Method for manufacturing semiconductor substrate, composition for forming resist underlayer film, and method for manufacturing nitrogen-containing compound

Abstract

Provided is a method for producing a semiconductor substrate using a composition capable of forming a film excellent in filling properties and planarity, a composition for forming an antireflection film, and a method for producing a nitrogen-containing compound. A method for producing a semiconductor substrate includes: a step of directly or indirectly applying a composition for forming an antireflection film on a substrate; a step of directly or indirectly forming an antireflection pattern on an antireflection film formed by the application step; and a step of performing etching with the antireflection pattern as a mask, and the composition for forming an antireflection film contains a nitrogen-containing compound and a solvent, the nitrogen-containing compound including a partial structure represented by the following formula (1). (In formula (1), Ar 1 is a substituted or unsubstituted aromatic ring having 5 to 40 ring members including a carbon-carbon double bond in the formula. Each is a bonding site to another structure in the nitrogen-containing compound.)

Description

Technical Field

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

[0002] In the manufacture of semiconductor devices, for example, a multilayer resist process is used. This process involves exposing and developing a resist film, which is a resist film layered on a substrate and containing an organic substrate or a silicon-containing film, to form a resist pattern. In this process, the resist substrate is etched using the resist pattern as a mask, and the substrate is then etched using the resulting resist substrate pattern as a mask, thereby forming the desired pattern on the semiconductor substrate.

[0003] Various studies have been conducted on the materials used in this composition for forming the resist underlayer (refer to International Publication No. 2011 / 108365).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: International Publication No. 2011 / 108365 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] Recently, there has been an increase in the use of substrates with patterns such as grooves and holes. For compositions used to form resist underlayer films, there is a requirement for the ability to be fully embedded in the pattern of the substrate and the flatness to form a flat film regardless of the presence or absence of a pattern.

[0009] The present invention is based on the above-described circumstances, and its object is to provide a method for manufacturing a semiconductor substrate using a composition capable of forming a film with excellent embedding and flatness, a composition for forming a resist underlayer film, and a method for manufacturing a nitrogen-containing compound.

[0010] Technical means to solve the problem

[0011] In one embodiment, the present invention relates to a method for manufacturing a semiconductor substrate, comprising:

[0012] The process of directly or indirectly coating a composition for forming a resist underlayer film on a substrate;

[0013] The process of directly or indirectly forming a resist pattern on the resist underlayer film formed by the coating process; and

[0014] An etching process is performed using the resist pattern as a mask, and

[0015] The composition for forming the resist underlayer film contains:

[0016] Nitrogen-containing compounds (hereinafter also referred to as "[A] compounds"); and

[0017] Solvent (hereinafter also referred to as "[B] solvent"),

[0018] The nitrogen-containing compound comprises a partial structure represented by the following formula (1) (hereinafter also referred to as "partial structure (1)").

[0019] [Chemistry 1]

[0020]

[0021] (In formula (1),

[0022] Ar 1 It is an aromatic ring with 5 to 40 substituted or unsubstituted carbon-carbon double bonds in the inclusion formula;

[0023] (These are the bonds formed with other structures in the nitrogen-containing compound, respectively)

[0024] According to the semiconductor substrate manufacturing method, by using a specified resist underlayer film forming composition in the coating process, a resist underlayer film with excellent embedding and flatness can be formed, thus enabling the manufacture of a semiconductor substrate with a good pattern shape. While the reason is uncertain, it can be inferred as follows: The partial structure (1) of the [A] compound contains OH or NH groups, thus increasing the polarity of the [A] compound as a whole. Consequently, its affinity for hydrophilic substrates with SiON films, SiO2, etc., is particularly enhanced. Simultaneously, the stability of the [A] compound at the substrate surface is improved by the coordination of the OH and NH groups of the partial structure (1) to metal atoms (e.g., silicon atoms, titanium atoms, etc.) on the substrate surface (the [A] compound acts as a bidentate ligand coordinated to the metal atoms). It is speculated that through these combined effects, the resist underlayer film forming composition can form a resist underlayer film with excellent embedding and flatness.

[0025] In another embodiment, the present invention relates to a composition for forming a resist underlayer film, comprising:

[0026] Nitrogen compounds, and

[0027] solvent,

[0028] The nitrogen-containing compound comprises a portion of the structure represented by the following formula (1).

[0029] [Chemistry 2]

[0030]

[0031] (In formula (1),

[0032] Ar 1 It is an aromatic ring with 5 to 40 substituted or unsubstituted carbon-carbon double bonds in the inclusion formula;

[0033] (These are the bonds formed with other structures in the nitrogen-containing compound, respectively)

[0034] In another embodiment, the present invention relates to a method for manufacturing a nitrogen-containing compound, comprising:

[0035] A process for reacting a compound represented by formula (a) (hereinafter also referred to as "[a] compound") with a compound represented by formula (b) (hereinafter also referred to as "[b] compound") and a compound or ammonium salt represented by formula (c) (hereinafter also referred to as "[c] compound").

[0036] [Chemistry 3]

[0037]

[0038] (In formula (a), Ar 1 It is an aromatic ring with 5 to 40 substituted or unsubstituted carbon-carbon double bonds in the inclusion formula;

[0039] In equation (b), R 1 It consists of hydrogen atoms or n atoms with 1 to 40 carbon atoms. 1 Valence organic group; n 1 Integers from 1 to 4; in R 1 In the case of hydrogen atoms, n 1 =1;

[0040] In equation (c), R 2 It consists of hydrogen atoms or n atoms with 1 to 40 carbon atoms. 2 Valence organic group; n 2 Integers from 1 to 4; in R 2 In the case of hydrogen atoms, n 2 (1)

[0041] In this specification, the term "ring number" refers to the number of atoms that make up the ring. For example, the biphenyl ring has 12 ring elements, the naphthalene ring has 10 ring elements, and the fluorene ring has 13 ring elements. The term "condensed ring structure" refers to a structure in which adjacent rings share a common edge (two adjacent atoms). The term "organic group" refers to a group having at least one carbon atom.

[0042] In this specification, the term "hydrocarbon group" includes chain hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups. The term "hydrocarbon group" includes saturated hydrocarbon groups and unsaturated hydrocarbon groups. "Chain hydrocarbon group" refers to a hydrocarbon group that contains only a chain structure and no ring structure, including both straight-chain hydrocarbon groups and branched-chain hydrocarbon groups. "Alicyclic hydrocarbon group" refers to a hydrocarbon group that contains only an alicyclic structure and no aromatic ring structure as its ring structure, including both monocyclic and polycyclic alicyclic hydrocarbon groups (wherein, it is not necessary to contain only an alicyclic structure; a chain structure may also be included in a portion thereof). "Aromatic hydrocarbon group" refers to a hydrocarbon group that contains an aromatic ring structure as its ring structure (wherein, it is not necessary to contain only an aromatic ring structure; an alicyclic structure or a chain structure may also be included in a portion thereof).

[0043] The effects of the invention

[0044] By employing the aforementioned semiconductor substrate manufacturing method, a semiconductor substrate with excellent pattern shape can be obtained due to the formation of a resist underlayer film with excellent embedding and planarity. The resist underlayer film forming composition can form a film with excellent embedding and planarity. The nitrogen-containing compound manufacturing method can efficiently produce nitrogen-containing compounds preferred as components of the resist underlayer film forming composition. Therefore, these are preferably suitable for the manufacture of semiconductor devices that are expected to undergo further miniaturization in the future. Attached Figure Description

[0045] [ Figure 1 [Illustrated plan view] is a schematic diagram used to illustrate the evaluation method for flatness. Detailed Implementation

[0046] Hereinafter, methods for manufacturing semiconductor substrates, compositions for forming resist underlayer films, and methods for manufacturing nitrogen-containing compounds according to various embodiments of the present invention will be described in detail. Furthermore, combinations of preferred embodiments are also preferred.

[0047] Manufacturing Methods of Semiconductor Substrates

[0048] The method for manufacturing the semiconductor substrate includes: a step of directly or indirectly coating a composition for forming a resist underlayer film onto a substrate (hereinafter also referred to as the "coating step"); a step of directly or indirectly forming a resist pattern on the resist underlayer film formed by the coating step (hereinafter also referred to as the "resist pattern forming step"); and a step of etching using the resist pattern as a mask (hereinafter also referred to as the "etching step").

[0049] The semiconductor substrate manufacturing method may, as needed, include a step of heating the resist underlayer film formed by the coating step (hereinafter also referred to as the "heating step") before the resist patterning step.

[0050] The semiconductor substrate manufacturing method may also include, as needed, a step of forming a silicon-containing film directly or indirectly relative to the resist underlayer film before the resist pattern is formed (hereinafter also referred to as the "silicon-containing film formation step").

[0051] The following describes the resist underlayer film formation composition used in the semiconductor substrate manufacturing method, as well as each step including the heating step and the silicon-containing film formation step, which are optional steps.

[0052] <Composition for forming resist underlayer film>

[0053] The resist underlayer film forming composition contains compound [A] and solvent [B]. The resist underlayer film forming composition may also contain any components without impairing the effects of the invention.

[0054] The components contained in the composition for forming the resist underlayer film are described below.

[0055] <[A]compound>

[0056] [A] The compound comprises a portion of the structure represented by formula (1) below. The number of portions of structure (1) in [A] The compound may be one or more. The composition for forming the resist underlayer film may contain one or more [A] compounds.

[0057] [Chemistry 4]

[0058]

[0059] (In formula (1),

[0060] Ar 1 It is an aromatic ring with 5 to 40 substituted or unsubstituted carbon-carbon double bonds in the inclusion formula;

[0061] (These are the bonds formed with other structures in the nitrogen-containing compound, respectively)

[0062] The carbon-carbon double bond in equation (1) represents a bond formed by a cyclic π-electron conjugation (resonance) system.

[0063] In the above formula (1), Ar is used as 1Aromatic rings with 5 to 40 ring elements, such as: benzene rings, naphthalene rings, anthracene rings, fennel rings, pyrene rings, fluorene rings, perylene rings, cardamom rings, and other aromatic hydrocarbon 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, triazine rings, and other aromatic heterocycles, or combinations thereof. These ring combinations can be any of the following: condensed rings, ring aggregates (structures where two rings are bonded by a single bond), or spirocyclic structures. The Ar... 1 The aromatic ring is preferably selected from at least one aromatic hydrocarbon ring in the group consisting of benzene ring, naphthalene ring, anthracene ring, fenestration ring, pyrene ring, fluorene ring, perylene ring and cardamom ring, more preferably benzene ring, naphthalene ring or pyrene ring.

[0064] Ar 1 It may have substituents. Examples of substituents include: monovalent chain hydrocarbons with 1 to 10 carbon atoms, halogen atoms such as fluorine, chlorine, bromine, and iodine atoms, alkoxy groups such as methoxy, ethoxy, and propoxy, alkoxycarbonyl groups such as methoxycarbonyl and ethoxycarbonyl, alkoxycarbonyl groups such as methoxycarbonyloxy and ethoxycarbonyloxy, acyl groups such as formyl, acetyl, propionyl, and butyryl, cyano, and nitro groups.

[0065] [A] The compound may also be a low molecular weight compound containing part of structure (1) (hereinafter also referred to as "[A1] compound") or a high molecular weight compound having two or more repeating units containing part of structure (1) (hereinafter also referred to as "[A2] polymer"). In this specification, "low molecular weight compound" means a compound with a relatively small molecular weight and no repeating units compared to "high molecular weight compound".

[0066] There are no particular limitations on the structures other than part of structure (1) in compound [A]. A suitable structure may be adopted depending on whether compound [A] is a compound [A1] or a polymer [A2]. As the other structures, hydrogen atoms or monovalent or divalent or higher organic groups having 1 to 40 carbon atoms are preferred. A divalent or higher organic group having 1 to 40 carbon atoms is a group formed by removing one or more hydrogen atoms from a monovalent organic group having 1 to 40 carbon atoms.

[0067] Examples of monovalent organic groups having 1 to 40 carbon atoms include: monovalent hydrocarbon groups having 1 to 40 carbon atoms, groups having divalent heteroatoms between carbon atoms or at the end of the carbon chain of the hydrocarbon group, groups in which some or all of the hydrogen atoms of the hydrocarbon group are substituted by a group having a monovalent heteroatom, or combinations thereof.

[0068] Examples of monovalent hydrocarbon groups with 1 to 20 carbon atoms include: monovalent chain hydrocarbon groups with 1 to 40 carbon atoms, monovalent alicyclic hydrocarbon groups with 3 to 40 carbon atoms, monovalent aromatic hydrocarbon groups with 6 to 40 carbon atoms, or combinations thereof.

[0069] Examples of monovalent chain hydrocarbon groups with 1 to 40 carbon atoms include: alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, and tert-butyl; alkenyl groups such as vinyl, propenyl, and butenyl; and alkynyl groups such as ethynyl, propynyl, and butynyl.

[0070] Examples of monovalent alicyclic hydrocarbon groups with 3 to 40 carbon atoms include: cyclopentyl, cyclohexyl and other cycloalkyl groups; cyclopropenyl, cyclopentenyl, cyclohexenyl and other cycloalkenyl groups; bridged cyclic saturated hydrocarbon groups such as norbornyl, adamantyl, tricyclodecyl and other bridged cyclic unsaturated hydrocarbon groups such as norbornyl, tricyclodecenyl and other other bridged cyclic unsaturated hydrocarbon groups.

[0071] As a monovalent aromatic hydrocarbon group with 6 to 40 carbon atoms, it is preferable to use Ar... 1 The radical shown in the figure is formed by removing a hydrogen atom from an aromatic hydrocarbon ring.

[0072] Examples of heteroatoms that form divalent or monovalent heteroatom-containing bases include: oxygen, nitrogen, sulfur, phosphorus, silicon, and halogen atoms. Examples of halogen atoms include: fluorine, chlorine, bromine, and iodine atoms.

[0073] Examples of divalent heteroatom-containing radicals include: -CO-, -CS-, -NH-, -O-, -S-, and radicals formed by combining these.

[0074] Examples of monovalent groups containing heteroatoms include: hydroxyl, sulfonyl, cyano, nitro, and halogen atoms.

[0075] The other structures preferably include an aromatic ring. Ar is preferably used as the aromatic ring. 1 The aromatic rings in the rings range from 5 to 40.

[0076] In the case where the [A] compound is an [A2] polymer, a repeating unit contains a partial structure (1) and a hydrogen atom or a monovalent or divalent or higher organic group having 1 to 40 carbon atoms as the other structure. The [A2] polymer may have repeating units containing partial structure (1) and repeating units not containing partial structure (1).

[0077] [A] The compound is preferably composed of at least three groups selected from the group consisting of OH, NH and NH2 groups, more preferably composed of at least two OH groups and at least one group selected from the group consisting of NH and NH2 groups, and even more preferably composed of at least two OH groups and at least two groups selected from the group consisting of NH and NH2 groups.

[0078] [A] The compound may have at least one group (hereinafter also referred to as "group (α)") selected from the group represented by formula (A-1) and the group represented by formula (A-2) as a substituent. As a result, the etch resistance or heat resistance of the obtained resist underlayer film can be improved.

[0079] [Chemistry 5]

[0080]

[0081] (In equations (A-1) and (A-2), R) 7 Each is independently a divalent organogroup or single bond with 1 to 20 carbon atoms; (For the bond formed with the carbon atom in the aromatic ring)

[0082] In equations (A-1) and (A-2), R is used as... 7 The divalent organic groups representing carbon numbers 1 to 20 can preferably be derived by removing one hydrogen atom from the monovalent organic groups representing carbon numbers 1 to 40 shown as the other structures described above. As R 7 Preferably, it is a divalent hydrocarbon group with 1 to 10 carbon atoms, such as methanediyl, ethanediyl, or phenylene, or a combination of these with -O-, more preferably methanediyl or a combination of methanediyl and -O-.

[0083] The base (α) is preferably Ar that constitutes the formula (1). 1 The aromatic ring or the aromatic ring bond in the other structure.

[0084] [A1] The compound is preferably a compound represented by the following formula (1-1), formula (1-2) or formula (1-3).

[0085] [Chemistry 6]

[0086]

[0087] (In equations (1-1), (1-2), and (1-3),

[0088] R 11a R 11b R 12a R 12b R 12c R12d R 13a and R 13b Each can be independently a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms;

[0089] R 11c and R 13c Each is an independent divalent organogroup having 1 to 40 carbon atoms;

[0090] Ar 1 This has the same meaning as equation (1); in equations (1-1) and (1-3), multiple Ar... 1 (Same or different)

[0091] As R 11a R 11b R 12a R 12b R 12c R 12d R 13a and R 13b The monovalent organic group representing 1 to 40 carbon atoms may preferably be a monovalent organic group representing 1 to 40 carbon atoms as shown in the other structures.

[0092] As R 11c and R 13c The divalent organic group representing carbon 1 to 40 may preferably be a group formed by removing one hydrogen atom from a monovalent organic group representing carbon 1 to 40 as the other structure described above.

[0093] While not limited to specific examples of [A1] compounds, examples such as those from formula (A1-1) to formula (A1-33) can be listed.

[0094] [Chemistry 7]

[0095]

[0096] [Chemistry 8]

[0097]

[0098] [Chemistry 9]

[0099]

[0100] [Chemistry 10]

[0101]

[0102] [Chemistry 11]

[0103]

[0104] [Chemistry 12]

[0105]

[0106] [Chemistry 13]

[0107]

[0108] [A2] The compound is preferably a repeating unit represented by the following formula (2-1), formula (2-2) or formula (2-3).

[0109] [Chemistry 14]

[0110]

[0111] (In equations (2-1), (2-2), and (2-3),

[0112] R 21a R 21b R 22a and R 22b Each can be independently a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms;

[0113] R 21c and R 22c R 23a and R 23b Each is an independent divalent organogroup having 1 to 40 carbon atoms;

[0114] Ar 1 This has the same meaning as equation (1); in equations (2-3), multiple Ar 1 (Same or different)

[0115] As R 21a R 21b R 22a and R 22b The monovalent organic group representing 1 to 40 carbon atoms may preferably be a monovalent organic group representing 1 to 40 carbon atoms as shown in the other structures.

[0116] As R 21c and R 22c R 23a and R 23b The divalent organic group representing carbon 1 to 40 may preferably be a group formed by removing one hydrogen atom from a monovalent organic group representing carbon 1 to 40 as the other structure described above.

[0117] As for the repeating units represented by the above formulas (2-1), (2-2) and (2-3), for example, the repeating units represented by the following formulas (A2-1) to (A2-6) can be listed.

[0118] [Chemistry 15]

[0119]

[0120] [Chemistry 16]

[0121]

[0122] Regarding the molecular weight of compound [A], regardless of whether compound [A] is a compound [A1] or a polymer [A2], it is preferably 600 or more. When compound [A] is a compound [A1], the lower limit of the molecular weight of compound [A1] is more preferably 700, and even more preferably 800. The upper limit of the molecular weight of compound [A1] is preferably 1800, and even more preferably 1500. When compound [A] is a polymer [A2], the lower limit of the molecular weight of polymer [A2] is more preferably 2000, and even more preferably 2500. The upper limit of the molecular weight of compound [A1] is preferably 8000, and even more preferably 7000. The molecular weight of compound [A1] is a value derived from its structural formula. The molecular weight of polymer [A2] is the weight-average molecular weight determined by gel permeation chromatography using monodisperse polystyrene as a standard.

[0123] The content of compound [A] in the composition for forming the resist underlayer film, excluding the solvent, is preferably 1% by mass or more. The content of compound [A] can 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.

[0124] <[A] Method for manufacturing compound>

[0125] The method for producing compound [A] includes a step of reacting compound [a] with compound [b] and compound [c]. In this method, compound [A] can be produced simply and efficiently through a three-component condensation reaction (Betti reaction) of compound [a] as a phenol, compound [b] as an aldehyde, and compound [c] as an amine.

[0126] ([a] compound)

[0127] [a] The compound is the compound represented by the following formula (a).

[0128] [Chemistry 17]

[0129]

[0130] (In formula (a), Ar 1 (Aromatic rings with 5 to 40 substituted or unsubstituted carbon-carbon double bonds in the inclusion formula)

[0131] As Ar 1 The aromatic rings with 5 to 40 ring elements in the formula (1) are preferably Ar rings. 1 The aromatic ring has 5 to 40 ring elements. Ar is preferably used as the substituent when the compound has substituents. 1 Possible substituents.

[0132] While not limited to specific examples of [a] compounds, examples such as formulas (a-1) to (a-11) can be listed.

[0133] [Chemistry 18]

[0134]

[0135] ([b]compound)

[0136] [b] The compound is the compound represented by the following formula (b).

[0137] [Chemistry 19]

[0138]

[0139] (In formula (b), R) 1 It consists of hydrogen atoms or n atoms with 1 to 40 carbon atoms. 1 Valence organic group; n 1 Integers from 1 to 4; in R 1 In the case of hydrogen atoms, n 1 (1)

[0140] As R 1 The n represents the number of carbon atoms from 1 to 40. 1 The valence organogroup can preferably be removed from a monovalent organogroup having 1 to 40 carbon atoms, as shown in other structures in the [A] compound. 1 A base consisting of -1) hydrogen atoms.

[0141] n 1 Preferably, it is an integer from 1 to 3, more preferably 1 or 2.

[0142] While not limited to specific examples of compounds, examples such as formulas (b-1) to (b-16) can be listed below.

[0143] [Chemistry 20]

[0144]

[0145] ([c] compound)

[0146] [c] The compound is the compound represented by the following formula (c).

[0147] [Chemistry 21]

[0148]

[0149] (In equation (c), R) 2 It consists of hydrogen atoms or n atoms with 1 to 40 carbon atoms. 2 Valence organic group; n 2 Integers from 1 to 4; in R 2 In the case of hydrogen atoms, n 2 (1)

[0150] As R 2 The n represents the number of carbon atoms from 1 to 40. 2 The valence organogroup can preferably be removed from a monovalent organogroup having 1 to 40 carbon atoms, as shown in other structures in the [A] compound. 2 A base consisting of -1) hydrogen atoms.

[0151] n 2 Preferably, it is an integer from 1 to 3, more preferably 1 or 2.

[0152] While not limited to specific examples of [c] compounds, examples such as formulas (c-1) to (c-14) can be listed below.

[0153] [Chemistry 22]

[0154]

[0155] The reaction of compound [a] with compounds [b] and [c] can be carried out according to existing methods, preferably in an inert gas environment such as nitrogen, in a reaction solvent. Typically, a batch reaction can be performed by mixing compound [a] with compounds [b] and [c] and heating. Depending on the reactivity of the reactants, a sequential reaction in which compound [b] reacts with compound [c] and then compound [a] reacts. The molar ratio of the reaction of compound [a] with compounds [b] and [c] can be suitably set considering the number of OH groups in compound [a], the number of CHO groups in compound [b], and the number of NH or NH2 groups in compound [c]. The lower limit of the reaction temperature is preferably 40°C, preferably 50°C. The upper limit of the reaction temperature is preferably 200°C, preferably 160°C, and more preferably 140°C. The temperature at which the solvent is heated to reflux can also be used. The lower limit of the reaction time is preferably 1 hour, preferably 2 hours, and preferably 5 hours. The upper limit of the reaction time is preferably 36 hours, more preferably 24 hours, and even more preferably 20 hours. The reaction temperature and reaction time for each successive reaction can be set within the range of the stated reaction temperature and reaction time for each stage. An acid catalyst may also be added during the reaction. There are no particular limitations on the acid catalyst; existing inorganic and organic acids can be used. After the reaction, compound [A] can be obtained through separation, purification, and drying. The reaction solvent, [B] solvent described later, is preferably used.

[0156] <[B] Solvent>

[0157] [B] There are no particular limitations on the solvent if it can dissolve or disperse the [A] compound and any other components that may be present as needed.

[0158] Examples of solvents that can be classified as [B] include: hydrocarbon solvents, ester solvents, alcohol solvents, ketone solvents, ether solvents, and nitrogen-containing solvents. A single [B] solvent can be used alone, or two or more solvents can be used in combination.

[0159] 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.

[0160] Examples of ester-based solvents include: carbonate solvents such as diethyl carbonate, monoacetic acid ester solvents such as methyl acetate and ethyl acetate, lactone solvents such as γ-butyrolactone, polyol partial ether carboxylic acid ester solvents such as diethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate, and lactate solvents such as methyl lactate and ethyl lactate.

[0161] Examples of alcohol-based solvents include: mono-alcohol solvents such as methanol, ethanol, n-propanol, and 1-butanol, and poly-alcohol solvents such as ethylene glycol and 1,2-propanediol.

[0162] Examples of ketone solvents include: chain ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, and cyclic ketone solvents such as cyclohexanone.

[0163] Examples of ether-based solvents include: chain ether solvents such as n-butyl ether, cyclic ether solvents such as tetrahydrofuran, and polyol ether solvents such as diethylene glycol monomethyl ether.

[0164] Examples of nitrogen-containing solvents include chain-like nitrogen-containing solvents such as N,N-dimethylacetamide and cyclic nitrogen-containing solvents such as N-methylpyrrolidone.

[0165] As the solvent for [B], ester-based solvents or ketone-based solvents are preferred, more preferably polyol partial ether carboxylic acid ester-based solvents or cyclic ketone-based solvents, and even more preferably propylene glycol monomethyl ether acetate or cyclohexanone.

[0166] The lower limit of the content of [B] solvent in the composition for forming the resist underlayer film is preferably 50% by mass, more preferably 60% by mass, and even more preferably 70% by mass. The upper limit of the content is preferably 99.9% by mass, more preferably 99% by mass, and even more preferably 95% by mass.

[0167] [Any ingredients]

[0168] The composition for forming the resist underlayer film may also contain any components without impairing the effects of the present invention. Examples of such components include, for example, acid generators, alkali generators, crosslinking agents, surfactants, and defoamers. Specific examples of alkali generators include: “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) 2110 ... "T (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 891 (Registered Trademark)", "POLYCAT (Registered Trademark) 8", "POLYCAT (Registered Trademark) 9", "POLYCAT (Registered Trademark) 12", "POLYCAT (Registered Trademark) 41" (the above are trade names, manufactured by San-Apro (stock)). As defoamers, existing defoamers can be used, including: alcohol defoamers, phosphate ester defoamers, fatty acid ester defoamers, polyether defoamers, silicone defoamers, etc. Examples of fatty acid ester defoamers 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 can also be used as defoamers. Any component can be used alone or in combination of two or more. The proportion of any component in the resist underlayer film forming composition can be suitably determined according to the type of any component, etc.

[0169] [Preparation method of the composition]

[0170] The composition for forming the resist underlayer film can be prepared by mixing compound [A], solvent [B] and any other components as needed in a specified proportion, preferably by filtering the obtained mixture using a membrane filter with a pore size of 0.5 μm or less.

[0171] [Coating Process]

[0172] In this process, a resist underlayer film forming composition is applied directly or indirectly onto a substrate. In this process, the resist underlayer film forming composition described above is used as the resist underlayer film forming composition.

[0173] The coating method for the composition used to form the resist underlayer film is not particularly limited, and suitable methods such as spin coating, cast coating, and roller coating can be used. A coating film is thus formed, and the resist underlayer film is formed by the volatilization of the [B] solvent.

[0174] Examples of substrates include silicon substrates, aluminum substrates, nickel substrates, chromium substrates, molybdenum substrates, tungsten substrates, copper substrates, tantalum substrates, titanium substrates, and other metal or semi-metal substrates, among which silicon substrates are preferred. The substrate may also be a substrate on which a silicon nitride film, an aluminum oxide film, a silicon dioxide film, a tantalum nitride film, a titanium nitride film, etc., are formed.

[0175] The substrate may have a pattern. Because of its excellent embedding properties, the resist underlayer film forming composition can form a good film while filling the gaps between patterns, even when the substrate has a pattern. Examples of the shape of the pattern 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 or more and 100 nm or less, and patterns containing recesses with a depth of 5 nm or more and 500 nm or less. Examples of hole patterns include patterns containing holes with a diameter of 5 nm or more and 100 nm or less, and patterns containing holes with a depth of 5 nm or more and 500 nm or less. Examples of pillar patterns include patterns containing pillars with a width of 5 nm or more and 100 nm or less, and patterns containing pillars with a height of 5 nm or more and 500 nm or less.

[0176] Examples of compositions for forming a resist underlayer film that are indirectly applied to a substrate include, for example, applying the composition to a low-dielectric insulating film or an organic underlayer film formed on the substrate.

[0177] [Heating Process]

[0178] In this process, the coating film formed by the 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].

[0179] The heating of the coating film can be performed in an atmospheric environment or in a nitrogen environment. The lower limit of the heating temperature is preferably 300°C, more preferably 320°C, and even more preferably 340°C. The upper limit of the heating temperature is preferably 600°C, more preferably 500°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, more preferably 600 seconds.

[0180] Furthermore, the resist underlayer can be exposed after the coating process. Plasma can also be exposed to the resist underlayer after the coating process. Ion implantation can also be performed on the resist underlayer after the coating process. Exposure of the resist underlayer improves its etch resistance. Exposure of the resist underlayer to plasma improves its etch resistance. Ion implantation of the resist underlayer improves its etch resistance.

[0181] The radiation used in the exposure of the resist underlayer film can be 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.

[0182] Methods for exposing the resist underlayer to plasma include, for example, the direct method based on placing the substrate in various gas environments and performing plasma discharge. The conditions for plasma exposure typically include a gas flow rate of 50 cc / min or more and 100 cc / min or less, and a power supply of 100 W or more and 1,500 W or less.

[0183] The lower limit for plasma exposure time is preferably 10 seconds, more preferably 30 seconds, and even more preferably 1 minute. The upper limit for said time is preferably 10 minutes, more preferably 5 minutes, and even more preferably 2 minutes.

[0184] Regarding plasma, plasma can be generated, for example, in an environment containing a mixture of H2 and Ar gases. In addition to H2 and Ar gases, carbon-containing gases such as CF4 or CH4 can also be introduced. Furthermore, at least one of CF4, NF3, CHF3, CO2, CH2F2, CH4, and C4F8 gases can be introduced to replace either or both of H2 and Ar gases.

[0185] Ion implantation into the resist underlayer involves implanting a dopant into the resist underlayer. Dopant can be selected from the group consisting of boron, carbon, nitrogen, phosphorus, arsenic, aluminum, and tungsten. The implantation energy used to apply a 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.

[0186] The lower limit for the average thickness of the formed resist underlayer film is preferably 30 nm, more preferably 50 nm, and even more preferably 100 nm. The upper limit for the average thickness is preferably 3,000 nm, more preferably 2,000 nm, and even more preferably 500 nm. Furthermore, the method for measuring the average thickness is based on the description in the examples.

[0187] [Silicone film formation process]

[0188] In this process, a silicon-containing film is formed directly or indirectly on the resist underlayer film formed by the coating process or the heating process. For example, a surface-modified resist film can be formed on the resist underlayer film indirectly. This surface-modified resist film is, for example, a film with a different contact angle with water than the resist underlayer film.

[0189] Silicon-containing films can be formed by coating with a silicon-containing film forming composition, chemical vapor deposition (CVD), atomic layer deposition (ALD), etc. Examples of methods for forming silicon-containing films by coating with a silicon-containing film forming composition include directly or indirectly coating the silicon-containing film forming composition onto a resist underlayer, and then exposing and / or heating the formed coating film to harden it. Commercially available silicon-containing film forming compositions include, for example, "NFC SOG01," "NFC SOG04," and "NFC SOG080" (all manufactured by JSR Corporation). Silicon oxide films, silicon nitride films, silicon oxynitride films, and amorphous silicon films can be formed by chemical vapor deposition (CVD) or atomic layer deposition (ALD).

[0190] Examples of radiation used in the exposure include: visible light, ultraviolet light, far ultraviolet light, X-rays, gamma rays and other electromagnetic waves, electron beams, molecular beams, ion beams and other particle beams.

[0191] The lower limit of the temperature for heating the coating film is preferably 90°C, more preferably 150°C, and even more preferably 200°C. The upper limit of the temperature is preferably 550°C, more preferably 450°C, and even more preferably 300°C.

[0192] The lower limit for the average thickness of the silicon-containing film is preferably 1 nm, more preferably 10 nm, and even more preferably 20 nm. The upper limit is preferably 20,000 nm, more preferably 1,000 nm, and even more preferably 100 nm. The average thickness of the silicon-containing film is a value obtained by measuring it using the same spectroscopic ellipsometer as the average thickness of the resist underlayer film.

[0193] [Resist Pattern Forming Process]

[0194] In this process, a resist pattern is formed directly or indirectly on the resist underlayer film. Examples of methods for performing this process include: using a resist composition, using nanoimprint lithography, and using a self-organizing composition. Examples of indirectly forming a resist pattern on the resist underlayer film include forming a resist pattern on a silicon-containing film.

[0195] Examples of such resist compositions include: positive or negative chemically amplified resist compositions containing a radiosensitive linear acid generator; positive resist compositions containing an alkali-soluble resin and a quinone diazide-based photosensitive agent; negative resist compositions containing an alkali-soluble resin and a crosslinking agent; and metal-containing resist compositions containing metals such as tin, zirconium, and hafnium.

[0196] Methods for applying the resist composition include, for example, spin coating. The pre-baking temperature and time can be adjusted appropriately depending on the type of resist composition used.

[0197] Next, the formed resist film is exposed to selective radiation. The radiation used in the exposure can be appropriately selected depending on the type of radioactive linear acid generator used in the resist composition, such as visible light, ultraviolet light, far ultraviolet light, X-rays, gamma rays, and other electromagnetic waves, electron beams, molecular beams, ion beams, and other particle beams. Among these, far ultraviolet light is preferred, more preferably KrF excimer laser light (wavelength 248 nm), ArF excimer laser light (wavelength 193 nm), F2 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, etc., hereinafter also referred to as "EUV (extreme ultraviolet)"), and even more preferably KrF excimer laser light, ArF excimer laser light, or EUV.

[0198] After exposure, post-baking can be performed to improve resolution, pattern outline, and developability. The temperature and time of post-baking can be appropriately determined according to the type of resist composition used.

[0199] Next, the exposed resist film is developed using a developing solution to form a resist pattern. The development can be alkaline or organic solvent development. Examples of alkaline developing solutions include ammonia, triethanolamine, tetramethyl ammonium hydroxide (TMAH), and tetraethyl ammonium hydroxide, etc. Appropriate amounts of water-soluble organic solvents such as methanol and ethanol, and surfactants may also be added to these alkaline aqueous solutions. In the case of organic solvent development, examples of organic solvents, such as those exemplified as solvent [B] in the resist underlayer film forming composition described above, are also possible developing solutions.

[0200] After development using the developer, the material is cleaned and dried to form a specified resist pattern.

[0201] [Etching Process]

[0202] In this process, etching is performed using the resist pattern as a mask. The number of etching operations can be single or multiple; that is, etching can be performed sequentially using the pattern obtained through etching as a mask. From the viewpoint of obtaining a better pattern shape, multiple etching operations are preferred. In the case of multiple etching operations, for example, etching is performed sequentially in the order of the silicon film, the resist underlayer, and the substrate. Examples of etching methods include dry etching and wet etching. From the viewpoint of obtaining a better shape for the substrate pattern, dry etching is preferred. In dry etching, gas plasmas such as oxygen plasma can be used. Through this etching, a semiconductor substrate with a predetermined pattern can be obtained.

[0203] For dry etching, existing dry etching equipment can be used, for example. The etching gas used in dry etching can be appropriately selected based on the mask pattern and the elemental composition of the film being etched. Examples include: fluorine-based gases such as CHF3, CF4, C2F6, C3F8, and SF6; chlorine-based gases such as Cl2 and BCl3; oxygen-based gases such as O2, O3, and H2O; reducing gases such as H2, CO, CO2, CH4, C2H2, C2H4, C2H6, C3H4, C3H6, and C3H8; reducing gases such as HF, HI, HBr, HCl, NO, NH3, and BCl3; and inert gases such as He, N2, and Ar. These gases can also be mixed. When etching the substrate using the pattern of the resist underlayer as a mask, fluorine-based gases are typically used.

[0204] Compositions for forming resist underlayer films

[0205] The resist underlayer film forming composition contains compound [A] and solvent [B]. Preferably, the resist underlayer film forming composition used in the semiconductor substrate manufacturing method is employed.

[0206] Methods for manufacturing nitrogen-containing compounds

[0207] The method for manufacturing the nitrogen-containing compound includes a step of reacting compound [a] with compound [b] and compound [c]. Preferably, the method for manufacturing the nitrogen-containing compound is the method for manufacturing compound [A] in the resist underlayer film forming composition used in the semiconductor substrate manufacturing method.

[0208] Example

[0209] The present invention will now be described in detail based on embodiments, but the present invention is not limited to these embodiments.

[0210] [Weight-average molecular weight (Mw), Number-average molecular weight (Mn), Polydispersity index (PDI: Mw / Mn)]

[0211] Mw and Mn of the polymer were determined by gel permeation chromatography (GPC) using Tosoh (stock) columns (two “G2000HXL” and one “G3000HXL”) under analytical conditions of flow rate: 1.0 mL / min, dissolution solvent: tetrahydrofuran, and column temperature: 40 °C, with monodisperse polystyrene as the standard (detector: differential refractometer).

[0212] [Average membrane thickness]

[0213] The average thickness of the film was determined by measuring the film thickness at any nine points at a 5 cm interval, including the center, on the resist underlayer film formed on the silicon wafer (substrate) using a spectroellipsomerometer (JA WOOLLAM's "M2000D"). The average thickness of these film thicknesses was then calculated.

[0214] <[A] Synthesis of Compound>

[0215] In the synthesis of compound [A], compounds (a-1) to (a-7) represented by formulas (a-1) to (a-7) were used as compound [a], compounds (b-1) to (b-16) represented by formulas (b-1) to (b-16) were used as compound [b], and compounds (c-1) to (c-12) represented by formulas (c-1) to (c-12) were used as compound [c].

[0216] [Chemistry 23]

[0217]

[0218] [Chemistry 24]

[0219]

[0220] [Chemistry 25]

[0221]

[0222] <[A] Synthesis of Compound>

[0223] The following procedures were followed to synthesize compounds (A-1) to (A-35) that are represented by the formulas below as compounds [A].

[0224] [Example 1-1] (Synthesis of compound (A-1))

[0225] Under nitrogen atmosphere, 20.0 g of compound (a-1), 14.7 g of compound (b-1), 28.5 g of compound (c-1), and 200 g of tetrahydrofuran were added to a reaction vessel, and the reaction was carried out under reflux for 12 hours. After the reaction was completed, the reaction solution was transferred to a separatory funnel, and 400 g of methyl isobutyl ketone and 400 g of water were added to wash the organic phase. After separating the aqueous phase, the obtained organic phase was washed several times with water, and then concentrated using an evaporator. The residue was added dropwise to 400 g of diisopropyl ether to obtain a precipitate. The precipitate was recovered by suction filtration and washed several times with 100 g of diisopropyl ether. Then, it was dried in a vacuum dryer at 60 °C for 12 hours to obtain compound (A-1). The Mw of (A-1) is 875.

[0226] [Chemistry 26]

[0227]

[0228] [Examples 1-2 to Example 1-14, Example 1-16 to Example 1-22, Example 1-27, Example 1-29, Example 1-31 to Example 1-33] (Synthesis of compounds (A-2) to (A-14), (A-16) to (A-22), (A-27), (A-29), (A-31) to (A-33))

[0229] In addition to using the types and amounts of starting compounds shown in Table 1 below, compounds (A-2) to (A-14), (A-16) to (A-22), (A-27), (A-29), (A-31) to (A-33) were obtained as products under the same reaction conditions as in Synthesis Example A-1. Mw is shown in Table 1.

[0230] [Chemistry 27]

[0231]

[0232] [Chemistry 28]

[0233]

[0234] [Chemistry 29]

[0235]

[0236] [Chemistry 30]

[0237]

[0238] [Chemistry 31]

[0239]

[0240] [Chemistry 32]

[0241]

[0242] [Examples 1-15] (Synthesis of compound (A-15))

[0243] Under nitrogen atmosphere, 11.2 g of compound (b-2), 18.8 g of compound (c-1), 0.87 g of p-toluenesulfonic acid monohydrate, and 200 g of 1-butanol were added to a reaction vessel and reacted at 60°C for 2 hours. Then, 20.0 g of compound (a-3) was added, and the reaction was continued at 100°C for 12 hours. After the reaction was complete, the reaction solution was transferred to a separatory funnel, and 400 g of methyl isobutyl ketone and 400 g of water were added to wash the organic phase. After separating the aqueous phase, the obtained organic phase was washed several times with water. The solution was then concentrated using an evaporator, and the residue was added dropwise to 400 g of diisopropyl ether to obtain a precipitate. The precipitate was recovered by suction filtration and washed several times with 100 g of diisopropyl ether. Finally, the precipitate was dried in a vacuum dryer at 60°C for 12 hours to obtain compound (A-15). The Mw of (A-15) is 1055.

[0244] [Chemistry 33]

[0245]

[0246] [Examples 1-23 to 1-26, Examples 1-28, Examples 1-30, Examples 1-34 to 1-35] (Synthesis of compounds (A-23) to (A-26), (A-28), (A-30), (A-34) to (A-35))

[0247] Except for the types and amounts of starting compounds shown in Table 1 below, compounds (A-23) to (A-26), (A-28), (A-30), (A-34) to (A-35) were obtained as products under the same reaction conditions as in Synthesis Example A-15. Mw is shown in Table 1.

[0248] [Chemistry 34]

[0249]

[0250] [Chemistry 35]

[0251]

[0252] [Table 1]

[0253]

[0254] [Comparative Synthesis Example 1-1] (Synthesis of polymer (x-1))

[0255] Under nitrogen atmosphere, 250.0 g of m-cresol, 125.0 g of 37% formalin, and 2 g of oxalic anhydride were added to a reaction vessel. The reaction was carried out at 100°C for 3 hours and at 180°C for 1 hour. Unreacted monomers were then removed under reduced pressure to obtain polymer (x-1) represented by the following formula (x-1). The Mw of the obtained polymer (x-1) is 11,000.

[0256] [Chemistry 36]

[0257]

[0258] <Preparation of Compositions for Forming Resist Underlayer Film>

[0259] The following shows the [A] compound, comparative compound, [B] solvent, [C] acid generator, [D] crosslinking agent and other components used in the preparation of the composition for forming the resist underlayer film.

[0260] [[A]compound]

[0261] A-1 to A-35: The synthesized compounds (A-1) to (A-35)

[0262] [[B]solvent]

[0263] B-1: Propylene glycol monomethyl ether acetate

[0264] B-2: Cyclohexanone

[0265] [[C] Acid generating agent]

[0266] C-1: The compound represented by the following formula (C-1)

[0267] [Chemistry 37]

[0268]

[0269] [[D] Crosslinking agent]

[0270] D-1: The compound represented by the following formula (D-1)

[0271] [Chemistry 38]

[0272]

[0273] D-2: The compound represented by the following formula (D-2)

[0274] [Chemistry 39]

[0275]

[0276] [Other ingredients]

[0277] x-1: The synthesized polymer (x-1)

[0278] [Example 2-1]

[0279] Three parts by mass of compound (A-1) as [A] were dissolved in 97 parts by mass of solvent (B-1) as [B]. The obtained solution was filtered using a polytetrafluoroethylene (PTFE) membrane filter with a pore size of 0.45 μm to prepare composition (J-1).

[0280] [Examples 2-2 to 2-46 and Comparative Example 2-1]

[0281] Compositions (J-2) to (J-46) and (CJ-1) were prepared in the same manner as in Examples 2-1, except that the ingredients of the types and amounts shown in Table 2 below were not used. “-” in Table 2 indicates that the corresponding ingredients were not used.

[0282] [Table 2]

[0283]

[0284] <Evaluation>

[0285] [Examples 3-1 to 3-46 and Comparative Example 3-1]

[0286] The composition for forming the resist underlayer film prepared herein was used, and its landfill performance and flatness were evaluated by the following methods. The evaluation results are shown in Table 3 below.

[0287] [Landfill]

[0288] Using a spin coater (Tokyo Electron, Ltd.'s "LITHIUS ProZ"), the resist underlayer film forming composition was applied to a substrate with a trench pattern having a depth of 65 nm and widths of 20 nm and 25 nm by spin coating. The spin coater was set to conditions that would allow for the formation of a film-coated substrate with an average film thickness of 100 nm. Next, the substrate was heated at 400°C for 90 seconds in atmospheric conditions 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 (Hitachi High Technologies, Ltd.'s "S-4800") to evaluate its embedding properties. Regarding the embedding performance, if the resist underlayer film is embedded to the bottom of the 20 nm wide spatial pattern of the substrate, it is rated as "A" (good); if it is not embedded to the bottom of the 20 nm wide spatial pattern, but is embedded to the bottom of the 25 nm wide spatial pattern, it is rated as "B" (slightly good); and if it is not embedded to the bottom of the 25 nm wide spatial pattern, it is rated as "C" (poor).

[0289] Flatness

[0290] Using a spin coater (Tokyo Electron Inc.'s "CLEAN TRACK ACT12"), the prepared composition was applied to a surface such as... Figure 1 A silicon substrate 1 with a trench pattern of 150 nm depth and 10 μm width was formed as shown. Next, the substrate was heated at 250°C for 60 seconds in atmospheric environment and then cooled at 23°C for 60 seconds, thereby forming a resist underlayer film 2 with an average thickness of 200 nm in the non-trench pattern portion. Then, the substrate was heated at 350°C for 60 seconds in atmospheric environment and then cooled at 23°C for 60 seconds to obtain a silicon substrate with a resist underlayer film. The cross-sectional shape of the silicon substrate with the resist underlayer film was observed using a scanning electron microscope (Hitachi High Technologies, Inc.'s "S-4800"). The difference (ΔFT) between the height of the central portion b of the trench pattern and the height of the non-trench pattern portion a located 5 μm from the end of the trench pattern was used as an indicator of flatness. Regarding flatness, a rating of "A" (Good) is given when the ΔFT is less than 20 nm, a rating of "B" (Slightly Good) is given when the ΔFT is 20 nm or more but less than 30 nm, and a rating of "C" (Poor) is given when the ΔFT is 30 nm or more. Furthermore, Figure 1The height difference shown is an exaggeration of the actual value.

[0291] [Table 3]

[0292]

[0293] As can be seen from the results in Table 3, the composition of the examples and the resist underlayer film formed by the compositions also have superior filling properties and flatness compared with the comparative examples.

[0294] Industrial availability

[0295] The semiconductor substrate manufacturing method of the present invention enables the formation of a resist underlayer film that exhibits excellent filling properties, effectively filling the substrate pattern, and also excellent flatness after filling. The resist underlayer film forming composition of the present invention enables the formation of a resist underlayer film with both excellent filling and flatness. The nitrogen-containing compound manufacturing method of the present invention efficiently manufactures nitrogen-containing compounds preferred as components of the resist underlayer film forming composition for forming the resist underlayer film. Therefore, these are preferably used in the manufacture of semiconductor devices that are expected to be further miniaturized in the future.

[0296] Explanation of icon numbers

[0297] 1. Silicon substrate

[0298] 2. Resist underlayer film

Claims

1. A method for manufacturing a semiconductor substrate, comprising: The process of directly or indirectly coating a composition for forming a resist underlayer film on a substrate; The process of directly or indirectly forming a resist pattern on the resist underlayer film formed by the coating process; and An etching process is performed using the resist pattern as a mask, and The composition for forming the resist underlayer film contains: Nitrogen compounds, and solvent, The nitrogen-containing compound comprises a portion of the structure represented by the following formula (1). [Chemistry 1] (In formula (1), Ar 1 It is an aromatic ring with 5 to 40 substituted or unsubstituted carbon-carbon double bonds in the inclusion formula; (These are bonds formed with other structures in the nitrogen-containing compound).

2. The method for manufacturing a semiconductor substrate according to claim 1, further comprising: Before the resist pattern is formed, The process of forming a silicon-containing film directly or indirectly relative to the resist underlayer film.

3. A composition for forming a resist underlayer film, comprising: Nitrogen compounds, and solvent, The nitrogen-containing compound comprises a portion of the structure represented by the following formula (1). [Chemistry 2] (In formula (1), Ar 1 It is an aromatic ring with 5 to 40 substituted or unsubstituted carbon-carbon double bonds in the inclusion formula; (These are bonds formed with other structures in the nitrogen-containing compound).

4. The composition for forming a resist underlayer film according to claim 3, wherein, The nitrogen-containing compound comprises at least three groups selected from the group consisting of OH, NH and NH2 groups.

5. The composition for forming a resist underlayer film according to claim 3, wherein, The nitrogen-containing compound has a molecular weight of 600 or higher.

6. The composition for forming a resist underlayer film according to claim 3, wherein, The nitrogen-containing compound is a compound represented by formula (1-1), formula (1-2), or formula (1-3). [Chemistry 3] (In equations (1-1), (1-2), and (1-3), R 11a R 11b R 12a R 12b R 12c R 12d R 13a and R 13b Each can be independently a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms; R 11c and R 13c Each is an independent divalent organogroup having 1 to 40 carbon atoms; Ar 1 This has the same meaning as equation (1); in equations (1-1) and (1-3), multiple Ar... 1 (Same or different from each other).

7. The composition for forming a resist underlayer film according to claim 3, wherein, The nitrogen-containing compound has repeating units represented by the following formula (2-1), formula (2-2) or formula (2-3). [Chemistry 4] (In equations (2-1), (2-2), and (2-3), R 21a R 21b R 22a and R 22b Each can be independently a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms; R 21c and R 22c R 23a and R 23b Each is an independent divalent organogroup having 1 to 40 carbon atoms; Ar 1 This has the same meaning as equation (1); in equations (2-3), multiple Ar 1 (Same or different from each other).

8. The composition for forming a resist underlayer film according to claim 3, wherein, The nitrogen-containing compound accounts for 1% or more of the components other than the solvent in the composition for forming the resist underlayer film.

9. A method for manufacturing a nitrogen-containing compound, comprising: A process for reacting the compound represented by formula (a) with the compound represented by formula (b) and the compound or ammonium salt represented by formula (c). [Chemistry 5] (In formula (a), Ar 1 It is an aromatic ring with 5 to 40 substituted or unsubstituted carbon-carbon double bonds in the inclusion formula; In equation (b), R 1 It consists of hydrogen atoms or n atoms with 1 to 40 carbon atoms. 1 Valence organic group; n 1 Integers from 1 to 4; in R 1 In the case of hydrogen atoms, n 1 =1; In equation (c), R 2 It consists of hydrogen atoms or n atoms with 1 to 40 carbon atoms. 2 Valence organic group; n 2 Integers from 1 to 4; in R 2 In the case of hydrogen atoms, n 2 (1).

10. The method for manufacturing a nitrogen-containing compound according to claim 9, wherein, After reacting the compound represented by formula (b) with the compound represented by formula (c) or an ammonium salt, the compound represented by formula (a) is reacted.

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