Method for manufacturing a semiconductor substrate and composition

Abstract

To provide a method for producing a semiconductor substrate using a resist underlayer film-forming composition, capable of forming a film having excellent etching resistance, heat resistance and bending resistance; and a composition.SOLUTION: A method for producing a semiconductor substrate includes the steps of: coating a substrate with a resist underlayer film-forming composition directly or indirectly; forming a resist pattern directly or indirectly on a resist underlayer film formed by the coating step; and performing etching with the resist pattern as a mask. The resist underlayer film-forming composition comprises a partial structure represented by a following formula (i), a polymer comprising a cross-linkable group, and a solvent. (In the formula (i), Ar1 is an aromatic ring).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to a method for manufacturing a semiconductor substrate and a composition. [Background technology]

[0002] In the manufacturing of semiconductor devices, for example, a multilayer resist process is used in which a resist film, which is laminated on a substrate via a resist underlayer such as an organic underlayer film or a silicon-containing film, is exposed and developed to form a resist pattern. In this process, the resist underlayer film is etched using this resist pattern as a mask, and the substrate is further etched using the resulting resist underlayer film pattern as a mask, thereby forming a desired pattern on the semiconductor substrate (see Japanese Patent Publication No. 2004-177668).

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

[0004] [Patent Document 1] Japanese Patent Publication No. 2004-177668 [Patent Document 2] International Publication No. 2011 / 108365 [Overview of the project] [Problems that the invention aims to solve]

[0005] In multilayer resist processes, the organic underlayer film, which serves as the underlayer film for the resist, is required to have etching resistance, heat resistance, and bending resistance.

[0006] The present invention has been made based on the above circumstances, and an object thereof is to provide a method for manufacturing a semiconductor substrate and a composition using a composition for forming a resist underlayer film capable of forming a film excellent in etching resistance, heat resistance, and bend resistance.

Means for Solving the Problems

[0007] In one embodiment, the present invention includes a step of coating a composition for forming a resist underlayer film directly or indirectly on a substrate, a step of forming a resist pattern directly or indirectly on the resist underlayer film formed by the coating step, and a step of performing etching using the resist pattern as a mask and includes wherein the composition for forming a resist underlayer film contains a polymer having a partial structure represented by the following formula (i) and a crosslinkable group (hereinafter, also referred to as "[A] polymer"), a solvent (hereinafter, also referred to as "[B] solvent") and relates to a method for manufacturing a semiconductor substrate.

Chemical Formula

[0008] In the present specification, "the number of ring members" means the number of atoms constituting the ring. For example, the number of ring members of a biphenyl ring is 12, the number of ring members of a naphthalene ring is 10, and the number of ring members of a fluorene ring is 13.

[0009] In another embodiment, the present invention includes a polymer having a partial structure represented by the following formula (i) and a crosslinkable group, a solvent Relates to a composition containing

Chemical formula

Advantages of the Invention

[0010] According to the method for manufacturing the semiconductor substrate, a resist underlayer film excellent in etching resistance, heat resistance, and bending resistance can be formed, so that a good semiconductor substrate can be obtained. According to the composition, a film excellent in etching resistance, heat resistance, and bending resistance can be formed. Therefore, these can be suitably used for manufacturing semiconductor devices and the like, which are expected to further miniaturize in the future.

Brief Description of the Drawings

[0011] [Figure 1] It is a schematic plan view for explaining a method for evaluating bending resistance.

Embodiments for Carrying Out the Invention

[0012] Hereinafter, the method for manufacturing a semiconductor substrate and the composition according to each embodiment of the present invention will be described in detail.

[0013] 《Method for Manufacturing a Semiconductor Substrate》 The method for manufacturing the semiconductor substrate includes a step of coating a composition for forming a resist underlayer film directly or indirectly on a substrate (hereinafter, also referred to as "coating step"), a step of forming a resist pattern directly or indirectly on the resist underlayer film formed by the above coating step (hereinafter, also referred to as "resist pattern forming step"), and a step of performing etching using the resist pattern as a mask (hereinafter, also referred to as "etching step").

[0014] According to the semiconductor substrate manufacturing method, by using the composition described below as the resist underlayer film formation composition in the coating step, a resist underlayer film with excellent etching resistance, heat resistance, and bending resistance can be formed, making it possible to manufacture a semiconductor substrate with a good pattern shape.

[0015] The method for manufacturing the semiconductor substrate may further include, if necessary, a step of forming a silicon-containing film directly or indirectly on the resist underlayer film (hereinafter also referred to as the "silicon-containing film formation step").

[0016] The following describes the composition and each step used in the manufacturing method of the semiconductor substrate.

[0017] <Composition> The composition for forming a resist underlayer film contains [A] a polymer and [B] a solvent. The composition may contain optional components as long as they do not impair the effects of the present invention.

[0018] The composition, by containing [A] polymer and [B] solvent, can form a film with excellent etching resistance, heat resistance, and bending resistance. Therefore, the composition can be used as a composition for forming films. More specifically, the composition can be suitably used as a composition for forming a resist underlayer film in a multilayer resist process.

[0019] The following describes each component contained in the composition.

[0020] <[A] Polymer> [A] The polymer has a substructure represented by the following formula (i) and a crosslinkable group. [A] The polymer may have two or more substructures represented by the following formula (i) and two or more crosslinkable groups. The composition may contain one or more [A] polymers. [ka] (In formula (i), Ar 1 is a substituted or unsubstituted aromatic ring having 5 to 20 ring members that forms a condensed ring structure together with two adjacent carbon atoms in the above formula (i). R 1 is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. * is a bond with another structure in the above polymer.)

[0021] Ar 1 The aromatic ring having 5 to 20 ring members represented by, for example, an aromatic hydrocarbon ring such as a benzene ring, naphthalene ring, anthracene ring, phenalene ring, phenanthrene ring, pyrene ring, fluorene ring, perylene ring, etc., a furan ring, pyrrole ring, thiophene ring, phosphole ring, pyrazole ring, oxazole ring, isoxazole ring, thiazole ring, pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, triazine ring, etc. of an aromatic heterocyclic ring, or a combination thereof, etc. Among these, the aromatic ring of the above Ar 1 is preferably a benzene ring.

[0022] Ar 1 may have a substituent. Examples of the substituent include a monovalent chain hydrocarbon group having 1 to 10 carbon atoms, a halogen atom such as a fluorine atom, chlorine atom, bromine atom, iodine atom, etc., an alkoxy group such as a methoxy group, ethoxy group, propoxy group, etc., an alkoxycarbonyl group such as a methoxycarbonyl group, ethoxycarbonyl group, etc., an alkoxycarbonyloxy group such as a methoxycarbonyloxy group, ethoxycarbonyloxy group, etc., an acyl group such as a formyl group, acetyl group, propionyl group, butyryl group, etc., a cyano group, a nitro group, etc.

[0023] R 1 Examples of the monovalent organic group having 1 to 20 carbon atoms represented by include, for example, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a group having a divalent heteroatom-containing group between carbon-carbon of this hydrocarbon group, a group in which part or all of the hydrogen atoms of the above hydrocarbon group are substituted with a monovalent heteroatom-containing group, or a combination thereof, etc.

[0024] Examples of monovalent hydrocarbon groups having 1 to 20 carbon atoms include monovalent linear hydrocarbon groups having 1 to 20 carbon atoms, monovalent alicyclic hydrocarbon groups having 4 to 20 carbon atoms, monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms, or combinations thereof.

[0025] In this specification, "hydrocarbon group" includes linear hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups. This "hydrocarbon group" includes saturated hydrocarbon groups and unsaturated hydrocarbon groups. "Linear hydrocarbon group" means a hydrocarbon group that does not contain a ring structure and consists only of a linear structure, and includes both linear hydrocarbon groups and branched hydrocarbon groups. "Alicyclic hydrocarbon group" means a hydrocarbon group that contains only an alicyclic structure as its ring structure and does not contain an aromatic ring structure, and includes both monocyclic alicyclic hydrocarbon groups and polycyclic alicyclic hydrocarbon groups (however, it is not necessary to consist only of an alicyclic structure, and it may contain a linear structure as part of it). "Aromatic hydrocarbon group" means a hydrocarbon group that contains an aromatic ring structure as its ring structure (however, it is not necessary to consist only of an aromatic ring structure, and it may contain an alicyclic structure or a linear structure as part of it).

[0026] Examples of monovalent chain hydrocarbon groups having 1 to 20 carbon atoms include alkyl groups such as methyl, ethyl, n-propyl, i-propyl, n-butyl, sec-butyl, and tert-butyl groups; alkenyl groups such as ethenyl, propenyl, and butenyl groups; and alkynyl groups such as ethynyl, propynyl, and butynyl groups.

[0027] Examples of monovalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms include cycloalkyl groups such as cyclopentyl and cyclohexyl groups; cycloalkenyl groups such as cyclopropenyl, cyclopentenyl, and cyclohexenyl groups; bridged ring saturated hydrocarbon groups such as norbornyl, adamantyl, and tricyclodecyl groups; and bridged ring unsaturated hydrocarbon groups such as norbornyl and tricyclodecenyl groups.

[0028] Examples of monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms include phenyl, tolyl, naphthyl, anthracenyl, and pyrenyl groups.

[0029] Examples of heteroatoms that constitute a divalent or monovalent heteroatom-containing group include oxygen, nitrogen, sulfur, phosphorus, silicon, and halogen atoms. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms.

[0030] Examples of divalent heteroatom-containing groups include -CO-, -CS-, -NH-, -O-, -S-, and combinations thereof.

[0031] Examples of monovalent heteroatom-containing groups include hydroxyl groups, sulfanyl groups, cyano groups, nitro groups, and halogen atoms.

[0032] The crosslinkable group is not particularly limited as long as it is a group that forms a crosslinked structure between molecules through a reaction under heating conditions, active energy ray irradiation conditions, acidic conditions, etc. Preferably, the crosslinkable group is at least one group selected from the group consisting of epoxy groups, glycidyl groups, vinyl groups, allyl groups, groups represented by the following formula (2-1), and groups represented by the following formula (2-2). [ka] (In equations (2-1) and (2-2), R 7 Each of these is independently a divalent organic group or single bond having 1 to 20 carbon atoms. * represents a bond with a carbon or nitrogen atom in the polymer described above.

[0033] In the above equations (2-1) and (2-2), R 7 As a divalent organic group having 1 to 20 carbon atoms represented by the above formula (i), R 1 Examples include groups obtained by removing one hydrogen atom from a monovalent organic group. 7Preferably, the group is a divalent hydrocarbon group having 1 to 10 carbon atoms, such as a methanediyl group, an ethanediyl group, or a phenylene group; a combination of a divalent hydrocarbon group having 1 to 10 carbon atoms and -O-; or a single bond; more preferably, a methanediyl group, a combination of a methanediyl group and -O-; or a single bond.

[0034] The above R 1 It is preferable that the group is represented by formula (2-1) or formula (2-2). In particular, the above R 1 However, the group is represented by the above formula (2-1), and it is more preferable that the group is represented by the following formula (2-1-1). [ka]

[0035] [A] The polymer preferably has repeating units represented by the following formula (1). That is, the polymer preferably has a substructure represented by the above formula (i) as a substructure of the repeating units constituting the polymer. Therefore, the description of the substructure represented by the above formula (i) can be suitably applied to the structure corresponding to the substructure represented by the above formula (i) in the repeating unit represented by the following formula (1). Structures other than the substructure represented by the above formula (i) will be described below. [ka] (In formula (1), Ar 1 and R 1 This is equivalent to equation (i) above. Ar 2 (It is a divalent group having an aromatic ring with 5 to 40 members.)

[0036] In the above formula (1), Ar 2 As for aromatic rings with 5 to 40 members in the above formula (i), Ar 1 Examples include groups in which the number of carbon atoms in an aromatic ring with 5 to 20 members is extended up to 40 (e.g., coronene). 2It is preferable that the aromatic ring is at least one aromatic hydrocarbon ring selected from the group consisting of a benzene ring, naphthalene ring, anthracene ring, phenalene ring, phenanthrene ring, pyrene ring, fluorene ring, perylene ring, and coronene ring. 2 The aromatic ring is more preferably an anthracene ring, a phenanthrene ring, a pyrene ring, or a fluorene ring.

[0037] The above Ar 2 Preferably, it has at least one group selected from the group consisting of the group represented by the following formula (2-1) and the group represented by the following formula (2-2). [ka] (In equations (2-1) and (2-2), R 7 Each of these is independently a divalent organic group or single bond having 1 to 20 carbon atoms. * is the Ar mentioned above. 2 (This is a bond with a carbon atom.)

[0038] Among them, the above Ar 2 However, it is more preferable that the group has a group represented by the above formula (2-1), and that the group is represented by the following formula (2-1-1). [ka]

[0039] The hydrogen atom content relative to the total atoms constituting the polymer is preferably 4.8 wt% or less in terms of bending resistance. The upper limit of the hydrogen atom content is more preferably 4.6 wt%, even more preferably 4.5 wt%, and particularly preferably 4.4 wt%. The lower limit of the hydrogen atom content is preferable as it is small, but may be 2.2 wt%, 2.4 wt%, 2.6 wt%, or 2.8 wt%.

[0040] The carbon atom content relative to the total atoms constituting the polymer is preferably 75.0 wt% or more in terms of etching resistance and heat resistance. The lower limit of the carbon atom content is more preferably 76.0 wt%, even more preferably 78.0 wt%, and particularly preferably 80.0 wt%. The upper limit of the carbon atom content is preferable as it is higher, but it may be 95.0 wt%, 94.0 wt%, 93.0 wt%, or 92.0 wt%.

[0041] Examples of repeating units represented by formula (1) above include those represented by formulas (1-1) to (1-18) below.

[0042] [ka]

[0043] [ka]

[0044] [ka]

[0045] Among these, repeating units represented by the above formulas (1-1) to (1-8) and (1-12) are preferred.

[0046] [A] The polymer may have two or more repeating units represented by formula (1) above. Furthermore, the polymer may have repeating units other than those represented by formula (1) above. Examples of such repeating units include repeating units obtained by removing the crosslinking group from the repeating unit represented by formula (1) above.

[0047] [A] The lower limit of the weight-average molecular weight of the polymer is preferably 500, more preferably 1000, even more preferably 1500, and particularly preferably 2000. The upper limit of the molecular weight is preferably 10000, more preferably 8000, even more preferably 7000, and particularly preferably 6000. The method for measuring the weight-average molecular weight is as described in the examples.

[0048] The lower limit of the content of polymer [A] in the composition is preferably 2% by mass, more preferably 4% by mass, even more preferably 6% by mass, and particularly preferably 8% by mass, based on the total mass of polymer [A] and solvent [B]. The upper limit of the above content is preferably 30% by mass, more preferably 25% by mass, even more preferably 20% by mass, and particularly preferably 15% by mass, based on the total mass of polymer [A] and solvent [B].

[0049] <[A] Method for producing polymer> [A] The polymer typically consists of an isatin derivative as a precursor that gives the substructure represented by formula (i) above, and Ar of formula (1) above. 2 It can be produced by acid addition condensation with an aromatic ring compound as a precursor, followed by a condensation reaction to an aromatic aldehyde corresponding to the group represented by formula (2-1) or (2-2) above and / or a nucleophilic substitution reaction to a halogenated hydrocarbon under alkaline conditions. The acid catalyst is not particularly limited, and known inorganic and organic acids can be used. After the reaction, the polymer [A] can be obtained by separation, purification, drying, etc. The solvent [B] described later can be suitably used as the reaction solvent.

[0050] Furthermore, it is thought that, in addition to the repeating unit represented by formula (1) above, a repeating unit represented by formula (1') below may also be produced as a by-reactant during the above acid addition condensation.

[0051] [ka] (In formula (1´), Ar 1 Ar 2 and R 1This is equivalent to equation (1) above.

[0052] <[B] Solvent> [B] The solvent is not particularly limited as long as it can dissolve or disperse the [A] polymer and any optional components it may contain.

[0053] [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.

[0054] 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.

[0055] 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.

[0056] Examples of alcohol-based solvents include monoalcohol solvents such as methanol, ethanol, and n-propanol, and polyhydric alcohol solvents such as ethylene glycol and 1,2-propylene glycol.

[0057] Examples of ketone solvents include linear ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, and cyclic ketone solvents such as cyclohexanone.

[0058] Examples of ether-based solvents include linear ether solvents such as n-butyl ether, polyhydric alcohol ether solvents such as cyclic ether solvents such as tetrahydrofuran, and polyhydric alcohol partial ether solvents such as diethylene glycol monomethyl ether.

[0059] Examples of nitrogen-containing solvents include linear nitrogen-containing solvents such as N,N-dimethylacetamide and cyclic nitrogen-containing solvents such as N-methylpyrrolidone.

[0060] [B] The solvent is preferably an ester solvent or a ketone solvent, more preferably a polyhydric alcohol partial ether carboxylate solvent or a cyclic ketone solvent, and even more preferably propylene glycol acetate monomethyl ether or cyclohexanone.

[0061] The lower limit of the content of solvent [B] in the 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.

[0062] [Optional ingredients] The 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, and surfactants. Optional components can be used individually or in combination of two or more. The proportion of optional components in the composition can be appropriately determined depending on the type of optional component.

[0063] [Method for preparing the composition] The composition can be prepared by mixing [A] polymer, [B] solvent, and optionally any other components in predetermined proportions, and preferably by filtering the resulting mixture through a membrane filter with a pore size of 0.5 μm or less.

[0064] [Coating Process] In this process, a resist underlayer film formation composition is applied to the substrate either directly or indirectly. In this process, the above-mentioned composition is used as the resist underlayer film formation composition.

[0065] The coating method for the resist underlayer film formation composition is not particularly limited and can be carried out by any suitable method, such as rotary coating, casting coating, or roll coating. A coating film is formed as a result, and the resist underlayer film is formed when the solvent [B] volatilizes.

[0066] 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.

[0067] Examples of indirectly coating a substrate with a resist underlayer film formation composition include coating a silicon-containing film formed on the substrate (described later) with the resist underlayer film formation composition.

[0068] [Heating process] In this step, the coating film formed by the above coating step is heated. Heating the coating film promotes the formation of the resist underlayer film. More specifically, heating the coating film promotes the volatilization of solvent [B], etc.

[0069] 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 200°C, more preferably 250°C, and even more preferably 300°C. The upper limit of the heating temperature is preferably 600°C, and more preferably 500°C. The lower limit of the heating time is preferably 15 seconds, and more preferably 30 seconds. The upper limit of the heating time is preferably 1,200 seconds, and more preferably 600 seconds.

[0070] The lower limit of the average thickness of the resist underlayer film formed is preferably 30 nm, more preferably 50 nm, and even more preferably 100 nm. The upper limit of the average thickness is preferably 3,000 nm, more preferably 2,000 nm, and even more preferably 500 nm. The method for measuring the average thickness is as described in the examples.

[0071] [Silicon-containing film formation process] In this process, a silicon-containing film is formed directly or indirectly on the resist underlayer film formed by the coating process or the heating process described above. An example of indirectly forming a silicon-containing film on the resist underlayer film is when a surface modification film of the resist underlayer film is formed on the resist underlayer film. The surface modification film of the resist underlayer film is, for example, a film whose contact angle with water is different from that of the resist underlayer film.

[0072] Silicon-containing films can be formed by coating with a silicon-containing film-forming composition, chemical vapor deposition (CVD), atomic layer deposition (ALD), etc. A method for forming a silicon-containing film by coating with a silicon-containing film-forming composition includes, for example, directly or indirectly coating the resist underlayer with the silicon-containing film-forming composition, and then curing the resulting coated film by exposure and / or heating. Commercially available silicon-containing film-forming compositions include, for example, "NFC SOG01," "NFC SOG04," and "NFC SOG080" (all from 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).

[0073] Examples of radiation used in the above exposure include electromagnetic waves such as visible light, ultraviolet rays, far ultraviolet rays, X-rays, and gamma rays, as well as particle beams such as electron beams, molecular beams, and ion beams.

[0074] The lower limit of the temperature when heating the coating film is preferably 90°C, more preferably 150°C, and even more preferably 200°C. The upper limit of the above temperature is preferably 550°C, more preferably 450°C, and even more preferably 300°C.

[0075] The lower limit of the average thickness of the silicon-containing film is preferably 1 nm, more preferably 10 nm, and even more preferably 20 nm. The upper limit is preferably 20,000 nm, more preferably 1,000 nm, and even more preferably 100 nm. The average thickness of the silicon-containing film is the value measured using the spectroscopic ellipsometer described above, similar to the average thickness of the resist underlayer film.

[0076] [Resist pattern formation process] In this process, a resist pattern is formed directly or indirectly on the resist underlayer film. Methods for performing this process include, for example, using a resist composition, using a nanoimprint method, or using a self-assembled composition. An example of indirectly forming a resist pattern on the resist underlayer film is forming a resist pattern on the silicon-containing film.

[0077] Examples of the above-mentioned resist compositions include positive or negative type chemically amplified resist compositions containing a radiation-sensitive acid generator, positive type resist compositions containing an alkali-soluble resin and a quinone diazide-based photosensitive agent, and negative type resist compositions containing an alkali-soluble resin and a crosslinking agent.

[0078] Examples of coating methods for the resist composition include rotary coating. The pre-baking temperature and time can be appropriately adjusted depending on the type of resist composition used.

[0079] Next, the resist film formed above is exposed by selective radiation irradiation. The radiation used for exposure can be appropriately selected depending on the type of radiation-sensitive acid generator used in the resist composition, and examples include electromagnetic waves such as visible light, ultraviolet light, far ultraviolet light, X-rays, and gamma rays, and particle beams such as electron beams, molecular beams, and ion beams. Among these, far ultraviolet light is preferred, 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, hereinafter also referred to as "EUV") is more preferred, and KrF excimer laser light, ArF excimer laser light, or EUV is even more preferred.

[0080] After the exposure described above, post-baking can be performed to improve resolution, pattern profile, developability, etc. The temperature and time of this post-baking can be appropriately determined depending on the type of resist composition used, etc.

[0081] Next, the exposed resist film is developed with a developer to form a resist pattern. This development may be alkaline development or organic solvent development. Examples of developers for alkaline development include basic aqueous solutions such as ammonia, triethanolamine, tetramethylammonium hydroxide (TMAH), and tetraethylammonium hydroxide. These basic aqueous solutions may also have appropriate amounts of water-soluble organic solvents such as methanol and ethanol, or surfactants added to them. For organic solvent development, examples of developers include the various organic solvents exemplified as solvent [B] in the above-mentioned composition.

[0082] After development with the above-mentioned developer, the resist pattern is formed by washing and drying.

[0083] [Etching process] In this process, etching is performed using the resist pattern described above as a mask. The etching can be performed once or multiple times, i.e., sequentially using the patterns obtained by etching as masks. From the viewpoint of obtaining a pattern with a better shape, multiple etchings are preferred. When multiple etchings are performed, for example, the silicon-containing film, the resist underlayer film, and the substrate are etched sequentially. Examples of etching methods include dry etching and wet etching. From the viewpoint of obtaining a better shape for the substrate pattern, dry etching is preferred. For this dry etching, gas plasma such as oxygen plasma is used. By performing the above etching, a semiconductor substrate having a predetermined pattern is obtained.

[0084] Dry etching can be performed, for example, using a known dry etching apparatus. The etching gas used for dry etching can be appropriately selected depending on the mask pattern, the elemental composition of the film to be etched, etc. Examples include fluorine-based gases such as CHF3, CF4, C2F6, C3F8, SF6; chlorine-based gases such as Cl2, BCl3; oxygen-based gases such as O2, O3, H2O; reducing gases such as H2, NH3, CO, CO2, CH4, C2H2, C2H4, C2H6, C3H4, C3H6, C3H8, HF, HI, HBr, HCl, NO, NH3, BCl3; and inert gases such as He, N2, Ar. These gases can also be used in mixtures. When etching a substrate using the pattern of the resist underlayer film as a mask, fluorine-based gases are usually used.

[0085] 《Composition》 The composition contains [A] a polymer and [B] a solvent. The composition can preferably be one used in the above-mentioned semiconductor substrate manufacturing method. [Examples]

[0086] The present invention will be described in detail below based on examples, but the present invention is not limited to these examples.

[0087] [Weight average molecular weight (Mw)] The mass (Mw) of the polymer was measured by gel permeation chromatography (detector: differential refractometer) using monodisperse polystyrene as the standard, under the analytical conditions of Tosoh Corporation's GPC columns (two "G2000HXL" columns, one "G3000HXL" column, and one "G4000HXL" column), flow rate: 1.0 mL / min, elution solvent: tetrahydrofuran, column temperature: 40°C.

[0088] [Average thickness of the resist underlayer] The average thickness of the resist underlayer was determined by measuring the film thickness at nine arbitrary points spaced 5 cm apart, including the center of the resist underlayer, using a spectroscopic ellipsometer (JAWOOLLAM's "M2000D"). The average of these film thicknesses was then calculated.

[0089] <[A] Synthesis of polymers> Polymers having repeating units represented by the following formulas (A-1) to (A-14) and (x-1) to (x-2) (hereinafter also referred to as "polymer (A-1)", etc.) were synthesized according to the procedure shown below. In the following formulas, if a number is attached to a repeating unit, it indicates the content percentage (mol%) of that repeating unit.

[0090] [Synthesis Example 1] (Synthesis of polymer (a-1)) In a reaction vessel, 20.0 g of fluorene, 17.7 g of isatin, and 130.0 g of 1,2-dichloroethane were charged under a nitrogen atmosphere and dissolved at room temperature. A solution of 17.3 g of methanesulfonic acid in 20.0 g of 1,2-dichloroethane was added to the reaction solution, and the mixture was heated to 80°C and reacted for 8 hours. After the reaction was complete, the mixture was cooled to room temperature, and the solution was added dropwise to 500 g of methanol to obtain a precipitate. The precipitate was collected by suction filtration and washed several times with 100 g of methanol. Subsequently, the polymer (a-1), represented by the following formula (a-1), was obtained by drying in a vacuum dryer at 60°C for 12 hours. The Mw of polymer (a-1) was 2,800.

[0091] [ka]

[0092] [Synthesis Example 2] (Synthesis of polymer (A-1)) In a reaction vessel, under a nitrogen atmosphere, 3.0 g of polymer (a-1), 28.6 g of tetrahydrofuran, 1.6 g of m-ethynylbenzaldehyde, and 0.9 g of tetrabutylammonium bromide were added and stirred for several minutes. Then, 5.6 g of tetramethylammonium hydroxide (25% aqueous solution) was slowly added dropwise at room temperature. After the addition was complete, the reaction was allowed to continue at room temperature for another 6 hours. After the reaction was complete, the reaction solution was transferred to a separatory funnel, and the organic phase was washed several times with 200 g of methyl isobutyl ketone and 200 g of 5% aqueous oxalic acid solution. After separating the aqueous phase, the obtained organic phase was concentrated using an evaporator, and the residue was added dropwise to 100 g of methanol to obtain a precipitate. The precipitate was collected by suction filtration and washed several times with 100 g of methanol. Subsequently, polymer (A-1), represented by the following formula (A-1), was obtained by drying at 60°C for 12 hours using a vacuum dryer. The Mw of polymer (A-1) was 3,200.

[0093] [ka]

[0094] [Synthesis Example 3] (Synthesis of polymer (a-2)) Polymer (a-2), represented by the following formula (a-2), was obtained in the same manner as in Synthesis Example 1, except that 17.7 g of isatin was replaced with 26.8 g of 1-phenylisatin. The Mw of polymer (a-2) was 2,400.

[0095] [ka]

[0096] [Synthesis Example 4] (Synthesis of Polymer (A-2)) Polymer (A-2), represented by the following formula (A-2), was obtained in the same manner as in Synthesis Example 2, except that 3.0 g of polymer (a-1) was replaced with 3.0 g of polymer (a-2). The Mw of polymer (A-2) was 2,800.

[0097] [ka]

[0098] [Synthesis Example 5] (Synthesis of polymer (A-3)) In a reaction vessel, under a nitrogen atmosphere, 3.0 g of polymer (a-1), 38.1 g of tetrahydrofuran, 2.8 g of 1-pyrenecarboxaldehyde, and 0.9 g of tetrabutylammonium bromide were added and stirred for several minutes. Then, 5.6 g of tetramethylammonium hydroxide (25% aqueous solution) was slowly added dropwise at room temperature. After the addition was complete, the reaction was continued at room temperature for a further 3 hours. Subsequently, 1.4 g of propargyl bromide was added, and the temperature was raised to 60°C, where the reaction was continued for a further 6 hours. After the reaction was complete, the reaction solution was transferred to a separatory funnel, and the organic phase was washed several times with 200 g of cyclohexanone and 200 g of 5% aqueous oxalic acid solution. After separating the aqueous phase, the obtained organic phase was concentrated in an evaporator, and the residue was added dropwise to 100 g of methanol to obtain a precipitate. The precipitate was collected by suction filtration and washed several times with 100 g of methanol. Then, polymer (A-3), represented by the following formula (A-3), was obtained by drying at 60°C for 12 hours using a vacuum dryer. The Mw of polymer (A-3) was 3,600.

[0099] [ka]

[0100] [Synthesis Example 6] (Synthesis of Polymer (A-4)) Polymer (A-4), represented by the following formula (A-4), was obtained in the same manner as in Synthesis Example 5, except that 2.8 g of 1-pyrenecarboxaldehyde was replaced with 2.5 g of 9-phenanthrenecarboxaldehyde. The Mw of polymer (A-4) was 3,700.

[0101] [ka]

[0102] [Synthesis Example 7] (Synthesis of polymer (a-3)) Polymer (a-3), represented by the following formula (a-3), was obtained in the same manner as in Synthesis Example 1, except that 20.0 g of fluorene was replaced with 24.4 g of pyrene. The Mw of polymer (a-3) was 2,500.

[0103] [ka]

[0104] [Synthesis Example 8] (Synthesis of polymer (a-4)) Polymer (a-4), represented by the following formula (a-4), was obtained in the same manner as in Synthesis Example 1, except that 20.0 g of fluorene was replaced with 21.4 g of phenanthrene. The Mw of polymer (a-4) was 2,800.

[0105] [ka]

[0106] [Synthesis Example 9] (Synthesis of polymer (a-5)) Polymer (a-5), represented by the following formula (a-5), was obtained in the same manner as in Synthesis Example 1, except that 20.0 g of fluorene was replaced with 21.4 g of anthracene. The Mw of polymer (a-5) was 2,400.

[0107] [ka]

[0108] [Synthesis Example 10] (Synthesis of Polymer (A-5)) In a reaction vessel, under a nitrogen atmosphere, 3.0 g of polymer (a-3), 38.1 g of tetrahydrofuran, 1.4 g of propargyl bromide, and 0.9 g of tetrabutylammonium bromide were added and stirred for several minutes. Then, 5.6 g of tetramethylammonium hydroxide (25% aqueous solution) was slowly added dropwise at room temperature. After the addition was complete, the temperature was raised to 60°C and the reaction was continued for another 6 hours. After the reaction was complete, the reaction solution was transferred to a separatory funnel, and the organic phase was washed several times with 200 g of methyl isobutyl ketone and 200 g of 5% aqueous oxalic acid solution. After separating the aqueous phase, the obtained organic phase was concentrated using an evaporator, and the residue was added dropwise to 100 g of methanol to obtain a precipitate. The precipitate was collected by suction filtration and washed several times with 100 g of methanol. Subsequently, polymer (A-5), represented by the following formula (A-5), was obtained by drying at 60°C for 12 hours using a vacuum dryer. The Mw of polymer (A-5) was 2,700.

[0109] [Synthesis Example 11] (Synthesis of polymer (A-6)) Polymer (A-6), represented by the following formula (A-6), was obtained in the same manner as in Synthesis Example 10, except that 3.0 g of polymer (a-3) was replaced with 3.0 g of polymer (a-4). The Mw of polymer (A-6) was 2,900.

[0110] [Synthesis Example 12] (Synthesis of polymer (A-7)) Similarly, polymer (A-7), represented by the following formula (A-7), was obtained in the same manner as in Synthesis Example 10, except that 3.0 g of polymer (a-3) was replaced with 3.0 g of polymer (a-5). The Mw of polymer (A-7) was 2,600.

[0111] [ka]

[0112] [Synthesis Example 13] (Synthesis of polymer (A-8)) In a reaction vessel, under a nitrogen atmosphere, 3.0 g of polymer (a-1), 40.0 g of tetrahydrofuran, 4.2 g of propargyl bromide, and 0.9 g of tetrabutylammonium bromide were added and stirred for several minutes. Then, 2.9 g of 50% NaOH aqueous solution was slowly added dropwise at room temperature. After the addition was complete, the temperature was raised to 60°C and the reaction was continued for another 6 hours. After the reaction was complete, the reaction solution was transferred to a separatory funnel, and the organic phase was washed several times with 200 g of methyl isobutyl ketone and 200 g of 5% oxalic acid aqueous solution. After separating the aqueous phase, the obtained organic phase was concentrated using an evaporator, and the residue was added dropwise to 100 g of methanol to obtain a precipitate. The precipitate was collected by suction filtration and washed several times with 100 g of methanol. Subsequently, polymer (A-8), represented by the following formula (A-8), was obtained by drying at 60°C for 12 hours using a vacuum dryer. The Mw of polymer (A-8) was 3,000.

[0113] [Synthesis Example 14] (Synthesis of Polymer (A-9)) Polymer (A-9), represented by the following formula (A-9), was obtained in the same manner as in Synthesis Example 13, except that 3.0 g of polymer (a-1) was replaced with 3.5 g of polymer (a-2). The Mw of polymer (A-9) was 2,950.

[0114] [ka]

[0115] [Synthesis Example 15] (Synthesis of polymer (A-10)) Polymer (A-10), represented by the following formula (A-10), was obtained in the same manner as in Synthesis Example 10, except that 1.4 g of propargyl bromide was replaced with 1.5 g of bromoacetonitrile. The Mw of polymer (A-10) was 2,700.

[0116] [ka]

[0117] [Synthesis Example 16] (Synthesis of Polymer (A-11)) Polymer (A-11), represented by the following formula (A-11), was obtained in the same manner as in Synthesis Example 13, except that 4.2 g of propargyl bromide was replaced with 4.3 g of bromoacetonitrile. The Mw of polymer (A-11) was 2,950.

[0118] [ka]

[0119] [Synthesis Example 17] (Synthesis of polymer (A-12)) Polymer (A-12), represented by the following formula (A-12), was obtained in the same manner as in Synthesis Example 13, except that 3.0 g of polymer (a-1) was replaced with 3.5 g of polymer (a-2) and 4.2 g of propargyl bromide was replaced with 4.3 g of bromoacetonitrile. The Mw of polymer (A-12) was 2,950.

[0120] [ka]

[0121] [Synthesis Example 18] (Synthesis of polymer (a-6)) Polymer (a-6), represented by the following formula (a-6), was obtained in the same manner as in Synthesis Example 1, except that 20.0 g of fluorene was replaced with a mixture of 10.0 g of fluorene and 12.2 g of pyrene, and 17.7 g of isatin was replaced with 26.8 g of 1-phenylisatin. The Mw of polymer (a-6) was 3,100.

[0122] [ka]

[0123] [Synthesis Example 19] (Synthesis of polymer (A-13)) Polymer (A-13), represented by the following formula (A-13), was obtained in the same manner as in Synthesis Example 2, except that 3.0 g of polymer (a-1) was replaced with 3.0 g of polymer (a-6). The Mw of polymer (A-13) was 3,500.

[0124] [ka]

[0125] [Synthesis Example 20] (Synthesis of polymer (a-7)) Polymer (a-7), represented by the following formula (a-7), was obtained in the same manner as in Synthesis Example 1, except that 20.0 g of fluorene was replaced with a mixture of 10.0 g of fluorene and 12.2 g of pyrene. The Mw of polymer (a-7) was 3,300.

[0126] [ka]

[0127] [Synthesis Example 21] (Synthesis of polymer (A-14)) Polymer (A-14), represented by the following formula (A-14), was obtained in the same manner as in Synthesis Example 13, except that 3.0 g of polymer (a-1) was replaced with 3.0 g of polymer (a-7). The Mw of polymer (A-14) was 3,500.

[0128] [ka]

[0129] [Comparative Synthesis Example 1] (Synthesis of polymer (x-1)) In a reaction vessel, under a nitrogen atmosphere, 250.0 g of m-cresol, 125.0 g of 37% by mass formalin, and 2 g of oxalic anhydride were added. The mixture was reacted at 100°C for 3 hours and then at 180°C for 1 hour. After that, unreacted monomers were removed under reduced pressure to obtain polymer (x-1) represented by the following formula (x-1). The Mw of the obtained polymer (x-1) was 11,000.

[0130] [ka]

[0131] [Comparative Synthesis Example 2] (Synthesis of polymer (x-2)) 8.0 g of 9,9-bis(4-hydroxyphenyl)fluorene, 0.8 g of paraformaldehyde, and 21.5 g of methyl isobutyl ketone were added to a reaction vessel and heated to 80°C under a nitrogen atmosphere to dissolve the compounds. A solution of 0.8 g of p-toluenesulfonic acid monohydrate in methyl isobutyl ketone (5.0 g) was added to the reaction vessel and the mixture was heated to 115°C and reacted for 15 hours. After the reaction was complete, the reaction solution was transferred to a separatory funnel and the organic phase was washed with 100 g of methyl isobutyl ketone and 200 g of water. After separating the aqueous phase, the obtained organic phase was concentrated in an evaporator, and the residue was added dropwise to 300 g of methanol to obtain a precipitate. The precipitate was collected by suction filtration and washed several times with 100 g of methanol. Subsequently, the polymer (x-2), represented by the following formula (x-2), was obtained by drying at 60°C for 12 hours using a vacuum dryer. The Mw of the obtained polymer (x-2) was 8,000.

[0132] [ka]

[0133] <Preparation of composition> The polymer, solvent, acid generator, and crosslinking agent used in the preparation of the composition are described below.

[0134] [[A] Polymerization] Examples: Compounds synthesized above (A-1) to (A-14) Comparative example: The polymers (x-1) to (x-2) synthesized above.

[0135] [[B] solvent] B-1: Propylene glycol monomethyl ether acetate B-2: Cyclohexanone

[0136] [[C] Acid Generator] C-1: Bis(4-t-butylphenyl)iodonium nonafluoro-n-butanesulfonate (compound represented by the following formula (C-1))

[0137] [ka]

[0138] [[D] Crosslinking agent] D-1: Compound represented by the following formula (D-1)

[0139] [ka]

[0140] D-2: Compound represented by the following formula (D-2)

[0141] [ka]

[0142] [Example 1-1] [A] 10 parts by mass of (A-1) as a polymer was dissolved in [B] 90 parts by mass of (B-1) as a solvent. The resulting solution was filtered through a polytetrafluoroethylene (PTFE) membrane filter with a pore size of 0.45 μm to prepare composition (J-1).

[0143] [Examples 1-2 to 1-19 and Comparative Examples 1-1 to 1-2] Compositions (J-2) to (J-19) and (CJ-1) to (CJ-2) were prepared in the same manner as in Example 1, except that the components used were of the types and in quantities shown in Table 1 below. In Table 1, "-" in the columns "[A] Polymer", "[C] Acid Generator", and "[D] Crosslinking Agent" indicates that the corresponding component was not used.

[0144] [Table 1]

[0145] <Rating> The compositions obtained above were evaluated for etching resistance, heat resistance, bending resistance, and the hydrogen and carbon atom content in the coating film of the compositions using the following methods. The evaluation results are shown in Table 2 below.

[0146] [Etching 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 350°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 processed using an etching apparatus (TACTRAS from Tokyo Electron Ltd.) under the following conditions: CF4 / Ar=110 / 440 sccm, PRESS.=30 MT, HF RF (high-frequency power for plasma generation)=500 W, LF RF (high-frequency power for bias)=3000 W, DCS=-150 V, RDC (gas center flow rate ratio)=50%, and 30 seconds. The etching rate (nm / min) was calculated from the average thickness of the film before and after processing. Next, the etching rate of Comparative Example 1 was used as the baseline, and the ratio to Comparative Example 1 was calculated. This ratio was used as a measure of etching resistance. Etching resistance was evaluated as follows: if the above ratio was 0.90 or less, it was "A" (excellent); if it was greater than 0.90 but less than 0.92, it was "B" (good); and if it was 0.92 or more, it was "C" (poor). In Table 2, "-" indicates that it is an evaluation criterion for etching resistance.

[0147] [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. 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. M L ={(m1-m2) / m1}×100 Here, 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). 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%, and "C" (poor) if it was 10% or more.

[0148] [Bending resistance] The above-prepared composition was coated onto a silicon substrate on which a silicon dioxide film with an average thickness of 500 nm had been formed, using a spin coater (CLEAN TRACK ACT12 from Tokyo Electron Ltd.) by rotary coating. Next, the substrate was heated at 350°C for 60 seconds in an air atmosphere, and then cooled at 23°C for 60 seconds to obtain a film-coated substrate with a resist underlayer film with an average thickness of 200 nm. On the above-prepared film-coated substrate, a silicon-containing film-forming composition (NFC SOG080 from JSR Corporation) was coated using a rotary coating method, and then heated at 200°C for 60 seconds in an air atmosphere, and further heated at 300°C for 60 seconds to form a silicon-containing film with an average thickness of 50 nm. An ArF resist composition (AR1682J from JSR Corporation) was coated onto the silicon-containing film using a rotary coating method, and the film was heated (fired) at 130°C for 60 seconds in an air atmosphere to form a resist film with an average thickness of 200 nm. The resist film was exposed using an ArF excimer laser exposure apparatus (lens numerical aperture 0.78, exposure wavelength 193 nm) through a 1:1 line-and-space mask pattern with a target size of 100 nm, with varying exposure levels. After exposure, the film was heated (fired) at 130°C for 60 seconds in an air atmosphere, developed at 25°C for 1 minute using a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (TMAH), washed with water, and dried to obtain a substrate on which a line-and-space resist pattern with a 200 nm pitch and line widths ranging from 30 nm to 100 nm was formed.

[0149] Using the above resist pattern as a mask, the silicon-containing film was etched using the above etching apparatus under the conditions CF4 = 200 sccm, PRESS. = 85 mT, HF RF (high-frequency power for plasma generation) = 500 W, LF RF (high-frequency power for bias) = ​​0 W, DCS = -150 V, and RDC (gas center flow rate ratio) = 50% to obtain a substrate with a pattern formed on the silicon-containing film. Next, using the above silicon-containing film pattern as a mask, the resist underlayer film was etched using the above etching apparatus under the conditions O2 = 400 sccm, PRESS. = 25 mT, HF RF (high-frequency power for plasma generation) = 400 W, LF RF (high-frequency power for bias) = ​​0 W, DCS = 0 V, and RDC (gas center flow rate ratio) = 50% to obtain a substrate with a pattern formed on the resist underlayer film. Using the above resist underlayer pattern as a mask, the silicon dioxide film was etched using the above etching apparatus under the following conditions: CF4 = 180 sccm, Ar = 360 sccm, PRESS. = 150 mT, HF RF (high-frequency power for plasma generation) = 1,000 W, LF RF (high-frequency power for bias) = ​​1,000 W, DCS = -150 V, RDC (gas center flow rate ratio) = 50%, and for 60 seconds, to obtain a substrate on which a pattern was formed on the silicon dioxide film.

[0150] Subsequently, for the substrate on which the silicon dioxide film pattern was formed, images of the shape of the resist underlayer film pattern for each line width were obtained by magnifying 250,000 times using a scanning electron microscope (Hitachi High-Technologies Corporation's "CG-4000"). By processing these images, as shown in Figure 1, the LER (line edge roughness) was defined as the 3-sigma value obtained by tripling the standard deviation calculated from the position Xn (n=1~10) in the line width direction, measured at 100 nm intervals on the lateral side surface 3a of the 1,000 nm long resist underlayer film pattern 3 (line pattern), and the average position Xa of these line width directions. The LER, which indicates the degree of curvature of the resist underlayer film pattern, increases as the line width of the resist underlayer film pattern becomes narrower. Bending resistance was evaluated as follows: "A" (good) if the line width of the film pattern with a LER of 5.5 nm was less than 40.0 nm; "B" (fairly good) if it was between 40.0 nm and 45.0 nm; and "C" (poor) if it was 45.0 nm or more. Note that the degree of bending of the film pattern shown in Figure 1 is exaggerated compared to the actual degree.

[0151] [Table 2]

[0152] As can be seen from the results in Table 2, the resist underlayer film formed from the composition of the example showed superior etching resistance, heat resistance, and bending resistance compared to the resist underlayer film formed from the composition of the comparative example. [Industrial applicability]

[0153] The semiconductor substrate manufacturing method of the present invention makes it possible to obtain a substrate with good patterning. The composition of the present invention can form a resist underlayer film with excellent etching resistance, heat resistance, and bending resistance. Therefore, these can be suitably used in the manufacture of semiconductor devices, for which further miniaturization is expected in the future. [Explanation of Symbols]

[0154] 3. Resist Underlayer Pattern 3a Lateral view of the resist underlayer pattern

Claims

1. A step of coating a resist underlayer film formation composition directly or indirectly onto a substrate, A step of forming a resist pattern directly or indirectly on the resist underlayer film formed by the above coating step, A process of etching using the above resist pattern as a mask. Includes, The above resist underlayer film forming composition, A polymer having a crosslinking group, solvent and It contains, The above polymer has repeating units represented by the following formula (1), A method for manufacturing a semiconductor substrate, wherein the above crosslinkable group is at least one group selected from the group consisting of epoxy groups, glycidyl groups, vinyl groups, allyl groups, groups represented by the following formula (2-1), and groups represented by the following formula (2-2). 【Chemistry 1】 (In formula (1), Ar １ R is a substituted or unsubstituted aromatic ring with 5 to 20 members that forms a fused ring structure together with the two adjacent carbon atoms in formula (1) above. １ Ar is a monovalent organic group having 1 to 20 carbon atoms. ２ (It is a divalent group having an aromatic ring with 5 to 40 members.) 【Chemistry 2】 (In formulas (2-1) and (2-2), R7 is independently a divalent organic group having 1 to 20 carbon atoms or a single bond. * indicates a bond with a carbon or nitrogen atom in the polymer.)

2. The above R １ The method for manufacturing a semiconductor substrate according to claim 1, wherein is a group represented by formula (2-1) or a group represented by formula (2-2) above.

3. The above Ar ２ The method for manufacturing a semiconductor substrate according to claim 1, wherein the substrate has at least one group selected from the group consisting of a group represented by the following formula (2-1) and a group represented by the following formula (2-2). 【Transformation 3】 (In equations (2-1) and (2-2), R ７ Each of these is independently a divalent organic group or single bond having 1 to 20 carbon atoms. * is the above Ar ２ (This is a bond with a carbon atom.)

4. Before forming the above resist pattern, A step of forming a silicon-containing film directly or indirectly on the resist underlayer film described above. A method for manufacturing a semiconductor substrate according to any one of claims 1 to 3, further comprising:

5. A step of coating a resist underlayer film formation composition directly or indirectly onto a substrate, A step of forming a resist pattern directly or indirectly on the resist underlayer film formed by the above coating step, A process of etching using the above resist pattern as a mask. The above-mentioned resist underlayer film formation composition used in a semiconductor substrate manufacturing method, A polymer having a crosslinking group, solvent and It contains, The above polymer has repeating units represented by the following formula (1), The above crosslinkable group is at least one group selected from the group consisting of epoxy groups, glycidyl groups, vinyl groups, allyl groups, groups represented by the following formula (2-1), and groups represented by the following formula (2-2), in a composition for forming a resist underlayer film. 【Chemistry 4】 (In formula (1), Ar １ is a substituted or unsubstituted aromatic ring having 5 to 20 ring members that forms a condensed ring structure together with two adjacent carbon atoms in the above formula (1). R １ is a monovalent organic group having 1 to 20 carbon atoms. Ar ２ is a divalent group having an aromatic ring with 5 to 40 ring members.) 【Transformation 5】 (In formulas (2-1) and (2-2), R7 is independently a divalent organic group having 1 to 20 carbon atoms or a single bond. * indicates a bond with a carbon or nitrogen atom in the polymer.)

6. The above R １ The resist underlayer film forming composition according to claim 5, wherein is a group represented by formula (2-1) or a group represented by formula (2-2).

7. The above R １ The resist underlayer film forming composition according to claim 6, wherein the group is represented by the above formula (2-1), and the group is represented by the following formula (2-1-1). 【Transformation 6】

8. The above Ar ２ The resist underlayer film forming composition according to claim 5, wherein the composition has at least one group selected from the group consisting of a group represented by the following formula (2-1) and a group represented by the following formula (2-2). 【Transformation 7】 (In equations (2-1) and (2-2), R ７ Each of these is independently a divalent organic group or single bond having 1 to 20 carbon atoms. * is the above Ar ２ (This is a bond with a carbon atom.)

9. The above Ar ２ The resist underlayer film forming composition according to claim 8, wherein the composition has a group represented by the above formula (2-1), and the group is represented by the following formula (2-1-1). 【Transformation 8】

10. The above Ar １ A resist underlayer film forming composition according to any one of claims 5 to 9, wherein the aromatic ring is a benzene ring.

11. The above Ar ２ The resist underlayer film forming composition according to claim 5, 8, or 9, wherein the aromatic ring is at least one aromatic hydrocarbon ring selected from the group consisting of a benzene ring, a naphthalene ring, anthracene ring, a phenalene ring, a phenanthrene ring, a pyrene ring, a fluorene ring, a perylene ring, and a coronene ring.

12. A resist underlayer film forming composition according to any one of claims 5 to 11, wherein the content ratio of hydrogen atoms to the total atoms constituting the polymer is 4.8 wt% or less.

13. A resist underlayer film forming composition according to any one of claims 5 to 12, wherein the content ratio of carbon atoms to the total atoms constituting the polymer is 75.0 wt% or more.

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