by Q include amino groups, methylamino groups, dimethylamino groups, diethylamino groups, and dipropylamino groups. Among these, dimethylamino groups and diethylamino groups are preferred.

[0155] The following describes preferred combinations of a metal atom represented by M and a hydrolyzable group represented by Q. When the metal atom represented by M is tin, the hydrolyzable group represented by Q is preferably a substituted or unsubstituted ethynyl group, a halogen atom, an alkoxy group, an alkylcarbonyloxy group, and a substituted or unsubstituted amino group, with a halogen atom being more preferred. When the metal atom represented by M is germanium, the hydrolyzable group represented by Q is preferably a halogen atom, an alkoxy group, an alkylcarbonyloxy group, and a substituted or unsubstituted amino group. When the metal atom represented by M is hafnium, zirconium, or titanium, the hydrolyzable group represented by Q is preferably a halogen atom, an alkoxy group, or an alkylcarbonyloxy group.

[0156] L Ａ Ligands represented by this include monodentate ligands and polydentate ligands.

[0157] Examples of the monodentate ligands mentioned above include hydroxo ligands, nitro ligands, and ammonia ligands.

[0158] Examples of the polydentate ligands mentioned above include hydroxy acid esters, β-diketones, β-ketoesters, malonic acid diesters in which the α-carbon atom may be substituted, hydrocarbons having a π bond, ligands derived from these compounds, and diphosphines.

[0159] Examples of the above-mentioned diphosphines include 1,1-bis(diphenylphosphino)methane, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl, and 1,1'-bis(diphenylphosphino)ferrocene.

[0160] L Ａ The monovalent organic group represented by is R in the above formulas (2-1) to (2-8). ７ Monovalent organic groups having 1 to 20 carbon atoms, as shown above, can be suitably used.

[0161] L Ａ The lower limit of the number of carbon atoms in the monovalent organic group represented by is preferably 2, and more preferably 3. On the other hand, the upper limit of the number of carbon atoms is preferably 10, and more preferably 5. １ The monovalent organic group represented by is preferably a substituted or unsubstituted hydrocarbon group, more preferably a substituted or unsubstituted linear hydrocarbon group or a substituted or unsubstituted aromatic hydrocarbon group, even more preferably a substituted or unsubstituted alkyl group or a substituted or unsubstituted aralkyl group, and particularly preferably an isopropyl group or a benzyl group.

[0162] For a1, 1 and 2 are preferred, with 1 being more preferred.

[0163] b1 is preferably an integer between 2 and 4. By setting b1 to the above value, the proportion of metal atoms in the metal-containing compound (A) can be increased, and the generation of secondary electrons by the metal-containing compound (A) can be promoted more effectively. As a result, the rectangularity of the pattern can be improved.

[0164] As the metal compound precursor (1), a metal halide compound is preferred, and isopropyltin trichloride or benzyltin trichloride is more preferred.

[0165] A method for carrying out a hydrolysis condensation reaction with a metal compound precursor (1) includes, for example, stirring the metal compound precursor (1) in water or a water-containing solvent in the presence of a base such as tetramethylammonium hydroxide, which can be used as needed. In this case, other compounds having hydrolyzable groups may be added as needed. The lower limit of the amount of water used in this hydrolysis condensation reaction is preferably 0.2 moles, more preferably 1 mole, and even more preferably 3 moles, relative to the hydrolyzable groups present in the metal compound precursor (1). By setting the amount of water in the hydrolysis condensation reaction within the above range, a metal-containing compound (A) can be efficiently obtained.

[0166] In the synthesis reaction of the metal-containing compound (A), in addition to the metal compound precursor (1), L in the compound of formula (4) above is also present. Ａ Compounds that can act as polydentate ligands or crosslinking ligands, etc., represented by the formula, may be added. Examples of compounds that can act as crosslinking ligands include compounds having two or more coordinating groups such as hydroxyl groups, isocyanate groups, amino groups, ester groups, and amide groups.

[0167] The lower limit of the temperature for the synthesis reaction of the metal-containing compound (A) is preferably 0°C, more preferably 10°C. The upper limit of the above temperature is preferably 150°C, more preferably 100°C, and even more preferably 50°C.

[0168] The lower limit of the time for the synthesis reaction of the metal-containing compound (A) is preferably 1 minute, more preferably 10 minutes, and even more preferably 1 hour. The upper limit of the above time is preferably 100 hours, more preferably 50 hours, even more preferably 24 hours, and particularly preferably 4 hours.

[0169] (Solvent (F)) An organic solvent is preferred as solvent (F). Specific examples of this organic solvent include, for example, those similar to those exemplified as solvent [B] in the above-mentioned underlayer film-forming composition for metal-containing resist films.

[0170] As the solvent (F), an ether-based solvent is preferred, and propylene glycol monoethyl ether is more preferred.

[0171] (Other optional components) In addition to the metal-containing compound (A) and solvent (F), the metal-containing resist film forming composition may also contain other optional components such as ligands and surfactants.

[0172] (Compounds that can act as ligands) Examples of compounds that can act as ligands include compounds that can act as polydentate ligands or bridging ligands, and specifically include those similar to the compounds that can act as polydentate ligands or bridging ligands exemplified in the synthesis method of metal-containing compound (A).

[0173] (Surfactants) Surfactants are components that improve the applicability, striation, etc. Examples of surfactants include nonionic surfactants such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, polyethylene glycol dilaurate, and polyethylene glycol distearate, as well as the following trade names: KP341 (Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, and Polyflow No. Examples include 95 (Kyoeisha Chemical Co., Ltd.), F-Top EF301, EF303, EF352 (all from Tochem Products Co., Ltd.), Megafac F171, F173 (both from Dainippon Ink and Chemicals, Inc.), Florard FC430, FC431 (both from Sumitomo 3M Co., Ltd.), Asahiguard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 (all from Asahi Glass Co., Ltd.).

[0174] (Method for preparing a composition for forming a metal-containing resist film) A composition for forming a metal-containing resist film can be prepared, for example, by mixing a metal-containing compound (A) and a solvent (F) with other optional components in a predetermined ratio, and preferably by filtering the resulting mixture through a membrane filter with a pore size of 0.4 μm or less. It is preferable that the content of the metal-containing compound (A) in the components other than the solvent (F) in the above metal-containing resist film forming composition is 50% by mass or more. The lower limit of the content of the metal-containing compound (A) is more preferably 60% by mass, and even more preferably 70% by mass. On the other hand, the upper limit of the above content is preferably 100% by mass, but may also be 98% by mass or 95% by mass.

[0175] To explain this resist film formation process in more detail, for example, a metal-containing resist film forming composition is applied so that the metal-containing resist film to be formed has a predetermined thickness, and then the solvent in the coated film is evaporated by pre-baking (hereinafter also referred to as "PB") to form the metal-containing resist film.

[0176] The PB temperature and PB time can be appropriately determined depending on the type of metal-containing resist film forming composition used. The lower limit of the PB temperature is preferably 30°C, and more preferably 50°C. The upper limit of the PB temperature is preferably 200°C, and more preferably 150°C. The lower limit of the PB time is preferably 10 seconds, and more preferably 30 seconds. The upper limit of the PB time is preferably 600 seconds, and more preferably 300 seconds.

[0177] [Exposure Process] In this process, the metal-containing resist film is exposed to radiation.

[0178] The radiation used for exposure can be appropriately selected depending on the type of metal-containing resist film forming composition used. Examples include 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. Among these, electron beams or far ultraviolet light are preferred, and electron beams or KrF excimer laser light (wavelength 248 nm), ArF excimer laser light (wavelength 193 nm), F ２ Excimer laser light (wavelength 157 nm), Kr２ Excimer laser light (wavelength 147 nm), ArKr excimer laser light (wavelength 134 nm), or extreme ultraviolet light (wavelength 13.5 nm, also known as "EUV") is more preferred, and electron beams or EUV are even more preferred. Furthermore, the exposure conditions can be appropriately determined depending on the type of metal-containing resist film forming composition used, etc.

[0179] Furthermore, in this process, after exposure, post-exposure baking (hereinafter also referred to as "PEB") can be performed to improve the performance of the metal-containing resist film, such as resolution, pattern profile, and developability. The PEB temperature and PEB time can be appropriately determined according to the type of metal-containing resist film forming composition used. The lower limit of the PEB temperature is preferably 50°C, and more preferably 70°C. The upper limit of the PEB temperature is preferably 200°C, and more preferably 150°C. The lower limit of the PEB time is preferably 10 seconds, and more preferably 30 seconds. The upper limit of the PEB time is preferably 600 seconds, and more preferably 300 seconds.

[0180] [Development Process] In this process, at least the exposed metal-containing resist film is developed. At this time, a portion of the resist underlayer may also be developed. Depending on the type of metal-containing resist film forming composition, development may be by dissolution in a developer solution, by volatilization by heating or reduced pressure, or by etching. This allows a resist pattern to be formed.

[0181] Examples of developers used when employing the above-mentioned developer include alkaline aqueous solutions (alkaline developer) and organic solvent-containing solutions (organic solvent developer).

[0182] The basic solution for alkaline development is not particularly limited, and known basic solutions can be used. Examples of basic solutions for alkaline development include alkaline aqueous solutions in which at least one alkaline compound such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide (TMAH), pyrrole, piperidine, choline, 1,8-diazabicyclo-[5.4.0]-7-undecene, and 1,5-diazabicyclo-[4.3.0]-5-nonene is dissolved. Among these, aqueous TMAH is preferred, and a 2.38% by mass aqueous TMAH solution is more preferred.

[0183] Examples of organic solvent developers used in organic solvent development include those similar to those exemplified as solvent [B] above. Preferred organic solvents include ester solvents, ether solvents, alcohol solvents, ketone solvents and / or hydrocarbon solvents, with ketone solvents being more preferred, and 2-heptanone being particularly preferred.

[0184] Etching methods include dry etching and wet etching. Dry etching using hydrogen bromide or the like is preferred as the etching method.

[0185] In this process, washing and / or drying may be performed after development as described above. Furthermore, etching may be performed using the resist pattern as a mask. The above-described method can be suitably used as the etching method.

[0186] The present invention will be described in detail below based on examples, but the present invention is not limited to these examples.

[0187] [Weight-average molecular weight (Mw), number-average molecular weight (Mn)] The Mw and Mn of the polymers were measured by gel permeation chromatography (detector: differential refractometer) using monodisperse polystyrene as the standard, under analytical conditions of Tosoh Corporation's GPC columns (two "G2000HXL" columns and one "G3000HXL" column), flow rate: 1.0 mL / min, elution solvent: tetrahydrofuran, column temperature: 40°C.

[0188] [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.

[0189] <Synthesis of Polymer [A] and Comparative Polymer> Polymers [A] having repeating units represented by the following formulas (A-1) to (A-24) were synthesized according to the procedure shown below. A comparative polymer having repeating units represented by the following formula (CA-1) was also synthesized. In the following formulas, the numbers attached to each repeating unit indicate the content percentage (mol%) of that repeating unit. The composition ratio is １３ Confirmed via C-NMR.

[0190]

[0191]

[0192]

[0193]

[0194]

[0195]

[0196]

[0197] The following monomers (a-1) to (a-16) (hereinafter also referred to as "[a] compounds"), the following compounds (b-1) to (b-8) (hereinafter also referred to as "[b] compounds"), and the following compounds (c-1) to (c-5) (hereinafter also referred to as "[c] compounds") were used in the synthesis of the [A] polymer and the comparative polymer.

[0198]

[0199]

[0200]

[0201]

[0202] <[A] Synthesis of Polymer Precursors> [Synthesis Example 1-1] (Synthesis of Polymer (x-21)) In a reaction vessel, under a nitrogen atmosphere, 3.0 g of (a-14), 6.00 g of (c-3), 12.52 g of (c-4), and 87.30 g of methyl isobutyl ketone were charged and dissolved. 1.00 g of p-toluenesulfonic acid monohydrate was added to the reaction vessel, and the mixture was heated to 85°C and reacted for 4 hours. After the reaction was complete, the reaction solution was transferred to a separatory funnel, and the organic phase was washed with 200 g of methyl isobutyl ketone and 400 g of water. After separating the aqueous phase, the obtained organic phase was concentrated in an evaporator, and the residue was added dropwise to 500 g of methanol to obtain a precipitate. The precipitate was recovered by suction filtration and washed several times with 100 g of methanol. Then, the polymer (x-21), represented by the following formula (x-21), was obtained by drying at 60°C for 12 hours using a vacuum dryer.

[0203]

[0204] [Synthesis Example 1-2] (Synthesis of polymer (x-22)) Except that 3.0 g of (a-14) and 12.52 g of (c-4) were changed to 16.50 g of (a-15), polymer (x-22) represented by the following formula (x-22) was obtained in the same manner as in Synthesis Example 1-1.

[0205]

[0206] [Synthesis Example 1-3] (Synthesis of polymer (x-24)) Except that 3.0 g of (a-14) and 12.52 g of (c-4) were changed to 13.00 g of (a-16), polymer (x-24) represented by the following formula (x-24) was obtained in the same manner as in Synthesis Example 1-1.

[0207]

[0208] [Synthesis Example 2-1] (Synthesis of Polymer (A-1)) 6.00 g of 4-methyl-2-pentanone was placed in a reaction vessel and maintained at 80°C. A mixture of 6.00 g of compound (a-1), 1.35 g of dimethyl-2,2-azobis(2-methylpropionate), and 12.00 g of 4-methyl-2-pentanone was added dropwise from a feeder over 3 hours. The mixture was then stirred at 80°C for 3 hours. The resulting polymerization solution was precipitated and purified with five times the volume of heptane to obtain the white solid polymer (A-1). The Mw and Mn of the obtained polymer [A] and comparative polymer (CA-1) are shown together in Table 1. In the table, "-" indicates that the corresponding component was not used. The same applies to subsequent tables.

[0209] [Synthesis Examples 2-2 to 2-20, Synthesis Example 2-23, and Comparative Synthesis Example 3-1] (Synthesis of polymers (A-2) to (A-20), (A-23), and comparative polymer (CA-1)) Polymers (A-2) to (A-20), (A-23), and comparative polymer (CA-1) were synthesized in the same manner as polymer (A-1), except that compound (a-1) was the type and amount of compound [a], compound [b], and compound [c] shown in Table 1.

[0210] [Synthesis Example 2-21] (Synthesis of Polymer (A-21)) In a reaction vessel under a nitrogen atmosphere, 16.80 g of the above polymer (x-21), 27.9 g of (c-5), 90 g of methyl isobutyl ketone, and 45.0 g of methanol were added and stirred. Then, 85.5 g of 25% by mass aqueous solution of tetramethylammonium hydroxide was added and the mixture was reacted at 50°C for 6 hours. After cooling the reaction solution to 30°C, 200.0 g of 5% by mass aqueous solution of oxalic acid was added. After removing the aqueous phase, the obtained organic phase was concentrated in an evaporator, and the residue was added dropwise to 500 g of methanol to obtain a precipitate. The precipitate was recovered by suction filtration and washed several times with 100 g of methanol. Then, polymer (A-21) was obtained by drying in a vacuum dryer at 60°C for 12 hours. The Mw of (A-21) was 4500 and the Mn was 3000.

[0211] [Synthesis Example 2-22] (Synthesis of polymer (A-22)) Polymer (A-22) was obtained in the same manner as in Synthesis Example 2-21, except that 16.80 g of (x-21) was replaced with 14.10 g of (x-22). The Mw of (A-22) was 4800 and the Mn was 3100.

[0212] [Synthesis Example 2-24] (Synthesis of polymer (A-24)) Polymer (A-24) was obtained in the same manner as in Synthesis Example 2-21, except that 16.80 g of (x-21) was replaced with 11.30 g of (x-24). The Mw of (A-24) was 4500 and the Mn was 3000.

[0213]

[0214] <Preparation of Underlayer Forming Composition for Metal-Containing Resist Films> The following describes the polymer, solvent, comparative polymer (CA-1), acid generator, and crosslinking agent used in the preparation of the underlayer forming composition for metal-containing resist films (hereinafter also referred to as "the composition").

[0215] [A Polymer] A-1 to A-24: The polymers synthesized above (A-1) to (A-24)

[0216] [Comparative Polymer (CA-1)] CA-1: The polymer synthesized above (CA-1)

[0217] [B Solvent] B-1: Propylene glycol monomethyl ether acetate B-2: Propylene glycol monomethyl ether

[0218] [C] Acid Generators C-1: Compound represented by the following formula (C-1) C-2: Compound represented by the following formula (C-2)

[0219]

[0220] [D] Crosslinking agent: D-1: Compound represented by the following formula (D-1) D-2: Compound represented by the following formula (D-2)

[0221]

[0222] [Example 1-1] [A] 100 parts by mass of (A-1) as a polymer was dissolved in [B] 6,000 parts by mass of (B-1) and 14,000 parts by mass of (B-2) as solvents. The resulting solution was filtered through a polytetrafluoroethylene (PTFE) membrane filter with a pore size of 0.45 μm to prepare composition (J-1).

[0223] [Examples 1-2 to 1-27 and Comparative Example 1-1] Compositions (J-2) to (J-27) and (CJ-1) were prepared in the same manner as in Example 1-1, except that the components used were of the types and in the amounts shown in Table 2 below.

[0224]

[0225] <Evaluation> Using the compositions prepared above, the rectangularity of the resist patterns obtained by EUV exposure using the metal-containing resist film formation compositions was evaluated by the following method. The evaluation results are shown in Table 3 below.

[0226] <Preparation of Resist Composition (R-1)> Compound (S-1) used in the preparation of resist composition (R-1) was synthesized by the following procedure. In a reaction vessel, 6.5 parts by mass of isopropyltin trichloride was added while stirring 150 mL of 0.5 N aqueous sodium hydroxide solution, and the mixture was stirred for 2 hours. The precipitated material was filtered off, washed twice with 50 parts by mass of water, and then dried to obtain compound (S-1). Compound (S-1) is the oxidized hydroxide product (i-PrSnO) of the hydrolysis product of isopropyltin trichloride. （３／２-ｘ／２） (OH) ｘ (The structural units were defined as 0 < x < 3).

[0227] Two parts by mass of the synthesized compound (S-1) were mixed with 98 parts by mass of propylene glycol monoethyl ether. The resulting mixture was then filtered to remove residual water using an activated 4 Å molecular sieve, and then filtered through a 0.2 μm pore size filter to prepare the resist composition (R-1).

[0228] [Rectangular Resist Pattern (EUV Exposure, Wet Development)] An organic underlayer film formation material (HM8006 from JSR Corporation) was applied to a 12-inch silicon wafer by a rotary coating method using a spin coater (CLEAN TRACK ACT12 from Tokyo Electron Limited), and then heated at 250°C for 60 seconds to form an organic underlayer film with an average thickness of 100 nm. The resist underlayer film formation composition prepared above was applied to this organic underlayer film, heated at 220°C for 60 seconds, and then cooled at 23°C for 30 seconds to form a resist underlayer film with an average thickness of 5 nm. The resist composition (R-1) was applied to this resist underlayer film by a rotary coating method using the spin coater, and after a predetermined time had elapsed, heated at 90°C for 60 seconds and then cooled at 23°C for 30 seconds to form a resist film with an average thickness of 35 nm. The resist film was exposed using an EUV scanner (ASML's "TWINSCAN NXE:3300B" (NA 0.3, sigma 0.9, quadruple pole illumination, wafer-mounted 1:1 line-and-space mask with a line width of 16 nm)). After exposure, the substrate was heated at 110°C for 60 seconds, then cooled at 23°C for 60 seconds. Subsequently, it was developed using the paddle method with 2-heptanone (20-25°C) and dried to obtain an evaluation substrate with a resist pattern formed on it. A scanning electron microscope (Hitachi High-Tech Corporation's "CG-6300") was used to measure and observe the resist pattern on the evaluation substrate. The rectangularity of the resist pattern was evaluated as "A" (good) if the cross-sectional shape of the pattern was rectangular, and "B" (poor) if there was a hem in the cross-section of the pattern.

[0229] [Resist Pattern Peeling (EUV Exposure)] The resist pattern was measured and observed in the same manner as for the evaluation of the resist pattern rectangularity. Resist pattern peeling was evaluated as "A" (good) if no peeling occurred, and "B" (poor) if peeling occurred.

[0230]

[0231] [Rectangular Resist Pattern (EUV Exposure, Dry Development)] An organic underlayer film formation material (HM8006 from JSR Corporation) was applied to a 12-inch silicon wafer by a rotary coating method using a spin coater (CLEAN TRACK ACT12 from Tokyo Electron Limited), and then heated at 250°C for 60 seconds to form an organic underlayer film with an average thickness of 100 nm. The resist underlayer film formation composition prepared above was applied to this organic underlayer film, heated at 220°C for 60 seconds, and then cooled at 23°C for 30 seconds to form a resist underlayer film with an average thickness of 5 nm. The resist composition (R-1) was applied to this resist underlayer film by a rotary coating method using the spin coater, and after a predetermined time had elapsed, heated at 90°C for 60 seconds and then cooled at 23°C for 30 seconds to form a resist film with an average thickness of 35 nm. The resist film was exposed using an EUV scanner (ASML's "TWINSCAN NXE:3300B" (NA 0.3, sigma 0.9, quadruple pole illumination, wafer-mounted 1:1 line-and-space mask with a line width of 16 nm)). After exposure, the substrate was heated at 110°C for 60 seconds, then cooled at 23°C for 60 seconds. Subsequently, an evaluation substrate with a resist pattern was obtained by developing it with hydrogen bromide. A scanning electron microscope (Hitachi High-Tech Corporation's "CG-6300") was used to measure and observe the resist pattern on the evaluation substrate. The rectangularity of the resist pattern was evaluated as "A" (good) if the cross-sectional shape of the pattern was rectangular, and "B" (poor) if there was a drooping edge in the cross-section of the pattern.

[0232] [Resist Pattern Peeling (EUV Exposure)] The resist pattern was measured and observed in the same manner as for the evaluation of the resist pattern rectangularity. Resist pattern peeling was evaluated as "A" (good) if no peeling occurred, and "B" (poor) if peeling occurred.

[0233]

[0234] As can be seen from the results in Tables 3 and 4, the resist underlayer film formed from the composition of the example showed superior resistance pattern rectangularity and resistance pattern peeling suppression compared to the resist underlayer film formed from the composition of the comparative example.

[0235] The metal-containing resist film underlayer forming composition of the present invention makes it possible to form a film with excellent rectangularity of the resist pattern and excellent peeling suppression. The semiconductor substrate manufacturing method of the present invention uses a metal-containing resist film underlayer forming composition that can form a resist underlayer with excellent rectangularity of the resist pattern and excellent peeling suppression, thus enabling efficient manufacturing of semiconductor substrates. Therefore, these can be suitably used in the manufacture of semiconductor devices and the like.

Claims

1. A lower layer film forming composition for a metal-containing resist film, which contains a polymer and a solvent, wherein the polymer has a partial structure represented by the following formula (a-1) or formula (a-2), and at least one monovalent group (X) selected from the group consisting of a group represented by the following formula (2-1), a group represented by the following formula (2-2), a group represented by the following formula (2-3), a group represented by the following formula (2-4), a group represented by the following formula (2-5), a group represented by the following formula (2-6), a group represented by the following formula (2-7), and a group represented by the following formula (2-8). (In the above formula (a-1) and formula (a-2), * is a bond with another atom constituting the polymer. R １ and R ２ are each independently the monovalent group (X), a monovalent organic group having 1 to 20 carbon atoms other than the monovalent group (X), a halogen atom, a hydroxy group, or a nitro group. The bond represented by the following formula is a single bond or a double bond.) n １ and n ２ are each independently an integer of 0 to 4. n １ or n ２ When it is 2 or more, a plurality of R １ or R ２ are each the same as or different from each other.) (In the above formulas (2-1) to (2-8), R ７ are each independently a divalent organic group having 1 to 20 carbon atoms or a single bond. R ８ , R ９ , R １０ and R １３ are each independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. Cy is a ring structure having 3 to 20 ring members formed together with two carbon atoms in the formula (2-2). R １１ is a hydrogen atom, a monovalent organic group having 1 to 20 carbon atoms or a single bond. R １２ is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. ** is a bond with an atom constituting Cy. However, when R １１ is a single bond, R １１ binds to **. * is a bond with an atom constituting the polymer.) 2. The polymer has repeating units represented by the following formulas (A1-1), (A1-2), (A2-1), or (A2-2), as described in claim 1, for forming an underlayer film for a metal-containing resist film. (In the above formulas (A1-1), (A1-2), (A2-1), and (A2-2), W is independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. １ , R ２ , n １ and n ２ Furthermore, the combination represented by the following formula is equivalent to formulas (a-1) and (a-2) above.

3. The underlayer film forming composition for a metal-containing resist film according to claim 1 or claim 2, wherein the polymer has repeating units represented by the following formula (B-1) or repeating units represented by the following formula (B-2). (In equations (B-1) and (B-2), R ３ L is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms. １ This is a single bond or 1+n ３ It is a valence linking group. Each X is independently at least one monovalent group (X) selected from the group consisting of the group represented by formula (2-1), the group represented by formula (2-2), the group represented by formula (2-3), the group represented by formula (2-4), the group represented by formula (2-5), the group represented by formula (2-6), the group represented by formula (2-7), and the group represented by formula (2-8). However, * in formulas (2-1) to (2-8) is L １ or L ２ This is a bonding bond with the constituent atoms. If there are multiple X atoms, they can be identical or different from each other. ３ Each of these is an integer between 1 and 4, independently of the others. ２ This is a substituted or unsubstituted aromatic ring with 3 to 20 carbon atoms. ２ L is a single bond or a divalent linking group. ２ If there are multiple L ２ They are either identical or different from each other. ２ (This refers to a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.) 4. The metal-containing resist film is formed by a metal-containing resist film forming composition, the metal-containing resist film forming composition contains a metal-containing compound and a solvent, and the metal-containing compound is present in the metal-containing resist film forming composition with a content of 50% by mass or more of the components other than the solvent, according to claim 1 or claim 2.

5. A method for manufacturing a semiconductor substrate, comprising the steps of: coating a substrate directly or indirectly with a metal-containing resist film underlayer composition; forming a metal-containing resist film on the resist underlayer film formed by the coating step of the metal-containing resist film underlayer composition; exposing the metal-containing resist film with radiation; and developing at least the exposed metal-containing resist film, wherein the metal-containing resist film underlayer composition comprises a polymer and a solvent, and the polymer has a substructure represented by the following formula (a-1) or formula (a-2), and at least one monovalent group (X) selected from the group consisting of a group represented by the following formula (2-1), a group represented by the following formula (2-2), a group represented by the following formula (2-3), a group represented by the following formula (2-4), a group represented by the following formula (2-5), a group represented by the following formula (2-6), a group represented by the following formula (2-7), and a group represented by the following formula (2-8). (In formulas (a-1) and (a-2) above, * represents a bond with another atom constituting the polymer. R １ and R ２ Each of these is independently a monovalent group (X), a monovalent organic group having 1 to 20 carbon atoms other than the monovalent group (X), a halogen atom, a hydroxyl group, or a nitro group. The bond represented by the following formula is either a single bond or a double bond. n １ and n ２ Each of these is an independent integer between 0 and 4. １ or n ２ If there are two or more, multiple R １ or R ２ (These are either identical or different from each other.) (In the above equations (2-1) to (2-8), R ７ Each of these is independently a divalent organic group or single bond having 1 to 20 carbon atoms. ８ , R ９ , R １０ and R １３ Each of these is independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. Cy is a ring structure with 3 to 20 members, formed together with the two carbon atoms in formula (2-2). １１ R is a hydrogen atom, a monovalent organic group having 1 to 20 carbon atoms, or a single bond. １２ is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. ** is a bond with an atom constituting Cy. However, R １１ If it is a single bond, R １１ It bonds with **. * represents the bonding site with each atom that makes up the polymer.

6. The method for manufacturing a semiconductor substrate according to claim 5, wherein the polymer has repeating units represented by the following formulas (A1-1), (A1-2), (A2-1), or (A2-2). (In the above formulas (A1-1), (A1-2), (A2-1), and (A2-2), W is independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. １ , R ２ , n １ and n ２ Furthermore, the combination represented by the following formula is equivalent to formulas (a-1) and (a-2) above.

7. The method for manufacturing a semiconductor substrate according to claim 5 or claim 6, wherein the polymer has repeating units represented by the following formula (B-1) or repeating units represented by the following formula (B-2). (In equations (B-1) and (B-2), R ３ L is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms. １ This is a single bond or 1+n ３ It is a valence linking group. Each X is independently at least one monovalent group (X) selected from the group consisting of the group represented by formula (2-1), the group represented by formula (2-2), the group represented by formula (2-3), the group represented by formula (2-4), the group represented by formula (2-5), the group represented by formula (2-6), the group represented by formula (2-7), and the group represented by formula (2-8). However, * in formulas (2-1) to (2-8) is L １ or L ２ This is a bonding bond with the constituent atoms. If there are multiple X atoms, they can be identical or different from each other. ３ Each of these is an integer between 1 and 4, independently of the others. ２ This is a substituted or unsubstituted aromatic ring with 3 to 20 carbon atoms. ２ L is a single bond or a divalent linking group. ２ If there are multiple L ２ They are either identical or different from each other. ２ (This refers to a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.) 8. The method for manufacturing a semiconductor substrate according to claim 5 or claim 6, wherein the metal-containing resist film is formed using a metal-containing resist film forming composition, the metal-containing resist film forming composition contains a metal-containing compound and a solvent, and the proportion of the metal-containing compound in the metal-containing resist film forming composition other than the solvent is 50% by mass or more.

Images