Composition for forming nitrogen-containing film and method for manufacturing semiconductor substrate

Abstract

Provided are a composition for forming a nitrogen-containing film with which a nitrogen-containing film having excellent heat resistance and embeddability can be formed, and a method for manufacturing a semiconductor substrate. This composition for forming a nitrogen-containing film contains a nitrogen-containing compound and a solvent. The nitrogen-containing compound is a compound represented by formula (A0) or formula (A1), or a polymer having a repeating unit represented by formula (A2) or formula (A3). (In the formulas, each X is independently -O-, -S-, or -NR'-. R' is a hydrogen atom or a monovalent hydrocarbon group having 1-20 carbon atoms. Ra and Rb are each independently a monovalent organic group having 1-40 carbon atoms. Each Ar1 is independently a substituted or unsubstituted aromatic ring having 3-40 carbon atoms.)

Description

Composition for forming nitrogen-containing films and method for manufacturing semiconductor substrates

[0001] This invention relates to a nitrogen-containing film-forming composition and a method for manufacturing a semiconductor substrate.

[0002] The transistor structure of logic semiconductors has changed from planar FETs to FinFETs and GAA nanosheets as transistor circuits have become smaller. Furthermore, the most advanced transistor structures for logic semiconductors are expected to be fork sheets and CFETs. An organic film is formed on the pattern that will become the transistor structure of fork sheets and CFETs, a portion of this organic film is removed by etching, exposing a part of the pattern, and a film is formed on the exposed pattern by ALD (Atomic Layer Deposition). Therefore, the organic film is required to have heat resistance to the high temperatures during ALD deposition.

[0003] Various studies have been conducted on organic film-forming compositions with excellent heat resistance (Japanese Patent Publication No. 6923301).

[0004] Patent No. 6923301

[0005] Compositions for forming organic films require both heat resistance to high temperatures during ALD film formation and embedding properties that allow them to be sufficiently embedded in patterns.

[0006] The present invention was made based on the circumstances described above, and its purpose is to provide a nitrogen-containing film-forming composition and a semiconductor substrate manufacturing method that can form a nitrogen-containing film with excellent heat resistance and embedding properties.

[0007] The present invention relates to a nitrogen-containing film-forming composition, in one embodiment, which contains a nitrogen-containing compound (hereinafter also referred to as "[A] compound") and a solvent (hereinafter also referred to as "[B] solvent), wherein the nitrogen-containing compound is a compound represented by the following formula (A0) or the following formula (A1) (hereinafter also referred to as "[A0] compound, etc."), or a polymer having repeating units represented by the following formula (A2) or the following formula (A3) (hereinafter also referred to as "[A2] polymer, etc."). (In formulas (A0) to (A3), R ａ and Rｂ is, independently of each other, a monovalent organic group having 1 to 40 carbon atoms. X is, independently of each other, -O-, -S- or -NR'-; R' is a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms. Ar １ is, independently of each other, a substituted or unsubstituted aromatic ring having 3 to 40 carbon atoms. s is an integer of 1 to 4. When s is 2 or more, a plurality of X, R ａ and Ar １ are the same as or different from each other. t is an integer of 1 to 4. When t is 2 or more, a plurality of X, R ａ , R ｂ and Ar １ are the same as or different from each other. u is an integer of 1 to 4. When u is 2 or more, a plurality of X, R ａ , R ｂ and Ar １ are the same as or different from each other. W ０ is an s-valent organic group having 1 to 40 carbon atoms. W １ is a t-valent organic group having 1 to 40 carbon atoms when t is 1, 3 or 4, and is a divalent organic group having 1 to 40 carbon atoms, a single bond or a divalent heteroatom-containing linking group when t is 2. W ２ is a divalent organic group having 1 to 40 carbon atoms, a single bond or a divalent heteroatom-containing linking group. Ar ２ is a divalent group containing a substituted or unsubstituted aromatic ring having 3 to 40 carbon atoms. W ３ is a u-valent organic group having 1 to 40 carbon atoms when u is 1, 3 or 4, and is a divalent organic group having 1 to 40 carbon atoms, a single bond or a divalent heteroatom-containing linking group when u is 2. R ｃ is a monovalent organic group having 1 to 40 carbon atoms. However, in the above formula (A3), when u is 2 or more, one of the bonds extending from the carbon atom to which R ｃ is bonded to one aromatic ring of u Ar １ , and the other bond is bonded to another aromatic ring of u Ar １ . The other bond is bonded to another aromatic ring of u Ar １ . )

[0008] The nitrogen-containing film-forming composition in question can form a nitrogen-containing film with excellent heat resistance and embedding properties. Although the reason for this is not entirely clear, it is presumed to be as follows: Compound [A] has a relatively polar structure consisting of an amide bond and a (thio) ether bond, which allows it to exhibit good solubility and, as a result, excellent embedding properties. In addition, the Ar compounds of formulas (A0) to (A3) １ Of the carbon atoms that make up the R ａ The carbon atom to which -X- is bonded and the carbon atom to which -CO-NH- is bonded are adjacent to each other (Ar １ If it is a benzene ring, then R ａ Because -X- and -CO-NH- are in an ortho position relative to each other, when a nitrogen-containing film is formed with compound [A], a specific structure is formed by the reaction of the amide bond and the (thio)ether bond, in which a five-membered heterocyclic ring containing two heteroatoms and an aromatic ring are fused. Since this specific structure is rigid and chemically stable, it can improve the heat resistance of the nitrogen-containing film. It is presumed that these effects work together to form a nitrogen-containing film with excellent heat resistance and embedding properties.

[0009] In other embodiments, the present invention relates to a method for manufacturing a semiconductor substrate, comprising the steps of: coating a patterned substrate with a nitrogen-containing film-forming composition; and etching the nitrogen-containing film formed by the coating step, wherein the nitrogen-containing film-forming composition contains a nitrogen-containing compound and a solvent, and the nitrogen-containing compound is a compound represented by the following formula (A0) or formula (A1), or a polymer having repeating units represented by the following formula (A2) or formula (A3). (In formulas (A0) to (A3), R ａ and R ｂ Each of these is independently a monovalent organic group having 1 to 40 carbon atoms. Each of these is independently -O-, -S-, or -NR'-. R' is a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms. Ar １Each is independently a substituted or unsubstituted aromatic ring with 3 to 40 carbon atoms. s is an integer from 1 to 4. If s is 2 or greater, there are multiple X, R ａ and Ar １ Each of them is either the same or different from the others. t is an integer from 1 to 4. If t is 2 or greater, there are multiple X, R ａ , R ｂ and Ar １ Each of them is either identical or different from the others. u is an integer from 1 to 4. If u is 2 or greater, there are multiple X, R. ａ , R ｂ and Ar １ These are either identical or different from each other. ０ This is an organic group with 1 to 40 carbon atoms and an s-valence. １ When t is 1, 3, or 4, it is a t-valent organic group having 1 to 40 carbon atoms, and when t is 2, it is a divalent organic group having 1 to 40 carbon atoms, a single bond, or a divalent heteroatom-containing linking group. ２ Ar is a divalent organic group having 1 to 40 carbon atoms, a single bond, or a linking group containing a divalent heteroatom. ２ This is a divalent group containing a substituted or unsubstituted aromatic ring with 3 to 40 carbon atoms. ３ When u is 1, 3, or 4, it is a u-valent organic group having 1 to 40 carbon atoms, and when u is 2, it is a divalent organic group having 1 to 40 carbon atoms, a single bond, or a divalent heteroatom-containing linking group. ｃ is a monovalent organic group having 1 to 40 carbon atoms. However, in the above formula (A3), if u is 2 or more, R ｃ Ar from the carbon atom to which it is bonded １ One of the connecting bonds extending in this direction is made up of u Ar １ One of the aromatic rings is bonded, and the other bond consists of u Ar １ (It binds to other aromatic rings among them.)

[0010] In this specification, "fused ring" refers to a polycyclic structure formed by adjacent rings sharing one edge (two adjacent atoms). "Organic group" refers to a group containing at least one carbon atom. In this specification, "Me" in structural formulas represents a methyl group.

[0011] The nitrogen-containing film-forming composition allows for the formation of a nitrogen-containing film with excellent heat resistance and embedding properties. The semiconductor substrate manufacturing method allows for the formation of a nitrogen-containing film with excellent heat resistance and embedding properties, resulting in a high yield of semiconductor substrates with well-processed pattern structures. Therefore, these can be suitably used in the manufacture of semiconductor devices, where further miniaturization is expected in the future.

[0012] The nitrogen-containing film-forming compositions and semiconductor substrate manufacturing methods according to each embodiment of the present invention will be described in detail below. Preferred combinations of embodiments are also preferred.

[0013] Composition for forming nitrogen-containing film The composition for forming nitrogen-containing film contains compound [A] and solvent [B]. The composition for forming nitrogen-containing film may contain optional components as long as they do not impair the effects of the present invention.

[0014] The following describes each component contained in the nitrogen-containing film-forming composition.

[0015] <[A] Compound> The [A] compound is a compound represented by the following formula (A0) or formula (A1), or a polymer having repeating units represented by the following formula (A2) or formula (A3). The nitrogen-containing film-forming composition may contain one or more [A] compounds. The [A2] polymer may have one or more repeating units represented by the following formula (A2). The [A3] polymer may have one or more repeating units represented by the following formula (A3). (In formulas (A0) to (A3), R ａ and R ｂ Each of these is independently a monovalent organic group having 1 to 40 carbon atoms. Each of these is independently -O-, -S-, or -NR'-. R' is a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms. Ar １ Each is independently a substituted or unsubstituted aromatic ring with 3 to 40 carbon atoms. s is an integer from 1 to 4. If s is 2 or greater, there are multiple X, R ａ and Ar １Each of them is either the same or different from the others. t is an integer from 1 to 4. If t is 2 or greater, there are multiple X, R ａ , R ｂ and Ar １ Each of them is either identical or different from the others. u is an integer from 1 to 4. If u is 2 or greater, there are multiple X, R. ａ , R ｂ and Ar １ These are either identical or different from each other. ０ This is an organic group with 1 to 40 carbon atoms and an s-valence. １ When t is 1, 3, or 4, it is a t-valent organic group having 1 to 40 carbon atoms, and when t is 2, it is a divalent organic group having 1 to 40 carbon atoms, a single bond, or a divalent heteroatom-containing linking group. ２ Ar is a divalent organic group having 1 to 40 carbon atoms, a single bond, or a linking group containing a divalent heteroatom. ２ This is a divalent group containing a substituted or unsubstituted aromatic ring with 3 to 40 carbon atoms. ３ When u is 1, 3, or 4, it is a u-valent organic group having 1 to 40 carbon atoms, and when u is 2, it is a divalent organic group having 1 to 40 carbon atoms, a single bond, or a divalent heteroatom-containing linking group. ｃ is a monovalent organic group having 1 to 40 carbon atoms. However, in the above formula (A3), if u is 2 or more, R ｃ Ar from the carbon atom to which it is bonded １ One of the connecting bonds extending in this direction is made up of u Ar １ One of the aromatic rings is bonded, and the other bond consists of u Ar １ (It binds to other aromatic rings among them.)

[0016] In the above formulas (A0) to (A3), R ａ and R ｂ Examples of monovalent organic groups having 1 to 40 carbon atoms represented by include monovalent hydrocarbon groups having 1 to 40 carbon atoms, groups having a divalent heteroatom-containing linking group between carbon atoms of the hydrocarbon group or at the terminal end of the hydrocarbon group (hereinafter also referred to as "group (α)"), groups in which some or all of the hydrogen atoms of the hydrocarbon group or group (α) are replaced with monovalent heteroatom-containing substituents, or groups that combine these.

[0017] Examples of monovalent hydrocarbon groups having 1 to 40 carbon atoms include monovalent linear hydrocarbon groups having 1 to 40 carbon atoms, monovalent alicyclic hydrocarbon groups having 3 to 40 carbon atoms, monovalent aromatic hydrocarbon groups having 6 to 40 carbon atoms, or groups combining these.

[0018] Examples of monovalent chain hydrocarbon groups having 1 to 40 carbon atoms include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, s-butyl, and t-butyl groups; alkenyl groups such as ethenyl, propenyl, and butenyl groups; and alkynyl groups such as ethynyl, propynyl, and butynyl groups.

[0019] Examples of monovalent alicyclic hydrocarbon groups having 3 to 40 carbon atoms include cycloalkyl groups such as cyclopentyl and cyclohexyl groups; cycloalkenyl groups such as cyclopropenyl, cyclopentenyl, and cyclohexenyl groups; bridged ring saturated hydrocarbon groups such as norbornyl, adamantyl, and tricyclodecyl groups; and bridged ring unsaturated hydrocarbon groups such as norbornyl and tricyclodecenyl groups.

[0020] Examples of monovalent aromatic hydrocarbon groups having 6 to 40 carbon atoms include aryl groups such as phenyl, tolyl, xyl, naphthyl, anthracenyl, pyrenyl, and fluorenyl groups; and aralkyl groups such as benzyl and phenethyl groups.

[0021] 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.

[0022] Examples of divalent heteroatom-containing linking groups include -CO-, -CS-, -NR'-, -O-, -S-, and -SO ２ - and combinations thereof are examples. R' is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms.

[0023] Examples of monovalent heteroatom-containing substituents include hydroxyl groups, sulfanyl groups, cyano groups, nitro groups, amino groups, and halogen atoms.

[0024] R ａ Each of these is preferably independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 40 carbon atoms, or a group having a divalent heteroatom-containing linking group at the end of the hydrocarbon group. ａ In this, the monovalent hydrocarbon group having 1 to 40 carbon atoms is R ａ Examples of monovalent organic groups having 1 to 40 carbon atoms include monovalent hydrocarbon groups having 1 to 40 carbon atoms. Among these, preferred monovalent hydrocarbon groups having 1 to 40 carbon atoms include the monovalent linear hydrocarbons having 1 to 40 carbon atoms, the monovalent aromatic hydrocarbon groups having 6 to 40 carbon atoms, or combinations thereof; more preferred are monovalent linear saturated hydrocarbon groups having 1 to 10 carbon atoms, monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms, or combinations thereof; and even more preferred are methyl groups, ethyl groups, n-propyl groups, isopropyl groups, n-butyl groups, isobutyl groups, s-butyl groups, t-butyl groups, phenyl groups, naphthyl groups, or combinations thereof. ａ As for the divalent heteroatom-containing linking group in this, -OCO- ＊ This is preferable. * indicates a coupling on the X side.

[0025] R ａ If the hydrocarbon group in the above has substituents, examples of substituents include halogen atoms such as fluorine, chlorine, bromine, and iodine atoms; hydroxyl groups; carboxyl groups; cyano groups; nitro groups; amino groups; alkoxy groups; alkoxycarbonyl groups; alkoxycarbonyloxy groups; acyl groups; alkylcarbonyloxy groups, ethenyl groups (vinyl groups), ethynyl groups, or groups in which the hydrogen atoms of these groups are substituted with halogen atoms; oxo groups (=O), etc.

[0026] As for the monovalent hydrocarbon group having 1 to 20 carbon atoms in the -NR'- of X, R ａ Among the monovalent hydrocarbon groups having 1 to 40 carbon atoms shown above, groups corresponding to 1 to 20 carbon atoms can be suitably adopted.

[0027] X is preferably -O-.

[0028] Ar １ Examples of aromatic rings having 3 to 40 carbon atoms in this context include aromatic hydrocarbon rings having 6 to 40 carbon atoms such as benzene rings, naphthalene rings, anthracene rings, phenalene rings, phenanthrene rings, pyrene rings, fluorene rings, perylene rings, coronene rings, and biphenyl rings; aromatic heterocyclic rings having 3 to 40 carbon atoms such as triazole rings, imidazole rings, furan rings, pyrrole rings, thiophene rings, phosphole rings, pyrazole rings, oxazole rings, isoxazole rings, thiazole rings, pyridine rings, pyrazine rings, pyrimidine rings, pyridazine rings, and triazine rings; or combinations thereof. These combinations of rings may be fused rings, ring aggregates (structures in which two rings are joined by a single bond), or spiro structures. Among these, Ar １ In this compound, a benzene ring is preferred as the aromatic ring having 3 to 40 carbon atoms.

[0029] Ar １ If the aromatic ring in has substituents, the substituents are R ａ The substituents that the hydrocarbon group in the above-mentioned material may have can be suitably adopted.

[0030] In the above formula (A0), W ０ As an s-valent organic group having 1 to 40 carbon atoms, R ａ A group obtained by removing s-1 hydrogen atoms from the above-mentioned monovalent organic group having 1 to 40 carbon atoms can be suitably adopted.

[0031] W ０ It is preferable that the hydrocarbon group is a substituted or unsubstituted hydrocarbon group having 1 to 40 carbon atoms with an s-valence, or a group having a divalent heteroatom-containing linking group between the carbon atoms of the hydrocarbon group. ０ As for the s-valent hydrocarbon groups with 1 to 40 carbon atoms, R ａA group obtained by removing s hydrogen atoms from a hydrocarbon corresponding to the monovalent hydrocarbon group having 1 to 40 carbon atoms shown above can be preferably employed. As the hydrocarbon group having 1 to 40 carbon atoms, a hydrocarbon corresponding to the monovalent chain hydrocarbon having 1 to 40 carbon atoms, an aromatic hydrocarbon corresponding to the monovalent aromatic hydrocarbon group having 6 to 40 carbon atoms, or a combination thereof is preferable, a chain saturated hydrocarbon corresponding to the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, an aromatic hydrocarbon corresponding to the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, or a combination thereof is more preferable, and methane, ethane, propane, butane, benzene, naphthalene, fluorene, or a combination thereof is even more preferable. W ０ As the divalent heteroatom-containing linking group in, R ａ The divalent heteroatom-containing linking group shown above can be preferably employed.

[0032] W ０ When the s-valent hydrocarbon group having 1 to 40 carbon atoms in has a substituent, as the substituent, R ａ The substituent that the hydrocarbon group in may have can be preferably employed.

[0033] s is preferably an integer of 1 to 3, and more preferably 2 or 3.

[0034] In the above formula (A1) and formula (A3), R ｂ is preferably a substituted or unsubstituted monovalent aromatic ring having 6 to 40 carbon atoms. As the monovalent aromatic ring having 6 to 40 carbon atoms in R ｂ a ring obtained by removing one hydrogen atom from an aromatic ring corresponding to 6 to 40 carbon atoms among the aromatic rings having 3 to 40 carbon atoms in Ar of the above formula (A0) can be preferably employed. As the aromatic ring in R １ a benzene ring, a naphthalene ring, an anthracene ring, a phenalene ring, a phenanthrene ring, a pyrene ring, a fluorene ring are preferable, and a benzene ring, a naphthalene ring, a pyrene ring are more preferable. ｂ When the aromatic ring in R has a substituent, as the substituent, R of the above formula (A0)

[0035] R ｂ when the aromatic ring in has a substituent, as the substituent, R of the above formula (A0) ａThe substituents that the hydrocarbon group in may have can be preferably employed.

[0036] In the above formula (A1), W １ As the t-valent organic group having 1 to 40 carbon atoms represented by, a group obtained by removing t - 1 hydrogen atoms from the monovalent organic group having 1 to 40 carbon atoms represented by R in the above formula (A0) can be preferably employed. ａ As the t-valent organic group having 1 to 40 carbon atoms represented by, a substituted or unsubstituted t-valent hydrocarbon group having 1 to 40 carbon atoms or a group having a divalent heteroatom-containing linking group between carbon-carbon atoms of the hydrocarbon group is preferable. As the t-valent hydrocarbon group having 1 to 40 carbon atoms in W

[0037] W １ A group obtained by removing t hydrogen atoms from the hydrocarbon corresponding to the monovalent hydrocarbon group having 1 to 40 carbon atoms shown in R in the above formula (A0) can be preferably employed. As the hydrocarbon group having 1 to 40 carbon atoms, a hydrocarbon corresponding to the monovalent chain hydrocarbon having 1 to 40 carbon atoms, an aromatic hydrocarbon corresponding to the monovalent aromatic hydrocarbon group having 6 to 40 carbon atoms or a combination thereof is preferable, a chain saturated hydrocarbon corresponding to the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, an aromatic hydrocarbon corresponding to the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms or a combination thereof is more preferable, and methane, ethane, propane, butane, benzene, naphthalene, fluorene or a combination thereof is even more preferable. As the divalent heteroatom-containing linking group in W １ A divalent heteroatom-containing linking group shown in R in the above formula (A0) can be preferably employed. ａ When the t-valent hydrocarbon group having 1 to 40 carbon atoms in W １ has a substituent, as the substituent, the substituents that the hydrocarbon group in R in the above formula (A0) may have can be preferably employed. ａ

[0038] W １ When the t-valent hydrocarbon group having 1 to 40 carbon atoms in W ａ has a substituent, as the substituent, the substituents that the hydrocarbon group in R in the above formula (A0) may have can be preferably employed.

[0039] t is preferably an integer of 1 to 3, more preferably 2 or 3, and even more preferably 2.

[0040] When t is 2, W １ The divalent heteroatom-containing linking group represented by the above formula (A0) is R ａ The divalent heteroatom-containing linking group shown above can be suitably adopted.

[0041] In the above formula (A2), W ２ As a divalent organic group having 1 to 40 carbon atoms represented by the above formula (A0), R ａ A monovalent organic group having 1 to 40 carbon atoms, represented by [formula], can be suitably used, with one hydrogen atom removed. ２ The divalent heteroatom-containing linking group in is R in the above formula (A0). ａ The divalent heteroatom-containing linking group shown can be suitably adopted.

[0042] W ２ It is preferable that this is a substituted or unsubstituted divalent hydrocarbon group having 1 to 40 carbon atoms, a single bond, or a divalent heteroatom-containing linking group. ２ In this, the divalent hydrocarbon group having 1 to 40 carbon atoms is R in the above formula (A0). ａ A group obtained by removing one hydrogen atom from a monovalent hydrocarbon group having 1 to 40 carbon atoms, as shown in [reference], can be suitably adopted. ２ The hydrocarbon groups mentioned above are preferably divalent chain hydrocarbon groups having 1 to 40 carbon atoms, divalent aromatic hydrocarbon groups having 6 to 40 carbon atoms, or combinations thereof; more preferably alkanediyl groups having 1 to 10 carbon atoms, arenediyl groups having 6 to 12 carbon atoms, or combinations thereof; and even more preferably methylene groups, ethanediyl groups, propanediyl groups, benzenediyl groups, naphthalenediyl groups, fluororangeyl groups, or combinations thereof.

[0043] W ２ If the divalent hydrocarbon group having 1 to 40 carbon atoms in the above formula has substituents, the substituents are R of formula (A0) above. ａ The substituents that the hydrocarbon group in the above-mentioned material may have can be suitably adopted.

[0044] In the above formula (A2), Ar ２ Ar is a divalent group containing a substituted or unsubstituted aromatic ring with 3 to 40 carbon atoms.２ In this context, the aromatic ring with 3 to 40 carbon atoms is Ar １ The aromatic rings with 3 to 40 carbon atoms shown above can be suitably used. ２ In Ar, the aromatic rings having 3 to 40 carbon atoms are preferably benzene rings, naphthalene rings, anthracene rings, phenalene rings, phenanthrene rings, pyrene rings, and fluorene rings, more preferably benzene rings, naphthalene rings, and pyrene rings, and even more preferably benzene rings. ２ If the aromatic ring having 3 to 40 carbon atoms in the above formula has substituents, the substituent is R of formula (A0) above. ａ The substituents that the hydrocarbon group in the above-mentioned material may have can be suitably adopted.

[0045] Ar ２ It is preferable that the group is an aromatic ring having 3 to 40 carbon atoms from which two hydrogen atoms have been removed, or a group formed by combining the above group with a divalent heteroatom-containing linking group. ２ The divalent heteroatom-containing linking group in is R in the above formula (A0). ａ The divalent heteroatom-containing linking group shown can be suitably adopted.

[0046] In the above formula (A3), W ３ As an organic group with 1 to 40 carbon atoms represented by the above formula (A0), R ａ A monovalent organic group having 1 to 40 carbon atoms, represented by [the formula shown], can be suitably used, with u-1 hydrogen atoms removed.

[0047] W ３ The organic group with 1 to 40 carbon atoms represented by is preferably a substituted or unsubstituted hydrocarbon group with 1 to 40 carbon atoms, or a group having a divalent heteroatom-containing linking group between the carbon atoms of the hydrocarbon group. ３ In the above formula (A0), the R is a u-valent hydrocarbon group having 1 to 40 carbon atoms. ａA group obtained by removing u hydrogen atoms from a hydrocarbon corresponding to a monovalent hydrocarbon group having 1 to 40 carbon atoms as shown above can be suitably adopted. The hydrocarbon group having 1 to 40 carbon atoms is preferably a hydrocarbon corresponding to a monovalent chain hydrocarbon having 1 to 40 carbon atoms, an aromatic hydrocarbon corresponding to a monovalent aromatic hydrocarbon group having 6 to 40 carbon atoms, or a combination thereof. More preferably, it is a chain saturated hydrocarbon corresponding to a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, an aromatic hydrocarbon corresponding to a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, or a combination thereof. Even more preferably, it is methane, ethane, propane, butane, benzene, naphthalene, fluorene, or a combination thereof. ３ The divalent heteroatom-containing linking group in is R in the above formula (A0). ａ The divalent heteroatom-containing linking group shown can be suitably adopted.

[0048] W ３ If the t-valent hydrocarbon group having 1 to 40 carbon atoms in the above formula has substituents, the substituents are R ａ The substituents that the hydrocarbon group in the above-mentioned material may have can be suitably adopted.

[0049] u is preferably an integer between 1 and 3, and more preferably 1 or 2.

[0050] When u is 2, W ３ The divalent heteroatom-containing linking group represented by the above formula (A0) is R ａ The divalent heteroatom-containing linking group shown above can be suitably adopted.

[0051] In the above formula (A3), R ｃ As a monovalent organic group having 1 to 40 carbon atoms represented by the above formula (A0), R ａ A monovalent organic group having 1 to 40 carbon atoms, represented by [the formula shown], can be suitably used.

[0052] R ｃ It is preferable that the group is a monovalent group containing a substituted or unsubstituted aromatic ring having 3 to 40 carbon atoms. ｃ As a monovalent group containing an aromatic ring with 3 to 40 carbon atoms represented by Ar, １A group obtained by removing one hydrogen atom from the above-mentioned aromatic ring having 3 to 40 carbon atoms can be suitably adopted. ｃ If the aromatic ring having 3 to 40 carbon atoms in the above formula has substituents, the substituent is R of formula (A0) above. ａ The substituents that the hydrocarbon group in the above-mentioned material may have can be suitably adopted.

[0053] [A0] Specific examples of compounds include, but are not limited to, the following formulas (A0-1) to (A0-4).

[0054]

[0055] [A1] Specific examples of compounds include, but are not limited to, the following formulas (A1-1) to (A1-8).

[0056]

[0057]

[0058] [A2] Specific examples of polymers include, but are not limited to, polymers having repeating units represented by the following formulas (A2-1) to (A2-20).

[0059]

[0060]

[0061]

[0062] [A3] Specific examples of compounds include, but are not limited to, the following formulas (A3-1) to (A3-6).

[0063]

[0064]

[0065] The molecular weight of compound [A] is preferably 500 or more, regardless of whether compound [A] is compound [A0], compound [A1], polymer [A2], or polymer [A3]. When compound [A] is compound [A0] or compound [A1], the lower limit of the molecular weight of compound [A0] or compound [A1] is more preferably 550, and even more preferably 600. The upper limit of the above molecular weight is preferably 2000, and even more preferably 2500. When compound [A] is polymer [A2] or polymer [A3], the lower limit of the molecular weight of polymer [A2] or polymer [A3] is more preferably 1500, and even more preferably 2000. The upper limit of the above molecular weight is preferably 8000, and even more preferably 6000. The molecular weights of compound [A0] and compound [A1] are values ​​obtained from the structural formula. The molecular weights of polymer [A2] and polymer [A3] are weight-average molecular weights measured by gel permeation chromatography using monodisperse polystyrene as the standard.

[0066] Preferably, the content of compound [A] in the components other than the solvent in the above nitrogen-containing film-forming composition is 1% by mass or more. The above content of compound [A] may be 5% by mass or more, 10% by mass or more, 20% by mass or more, 30% by mass or more, 40% by mass or more, 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, or 100% by mass.

[0067] <Method for Producing Compound [A]> Compound [A] can be produced according to known methods. Typically, an amide compound can be produced by a condensation reaction between a compound having a hydroxyl group, an amino group, or a sulfanyl group (hereinafter also referred to as "hydroxyl group, etc.") and an amino group adjacent to each other (hereinafter also referred to as "[a] compound") and a carboxylic acid derivative (hereinafter also referred to as "[b] compound"), and then protecting the hydroxyl group, etc. of this amide compound with a protective agent (hereinafter also referred to as "[c] compound") to produce a compound [A] in a simple and efficient manner.

[0068] ([a] compound) The [a] compound is preferably a compound represented by the following formula (a0) or formula (a1) (hereinafter also referred to as "[a0] compound," etc.). (In formulas (a0) to (a1), Ar １ Each is independently a substituted or unsubstituted aromatic ring having 3 to 40 carbon atoms. Each is independently -O-, -S-, or -NR''-. R'' is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or an acyl group. t is an integer from 1 to 4. If t is 2 or greater, there are multiple X and Ar １ These are either identical or different from each other. １ This is an organic group with 1 to 40 carbon atoms and a t-valence. However, when t is 2, W １ (This refers to a divalent organic group having 1 to 40 carbon atoms, a single bond, or a linking group containing a divalent heteroatom.)

[0069] Ar in the above equations (a0) to (a1) １ X, R'' are monovalent hydrocarbon groups having 1 to 20 carbon atoms, t and W １ In each of the above formulas (A0) to (A3), the corresponding structure can be suitably adopted. An example of the acyl group of R'' is an acetyl group.

[0070] [a] Specific examples of compounds include, but are not limited to, the following formulas (a-1) to (a-10).

[0071]

[0072] ([b] compound) The [b] compound is preferably a compound represented by the following formula (b). (In formula (b), W ０ Y is an organic group with 1 to 40 carbon atoms and an s-valence. Y is a hydroxyl group or a halogen atom. s is an integer from 1 to 4. If s is 2 or more, multiple Y groups are either identical or distinct from one another.

[0073] In the above formula (b), W ０ And s are W in the above formula (A0). ０The structure and the value of s can be suitably adopted.

[0074] A chlorine atom is preferred for Y.

[0075] [b] Specific examples of compounds include, but are not limited to, formulas (b-1) to (b-8) below.

[0076]

[0077] ([c] compound) A known hydroxyl group protecting agent can be used for the [c] compound.

[0078] [c] Specific examples of compounds include, but are not limited to, those of the following formulas (c-1) to (c-5).

[0079]

[0080] The reaction between compound [a] and compound [b] can be carried out according to known methods, preferably in a reaction solvent under an inert gas atmosphere such as a nitrogen gas atmosphere. Typically, the reaction can be carried out in batches by mixing compound [a] and compound [b] and preferably by heating. The molar ratio of the reaction between compound [a] and compound [b] can be appropriately set considering the number of combinations of two adjacent functional groups in compound [a] and the number of carboxyl groups or carboxylic acid halides in compound [b]. The lower limit of the reaction temperature is preferably 20°C and preferably 30°C. The upper limit of the reaction temperature is preferably 100°C and preferably 80°C. It may also be set to a temperature at which reflux of the solvent occurs. The lower limit of the reaction time is preferably 0.5 hours and preferably 1 hour. The upper limit of the reaction time is preferably 12 hours and preferably 6 hours. Catalysts such as amines may be added during the reaction. After the reaction, the amide compound can be obtained by separation, purification, drying, etc. As the reaction solvent, solvent [B] described later can be suitably used.

[0081] The protection of hydroxyl groups, etc., in amide compounds can be carried out in batches by mixing the amide compound and the protective agent under an atmospheric atmosphere and preferably heating the mixture. The molar ratio of the amide compound to the protective agent can be appropriately set considering the number of hydroxyl groups, etc., in the amide compound. The lower limit of the reaction temperature is preferably 40°C, and more preferably 60°C. The upper limit of the reaction temperature is preferably 140°C, and more preferably 120°C. The temperature may also be set to a temperature at which reflux of the solvent occurs. The lower limit of the reaction time is preferably 1 hour, and more preferably 2 hours. The upper limit of the reaction time is preferably 12 hours, and more preferably 8 hours. Catalysts such as amines may be added during the reaction. After the reaction, compound [A] can be obtained by separation, purification, drying, etc. The solvent [B] described later can be suitably used as the reaction solvent.

[0082] In the method for producing the compound [A], after reacting the amide compound with the aldehyde compound, protection such as a hydroxyl group may be performed. A novolac-type [A3] polymer can be suitably produced by acid addition condensation of the amide compound and the aldehyde compound.

[0083] The above aldehyde compound is not particularly limited, but it is preferably an aromatic ring-containing aldehyde compound. The aromatic ring in the aromatic ring-containing aldehyde compound is Ar of formula (A0) above. １ Aromatic rings with 3 to 40 carbon atoms, as shown in the diagram, can be suitably used.

[0084] Specific examples of the above aldehyde compounds include, but are not limited to, those represented by the following formulas (f-1) to (f-5).

[0085]

[0086] The acid addition condensation of the above amide compound and aldehyde compound may be carried out according to known methods. Preferably, it can be carried out in a reaction solvent under an inert gas atmosphere such as a nitrogen gas atmosphere. The reaction temperature is preferably set to a temperature at which heating reflux of the solvent occurs. The lower limit of the reaction time is preferably 1 hour, and preferably 2 hours. The upper limit of the reaction time is preferably 12 hours, and preferably 8 hours. An acid catalyst may be added during the reaction. The acid catalyst is not particularly limited, and known inorganic acids and organic acids can be used. After the reaction, compound [A] can be obtained by separation, purification, drying, etc. As the reaction solvent, solvent [B] described later can be suitably used.

[0087] <[B] Solvent> The [B] solvent is not particularly limited as long as it can dissolve or disperse the [A] compound and any optional components contained therein as needed.

[0088] [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.

[0089] Examples of hydrocarbon solvents include aliphatic hydrocarbon solvents such as n-pentane, n-hexane, and cyclohexane; aromatic hydrocarbon solvents such as benzene, toluene, and xylene; and halogenated hydrocarbons such as dichloromethane and 1,2-dichloroethane.

[0090] 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.

[0091] Examples of alcohol-based solvents include monoalcohol solvents such as methanol, ethanol, n-propanol, and 1-butanol, and polyhydric alcohol solvents such as ethylene glycol and 1,2-propylene glycol.

[0092] Examples of ketone solvents include linear ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, and cyclic ketone solvents such as cyclohexanone.

[0093] Examples of ether-based solvents include linear ether solvents such as n-butyl ether, cyclic ether solvents such as tetrahydrofuran and dioxane, polyhydric alcohol ether solvents such as ethylene glycol dimethyl ether, and polyhydric alcohol partial ether solvents such as diethylene glycol monomethyl ether.

[0094] Examples of nitrogen-containing solvents include linear nitrogen-containing solvents such as N,N-dimethylacetamide and N,N-dimethylformamide, and cyclic nitrogen-containing solvents such as N-methyl-2-pyrrolidone.

[0095] [B] As the solvent, ester solvents or ketone solvents are preferred, polyhydric alcohol partial ether carboxylate solvents or cyclic ketone solvents are more preferred, and propylene glycol acetate monomethyl ether or cyclohexanone is even more preferred.

[0096] The lower limit of the content of solvent [B] in the nitrogen-containing film-forming composition is preferably 50% by mass, more preferably 60% by mass, and still more preferably 70% by mass. The upper limit of the above content is preferably 99.9% by mass, more preferably 99% by mass, and still more preferably 95% by mass.

[0097] [Optional Components] The nitrogen-containing film-forming composition may contain optional components as long as they do not impair the effects of the present invention. Examples of optional components include acid generators, crosslinking agents, surfactants, base generators, 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.). These compounds may be used individually or in combination of two or more. As 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 the optional components in the nitrogen-containing film-forming composition can be appropriately determined depending on the type of optional component.

[0098] [Method for preparing a nitrogen-containing film-forming composition] The nitrogen-containing film-forming composition can be prepared by mixing [A] compound, [B] solvent, and optionally any other components in a predetermined ratio, and preferably by filtering the resulting mixture through a membrane filter with a pore size of 0.5 μm or less.

[0099] [Uses of the Nitrogen-Containing Film Forming Composition] This nitrogen-containing film forming composition is suitable for forming films that require good heat resistance and embedding properties. In particular, it is suitable for semiconductor manufacturing processes in which pattern miniaturization is progressing.

[0100] 《Method for Manufacturing Semiconductor Substrates》 The method for manufacturing the semiconductor substrate includes a step of coating a patterned substrate with a nitrogen-containing film-forming composition (hereinafter also referred to as the "coating step") and a step of etching the nitrogen-containing film formed by the coating step (hereinafter also referred to as the "etching step").

[0101] The method for manufacturing the semiconductor substrate preferably includes a step of heating the substrate in a first temperature range of 350°C or more and less than 500°C (hereinafter also referred to as the "first heating step") after the coating step and before the etching step.

[0102] The method for manufacturing the semiconductor substrate preferably further includes a step of heating the substrate to a second temperature range of 500°C or higher (hereinafter also referred to as the "second heating step") after the step of heating in the first temperature range and before the etching step.

[0103] The following describes each step in the manufacturing method of the semiconductor substrate.

[0104] [Coating Process] In this process, a nitrogen-containing film-forming composition is coated onto a patterned substrate. In this process, the nitrogen-containing film-forming composition described above is used.

[0105] The coating method for the nitrogen-containing film-forming 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 nitrogen-containing film is formed when the solvent [B] volatilizes.

[0106] Examples of substrates include metal or metalloid substrates such as silicon substrates, aluminum substrates, nickel substrates, chromium substrates, molybdenum substrates, tungsten substrates, copper substrates, tantalum substrates, and titanium substrates, with silicon substrates being preferred among these. The above substrates may also be substrates on which silicon nitride films, alumina films, silicon dioxide films, tantalum nitride films, titanium nitride films, etc., are formed.

[0107] The above substrate has a pattern. The nitrogen-containing film-forming composition has excellent embedding properties, so even when the substrate has a pattern, it can form a good film while filling the gaps between the patterns. Examples of the pattern shapes include trench patterns, line-and-space patterns, hole patterns, and pillar patterns. Examples of trench patterns and line-and-space patterns include patterns containing recesses with a width of 5 nm to 100 nm, and patterns containing recesses with a depth of 5 nm to 500 nm. Examples of hole patterns include patterns containing holes with a diameter of 5 nm to 100 nm, and patterns containing holes with a depth of 5 nm to 500 nm. Examples of pillar patterns include patterns containing pillars with a width of 5 nm to 100 nm, and patterns containing pillars with a height of 5 nm to 500 nm.

[0108] [First Heating Step] In this step, after the coating step and before the etching step, the substrate is heated in a first temperature range of 350°C to less than 500°C. Heating the coating film promotes the formation of a nitrogen-containing film. More specifically, heating the coating film promotes the volatilization of solvent [B]. In parallel with this, a cyclization reaction occurs between the amide bond in compound [A] and the protected hydroxyl group adjacent to the amide bond, etc., forming an oxazole-like structure. This enables the substrate to exhibit excellent heat resistance.

[0109] The above-mentioned coating film may be heated under an atmospheric environment or under a nitrogen atmosphere. The lower limit of the heating temperature is preferably 360°C, and more preferably 370°C. The upper limit of the heating temperature is preferably 460°C, and more preferably 440°C. The lower limit of the heating time is preferably 15 seconds, and more preferably 30 seconds. The upper limit of the heating time is preferably 1,200 seconds, and more preferably 600 seconds.

[0110] Furthermore, the nitrogen-containing film may be exposed to light after the above coating process. The nitrogen-containing film may be exposed to plasma after the above coating process. The nitrogen-containing film may be ion-implanted after the above coating process. Exposure of the nitrogen-containing film improves its etching resistance. Exposure of the nitrogen-containing film to plasma improves its etching resistance. Ion implantation of the nitrogen-containing film improves its etching resistance.

[0111] The radiation used for exposure of nitrogen-containing films is appropriately selected from electromagnetic waves such as visible light, ultraviolet light, far ultraviolet light, X-rays, and gamma rays; and particle beams such as electron beams, molecular beams, and ion beams.

[0112] Methods for exposing nitrogen-containing films to plasma include, for example, a direct method in which the substrate is placed in a gas atmosphere and plasma discharge is performed. Typical conditions for plasma exposure are a gas flow rate of 50 cc / min to 100 cc / min and a power supply of 100 W to 1,500 W.

[0113] The lower limit of the plasma exposure time is preferably 10 seconds, more preferably 30 seconds, and even more preferably 1 minute. The upper limit of the above time is preferably 10 minutes, more preferably 5 minutes, and even more preferably 2 minutes.

[0114] Plasma is, for example, H ２ Plasma is generated in an atmosphere of a mixed gas of gas and Ar gas. Also, H ２ In addition to gas and Ar gas, CF ４ Gas and CH ４ It is also possible to introduce carbon-containing gases such as gases. ２ Instead of either or both of gas and Ar gas, CF ４Gas, NF ３ Gas, CHF ３ Gas, CO ２ Gas, CH ２ F ２ Gas, CH ４ Gas and C ４ F ８ At least one of the gases may be introduced.

[0115] Ion implantation into a nitrogen-containing membrane involves implanting dopants into the membrane. Dopants can be selected from a group consisting of boron, carbon, nitrogen, phosphorus, arsenic, aluminum, and tungsten. The implantation energy used to apply voltage to the dopant ranges from approximately 0.5 keV to 60 keV, depending on the type of dopant used and the desired implantation depth.

[0116] The lower limit of the average thickness of the nitrogen-containing film formed is preferably 30 nm, more preferably 50 nm, and even more preferably 80 nm. The upper limit of the average thickness is preferably 3,000 nm, more preferably 2,000 nm, and even more preferably 500 nm. The method for measuring the average thickness is as described in the examples.

[0117] [Second Heating Step] In this step, after the step of heating in the first temperature range described above, and before the etching step described above, the substrate is heated in a second temperature range of 500°C or higher. This makes it possible to remove residual solvent from the first heating step and promote the cyclization of structures that were not completely cyclized, thereby further improving heat resistance.

[0118] The second heating step may be carried out in an atmospheric environment or in a nitrogen atmosphere. The lower limit of the heating temperature is preferably 550°C, and more preferably 580°C. The upper limit of the heating temperature is preferably 700°C, and more preferably 650°C. The lower limit of the heating time is preferably 15 seconds, and more preferably 30 seconds. The upper limit of the heating time is preferably 1,200 seconds, and more preferably 600 seconds.

[0119] [Etching Process] In this process, the nitrogen-containing film formed by the coating process (or the first heating process or second heating process as needed) is etched. Etching methods include dry etching and wet etching. Dry etching is preferred from the viewpoint of etching selectivity and efficiency. For this dry etching, gas plasma such as oxygen plasma is used. A semiconductor substrate having a predetermined pattern is obtained by the above etching process.

[0120] The present invention will be described in detail below based on examples, but the present invention is not limited to these examples.

[0121] [Weight-average molecular weight (Mw)] The Mw of the polymer was measured by gel permeation chromatography (detector: differential refractometer) using monodisperse polystyrene as the standard, under analytical conditions of flow rate: 1.0 mL / min, elution solvent: tetrahydrofuran, column temperature: 40°C, using GPC columns from Tosoh Corporation (two "G2000HXL" columns and one "G3000HXL" column).

[0122] [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.

[0123] <Synthesis of Compound [A]> Compounds (a-1) to (a-8), (b-1) to (b-6), (c-1) to (c-3), (e-1) to (e-5), and (f-1) were used in the synthesis of Compound [A].

[0124]

[0125]

[0126]

[0127]

[0128]

[0129] <Synthesis of Compound [A]> Compounds (A1-1) to (A1-5), (A0-1) to (A0-2), (A2-1) to (A2-16), and (A3-1) to (A3-5) were synthesized as [A] compounds according to the procedure shown below. In the following formulas, the values ​​accompanying the repeating units are molar ratios.

[0130]

[0131]

[0132]

[0133]

[0134]

[0135]

[0136]

[0137] [Synthesis Example 1-1] (Synthesis of Compound (A1-1)) Under a nitrogen atmosphere, 2.2 g of compound (a-1) and 1.7 g of pyridine were added to 10 g of N,N-dimethylacetamide in a reaction vessel and heated to 60°C to dissolve. 5 g of N,N-dimethylacetamide in which 3.8 g of compound (b-1) was dissolved was slowly added dropwise while maintaining the internal temperature at 60°C. After reacting at 60°C for 2 hours, it was allowed to cool to room temperature and added dropwise to 50 g of methanol / water (70 / 30 wt%). The resulting precipitate was collected by suction filtration and vacuum dried. The obtained solid was then redissolved in 20 g of N,N-dimethylacetamide, and 2.8 g of compound (c-1) was added in the presence of 3.4 g of 1,8-diazabicyclo[5.4.0]-7-undecene, and the mixture was reacted at 80°C for 4 hours. After the reaction was complete, the reaction solution was transferred to a separatory funnel, 100 g of cyclohexanone was added, and the mixture was washed several times with 50 g of 1% oxalic acid aqueous solution. The aqueous phase was then separated, and the organic phase was washed several times with water until the pH was neutral. After concentration using an evaporator, the mixture was added dropwise to methanol / water (70 / 30 wt%), the precipitate was collected by filtration, and the mixture was vacuum-dried to obtain compound (A1-1). The Mw of compound (A1-1) was 700.

[0138] [Synthesis Examples 1-2 to 1-6] (Synthesis of compounds (A1-2) to (A1-5) and (A0-1)) Compounds (A1-2) to (A1-5) and (A0-1) were obtained as products under the same reaction conditions as in Synthesis Example 1-1, except that the types and amounts of starting compounds shown in Table 1 were used. The molecular weights are shown in addition to those in Table 1.

[0139] [Synthesis Example 1-7] (Synthesis of Compound (A0-2)) Under a nitrogen atmosphere, 2.0 g of compound (a-3) and 4.0 g of pyridine were dissolved in 10 g of N,N-dimethylacetamide in a reaction vessel. 5 g of N,N-dimethylacetamide containing 1.3 g of compound (b-5) was added dropwise while maintaining an internal temperature of 40°C. After cooling, the precipitate obtained by adding the mixture dropwise to 50 g of methanol was collected by suction filtration. The obtained solid was then redissolved in 10 g of N,N-dimethylacetamide, and 1.3 g of compound (c-1) was added in the presence of 1.5 g of 1,8-diazabicyclo[5.4.0]-7-undecene, and the reaction was carried out at 80°C for 4 hours. After the reaction was complete, the reaction solution was transferred to a separatory funnel, 50 g of cyclohexanone was added, and the mixture was washed several times with 10 g of 1% oxalic acid aqueous solution. The aqueous phase was then separated, and the organic phase was washed several times with water until the pH became neutral. After concentration using an evaporator, the compound (A0-1) was obtained by adding it dropwise to methanol / water (70 / 30 wt%), filtering and recovering the precipitate, and then vacuum drying. The Mw of compound (A0-1) was 530.

[0140] [Synthesis Example 2-1] (Synthesis of Compound (A2-1)) Under a nitrogen atmosphere, 15.9 g of compound (a-1) and 14.0 g of triethylamine were added to 100 g of N,N-dimethylacetamide in a reaction vessel and heated to 60°C to dissolve. 10 g of N,N-dimethylacetamide in which 10.0 g of compound (b-5) was dissolved was slowly added dropwise while maintaining an internal temperature of 60°C. After reacting at 60°C for 2 hours, the mixture was allowed to cool to room temperature and added dropwise to 300 g of methanol / water (70 / 30 wt%). The resulting precipitate was collected by suction filtration and vacuum dried. The obtained solid was then redissolved in 100 g of N,N-dimethylacetamide, and 15.0 g of compound (c-1) was added in the presence of 8.9 g of 1,8-diazabicyclo[5.4.0]-7-undecene, and the mixture was reacted at 100°C for 5 hours. After the reaction was complete, the reaction solution was transferred to a separatory funnel, 200 g of cyclohexanone was added, and the mixture was washed several times with 100 g of 1% oxalic acid aqueous solution. The aqueous phase was then separated, and the organic phase was washed several times with water until the pH became neutral. After concentration using an evaporator, the mixture was added dropwise to methanol / water (70 / 30 wt%), the precipitate was collected by filtration, and the mixture was vacuum-dried to obtain compound (A2-1). The Mw of compound (A2-1) was 4700.

[0141] [Synthesis Examples 2-2 to 2-16] (Synthesis of Compounds (A2-2) to (A2-16)) Compounds (A2-2) to (A2-16) were obtained as products under the same reaction conditions as in Synthesis Example 2-1, except that the types and amounts of starting compounds shown in Table 2 were used. Mw is shown in addition to Table 2.

[0142] [Synthesis Example 3-1] (Synthesis of Compound (A3-1)) Compound (e-1) was obtained in the same manner as in Synthesis Example 1-1, except that the starting compounds were changed. Under a nitrogen atmosphere, 5.0 g of compound (e-1) and 2.2 g of compound (f-1) were dissolved in 50 g of 1,2-dichloroethane in a reaction vessel, and 0.2 g of methanesulfonic acid was added and the mixture was polymerized by heating under reflux for 4 hours. After cooling to room temperature, the mixture was added dropwise to 150 g of methanol / water (70 / 30 wt%). The resulting precipitate was collected by suction filtration and vacuum dried. The obtained solid was then redissolved in 50 g of N,N-dimethylacetamide, and 3.8 g of compound (c-1) was added in the presence of 3.5 g of 1,8-diazabicyclo[5.4.0]-7-undecene, and the mixture was reacted at 100°C for 5 hours. After the reaction was complete, the reaction solution was transferred to a separatory funnel, 100 g of cyclohexanone was added, and the mixture was washed several times with 50 g of 1% oxalic acid aqueous solution. The aqueous phase was then separated, and the organic phase was washed several times with water until the pH became neutral. After concentration using an evaporator, the mixture was added dropwise to methanol / water (70 / 30 wt%), the precipitate was collected by filtration, and the mixture was vacuum-dried to obtain compound (A3-1). The Mw of compound (A3-1) was 3460.

[0143] [Synthesis Examples 3-2 to 3-5] (Synthesis of Compounds (A3-2) to (A3-5)) Compounds (A3-2) to (A3-5) were obtained as products under the same reaction conditions as in Synthesis Example 3-1, except that the types and amounts of starting compounds shown in Table 3 were used. Mw is shown in conjunction with Table 3.

[0144] [Comparative Synthesis Example 1] (Synthesis of Compound (x-1)) In a reaction vessel under a nitrogen atmosphere, 100.0 g of 9,9-bis(4-hydroxyphenyl)fluorene, 300.0 g of propylene glycol monomethyl ether acetate, and 10.0 g of paraformaldehyde were charged, and 1.0 g of p-toluenesulfonic acid monohydrate was added. The reaction was carried out at 100°C for 16 hours. Subsequently, the polymerization reaction solution was added to 500.0 g of methanol / water (70 / 30 (mass ratio)) mixed solvent, the precipitate was collected on filter paper, and dried to obtain the compound (x-1) shown below. The Mw of compound (x-1) was 5,200.

[0145]

[0146]

[0147]

[0148]

[0149] <Preparation of Nitrogen-Containing Film Forming Composition> The following describes the [A] compound, [B] solvent, [C] acid generator, [D] crosslinking agent and polymer (x-1) used in the preparation of the nitrogen-containing film forming composition (hereinafter also referred to as "the composition").

[0150] [[A] Compounds] A1-1 to A1-5, A0-1 to A0-2, A2-1 to A2-16 and A3-1 to A3-5: The above synthesized compounds (A1-1) to (A1-5), (A0-1) to (A0-2), (A2-1) to (A2-16) and (A3-1) to (A3-5)

[0151] [B Solvent] B-1: Propylene glycol monomethyl ether acetate B-2: Cyclohexanone

[0152] [C] Acid Generator: C-1: Compound represented by the following formula (C-1)

[0153] [D] Crosslinking agent: D-1: Compound represented by the following formula (D-1)

[0154] [polymer (x-1)] x-1: The polymer (x-1) synthesized above

[0155] [Example 1-1] [A] 10 parts by mass of (A2-1) as a compound was dissolved in [B] 30 parts by mass of (B-1) and 60 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).

[0156] [Examples 1-2 to 1-29 and Comparative Example 1-1] Compositions (J-2) to (J-29) 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 4 below.

[0157]

[0158] <Evaluation> [Examples 2-1 to 2-29 and Comparative Example 2-1] The nitrogen-containing film-forming compositions prepared above were evaluated for heat resistance and embedding properties by the following method. The evaluation results are shown in Table 5 below.

[0159] [Heat Resistance] The above-prepared composition was coated onto a silicon wafer (substrate) using a spin coater (CLEAN TRACK ACT12 from Tokyo Electron Ltd.) by rotary coating. Next, the wafer was heated at 200°C for 60 seconds in an air atmosphere, and then cooled at 23°C for 60 seconds to form a film with an average thickness of 200 nm, obtaining a film-coated substrate with a resist underlayer film formed on the substrate. The film on the obtained film-coated substrate was scraped off to recover the powder, and the recovered powder was placed in a container used for measurement with a TG-DTA apparatus (TG-DTA2000SR from NETZSCH), and its mass before heating was measured. Next, using the TG-DTA apparatus, the powder was heated to 400°C in a nitrogen atmosphere at a heating rate of 10°C / min, and the mass of the powder at 400°C was measured. The mass loss rate (%) was then measured using the following formula, and this mass loss rate was used as a measure of heat resistance. Ｌ = {(m1-m2) / m1} × 100 where, in the above formula, M Ｌ m1 is the mass loss rate (%), m2 is the mass before heating (mg), and m2 is the mass at 400°C (mg).

[0160] Heat resistance is good when the mass loss rate of the sample powder is small, as this results in less sublimation and decomposition of the film during heating. In other words, a smaller mass loss rate indicates higher heat resistance. Heat resistance was evaluated as follows: "A" (excellent) if the mass loss rate was less than 5%, "B" (good) if it was between 5% and 10%, "C" (poor) if it was between 10% and 15%, and "D" (very poor) if it was 15% or more.

[0161] [Embedding Performance] The nitrogen-containing film-forming composition described above was applied to a substrate on which a trench pattern with a depth of 65 nm and a width of 20 nm was formed, using a spin coater (LITHIUS Pro Z from Tokyo Electron Limited) by rotary coating. The rotation conditions of the spin coater were set to obtain a film-coated substrate with an average thickness of 100 nm. Next, the substrate was heated at 400°C for 90 seconds in an air atmosphere, and then cooled at 23°C for 60 seconds. The cross-sectional shape of the substrate was observed (200,000x magnification) using a scanning electron microscope (S-4800 from Hitachi High-Technologies Corporation) to evaluate the embedding performance. Embedding performance was evaluated as "A" (good) if the nitrogen-containing film was embedded to the bottom of the 20 nm wide trench pattern on the substrate, and "B" (poor) if it was not embedded to the bottom of the 20 nm wide trench pattern.

[0162]

[0163] As can be seen from the results in Table 5, the compositions of the examples and the nitrogen-containing films formed from them exhibited superior heat resistance and embedding properties compared to the comparative examples.

[0164] The semiconductor substrate manufacturing method of the present invention makes it possible to form a nitrogen-containing film with excellent heat resistance and embedding properties. The nitrogen-containing film forming composition of the present invention also makes it possible to form a nitrogen-containing film with excellent embedding properties and flatness. Therefore, these can be suitably used in the manufacture of semiconductor devices, for which further miniaturization is expected in the future.

Claims

1. A nitrogen-containing film-forming composition comprising a nitrogen-containing compound and a solvent, wherein the nitrogen-containing compound is a compound represented by the following formula (A0) or formula (A1), or a polymer having repeating units represented by the following formula (A2) or formula (A3). (In formulas (A0) to (A3), X is independently -O-, -S-, or -NR'-. R' is a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms. ａ and R ｂ Each of these is independently a monovalent organic group having 1 to 40 carbon atoms. １ Each is independently a substituted or unsubstituted aromatic ring with 3 to 40 carbon atoms. s is an integer from 1 to 4. If s is 2 or greater, there are multiple X, R ａ and Ar １ Each of them is either the same or different from the others. t is an integer from 1 to 4. If t is 2 or greater, there are multiple X, R ａ , R ｂ and Ar １ These are either identical or different from one another. u is an integer between 1 and 4. When u is 2 or more, a plurality of X, R ａ , R ｂ and Ar １ are each the same as or different from one another. W ０ is an s-valent organic group having 1 to 40 carbon atoms. W １ is a t-valent organic group having 1 to 40 carbon atoms when t is 1, 3 or 4, a divalent organic group having 1 to 40 carbon atoms, a single bond or a divalent heteroatom-containing linking group when t is 2. W ２ is a divalent organic group having 1 to 40 carbon atoms, a single bond or a divalent heteroatom-containing linking group. Ar ２ is a divalent group containing a substituted or unsubstituted aromatic ring having 3 to 40 carbon atoms. W ３ is a u-valent organic group having 1 to 40 carbon atoms when u is 1, 3 or 4, a divalent organic group having 1 to 40 carbon atoms, a single bond or a divalent heteroatom-containing linking group when u is 2. R ｃ is a monovalent organic group having 1 to 40 carbon atoms. However, in the above formula (A3), when u is 2 or more, one of the bonds extending from the carbon atom to which R ｃ is bonded to one aromatic ring of the u Ar １ , and the other bond is bonded to another aromatic ring of the u Ar １ . １ .) 2. R ａ The nitrogen-containing film-forming composition according to claim 1, wherein each of the members is independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 40 carbon atoms, or a group having a divalent heteroatom-containing linking group at the end of the hydrocarbon group.

3. R ｂ The nitrogen-containing film-forming composition according to claim 1, wherein each of them is independently a substituted or unsubstituted monovalent aromatic ring having 6 to 40 carbon atoms.

4. Ar １ The nitrogen-containing film-forming composition according to claim 1, wherein each of them is independently a substituted or unsubstituted aromatic ring having 6 to 40 carbon atoms.

5. R ｃ The nitrogen-containing film-forming composition according to claim 1, wherein is a monovalent group comprising a substituted or unsubstituted aromatic ring having 3 to 40 carbon atoms.

6. The nitrogen-containing film-forming composition according to claim 1, wherein the molecular weight of the nitrogen-containing compound is 500 or more.

7. The nitrogen-containing film-forming composition according to claim 1, wherein the nitrogen-containing compound is present in the nitrogen-containing film-forming composition in proportion to the components other than the solvent in the nitrogen-containing film-forming composition, with a content of 1% by mass or more.

8. The nitrogen-containing film-forming composition according to claim 1, for use in semiconductor manufacturing processes.

9. A method for manufacturing a semiconductor substrate, comprising the steps of: coating a patterned substrate with a nitrogen-containing film-forming composition; and etching the nitrogen-containing film formed by the coating step, wherein the nitrogen-containing film-forming composition contains a nitrogen-containing compound and a solvent, and the nitrogen-containing compound is a compound represented by the following formula (A0) or the following formula (A1), or a polymer having repeating units represented by the following formula (A2) or the following formula (A3). (In formulas (A0) to (A3), X is independently -O-, -S-, or -NR'-. R' is a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms. ａ and R ｂ Each of these is independently a monovalent organic group having 1 to 40 carbon atoms. １ Each is independently a substituted or unsubstituted aromatic ring with 3 to 40 carbon atoms. s is an integer from 1 to 4. If s is 2 or greater, there are multiple X, R ａ and Ar １ Each of them is either the same or different from the others. t is an integer from 1 to 4. If t is 2 or greater, there are multiple X, R ａ , R ｂ and Ar １ These are either identical or different from one another. u is an integer between 1 and 4. If u is 2 or more, there are multiple X, R ａ , R ｂ and Ar １ These are either identical or different from each other. ０ This is an organic group with 1 to 40 carbon atoms and an s-valence. １ When t is 1, 3, or 4, it is an organic group with 1 to 40 carbon atoms and a t-valence, and when t is 2, W １ This refers to a divalent organic group having 1 to 40 carbon atoms, a single bond, or a linking group containing a divalent heteroatom. ２ Ar is a divalent organic group having 1 to 40 carbon atoms, a single bond, or a linking group containing a divalent heteroatom. ２ This is a divalent group containing a substituted or unsubstituted aromatic ring with 3 to 40 carbon atoms. ３ When u is 1, 3, or 4, it is a u-valent organic group having 1 to 40 carbon atoms, and when u is 2, it is a divalent organic group having 1 to 40 carbon atoms, a single bond, or a divalent heteroatom-containing linking group. ｃ is a monovalent organic group having 1 to 40 carbon atoms. However, in the above formula (A3), if u is 2 or more, R ｃ Ar from the carbon atom to which it is bonded １ One of the connecting bonds extending in this direction is made up of u Ar １ One of the aromatic rings is bonded, and the other bond consists of u Ar １ (It binds to other aromatic rings among them.) 10. A method for manufacturing a semiconductor substrate according to claim 9, comprising the step of heating the substrate in a first temperature range of 350°C or more and less than 500°C after the coating step and before the etching step.

11. The method for manufacturing a semiconductor substrate according to claim 10, further comprising the step of heating the substrate in the first temperature range described above, and before the etching step described above, in a second temperature range of 500°C or higher.

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