Method for manufacturing a semiconductor substrate and composition

Abstract

The purpose of the present invention is to provide a method for producing a semiconductor substrate using a composition from which a film having excellent etching resistance, heat resistance, and bending resistance can be formed, and a composition. This method for manufacturing a semiconductor substrate comprises: a step for applying a resist underlayer film-forming composition directly or indirectly to a substrate; a step for forming resist patterns directly or indirectly on the resist underlayer film formed in the application step; and a step for performing etching using the resist patterns as masks, the resist underlayer film-forming composition containing a solvent and a polymer having a repeating unit represented by formula (1). (In formula (1), Ar1 is a divalent group having a 5- to 40-membered aromatic ring. R0 is a monovalent group having a 5- to 40-membered aromatic ring and has at least one group selected from the group consisting of groups represented by formula (2-1) and groups represented by formula (2-2).) (In formulas (2-1) and (2-2), R7 each independently are a C1-20 divalent organic group or a single bond. * is a bond with a carbon atom in an aromatic ring.)

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a semiconductor substrate, a composition, a polymer, and a method for manufacturing a polymer.

Background Art

[0002] In the manufacture of semiconductor devices, for example, a multilayer resist process is used in which a resist film laminated via a resist underlayer film such as an organic underlayer film or a silicon-containing film on a substrate 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 semiconductor substrate is further etched using the obtained resist underlayer film pattern as a mask, whereby a desired pattern can be formed on the semiconductor substrate (see Japanese Patent Application Laid-Open No. 2004-177668).

[0003] Regarding materials used for such a composition for forming a resist underlayer film, various studies have been conducted (see International Publication No. 2011 / 108365).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

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

[0006] The present invention has been made based on the circumstances described above, and its objective is to provide a method for manufacturing a semiconductor substrate and a composition that uses a composition capable of forming a film with excellent etching resistance, heat resistance, and bending resistance. [Means for solving the problem]

[0007] In one embodiment, the present invention is 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 repeating units represented by the following formula (1) (hereinafter also referred to as "[A] polymer"), The solvent (hereinafter also referred to as "[B] solvent") and This invention relates to a method for manufacturing a semiconductor substrate containing [a specific substance]. [ka] (In formula (1), Ar 1 It is a divalent group having an aromatic ring with 5 to 40 members. 0 This is a monovalent group having an aromatic ring with 5 to 40 members, and having at least one group selected from the group consisting of the group represented by formula (2-1) and the group represented by formula (2-2) below. [ka] (In equations (2-1) and (2-2), R 7 Each of these is independently a divalent organic group or single bond with 1 to 20 carbon atoms. * represents a bond with a carbon atom in an aromatic ring.

[0008] In this specification, "ring member number" refers to the number of atoms that make up a ring. For example, the ring member number of a biphenyl ring is 12, the ring member number of a naphthalene ring is 10, and the ring member number of a fluorene ring is 13.

[0009] In other embodiments, the present invention A polymer having repeating units represented by the following formula (1), solvent and This relates to a composition containing [a certain substance]. [ka] (In formula (1), Ar 1 It is a divalent group having an aromatic ring with 5 to 40 members. 0 This is a monovalent group having an aromatic ring with 5 to 40 members, and having at least one group selected from the group consisting of the group represented by formula (2-1) and the group represented by formula (2-2) below. [ka] (In equations (2-1) and (2-2), R 7 Each of these is independently a divalent organic group or single bond with 1 to 20 carbon atoms. * represents a bond with a carbon atom in an aromatic ring. [Effects of the Invention]

[0010] According to the semiconductor substrate manufacturing method, a resist underlayer film with excellent etching resistance, heat resistance, and bending resistance can be formed, making it possible to obtain a semiconductor substrate with a good pattern shape. The composition allows for the formation of a film with excellent etching resistance, heat resistance, and bending resistance. Therefore, these can be suitably used in the manufacture of semiconductor devices, where further miniaturization is expected in the future. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic plan view illustrating the method for evaluating bending resistance. [Modes for carrying out the invention]

[0012] The following describes in detail the methods and compositions for manufacturing semiconductor substrates according to each embodiment of the present invention. Preferred combinations of embodiments are also preferred.

[0013] Method for manufacturing semiconductor substrates The method for manufacturing the semiconductor substrate comprises the steps of: coating the substrate directly or indirectly with a resist underlayer film formation composition (hereinafter also referred to as the "coating step"); forming a resist pattern directly or indirectly on the resist underlayer film formed by the coating step (hereinafter also referred to as the "resist pattern formation step"); and performing etching using the resist pattern as a mask (hereinafter also referred to as the "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] By containing [A] polymer and [B] solvent, the composition can form a film excellent in etching resistance, heat resistance, and bend resistance. Therefore, the composition can be used as a composition for forming a film. More specifically, the composition can be preferably used as a composition for forming a resist underlayer film in a multilayer resist process.

[0019] Hereinafter, each component contained in the composition will be described.

[0020] <[A] polymer> [A] polymer has a repeating unit represented by the following formula (1). [A] polymer may have two or more repeating units represented by the following formula (1). The composition can contain one or more [A] polymers. [Chemical formula] (In formula (1), Ar 1 is a divalent group having an aromatic ring with 5 to 40 ring members. R 0 is a monovalent group having an aromatic ring with 5 to 40 ring members, and 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).) [Chemical formula] (In formulas (2-1) and (2-2), R 7 are each independently a divalent organic group having 1 to 20 carbon atoms or a single bond. * is a bond to a carbon atom in the aromatic ring.)

[0021] In the above formula (1), Ar 1 and R 0Examples of aromatic rings with 5 to 40 members in the above Ar include aromatic hydrocarbon rings such as benzene rings, naphthalene rings, anthracene rings, phenalene rings, phenanthrene rings, pyrene rings, fluorene rings, perylene rings, and coronene rings; heteroaromatic rings such as furan rings, pyrrole rings, thiophene rings, phosphole rings, pyrazole rings, oxazole rings, isoxazole rings, thiazole rings, pyridine rings, pyrazine rings, pyrimidine rings, pyridazine rings, and triazine rings; or combinations thereof. 1 and R 0 The aromatic ring is preferably 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. 1 The aromatic ring is more preferably a benzene ring, a naphthalene ring, or a pyrene ring. 0 A benzene ring is more preferable as the aromatic ring.

[0022] In the above formula (1), Ar 1 and R 0 As a divalent group having an aromatic ring with 5 to 40 members represented by the above Ar 1 and R 0 Suitable examples include groups obtained by removing two hydrogen atoms from an aromatic ring with 5 to 40 members.

[0023] In the above equations (2-1) and (2-2), R 7 Examples of divalent organic groups having 1 to 20 carbon atoms represented by this formula include divalent hydrocarbon groups having 1 to 20 carbon atoms, groups having a divalent heteroatom-containing group between the carbon atoms of this hydrocarbon group, groups in which some or all of the hydrogen atoms of the hydrocarbon group are replaced with a monovalent heteroatom-containing group, or combinations thereof.

[0024] Examples of divalent hydrocarbon groups having 1 to 20 carbon atoms include divalent chain hydrocarbon groups having 1 to 20 carbon atoms, divalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms, divalent 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 divalent chain hydrocarbon groups having 1 to 20 carbon atoms include methanediyl, ethanediyl, propanediyl, butanediyl, hexanediyl, and octanediyl groups. Among these, alkanediyl groups having 1 to 8 carbon atoms are preferred.

[0027] Examples of divalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms include cycloalkanediyl groups such as cyclopentanediyl and cyclohexanediyl; cycloalkenediyl groups such as cyclopentenediyl and cyclohexenediyl; bridged ring saturated hydrocarbon groups such as norbornanediyl, adamantanediyl, and tricyclodecanediyl; and bridged ring unsaturated hydrocarbon groups such as norbornenediyl and tricyclodecenediyl.

[0028] Examples of divalent aromatic hydrocarbon groups having 6 to 20 carbon atoms include phenylene, naphthalenediyl, anthracenediyl, pyrenediyl, toluenediyl, and xylenediyl 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] R 7 The preferred elements are divalent hydrocarbon groups having 1 to 10 carbon atoms, such as methanediyl groups, ethanediyl groups, and phenylene groups, as well as -O- groups or combinations thereof, with methanediyl groups or combinations of methanediyl groups and -O- groups being more preferred.

[0033] The above R 0 However, it is preferable that the material has a group represented by the above formula (2-1), and that the group is represented by the following formula (2-1-1). [ka]

[0034] The above R 0 However, it is preferable that the group is a monovalent group having an aromatic ring with 5 to 40 members, and that it has at least two groups selected from the group consisting of the group represented by formula (2-1) and the group represented by formula (2-2). 0 It is more preferable that the compound has at least three groups selected from the group consisting of the group represented by formula (2-1) and the group represented by formula (2-2).

[0035] The above Ar 1 However, it is preferable to have at least one group selected from the group consisting of the group represented by formula (2-1) and the group represented by formula (2-2).

[0036] Ar 1 and R 0 The group may have substituents other than the group represented by formula (2-1) and the group represented by formula (2-2). Examples of substituents include monovalent chain hydrocarbon groups having 1 to 10 carbon atoms, halogen atoms such as fluorine, chlorine, bromine, and iodine, alkoxy groups such as methoxy, ethoxy, and propoxy groups, aryloxy groups such as phenoxy and naphthyloxy groups, alkoxycarbonyl groups such as methoxycarbonyl and ethoxycarbonyl groups, alkoxycarbonyloxy groups such as methoxycarbonyloxy and ethoxycarbonyloxy groups, acyl groups such as formyl, acetyl, propionyl, and butyryl groups, cyano groups, nitro groups, and hydroxyl groups.

[0037] Examples of repeating units represented by equation (1) above include those represented by equations (1-1) to (1-28) below. In the following equations, even if multiple repeating units are linked together, each repeating unit can be adopted independently.

[0038] [ka]

[0039] [ka]

[0040] [ka]

[0041] [ka]

[0042] [ka]

[0043] Among these, repeating units represented by formulas (1-1) to (1-10), (1-13) to (1-17), and (1-22) to (1-28) are preferred, and repeating units represented by formulas (1-5) to (1-8) are particularly preferred.

[0044] [A] The polymer may further have repeating units represented by the following formula (3). [ka] (In formula (3), Ar 5 It is a divalent group having an aromatic ring with 5 to 40 members. 1 R is a hydrogen atom or a monovalent organic group having 1 to 60 carbon atoms (however, R in formula (1) above) 0 Excluding the bases that fall under this category.)

[0045] Ar 5 As for aromatic rings with 5 to 40 members in the above formula (1), the Ar 1 Aromatic rings with 5 to 40 members can be suitably used in this product.

[0046] Ar 5 As a divalent group having an aromatic ring with 5 to 40 members represented by the above Ar 5 Suitable examples include groups obtained by removing two hydrogen atoms from an aromatic ring with 5 to 40 members.

[0047] R 1 As a monovalent organic group having 1 to 60 carbon atoms represented by the above formula (1), R 0 As long as the group is not one of the groups that fall under the above, it is not particularly limited, and examples include monovalent hydrocarbon groups having 1 to 60 carbon atoms, groups having a divalent heteroatom-containing group between the carbon atoms of the hydrocarbon group, groups in which some or all of the hydrogen atoms of the hydrocarbon group are replaced with a monovalent heteroatom-containing group, or combinations thereof. In formulas (i), (ii), (iii), and (iv) above, R 1 , R 2 , R 3 , R 4 , R 5 and R6 The groups exemplified as constituting monovalent organic groups having 1 to 20 carbon atoms, as represented by [the formula], can be suitably adopted as groups extending up to 60 carbon atoms.

[0048] Examples of repeating units represented by formula (3) above include those represented by formulas (3-1) to (3-8) below.

[0049] [ka]

[0050] [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.

[0051] 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].

[0052] <[A] Method for producing polymer> [A] Polymers typically consist of the Ar of formula (1) above. 1 A phenolic hydroxyl group is used as a precursor to give an aromatic ring compound, and the R of formula (1) above 0It can be produced by acid addition condensation with an aldehyde derivative having a phenolic hydroxyl group as a precursor, followed by a nucleophilic substitution reaction with a phenolic hydroxyl group to a halogenated hydrocarbon corresponding to the group represented by formula (2-1) or (2-2) above. 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.

[0053] <[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.

[0054] [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.

[0055] 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.

[0056] 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.

[0057] Examples of alcohol-based solvents include monoalcohol-based solvents such as methanol, ethanol, and n-propanol, and polyhydric alcohol-based solvents such as ethylene glycol and 1,2-propylene glycol.

[0058] Examples of ketone solvents include linear ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, and cyclic ketone solvents such as cyclohexanone.

[0059] 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.

[0060] Examples of nitrogen-containing solvents include linear nitrogen-containing solvents such as N,N-dimethylacetamide and cyclic nitrogen-containing solvents such as N-methylpyrrolidone.

[0061] [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.

[0062] 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.

[0063] The hydrogen atom content in the coating film of the composition after heating at 400°C for 90 seconds is preferably 26.0 atm% or less, more preferably 25.0 atm% or less, even more preferably 24.0 atm% or less, and particularly preferably 23.0 atm% or less. Furthermore, the carbon atom content in the coating film of the composition after heating at 400°C for 90 seconds is preferably 53.0 atm% or more, more preferably 54.0 atm% or more, even more preferably 55.0 atm% or more, and particularly preferably 56.0 atm% or more. By setting the hydrogen atom and carbon atom content of the coating film formed by the above composition within the above ranges after heating, the etching resistance and bending resistance of the resist underlayer film formed by the composition can be further improved. The method for measuring the hydrogen atom and carbon atom content of the coating film after heating is as described in the examples.

[0064] [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.

[0065] [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.

[0066] [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.

[0067] The coating method for the resist underlayer film formation composition is not particularly limited and can be carried out by any suitable method, such as rotary coating, casting coating, or roll coating. A coating film is formed thereafter, and the resist underlayer film is formed by the volatilization of the [B] solvent.

[0068] 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.

[0069] 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.

[0070] [Heating process] In this embodiment, a heating step may be included in which the coated film formed by the above coating step is heated. Heating the coated film promotes the formation of the resist underlayer film. More specifically, heating the coated film promotes the volatilization of the [B] solvent, etc.

[0071] 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 300°C, more preferably 320°C, and even more preferably 350°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.

[0072] Furthermore, the resist underlayer may be exposed after the above coating process. The resist underlayer may be exposed to plasma after the above coating process. Ion implantation may be performed on the resist underlayer after the above coating process. Exposure of the resist underlayer improves the etching resistance of the resist underlayer. Exposure of the resist underlayer improves the etching resistance of the resist underlayer. Ion implantation of the resist underlayer improves the etching resistance of the resist underlayer.

[0073] The radiation used for exposure of the resist underlayer film is appropriately selected from electromagnetic waves such as visible light, ultraviolet light, far ultraviolet light, X-rays, and gamma rays; and particle beams such as electron beams, molecular beams, and ion beams.

[0074] Methods for exposing the resist underlayer film to plasma include, for example, a direct method in which the substrate is placed in a gas atmosphere and plasma discharge is performed. Typical conditions for plasma exposure are a gas flow rate of 50 cc / min to 100 cc / min and a power supply of 100 W to 1,500 W.

[0075] The lower limit of the plasma exposure time is preferably 10 seconds, more preferably 30 seconds, and even more preferably 1 minute. The upper limit of the above time is preferably 10 minutes, more preferably 5 minutes, and even more preferably 2 minutes.

[0076] Plasma is generated, for example, in an atmosphere of a mixed gas of H2 and Ar. In addition to H2 and Ar, carbon-containing gases such as CF4 or CH4 may be introduced. Furthermore, at least one of the following gases may be introduced instead of either or both of H2 and Ar: CF4, NF3, CHF3, CO2, CH2F2, CH4, and C4F8.

[0077] Ion implantation into the resist underlayer involves implanting dopants into the resist underlayer. Dopants can be selected from a group consisting of boron, carbon, nitrogen, phosphorus, arsenic, aluminum, and tungsten. The implantation energy used to apply voltage to the dopant ranges from approximately 0.5 keV to 60 keV, depending on the type of dopant used and the desired implantation depth.

[0078] 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.

[0079] [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.

[0080] 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).

[0081] 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.

[0082] 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.

[0083] 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.

[0084] [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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] After development with the above-mentioned developer, the resist pattern is formed by washing and drying.

[0091] [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.

[0092] 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.

[0093] 《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]

[0094] The present invention will be described in detail below based on examples, but the present invention is not limited to these examples.

[0095] [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.

[0096] [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.

[0097] <[A] Synthesis of polymers> Polymers having repeating units represented by the following formulas (A-1) to (A-22) and (x-1) to (x-4) (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.

[0098] [Synthesis Example 1] (Synthesis of polymer (a-1)) In a reaction vessel, under a nitrogen atmosphere, 20.0 g of resorcinol, 25.1 g of 3,4-dihydroxybenzaldehyde, and 120.0 g of 1-butanol were charged and heated to 80°C to dissolve. A solution of 10.4 g of p-toluenesulfonic acid monohydrate in 15.0 g of 1-butanol 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 200 g of methyl isobutyl ketone and 400 g of water. After separating the aqueous phase, the obtained organic phase was concentrated in an evaporator, and the residue was added dropwise to 500 g of methanol to obtain a precipitate. The precipitate was 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 in a vacuum dryer at 60°C for 12 hours. The Mw of polymer (a-1) was 2,100.

[0099] [ka]

[0100] [Synthesis Example 2] (Synthesis of polymer (A-1)) In a reaction vessel under a nitrogen atmosphere, 15.0 g of the polymer (a-1), 34.9 g of propargyl bromide, 90 g of methyl isobutyl ketone, and 45.0 g of methanol were added and stirred. Then, 106.9 g of a 25% by mass aqueous solution of tetramethylammonium hydroxide was added, and the reaction was carried out at 50°C for 6 hours. After cooling the reaction solution to 30°C, 200.0 g of a 5% by mass aqueous solution of oxalic acid was added. After removing the aqueous phase, the obtained organic phase was concentrated using an evaporator, and the residue was added dropwise to 500 g of methanol to obtain a precipitate. The precipitate was recovered by suction filtration and washed several times with 100 g of methanol. Subsequently, 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 3,000.

[0101] [ka]

[0102] [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 20.0 g of resorcinol was replaced with 29.2 g of 2,7-dihydroxynaphthalene. The Mw of polymer (a-2) was 2,500.

[0103] [ka]

[0104] [Synthesis Example 4] (Synthesis of Polymer (A-2)) Except for changing (a-1) 15.0 g to (a-2) 18.3 g, the polymer (A-2) represented by the following formula (A-2) was obtained in the same manner as in Synthesis Example 2. The Mw of polymer (A-2) was 3,200.

[0105] [ka]

[0106] [Synthesis Example 5] (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 resorcinol was replaced with 29.1 g of 2,7-dihydroxynaphthalene and 25.1 g of 3,4-dihydroxybenzaldehyde was replaced with 28.1 g of 2,3,4-trihydroxybenzaldehyde. The Mw of polymer (a-3) was 2,700.

[0107] [ka]

[0108] [Synthesis Example 6] (Synthesis of Polymer (A-3)) Except for changing (a-1) 15.0 g to (a-3) 15.8 g, the polymer (A-3) represented by the following formula (A-3) was obtained in the same manner as in Synthesis Example 2. The Mw of polymer (A-3) was 3,800.

[0109] [ka]

[0110] [Synthesis Example 7] (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 resorcinol was replaced with 39.8 g of 1-hydroxypyrene. The Mw of polymer (a-4) was 3,000.

[0111] [ka]

[0112] [Synthesis Example 8] (Synthesis of polymer (A-4)) Except for changing (a-1) 15.0 g to (a-4) 24.8 g, the polymer (A-4) represented by the following formula (A-4) was obtained in the same manner as in Synthesis Example 2. The Mw of polymer (A-4) was 4,300.

[0113] [ka]

[0114] [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 resorcinol was replaced with 39.8 g of 1-hydroxypyrene and 25.1 g of 3,4-dihydroxybenzaldehyde was replaced with 28.1 g of 2,3,4-trihydroxybenzaldehyde. The Mw of polymer (a-5) was 2,500.

[0115] [ka]

[0116] [Synthesis Example 10] (Synthesis of Polymer (A-5)) Except for changing (a-1)15.0g to (a-5)20.8g, the polymer (A-5) represented by the following formula (A-5) was obtained in the same manner as in Synthesis Example 2. The Mw of polymer (A-5) was 3,600.

[0117] [ka]

[0118] [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 1, except that 20.0 g of resorcinol was replaced with 39.8 g of 1-hydroxypyrene and 25.1 g of 3,4-dihydroxybenzaldehyde was replaced with 28.1 g of 2,4,6-trihydroxybenzaldehyde. The Mw of polymer (a-6) was 2,300.

[0119] [ka]

[0120] [Synthesis Example 12] (Synthesis of polymer (A-6)) Except for changing (a-1)15.0g to (a-6)20.8g, the polymer (A-6) represented by the following formula (A-6) was obtained in the same manner as in Synthesis Example 2. The Mw of polymer (A-6) was 3,300.

[0121] [ka]

[0122] [Synthesis Example 13] (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 resorcinol was replaced with 39.8 g of 1-hydroxypyrene and 25.1 g of 3,4-dihydroxybenzaldehyde was replaced with 28.1 g of 3,4,5-trihydroxybenzaldehyde. The Mw of polymer (a-7) was 2,600.

[0123] [ka]

[0124] [Synthesis Example 14] (Synthesis of Polymer (A-7)) Except for changing (a-1) 15.0 g to (a-7) 20.8 g, the polymer (A-7) represented by the following formula (A-7) was obtained in the same manner as in Synthesis Example 2. The Mw of polymer (A-7) was 3,700.

[0125] [ka]

[0126] [Synthesis Example 15] (Synthesis of polymer (a-8)) Except for replacing 20.0 g of resorcinol with 39.8 g of 1-hydroxypyrene and 25.1 g of 3,4-dihydroxybenzaldehyde with 28.1 g of 2,4,5-trihydroxybenzaldehyde, the polymer (a-8) represented by the following formula (a-8) was obtained in the same manner as in Synthesis Example 1. The Mw of polymer (a-8) was 2,300.

[0127] [ka]

[0128] [Synthesis Example 16] (Synthesis of polymer (A-8)) Except for changing (a-1)15.0g to (a-8)20.8g, the polymer (A-8) represented by the following formula (A-8) was obtained in the same manner as in Synthesis Example 2. The Mw of polymer (A-8) was 3,400.

[0129] [ka]

[0130] [Synthesis Example 17] (Synthesis of polymer (a-9)) Except for replacing 20.0 g of resorcinol with 31.8 g of 1-hydroxypyrene and 9.9 g of 2,2'-dinaphthyl ether, the polymer (a-9) represented by the following formula (a-9) was obtained in the same manner as in Synthesis Example 1. The Mw of polymer (a-9) was 2,200.

[0131] [ka]

[0132] [Synthesis Example 18] (Synthesis of polymer (A-9)) Except for changing (a-1) 15.0 g to (a-9) 26.9 g, the polymer (A-9) represented by the following formula (A-9) was obtained in the same manner as in Synthesis Example 2. The Mw of polymer (A-9) was 3,200.

[0133] [ka]

[0134] [Synthesis Example 19] (Synthesis of polymer (a-10)) Except for substituting 20.0 g of resorcinol with 31.8 g of 1-hydroxypyrene and 9.9 g of 2,2'-dinaphthyl ether, and substituting 25.1 g of 3,4-dihydroxybenzaldehyde with 28.1 g of 2,4,6-trihydroxybenzaldehyde, the polymer (a-10) represented by the following formula (a-10) was obtained in the same manner as in Synthesis Example 1. The Mw of polymer (a-10) was 2,400.

[0135] [ka]

[0136] [Synthesis Example 20] (Synthesis of polymer (A-10)) Except for changing (a-1)15.0g to (a-10)22.3g, the polymer (A-10) represented by the following formula (A-10) was obtained in the same manner as in Synthesis Example 2. The Mw of polymer (A-10) was 3,500.

[0137] [ka]

[0138] [Synthesis Example 21] (Synthesis of polymer (a-11)) Except for substituting 20.0 g of resorcinol with 31.8 g of 1-hydroxypyrene and 9.9 g of 2,2'-dinaphthyl ether, and substituting 25.1 g of 3,4-dihydroxybenzaldehyde with 28.1 g of 2,3,4-trihydroxybenzaldehyde, the polymer (a-11) represented by the following formula (a-11) was obtained in the same manner as in Synthesis Example 1. The Mw of polymer (a-11) was 2,400.

[0139] [ka]

[0140] [Synthesis Example 22] (Synthesis of polymer (A-11)) Except for changing (a-1)15.0g to (a-11)22.3g, the polymer (A-11) represented by the following formula (A-11) was obtained in the same manner as in Synthesis Example 2. The Mw of polymer (A-11) was 3,400.

[0141] [ka]

[0142] [Synthesis Example 23] (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 1, except that 20.0 g of resorcinol was replaced with 31.8 g of 1-hydroxypyrene and 6.2 g of diphenyl ether, and 25.1 g of 3,4-dihydroxybenzaldehyde was replaced with 28.1 g of 2,3,4-trihydroxybenzaldehyde. The Mw of polymer (a-12) was 2,600.

[0143] [ka]

[0144] [Synthesis Example 24] (Synthesis of Polymer (A-12)) Except for changing (a-1)15.0g to (a-12)21.1g, the polymer (A-12) represented by the following formula (A-12) was obtained in the same manner as in Synthesis Example 2. The Mw of polymer (A-12) was 3,600.

[0145] [ka]

[0146] [Synthesis Example 25] (Synthesis of polymer (a-13)) Except for replacing 20.0 g of resorcinol with 31.8 g of 1-hydroxypyrene and 6.2 g of diphenyl ether, the polymer (a-13) represented by the following formula (a-13) was obtained in the same manner as in Synthesis Example 1. The Mw of polymer (a-13) was 2,900.

[0147] [ka]

[0148] [Synthesis Example 26] (Synthesis of Polymer (A-13)) Except for changing (a-1)15.0g to (a-13)25.4g, the polymer (A-13) represented by the following formula (A-13) was obtained in the same manner as in Synthesis Example 2. The Mw of polymer (A-13) was 4,100.

[0149] [ka]

[0150] [Synthesis Example 27] (Synthesis of Polymer (A-14)) Except for changing (a-1) 15.0 g to (a-4) 24.6 g and propargyl bromide 34.9 g to bromoacetonitrile 34.9 g, the polymer (A-14) represented by the following formula (A-14) was obtained in the same manner as in Synthesis Example 2. The Mw of polymer (A-14) was 4,500.

[0151] [ka]

[0152] [Synthesis Example 28] (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 1, except that 20.0 g of resorcinol was replaced with 63.9 g of 9,9'-bis(4-hydroxyphenyl)fluorene and 25.1 g of 3,4-dihydroxybenzaldehyde was replaced with 28.1 g of 2,3,4-trihydroxybenzaldehyde. The Mw of polymer (a-14) was 3,400.

[0153] [ka]

[0154] [Synthesis Example 29] (Synthesis of polymer (A-15)) Except for changing (a-1) 15.0 g to (a-14) 23.6 g, the polymer (A-15) represented by the following formula (A-15) was obtained in the same manner as in Synthesis Example 2. The Mw of polymer (A-15) was 5,000.

[0155] [ka]

[0156] [Synthesis Example 30] (Synthesis of Polymer (A-16)) Except for changing (a-1) 15.0 g to (a-5) 20.8 g and propargyl bromide 34.9 g to 4-bromo-1-butyne 39.0 g, the polymer (A-16) represented by the following formula (A-16) was obtained in the same manner as in Synthesis Example 2. The Mw of polymer (A-16) was 4,100.

[0157] [ka]

[0158] [Synthesis Example 31] (Synthesis of polymer (A-17)) Except for changing (a-1) 15.0 g to (a-2) 18.1 g and propargyl bromide 34.9 g to bromoacetonitrile 35.2 g, the polymer (A-17) represented by the following formula (A-17) was obtained in the same manner as in Synthesis Example 2. The Mw of polymer (A-17) was 3,300.

[0159] [ka]

[0160] [Synthesis Example 32] (Synthesis of polymer (a-15)) Except for replacing 20.0 g of resorcinol with 39.8 g of 1-hydroxypyrene and 25.1 g of 3,4-dihydroxybenzaldehyde with 33.4 g of 3,4-dihydroxy-5-nitrobenzaldehyde, the polymer (a-15) represented by the following formula (a-15) was obtained in the same manner as in Synthesis Example 1. The Mw of polymer (a-15) was 2,700.

[0161] [ka]

[0162] [Synthesis Example 33] (Synthesis of polymer (A-18)) Except for changing (a-1)15.0g to (a-15)28.1g, the polymer (A-18) represented by the following formula (A-18) was obtained in the same manner as in Synthesis Example 2. The Mw of polymer (A-18) was 3,800.

[0163] [ka]

[0164] [Synthesis Example 34] (Synthesis of Polymer (A-19)) Except for replacing (a-1) 15.0 g with (a-15) 28.1 g and propargyl bromide 34.9 g with bromoacetonitrile 35.2 g, the polymer (A-19) represented by the following formula (A-19) was obtained in the same manner as in Synthesis Example 2. The Mw of polymer (A-19) was 3,900.

[0165] [ka]

[0166] [Synthesis Example 35] (Synthesis of polymer (a-16)) Except for replacing 20.0 g of resorcinol with 23.0 g of anhydrous phloroglucinol, the polymer (a-16) represented by the following formula (a-16) was obtained in the same manner as in Synthesis Example 1. The Mw of polymer (a-16) was 2,400.

[0167] [ka]

[0168] [Synthesis Example 36] (Synthesis of Polymer (A-20)) Except for changing (a-1) 15.0 g to (a-16) 13.1 g, the polymer (A-20) represented by the following formula (A-20) was obtained in the same manner as in Synthesis Example 2. The Mw of polymer (A-20) was 3,500.

[0169] [ka]

[0170] [Synthesis Example 37] (Synthesis of Polymer (A-21)) Except for replacing (a-1) 15.0 g with (a-16) 13.1 g and propargyl bromide 34.9 g with bromoacetonitrile 35.2 g, the polymer (A-21) represented by the following formula (A-21) was obtained in the same manner as in Synthesis Example 2. The Mw of polymer (A-21) was 3,600.

[0171] [ka]

[0172] [Synthesis Example 38] (Synthesis of Polymer (A-22)) Except that 15.0 g of (a-1) was changed to 13.1 g of (a-16) and 34.9 g of propargyl bromide was changed to 57.3 g of 1-(bromomethyl)-4-ethynylbenzene, the polymer (A-22) represented by the following formula (A-22) was obtained in the same manner as in Synthesis Example 2. The Mw of the polymer (A-22) was 6,100.

[0173] [Chemical Formula]

[0174] [Comparative Synthesis Example 1] (Synthesis of Polymer (x-1)) Into a reaction vessel, 250.0 g of m-cresol, 125.0 g of 37 mass% formalin, and 2 g of oxalic anhydride were added under a nitrogen atmosphere, and the mixture was reacted at 100 °C for 3 hours and at 180 °C for 1 hour. Then, unreacted monomers were removed under reduced pressure to obtain a polymer (x-1) represented by the following formula (x-1). The Mw of the obtained polymer (x-1) was 11,000.

[0175] [Chemical Formula]

[0176] [Comparative Synthesis Example 2] (Synthesis of Polymer (x-2)) The polymer (x-2) was the same as the polymer (a-4), and the polymer (x-2) was obtained in the same manner as in Synthesis Example 7.

[0177] [Comparative Synthesis Example 3] (Synthesis of Polymer (x-3)) Except that 20.0 g of resorcinol was changed to 39.8 g of 1-hydroxypyrene and 25.1 g of 3,4-dihydroxybenzaldehyde was changed to 27.7 g of vanillin, the polymer (x-3) represented by the following formula (x-3) was obtained in the same manner as in Synthesis Example 1. The Mw of the polymer (x-3) was 3,400.

[0178] [ka]

[0179] [Comparative Synthesis Example 4] (Synthesis of polymer (x'-4)) In a reaction vessel, under a nitrogen atmosphere, 29.1 g of 2,7-dihydroxynaphthalene, 14.8 g of 37% by mass formaldehyde solution, and 87.3 g of methyl isobutyl ketone were charged and dissolved. After adding 1.0 g of p-toluenesulfonic acid monohydrate to the reaction vessel, the mixture was heated to 85°C and reacted for 4 hours. After the reaction was complete, the reaction solution was transferred to a separatory funnel, and the organic phase was washed with 200 g of methyl isobutyl ketone and 400 g of water. After separating the aqueous phase, the obtained organic phase was concentrated using an evaporator, and the residue 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 (x'-4), represented by the following formula (x'-4), was obtained by drying at 60°C for 12 hours using a vacuum dryer. The Mw of polymer (x'-4) was 3,400.

[0180] [ka]

[0181] [Comparative Synthesis Example 5] (Synthesis of polymer (x-4)) Except for changing (a-1) 15.0 g to (x'-4) 16.8 g, the polymer (x-4) represented by the following formula (x-4) was obtained in the same manner as in Synthesis Example 2. The Mw of polymer (x-4) was 4,500.

[0182] [ka]

[0183] <Preparation of Composition> The polymer, solvent, acid generator, and crosslinking agent used in the preparation of the composition are described below.

[0184] [[A] Polymer Example: The synthesized compounds (A-1) to (A-22) Comparative Example: The synthesized polymers (x-1) to (x-4)

[0185] [[B] Solvent B-1: Propylene glycol monomethyl ether acetate B-2: Cyclohexanone

[0186] [[C] Acid Generator C-1: Bis(4-t-butylphenyl)iodonium nonafluoro-n-butanesulfonate (compound represented by the following formula (C-1))

[0187]

Chemical Formula

[0188] [[D] Crosslinking Agent D-1: Compound represented by the following formula (D-1)

[0189]

Chemical Formula

[0190] D-2: Compound represented by the following formula (D-2)

[0191]

Chemical Formula

[0192] [Example 1-1] [10 parts by mass of (A-1) as [A] polymer was dissolved in 90 parts by mass of (B-1) as [B] solvent. The obtained solution was filtered through a polytetrafluoroethylene (PTFE) membrane filter with a pore size of 0.45 μm to prepare a composition (J-1).

[0193] [Examples 1-2 to 1-27 and Comparative Examples 1-1 to 1-4] Compositions (J-2) to (J-27) and (CJ-1) to (CJ-4) 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.

[0194] [Table 1]

[0195] <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.

[0196] [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.

[0197] [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.

[0198] [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.

[0199] 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.

[0200] 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.

[0201] [Percentage of hydrogen atoms and carbon atoms in the coating film of the composition] The above-prepared compositions (J-1) to (J-20) and (CJ-1) to (CJ-4) were 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 400°C for 90 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 powder was recovered by scraping the film from the obtained film-coated substrate, and the content ratio R' of hydrogen atoms, carbon atoms, and nitrogen atoms in the coating film was analyzed using a CHN simultaneous analyzer (MICRO CORDER JM10 from J-Science). H , R' C , R' N The (wt%) was measured. The oxygen atom content R' O (wt%) was calculated using the following formula. R' O =100-R' H -R' C-R' N Furthermore, the content ratio of hydrogen atoms and carbon atoms R is calculated using the following formula. H , R C (atm%) was calculated. R H =(R' H ) / {(R' H )+(R' C / 12)+(R' O / 16)+(R' N / 14)} × 100 R C =(R' C / 12) / {(R' H )+(R' C / 12)+(R' O / 16)+(R' N / 14)} × 100

[0202] [Table 2]

[0203] 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]

[0204] 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]

[0205] 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 repeating unit represented by the following formula (1) (excluding polymers having a repeating unit represented by the following formula (P10)), solvent and A method for manufacturing a semiconductor substrate containing [the specified ingredient]. 【Chemistry 1】 (In formula (1), Ar １ R is a divalent group having an aromatic ring with 5 to 40 members, and 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). ０ This is a monovalent group having an aromatic ring with 5 to 40 members, and having 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). 【Chemistry 2】 (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. * indicates a bond with a carbon atom in an aromatic ring. 【Transformation 3】

2. 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 claim 1, further comprising:

3. A polymer having a repeating unit represented by the following formula (1) (excluding polymers having a repeating unit represented by the following formula (P10)), solvent and A composition containing the following: 【Chemistry 4】 (In formula (1), Ar １ R is a divalent group having an aromatic ring with 5 to 40 members, and 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). ０ This is a monovalent group having an aromatic ring with 5 to 40 members, and having 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). 【Transformation 5】 (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. * indicates a bond with a carbon atom in an aromatic ring. 【Transformation 6】

4. The above R ０ The composition according to claim 3, wherein the group is a monovalent group having an aromatic ring with 5 to 40 members, and comprises at least two groups selected from the group consisting of the group represented by formula (2-1) and the group represented by formula (2-2).

5. The above R ０ The composition according to claim 3 or claim 4, 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 7】

6. The above Ar １ The composition according to claim 3 or claim 4, wherein the aromatic ring of １ is at least one aromatic hydrocarbon ring selected from the group consisting of a benzene ring, a naphthalene ring, an anthracene ring, a phenalene ring, a phenanthrene ring, a pyrene ring, a fluorene ring, a perylene ring, and a coronene ring.

7. The above R ０ The composition according to claim 3 or claim 4, 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.

8. The above R ０ The composition according to claim 3 or claim 4, wherein the aromatic ring is a benzene ring.

9. The composition according to claim 3 or claim 4, wherein the hydrogen atom content in the coating film after heating the coating film at 400°C for 90 seconds is 26.0 atm% or less.

10. The composition according to claim 3 or claim 4, wherein the carbon content in the coating film after heating the coating film at 400°C for 90 seconds is 53.0 atm% or more.

11. The composition according to claim 3 or claim 4, for forming a resist underlayer film.

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