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 and heat resistance can be formed; and a composition. Provided is a method for producing a semiconductor substrate which includes a step for directly or indirectly coating a substrate with a resist underlayer film-forming composition, a step for directly or indirectly forming a resist pattern on the resist underlayer film formed in the coating step, and a step for etching while using the resist pattern as a mask, wherein: the composition for forming the resist underlayer film contains a compound having a partial structure represented by formula (1), and a solvent; and the compound has at least one monovalent group which includes an aromatic heterocycle having a 5- to 20-membered ring. (In formula (1), Ar1 and Ar2 each independently represent a substituted or unsubstituted aromatic ring which has a 5- to 20-membered ring and forms a condensed ring structure and two adjacent carbon atoms in formula (1). R1 represents one or more groups selected from the group consisting of a monovalent ring including a substituted or unsubstituted aromatic ring having a 5- to 60-membered ring, and a monovalent group including an aromatic heterocycle having a 5- to 20-membered ring. L is a single bond or a divalent linking group. * and ** each represent a position which bonds to a section of said compound other than the partial structure represented by formula (1). m and n each independently represent an integer from 0 to 3. However, m+n is 1 or higher.)

Description

Technical Field

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

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 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, an organic underlayer film as a resist underlayer film is required to have etching resistance and heat 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 capable of forming a film excellent in etching resistance and heat 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 compound having a substructure represented by the following formula (1) (hereinafter also referred to as "[A] compound"), The solvent (hereinafter also referred to as "[B] solvent") and It contains, The above compound relates to a method for manufacturing a semiconductor substrate, having a monovalent group containing at least one aromatic heterocycle with 5 to 20 members. [ka] (In the above formula (1), Ar 1 and Ar 2 These are substituted or unsubstituted aromatic rings with 5 to 20 members, each independently forming a fused ring structure with two adjacent carbon atoms in formula (1) above. R 1 This is at least one group selected from the group consisting of monovalent groups containing substituted or unsubstituted aromatic rings with 5 to 60 members and monovalent groups containing aromatic heterocycles with 5 to 20 members. L is a single bond or a divalent linking group. * and ** indicate the sites in the above compound that bind to parts other than the substructure represented by formula (1), respectively. m and n are independent integers between 0 and 3, where m+n is greater than or equal to 1.

[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. A "fused ring structure" refers to a structure in which adjacent rings share one edge (two adjacent atoms).

[0009] In other embodiments, the present invention A compound having a substructure represented by the following formula (1), solvent and It contains, The above-mentioned compound relates to a composition having a monovalent group comprising at least one aromatic heterocycle with 5 to 20 members. [ka] (In the above formula (1), Ar 1 and Ar 2 These are substituted or unsubstituted aromatic rings with 5 to 20 members, each independently forming a fused ring structure with two adjacent carbon atoms in formula (1) above. R 1 This is at least one group selected from the group consisting of monovalent groups containing substituted or unsubstituted aromatic rings with 5 to 60 members and monovalent groups containing aromatic heterocycles with 5 to 20 members. L is a single bond or a divalent linking group. * and ** indicate the sites in the above compound that bind to parts other than the substructure represented by formula (1), respectively. m and n are independent integers between 0 and 3, where m+n is greater than or equal to 1. [Effects of the Invention]

[0010] The semiconductor substrate manufacturing method makes it possible to form a resist underlayer film with excellent etching resistance and heat resistance. The composition makes it possible to form a film with excellent etching resistance and heat resistance. Furthermore, the semiconductor substrate manufacturing method also makes it possible to suppress clogging of the drain pipes of semiconductor manufacturing equipment because the composition has excellent solubility in polar solvents. The composition makes it possible to suppress clogging of the drain pipes of semiconductor manufacturing equipment because the composition has excellent solubility in polar solvents. Therefore, these can be suitably used in the manufacture of semiconductor devices, which are expected to become even more miniaturized in the future. [Modes for carrying out the invention]

[0011] The following describes in detail the methods for manufacturing semiconductor substrates and compositions according to each embodiment of the present invention. A preferred combination of embodiments is also desirable.

[0012] Method for manufacturing semiconductor substrates The method for manufacturing the semiconductor substrate includes a step of coating the substrate directly or indirectly with a resist underlayer film formation composition (hereinafter also referred to as the "coating step"), a step of directly or indirectly forming a resist pattern on the resist underlayer film formed by the coating step (hereinafter also referred to as the "resist pattern formation step"), and a step of performing etching using the resist pattern as a mask (hereinafter also referred to as the "etching step").

[0013] According to the semiconductor substrate manufacturing method, by using the composition described below as the resist underlayer film formation composition in the coating process, it is possible to form a resist underlayer film with excellent etching resistance and heat resistance while suppressing clogging of the drain pipe of the semiconductor manufacturing equipment, thereby enabling the production of semiconductor substrates with good pattern shapes at a high yield. Examples of semiconductor manufacturing equipment include spin coaters (such as Tokyo Electron Limited's "CLEAN TRACK ACT12"), but in addition to the drainage of the resist underlayer film formation composition, the drain pipe of this spin coater also discharges drainage of the resist composition, silicon-containing film formation composition, and other materials. If the resist underlayer film formation composition has low solubility in polar solvents, the resist underlayer film formation composition may come into contact with a polar solvent different from the solvent in the resist underlayer film formation composition in the drain pipe, causing the resist underlayer film formation composition to precipitate and clog the drain pipe.

[0014] 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").

[0015] The following describes the composition used in the manufacturing method of the semiconductor substrate and each step of the process.

[0016] <Composition> The composition for forming a resist underlayer film contains compound [A] and solvent [B]. The composition may contain optional components as long as they do not impair the effects of the present invention.

[0017] The composition, by containing compound [A] and solvent [B], can form a film with excellent etching resistance and heat resistance while suppressing clogging of the drain pipe of semiconductor manufacturing equipment. 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.

[0018] The components contained in the composition will be described below.

[0019] <[A] compound> [A] compound has a partial structure represented by the following formula (1) (hereinafter also referred to as "partial structure (1)"). [A] compound may have two or more partial structures (1). When [A] compound has two or more partial structures (1), the plurality of partial structures (1) may be identical or different from each other. The composition can contain one or more [A] compounds. [Chemical formula] (In the above formula (1), Ar 1 and Ar 2 are each independently 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 at least one group selected from the group consisting of a monovalent group containing a substituted or unsubstituted aromatic ring having 5 to 60 ring members and a monovalent group containing an aromatic heterocyclic ring having 5 to 20 ring members. L is a single bond or a divalent linking group. * and ** each indicate a site that binds to a part other than the partial structure represented by the above formula (1) in the above compound. m and n are each independently an integer from 0 to 3. However, m + n is 1 or more.)

[0020] Ar 1 and Ar 2Aromatic rings with 5 to 20 members represented by include, for example, aromatic hydrocarbon rings such as benzene rings, naphthalene rings, anthracene rings, phenalene rings, phenanthrene rings, pyrene rings, fluorene rings, and perylene rings; aromatic heterocycles such as furan rings, pyrrole rings, thiophene rings, phosphole rings, pyrazole rings, oxazole rings, isoxazole rings, thiazole rings, imidazole rings, pyridine rings, pyrazine rings, pyrimidine rings, pyridazine rings, triazine rings, quinoline rings, isoquinoline rings, quinoxaline rings, quinazoline rings, sinnoline rings, benzofuran rings, isobenzofuran rings, indole rings, isoindole rings, benzothiophene rings, benzimidazole rings, indazole rings, benzoxazole rings, benzoisoxazole rings, benzothiazole rings, acridine rings, or combinations thereof. Among these, the above Ar 1 and Ar 2 Preferably, it 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, and a perylene ring, and Ar 1 and Ar 2 It is more preferable that the aromatic ring is a benzene ring.

[0021] Ar 1 and Ar 2 The compound may have substituents. 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, 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, and nitro groups.

[0022] R 1 As for aromatic rings with 5 to 60 members in the above formula (1), the Ar 1 and Ar 2Aromatic rings with 5 to 20 members, as represented by , can be suitably adopted, with the number of members extended up to 60. Examples of aromatic rings with more than 20 members include fused ring structures such as coronene rings, trinaphthylene rings, heptafen rings, heptacene rings, pyranthrene rings, ovalene rings, and hexabenzocoronene rings, and aggregated ring structures (polycyclic structures in which rings are linked by single bonds) such as tetraphenylbenzene rings, pentaphenylbenzene rings, and hexaphenylbenzene rings. 1 A monovalent group containing an aromatic ring with 5 to 60 members, as represented by the formula, is a group obtained by removing one hydrogen atom from the above aromatic ring with 5 to 60 members.

[0023] R 1 As for aromatic heterocycles with 5 to 20 ring members in the above formula (1), the Ar 1 and Ar 2 Aromatic heterocycles with 5 to 20 ring members, as exemplified above, can be suitably adopted. 1 The aromatic heterocycle preferably has a nitrogen atom. In particular, the above R 1 As the aromatic heterocycle, an indole ring is preferred. 1 Examples of monovalent groups containing aromatic heterocycles with 5 to 20 members, as represented by the formula, include groups obtained by removing one hydrogen atom from the above aromatic heterocycles with 5 to 20 members.

[0024] Examples of divalent linking groups represented by L include divalent linear or branched hydrocarbon groups having 1 to 10 carbon atoms, divalent alicyclic hydrocarbon groups having 4 to 12 carbon atoms, divalent aromatic hydrocarbon groups having 6 to 12 carbon atoms, one group selected from -CO-, -O-, -NH-, -S-, and cyclic acetal structures, or groups formed by combining two or more of these groups.

[0025] Examples of divalent linear or branched hydrocarbon groups having 1 to 10 carbon atoms include methanediyl group, ethanediyl group, propanediyl group, butanediyl group, hexanediyl group, and octanediyl group. Among these, alkanediyl groups having 1 to 8 carbon atoms are preferred.

[0026] Examples of the above-mentioned divalent alicyclic hydrocarbon groups having 4 to 12 carbon atoms include monocyclic cycloalkanediyl groups such as cyclopentanediyl and cyclohexanediyl groups, and polycyclic cycloalkanediyl groups such as norbornanediyl and adamantanediyl groups. Among these, cycloalkanediyl groups having 5 to 12 carbon atoms are preferred.

[0027] Examples of divalent aromatic hydrocarbon groups having 6 to 12 carbon atoms include benzenediyl groups and naphthalenediyl groups.

[0028] The above L is preferably a single bond.

[0029] m and n are preferably independent integers between 0 and 2. m+n is preferably 1 or 2.

[0030] [A] The compound has at least one monovalent group containing an aromatic heterocycle with 5 to 20 members. The monovalent group containing an aromatic heterocycle with 5 to 20 members is the above R 1 A monovalent group containing an aromatic heterocycle with 5 to 20 members represented by [A] can be suitably adopted. The compound may have the group in substructure (1), in a part other than substructure (1), or in both substructure (1) and the part other than substructure (1).

[0031] [A] Compound has etching resistance, heat resistance and solubility in polar solvents, as described above for R 1 A substructure (1) in which a monovalent group is a substituted or unsubstituted aromatic hydrocarbon ring with 6 to 60 members, and the above R 1 It is preferable that the compound has a substructure (1) which is a monovalent group containing an aromatic heterocycle with 5 to 20 members. In this case, the [A] compound will have at least two types of substructures (1).

[0032] In one embodiment, compound [A] is preferably a compound represented by the following formula (1-1) (hereinafter also referred to as "compound (1-1)"). [ka] (In the above formula (1-1), Ar 1 Ar 2 , R 1 And L are equivalent to equation (1) above. X is a (p+q) valent group containing a substituted or unsubstituted aromatic ring with 5 to 60 members, an ethendiyl group, or an ethindiyl group. R 3 It is a monovalent group containing an aromatic ring with 5 to 40 members. p is an integer between 1 and 10. If p is 2 or greater, multiple Ar 1 Ar 2 , R 1 And L are either identical or different from each other. q is an integer between 0 and 10. If q is 2 or greater, multiple R 3 They are either identical or different from one another.

[0033] In the above X, the aromatic ring with 5 to 60 members is R in formula (1) above. 1 Aromatic rings with 5 to 60 members can be suitably used in the above. X is a (p+q) valence group containing a substituted or unsubstituted aromatic ring with 5 to 60 members, and includes a group obtained by removing (p+q) hydrogen atoms from the above aromatic ring with 5 to 60 members. Substituents in X include the Ar of formula (1) above. 1 and Ar 2 The substituents that it may have can be suitably adopted.

[0034] The aromatic ring of X 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. In particular, the aromatic ring of X is preferably a benzene ring.

[0035] The above R 3 As the aromatic rings with 5 to 40 members in X, aromatic rings with 5 to 60 members corresponding to 5 to 40 members can be suitably adopted. 3A monovalent group containing an aromatic ring with 5 to 40 members, as represented by the above, is a group obtained by removing one hydrogen atom from the above aromatic ring with 5 to 40 members. 3 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.

[0036] Examples of compound (1-1) include compounds represented by the following formulas (1-1-1) to (1-1-9).

[0037] [ka]

[0038] [ka]

[0039] [ka]

[0040] [ka]

[0041] In the above equations (1-1-1) and (1-1-2), R 11 and R 12 The asterisk (*) represents a bond with the double bond at position 9 of the fluorene skeleton. 11 and R 12 The abundance ratio is based on moles. The abundance ratio is R 11 and R 12 This can be changed by adjusting the amount of raw material used.

[0042] [Synthesis method for compound (1-1)] Compound (1-1) can be synthesized by conventional methods, for example, according to the following synthesis scheme.

[0043] [ka] (In the scheme, * represents a bond with a fluorene ring. R 1 This is equivalent to equation (1-1) above.

[0044] A substituted fluorene is prepared as a starting material, and intermediate (1-1-a) or (1-1-b) is obtained by cyclization in the presence of a catalyst or the like. Then, intermediate (1-1-a) or (1-1-b) and R of the above formula (1-1) are used. 1 By reacting with an aldehyde having the structure shown, the target compound (1-1-A) or (1-1-B) can be synthesized. Other structures can also be synthesized by appropriately selecting the starting materials and the structure of the aldehyde. 1 Multiple types of aldehyde compounds with different structures are prepared in predetermined ratios, and these are reacted with an intermediate (1-1-a) to produce multiple types of R 1 A compound (1-1-A) having a predetermined abundance ratio can be synthesized.

[0045] In one embodiment, compound [A] is preferably a compound represented by the following formula (1-2) (hereinafter also referred to as "compound (1-2)"). [ka] (In the above formula (1-2), Ar 1 Ar 2 , R 1 And L are equivalent to equation (1) above. R 4 and R 5 Each of these is independently a monovalent group or a carbon-unsaturated bond-containing group containing an aromatic ring with 5 to 40 members. r and s are each independent integers between 1 and 10.

[0046] The above R 4 and R 5As a monovalent group containing an aromatic ring with 5 to 40 members represented by the above formula (1-2), R 3 A monovalent group containing an aromatic ring with 5 to 40 members, represented by the formula above, can be suitably used. In particular, the above R 4 and R 5 The aromatic rings are preferably at least one aromatic hydrocarbon ring selected independently 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.

[0047] R 4 and R 5 Examples of carbon-unsaturated bond-containing groups represented by include unsaturated chain hydrocarbon groups having 2 to 10 carbon atoms and possessing carbon-carbon double or triple bonds, such as ethenyl, ethynyl, allyl, and propargyl groups.

[0048] r and s are each preferably integers between 1 and 5, more preferably integers between 1 and 3, and even more preferably 1 or 2.

[0049] Examples of compounds (1-2) include those represented by the following formulas (1-2-1) to (1-2-3).

[0050] [ka]

[0051] [Synthesis method for compounds (1-2)] Compound (1-2) can be synthesized by conventional methods, for example, according to the following synthesis scheme.

[0052] [ka] (In the scheme, Ar q Ar is an aromatic hydrocarbon ring with 6 to 20 members. qAr may fuse with the cyclopentadienone structure shown in the scheme to form a fused ring. q If multiple Ar q These elements may fuse together to form a fused ring. (u is an integer between 1 and 4.)

[0053] The starting material is 2,7-diethinylfluorene, and the R of the above formula (1-2) 4 or R 5 The intermediate (1-2-a) is then reacted with a cyclopentadienone compound having the corresponding structure to obtain intermediate (1-2-a). Next, intermediate (1-2-a) is reacted with the R of formula (1-1) above. 1 The target compound (1-2-A) can be synthesized by reacting it with an aldehyde having the specified structure. Other structures can also be synthesized by appropriately selecting the starting material, cyclopentadienone compound, aldehyde compound, etc.

[0054] In one embodiment, the above compound is preferably a polymer having two or more repeating units of substructure (1). The polymer is preferably represented by the following formula (1-3). [ka] (In upper formula (1-3), Ar 1 Ar 2 , R 1 And L are equivalent to equation (1) above. L 2 This refers to a divalent group containing an aromatic ring with 5 to 60 members, an ethendiyl group, an ethindiyl group, or a combination thereof, or a single bond.

[0055] L 2 As a divalent group containing an aromatic ring with 5 to 60 members represented by the above formula (1), R 1 Examples include groups obtained by removing one hydrogen atom from a monovalent group containing an aromatic ring with 5 to 60 members.

[0056] The lower limit of the weight-average molecular weight (Mw) of the polymer is not particularly limited, but is preferably 1,000, more preferably 1,500, and even more preferably 2,000. The upper limit of the weight-average molecular weight (Mw) is preferably 15,000, more preferably 10,000, and even more preferably 8,000. The method for measuring the weight-average molecular weight (Mw) of the polymer is as described in the examples.

[0057] Examples of compounds (1-2) include those represented by the following formulas (1-3-1) to (1-3-6).

[0058] [ka]

[0059] [ka]

[0060] [Method for synthesizing polymers] The above polymer is typically obtained by standard methods as (ethynyl group substituted) fluorene, and L as needed. 2 An acid addition condensation reaction is carried out with the aromatic ring compound that gives the intermediate polymer. Then, the intermediate polymer and the R of formula (1-3) above are combined. 1 The desired polymer can be synthesized by reacting it with an aldehyde having the structure shown. Other structures can also be synthesized using starting materials and L 2 It can be synthesized by appropriately selecting the structure of the aromatic ring compound and aldehyde that give the desired effect.

[0061] The lower limit of the content of compound [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 compound [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 18% by mass, based on the total mass of compound [A] and solvent [B].

[0062] <[B] Solvent> [B] The solvent is not particularly limited as long as it can dissolve or disperse the [A] compound and any optional components it may contain.

[0063] [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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] Examples of ketone solvents include linear ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, and cyclic ketone solvents such as cyclohexanone.

[0068] 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.

[0069] Examples of nitrogen-containing solvents include linear nitrogen-containing solvents such as N,N-dimethylacetamide and cyclic nitrogen-containing solvents such as N-methylpyrrolidone.

[0070] [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.

[0071] 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.

[0072] [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.

[0073] [Method for preparing the composition] The composition can be prepared by mixing [A] compound, [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.

[0074] [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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] [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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] [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.

[0088] 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).

[0089] 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.

[0090] 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.

[0091] 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.

[0092] [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.

[0093] 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, negative type resist compositions containing an alkali-soluble resin and a crosslinking agent, and metal-containing resist compositions containing metals such as tin and zirconium.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] After development with the above-mentioned developer, the resist pattern is formed by washing and drying.

[0099] [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.

[0100] 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.

[0101] 《Composition》 The composition contains compound [A] and solvent [B]. The composition can preferably be one used in the above-mentioned semiconductor substrate manufacturing method. [Examples]

[0102] The present invention will be described in detail below based on examples, but the present invention is not limited to these examples.

[0103] [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.

[0104] [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.

[0105] [Synthesis Example 1] (Synthesis of compound (a-1)) In a reaction vessel, 20.0 g of 2-acetylfluorene and 20.0 g of m-xylene were charged under a nitrogen atmosphere and dissolved at 110°C. Next, 3.1 g of dodecylbenzenesulfonic acid was added and the mixture was heated to 140°C and reacted for 16 hours. After the reaction was complete, 80.0 g of xylene was added to the reaction solution to dilute it, then cooled to 50°C and added to 500.0 g of methanol to reprecipitate. The obtained precipitate was washed with toluene, the solid was collected on filter paper, and dried to obtain compound (a-1) represented below.

[0106] [ka]

[0107] [Synthesis Example 2] (Synthesis of Compound (A-1)) In a reaction vessel under a nitrogen atmosphere, 10.0 g of the above compound (a-1), 4.2 g of indole-3-carboxyaldehyde, 6.7 g of 1-pyrenecarboxaldehyde, 8.8 g of diazabicycloundecene, and 62.0 g of N,N-dimethylacetamide were added and reacted at 120°C for 15 hours. After cooling the reaction solution to 30°C, it was added to 200.0 g of methanol and reprecipitation was performed. The precipitate was collected on filter paper and dried to obtain compound (A-1) represented by the following formula. In the following formula, R 11 The ratio is the molar ratio.

[0108] [ka]

[0109] [Synthesis Example 3] (Synthesis of compound (a-2)) In a reaction vessel, under a nitrogen atmosphere, 20.0 g of bis(2-fluorenyl)acetylene, 21.7 g of tetraphenylcyclopentadienone, and 125.0 g of sulfolane were added and stirred at 50°C, then heated to 210°C and reacted for 8 hours. After the reaction was complete, it was cooled to 30°C and added to a mixed solution of 125.0 g of methanol and 50.0 g of water to reprecipitate. The obtained precipitate was recrystallized with toluene, the crystals were collected on filter paper, and dried to obtain compound (a-2) represented below.

[0110] [ka]

[0111] [Synthesis Example 4] (Synthesis of Compound (A-2)) In a reaction vessel under a nitrogen atmosphere, 10.0 g of the above compound (a-2), 4.5 g of indole-3-carboxyaldehyde, 7.2 g of 1-pyrenecarboxaldehyde, 9.5 g of diazabicycloundecene, and 76.0 g of N,N-dimethylacetamide were added and reacted at 120°C for 15 hours. After cooling the reaction solution to 30°C, it was added to 200.0 g of methanol and reprecipitation was performed. The precipitate was collected on filter paper and dried to obtain compound (A-2) represented by the following formula. In the following formula, R 12The ratio is the molar ratio.

[0112] [ka]

[0113] [Synthesis Example 5] (Synthesis of compound (a-3)) In a reaction vessel, under a nitrogen atmosphere, 100.0 g of 2,7-diethynylfluorene, 377.0 g of tetraphenylcyclopentadienone, and 1000.0 g of m-xylene were added and heated to 130°C for 10 hours. After the reaction was complete, the mixture was cooled to 30°C and added to 2100.0 g of methanol for reprecipitation. The resulting precipitate was dried to obtain compound (a-3) represented by (a-3) below.

[0114] [ka]

[0115] [Synthesis Example 6] (Synthesis of Compound (A-3)) In a reaction vessel, under a nitrogen atmosphere, 52.3 g of the above compound (a-3), 9.0 g of indole-3-carboxyaldehyde, 9.5 g of diazabicycloundecene, and 245.3 g of N,N-dimethylacetamide were added and reacted at 120°C for 15 hours. After cooling the reaction solution to 30°C, it was added to 200.0 g of methanol and reprecipitation occurred. The precipitate was collected on filter paper and dried to obtain compound (A-3) represented below.

[0116] [ka]

[0117] [Synthesis Example 7] (Synthesis of compound (a-4)) In a reaction vessel, 40.0 g of 1,3-diphenyl-2-propanone, 34.7 g of acenaphthenequinone, and 400.0 g of ethanol were added under a nitrogen atmosphere and heated to 70°C. Then, a mixed solution of 10.7 g of potassium hydroxide and 87.6 g of ethanol was added dropwise, and the reaction was carried out at 70°C for 9 hours. After the reaction solution was cooled to 30°C, the precipitate was collected on filter paper and dried to obtain compound (a-4) represented below.

[0118] [ka]

[0119] [Synthesis Example 8] (Synthesis of compound (a-5)) In a reaction vessel, under a nitrogen atmosphere, 2.2 g of 2,7-diethynylfluorene, 8.0 g of the above compound (a-4), and 80.0 g of m-xylene were added and heated to 130°C for 10 hours. After the reaction was complete, the mixture was cooled to 30°C and added to 250.0 g of methanol for reprecipitation. The resulting precipitate was dried to obtain compound (a-5), represented by (a-5) below.

[0120] [ka]

[0121] [Synthesis Example 9] (Synthesis of Compound (A-4)) Compound (A-4), represented by (A-4) below, was obtained in the same manner as in Synthesis Example 6, except that 52.3 g of compound (a-3) was replaced with 49.2 g of compound (a-5), and 245.3 g of N,N-dimethylacetamide was replaced with 232.7 g of N,N-dimethylacetamide.

[0122] [ka]

[0123] [Synthesis Example 10] (Synthesis of compound (a-6)) In a reaction vessel, under a nitrogen atmosphere, 12.5 g of 1,3-diphenyl-2-propanone, 9.8 g of 1,4-bisbenzyl, and 625.0 g of ethanol were added and heated to 70°C. Then, a mixed solution of 3.3 g of potassium hydroxide and 27.4 g of ethanol was added dropwise, and the reaction was carried out at 70°C for 9 hours. After the reaction solution was cooled to 30°C, the precipitate was collected on filter paper and dried to obtain compound (a-6) represented below.

[0124] [ka]

[0125] [Synthesis Example 11] (Synthesis of compound (a-7)) In a reaction vessel, under a nitrogen atmosphere, 5.5 g of 2-ethynylfluorene, 5.0 g of the above compound (a-6), and 50.0 g of m-xylene were added and heated to 130°C for 10 hours. After the reaction was complete, the mixture was cooled to 30°C and added to 150.0 g of methanol for reprecipitation. The resulting precipitate was dried to obtain compound (a-7), represented by (a-7) below.

[0126] [ka]

[0127] [Synthesis Example 12] (Synthesis of Compound (A-5)) Compound (A-5), represented by (A-5) below, was obtained in the same manner as in Synthesis Example 6, except that 52.3 g of compound (a-3) above was replaced with 28.7 g of compound (a-7) above, and 245.3 g of N,N-dimethylacetamide was replaced with 150.6 g of N,N-dimethylacetamide.

[0128] [ka]

[0129] [Synthesis Example 13] (Synthesis of compound (a-8)) In a reaction vessel, under a nitrogen atmosphere, 20.0 g of 2-bromofluorene, 17.1 g of 2-ethynylfluorene, 45.4 g of diisopropylamine, 0.9 g of triphenylphosphine, 0.2 g of copper(I) iodide, 0.3 g of palladium chloride, and 370.8 g of tetrahydrofuran were added and reacted at 60°C for 7 hours. After cooling the reaction solution to 30°C, the precipitate was collected on filter paper, washed with 300.0 g of ultrapure water, and dried to obtain compound (a-8) represented below.

[0130] [ka]

[0131] [Synthesis Example 14] (Synthesis of Compound (A-6)) Compound (A-6), represented below, was obtained in the same manner as in Synthesis Example 6, except that 52.3 g of compound (a-3) was replaced with 10.0 g of compound (a-8), and 245.3 g of N,N-dimethylacetamide was replaced with 76.1 g of N,N-dimethylacetamide.

[0132] [ka]

[0133] [Synthesis Example 15] (Synthesis of Compound (a-9)) Compound (a-9), represented below, was obtained in the same manner as in Synthesis Example 11, except that 5.5 g of 2-ethynylfluorene was replaced with 1.6 g of 2,7-diethynylfluorene. The Mw of compound (a-9) was 5,500.

[0134] [ka]

[0135] [Synthesis Example 16] (Synthesis of Compound (A-7)) Compound (A-7), represented below, was obtained in the same manner as in Synthesis Example 6, except that 52.3 g of compound (a-3) was replaced with 47.9 g of compound (a-9), and 245.3 g of N,N-dimethylacetamide was replaced with 227.7 g of N,N-dimethylacetamide. The Mw of compound (A-7) was 6,500.

[0136] [ka]

[0137] [Synthesis Example 17] (Synthesis of compound (a-10)) In a reaction vessel, under a nitrogen atmosphere, 10.0 g of fluorene, 11.6 g of methanesulfonic acid, and 50.0 g of 1,4-dioxane were added and heated to 80°C. Then, a mixed solution of 24.8 g of 9-ethynyl-9-fluorenol and 49.6 g of 1,4-dioxane was added dropwise, and the reaction was carried out at 80°C for 4 hours. After cooling the reaction solution to 30°C, it was added to 200.0 g of methanol and reprecipitation occurred. The precipitate was collected on filter paper and dried to obtain compound (a-10), represented by (a-10) below. The Mw of compound (a-10) was 3,000.

[0138] [ka]

[0139] [Synthesis Example 18] (Synthesis of Compound (A-8)) Compound (A-8), represented below, was obtained in the same manner as in Synthesis Example 6, except that 52.3 g of compound (a-3) was replaced with 19.9 g of compound (a-10), and 245.3 g of N,N-dimethylacetamide was replaced with 115.6 g of N,N-dimethylacetamide. The Mw of compound (A-8) was 4,200.

[0140] [ka]

[0141] [Synthesis Example 19] (Synthesis of compound (a-11)) In a reaction vessel, under a nitrogen atmosphere, 10.0 g of fluorene and 200.0 g of dichloromethane were added, and a mixed solution of 97.6 g of iron(III) chloride and 150.0 g of nitromethane was added dropwise. The reaction was carried out at room temperature for 50 hours. The precipitate was collected on filter paper, washed with 300.0 g of nitromethane, and dried to obtain compound (a-11), represented by (a-11) below. The Mw of compound (a-11) was 1,400.

[0142] [ka]

[0143] [Synthesis Example 20] (Synthesis of Compound (A-9)) Compound (A-9), represented below, was obtained in the same manner as in Synthesis Example 6, except that 52.3 g of compound (a-3) was replaced with 9.3 g of compound (a-11), and 245.3 g of N,N-dimethylacetamide was replaced with 73.1 g of N,N-dimethylacetamide. The Mw of compound (A-9) was 2,800.

[0144] [ka]

[0145] [Synthesis Example 21] (Synthesis of compound (a-12)) In a reaction vessel under a nitrogen atmosphere, 20.0 g of 2,7-dibromofluorene, 14.5 g of 2,7-diethynylfluorene, 34.4 g of diisopropylamine, 0.7 g of triphenylphosphine, 0.1 g of copper(I) iodide, 0.2 g of palladium chloride, and 345.5 g of tetrahydrofuran were added and reacted at 60°C for 7 hours. After cooling the reaction solution to 30°C, the precipitate was collected on filter paper, washed with 300.0 g of ultrapure water, and dried to obtain compound (a-12) represented below. The Mw of compound (a-12) was 3,400.

[0146] [ka]

[0147] [Synthesis Example 22] (Synthesis of Compound (A-10)) Compound (A-10), represented as shown below, was obtained in the same manner as in Synthesis Example 6, except that 52.3 g of compound (a-3) was replaced with 10.6 g of compound (a-12), and 245.3 g of N,N-dimethylacetamide was replaced with 78.5 g of N,N-dimethylacetamide. The Mw of compound (A-10) was 4,100.

[0148] [ka]

[0149] [Comparative Synthesis Example 1] (Synthesis of compound (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 removing unreacted monomers under reduced pressure, compound (x-1), represented by the following formula (x-1), was obtained. The Mw of the obtained compound (x-1) was 11,000.

[0150] [ka]

[0151] [Comparative Synthesis Example 2] (Synthesis of compound (x-2)) 100.0 g of 9,9-bis(4-hydroxyphenyl)fluorene, 300.0 g of propylene glycol monomethyl ether acetate, and 10.0 g of paraformaldehyde were charged into a reaction vessel, and 1.0 g of p-toluenesulfonic acid monohydrate was added. The reaction was carried out at 100°C for 16 hours. Subsequently, the polymerization reaction solution was added to 500.0 g of methanol / water (70 / 30 (mass ratio)) mixed solvent, the precipitate was collected on filter paper, and dried to obtain compound (x-2) represented by the following formula (x-2). The Mw of the obtained compound (x-2) was 5,200.

[0152] [ka]

[0153] [Comparative Synthesis Example 3] (Synthesis of compound (x-3)) 30.0 g of indole, 63.1 g of 6-hydroxy-1-hydroxypyrenecarboxaldehyde, and 186.1 g of 1-butanol were added to a reaction vessel and reacted at 115°C for 30 hours. After the reaction, 83.1 g of 4-tert-butylbenzaldehyde was added and the reaction was further carried out at 115°C for 20 hours. After cooling the reaction solution to 30°C, it was added to a 500.0 g methanol / water (70 / 30 (mass ratio)) mixed solvent, and the precipitate was collected on filter paper and dried to obtain compound (x-3) represented by the following formula (x-3). In the following formula, the numbers accompanying the repeating units represent the molar ratio of each repeating unit. The Mw of the obtained compound (x-3) was 1,800.

[0154] [ka]

[0155] [Comparative Synthesis Example 4] (Synthesis of compound (x'-4)) 10.0 g of fluorene, 7.6 g of 9-fluorenone, 18.1 g of trifluoromethanesulfonic acid, and 70.4 g of nitrobenzene were added to a reaction vessel and reacted at 120°C for 15 hours. After cooling the reaction solution to 30°C, it was added to 200.0 g of methanol / water (80 / 20 (mass ratio)) mixed solvent, and the precipitate was collected on filter paper and dried to obtain compound (x'-4) represented by the following formula (x'-4). The Mw of the obtained compound (x'-4) was 2,500.

[0156] [ka]

[0157] [Comparative Synthesis Example 5] (Synthesis of compound (x-4)) 10.0 g of (x'-4), 0.6 g of tetrabutylammonium iodide, 9.7 g of 25% sodium hydroxide aqueous solution, 2.1 g of 1-pyrenecarboxaldehyde, and 84.5 g of toluene were added to a reaction vessel and reacted at 60°C for 15 hours. After the reaction, 3.8 g of 4-ethynylbenzaldehyde was added and the reaction was continued at 60°C for another 10 hours. After cooling the reaction solution to 30°C, it was added to 100.0 g of methanol, the precipitate was collected on filter paper, and dried to obtain compound (x-4) represented by the following formula (x-4). In the following formula, the numbers accompanying the repeating units represent the molar ratio of each repeating unit. The Mw of the obtained compound (x-4) was 3,200.

[0158] [ka]

[0159] <Preparation of composition> The compounds [A], solvents [B], acid generators [C], and crosslinking agents [D] used in the preparation of the composition are shown below.

[0160] [[A] compound] Examples: Compounds synthesized above (A-1) to (A-10) Comparative example: Compounds (x-1) to (x-4) synthesized above

[0161] [[B] solvent] B-1: Propylene glycol monomethyl ether acetate B-2: Cyclohexanone

[0162] [[C] Acid Generator] C-1: Bis(4-t-butylphenyl)iodonium nonafluoro-n-butanesulfonate (a compound represented by the following formula (C-1))

[0163] [ka]

[0164] [[D] Crosslinking agent] D-1: Compound represented by the following formula (D-1)

[0165] [Chemical formula]

[0166] D-2: Compound represented by the following formula (D-2)

[0167] [Chemical formula]

[0168] [Example 1] [A] 15 parts by mass of (A-1) as a compound was dissolved in 85 parts by mass of (B-2) as a [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).

[0169] [Examples 2 to 15 and Comparative Examples 1 to 4] Compositions (J-2) to (J-15) and (CJ-1) to (CJ-4) were prepared in the same manner as in Example 1, except that each component of the type and content shown in Table 1 below was used. The "-" in the columns of "[A] Compound", "[C] Acid Generator", and "[D] Crosslinking Agent" in Table 1 indicates that the corresponding component was not used.

[0170] [Table 1]

[0171] [Evaluation] Using the above-obtained compositions, the solubility in a polar solvent, etching resistance, and heat resistance were evaluated by the following methods. The evaluation results are shown in Table 2 below.

[0172] [Solubility in a polar solvent] 5.0 g of the resist underlayer film forming composition prepared above was mixed with 3.0 g of 1-methoxy-2-propanol and stirred for 5 minutes, then allowed to stand for 10 minutes. If insoluble matter was observed visually after standing, it was evaluated as "C" (poor). If no insoluble matter was observed, an additional 2.0 g of 1-methoxy-2-propanol was added and stirred for 5 minutes, then allowed to stand for 10 minutes. If insoluble matter was observed visually after standing, it was evaluated as "B" (fairly good), and if no insoluble matter was observed, it was evaluated as "A" (good).

[0173] [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.

[0174] [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.

[0175] [Table 2]

[0176] As can be seen from the results in Table 2, the resist underlayer film formed from the compositions of the examples exhibited excellent solubility in polar solvents, etching resistance, and heat resistance. [Industrial applicability]

[0177] 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 has good solubility in polar solvents and can form a resist underlayer film with excellent etching resistance and heat resistance. Therefore, these can be suitably used in the manufacture of semiconductor devices, for which further miniaturization is expected in the future.

Claims

1. A compound having at least two substructures represented by the following formula (1), solvent and It contains, 【Chemistry 1】 (In the above formula (1), Ar １ and Ar ２ These are substituted or unsubstituted aromatic rings with 5 to 20 members, each independently forming a fused ring structure with two adjacent carbon atoms in formula (1) above. R １ This is at least one group selected from the group consisting of monovalent groups containing substituted or unsubstituted aromatic rings with 5 to 60 members and monovalent groups containing aromatic heterocycles with 5 to 20 members. L is a single bond or a divalent linking group. * and ** indicate the sites in the above compound that bind to parts other than the substructure represented by formula (1) above. m and n are independent integers between 0 and 3, except that m + n is greater than or equal to 1. The above compound, A substructure represented by formula (1) above, wherein R1 is a monovalent group containing a substituted or unsubstituted aromatic hydrocarbon ring with 6 to 60 members, The above R1 is a monovalent group containing an aromatic heterocycle with 5 to 20 members, and the substructure is represented by formula (1) above. A composition having the following characteristics.

2. The above R １ The composition according to claim 1, wherein the aromatic heterocycle has a nitrogen atom.

3. The above Ar １ and Ar ２ The composition according to claim 1 or 2, wherein each aromatic ring is independently 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, and a perylene ring.

4. The above Ar １ and Ar ２ The composition according to claim 1 or 2, wherein the aromatic ring is a benzene ring.

5. The composition according to claim 1 or 2, wherein L is a single bond.

6. The composition according to claim 1 or 2, wherein the above compound is a compound represented by the following formula (1-1). 【Chemistry 2】 (In the above equation (1-1), Ar １ 、Ar ２ 、R １ and L are synonymous with the above formula (1). X is a (p+q) valent group containing a substituted or unsubstituted aromatic ring with 5 to 60 members, an ethendiyl group, or an ethindiyl group. R ３ It is a monovalent group containing an aromatic ring with 5 to 40 members. p is an integer between 2 and 10. If p is 2 or greater, multiple Ar １ Ar ２ , R １ And L are either identical or different from each other. q is an integer between 0 and 10. If q is 2 or greater, multiple R ３ (They are either identical or different from each other.)

7. The composition according to claim 6, wherein the aromatic ring X 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 ３ The composition according to claim 6, 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.

9. The composition according to claim 6, wherein the aromatic ring of X is a benzene ring.

10. The composition according to claim 1 or 2, wherein the compound is a polymer having two or more repeating units of the substructure represented by the above formula (1).

11. The composition according to claim 1 or 2, for forming a resist underlayer film.

12. 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 compound having at least two substructures represented by the following formula (1), solvent and It contains, 【Transformation 3】 (In the above formula (1), Ar １ and Ar ２ These are substituted or unsubstituted aromatic rings with 5 to 20 members, each independently forming a fused ring structure with two adjacent carbon atoms in formula (1) above. R １ This is at least one group selected from the group consisting of monovalent groups containing substituted or unsubstituted aromatic rings with 5 to 60 members and monovalent groups containing aromatic heterocycles with 5 to 20 members. L is a single bond or a divalent linking group. * and ** indicate the sites in the above compound that bind to parts other than the substructure represented by formula (1) above. m and n are independent integers between 0 and 3, except that m + n is greater than or equal to 1. The above compound, A substructure represented by formula (1) above, wherein R1 is a monovalent group containing a substituted or unsubstituted aromatic hydrocarbon ring with 6 to 60 members, The above R1 is a monovalent group containing an aromatic heterocycle with 5 to 20 members, and the substructure is represented by formula (1) above. A composition having the following characteristics.

13. The above R １ A method for manufacturing a semiconductor substrate according to claim 12, wherein the aromatic heterocycle has a nitrogen atom.

14. The above Ar １ and Ar ２ The method for manufacturing a semiconductor substrate according to claim 12 or 13, wherein each aromatic ring is independently 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, and a perylene ring.

15. The above Ar １ and Ar ２ A method for manufacturing a semiconductor substrate according to claim 12 or 13, wherein the aromatic ring is a benzene ring.

16. The method for manufacturing a semiconductor substrate according to claim 12 or 13, wherein L is a single bond.

17. 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 12 or 13, further comprising:

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