Cyanate esters and their uses

Abstract

To provide a cyanate ester having an arene ring and a fluorene ring, and a use thereof.SOLUTION: The cyanate ester is represented by the following formula (1). The cyanate ester is suitable as a resist material for forming a resist underlayer film and / or a resist antireflection film. (In the formula, Z1 and Z2 each represent a benzene ring; Ar1 and Ar2 are the same or different and each represent an arene ring; R1, R2, R3 and R4 are the same or different and each represent a substituent; m and n each represent 0 or an integer of 1 or more; and p and q each represent an integer of 0-4.)SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to cyanate esters having arene rings, such as condensed polycyclic arene rings, and their applications, and in particular to cyanate esters with high etching resistance that are useful as resist materials for forming resist underlayer films, and their applications. [Background technology]

[0002] Cyanate esters form triazine rings through trimerization, creating highly heat-resistant polymers. Therefore, utilizing these properties, cyanate esters are used in a wide range of applications, including prepregs, composite materials, molding materials, printed circuit boards, electronic component encapsulation, and adhesives.

[0003] International Publication No. 2016 / 163456 (Patent Document 1) describes a lithography underlayer film forming material comprising a compound represented by the following formula (O).

[0004] [ka]

[0005] (In formula (O), X represents an oxygen atom or a sulfur atom or a non-bridged state, R 1 R is a 2n-valent group or single bond with 1 to 30 carbon atoms. 2 This includes linear, branched, or cyclic alkyl groups having 1 to 10 carbon atoms, aryl groups having 6 to 10 carbon atoms, linear, branched, or cyclic alkenyl groups having 2 to 10 carbon atoms, and the alkyl groups, alkenyl groups, and aryl groups may also include cyanate groups. (m1 is an integer from 0 to 4, at least one m1 is an integer from 1 to 4, m2 is an integer from 0 to 3 independently, and p is 0 or 1)

[0006] This reference 1 contains R 1The fluorene-9,9-diyl group is given as an example. Examples in this document include dibenzoxanthene disyanate and bis(4,4'-dicyanatobiphenyl-3-yl)biphenylmethane. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] International Publication No. 2016 / 163456 [Overview of the project] [Problems that the invention aims to solve]

[0008] However, this document does not specifically describe cyanate esters containing arene rings and fluorene rings, nor does it mention the use of such cyanate esters as resist materials, particularly as highly etching-resistant underlayer materials (underlayer-forming materials for lithography) or anti-reflective coating materials.

[0009] Therefore, the object of the present invention is to provide cyanate esters having an arene ring and a fluorene ring, and their applications (resist materials).

[0010] Another object of the present invention is to provide a resist underlayer or protective film material, or a resist anti-reflective film material, that has high etching resistance. [Means for solving the problem]

[0011] As a result of diligent research to achieve the above objectives, the inventors of the present invention discovered that cyanate esters in which an arene ring, particularly a condensed polycyclic arene ring, is introduced at the 9,9 position of the fluorene ring exhibit high heat resistance and high etching resistance, and are useful as materials for underlayer films (protective films) and / or anti-reflective films of resists, thus completing the present invention.

[0012] In other words, the cyanate ester of the present invention is represented by the following formula (1).

[0013] [Chemical formula]

[0014] (In the formula, Z 1 and Z 2 each represent the same or different arene rings, Ar 1 and Ar 2 each represent the same or different arene rings, R 1 R 2 R 3 and R 4 each represent the same or different substituents, m and n represent integers of 0 or 1 or more, and p and q represent integers of 0 to 4)

[0015] Z 1 and Z 2 may be a condensed polycyclic arene ring. The cyanate ester may be a compound represented by the following formula (1a).

[0016] [Chemical formula] <00(00242>

[0017] (In the formula, m and n represent integers of 0 to 6, R 1 R 2 R 3 and R 4 , and p and q are the same as in the above formula (1))

[0018] The cyanate ester may be at least one selected from 9,9-bis(6-cyanato-2-naphthyl)fluorene and 9,9-bis(5-cyanato-1-naphthyl)fluorene. The cyanate ester may be in a crystalline form. [[ID=6 ]]

[0019] The present invention also includes a resist material containing the cyanate ester. This resist material may be a resist underlayer film material and / or a resist antireflection film material. Note that the resist The material may further contain an organic solvent.

[0020] The present invention also includes a resist underlayer film and / or resist anti-reflective film (at least one resistance film selected from the resist underlayer film and the resist anti-reflective film, formed from a resist material containing the cyanate ester) said to be a resist material. That is, the resist underlayer film and / or resist anti-reflective film can be formed from the resist material said to be a resist material. The present invention also includes a method for forming the underlayer film and / or anti-reflective film, in which the resist material is applied directly or indirectly to a substrate and heated to form the underlayer film and / or anti-reflective film.

[0021] The present invention also includes a semiconductor device comprising a substrate, an underlying film and / or an anti-reflective film directly or indirectly formed on the substrate, and at least one photoresist layer formed on the underlying film and / or anti-reflective film, wherein at least the photoresist layer is formed in a predetermined pattern. In this semiconductor device, the underlying film and / or anti-reflective film is formed of the resist material.

[0022] Furthermore, the present invention also includes a pattern formation method, in which an underlayer film and / or anti-reflective film is formed on a substrate directly or indirectly with the resist material, at least one photoresist layer is formed on the underlayer film and / or anti-reflective film, and the photoresist layer is developed by irradiating (or exposing) it with energy rays in a predetermined pattern to form a pattern. In this method as well, the underlayer film and / or anti-reflective film is formed with the resist material.

[0023] In the present specification and claims, the number of carbon atoms in the substituent is defined as C1, C6, C 10 These are sometimes used to indicate this. For example, an alkyl group with 1 carbon atom is indicated as "C1 alkyl group", and an aryl group with 6 to 10 carbon atoms is indicated as "C 6-10 It is indicated by the "aryl group".

[0024] Furthermore, in this specification and the claims, the term "fluorene skeleton" (or "fluorene ring") is used to include skeletons that contain a fluorene skeleton, such as a benzofluorene skeleton (benzofluorene ring) and a dibenzofluorene skeleton (dibenzofluorene ring). [Effects of the Invention]

[0025] In this invention, since the cyanate ester has an arene ring and a fluorene ring, it has high heat resistance and etching resistance, making it suitable as a resist material. In particular, it has high etching resistance and is suitable as a material for forming a resist underlayer film (or protective film) and / or resist anti-reflective film. [Brief explanation of the drawing]

[0026] [Figure 1] Figure 1 is a graph showing the relationship between processing time (etching time) and film thickness in the examples and comparative examples. [Modes for carrying out the invention]

[0027] [Cyanate ester] In formula (1) above, which represents the cyanate ester of the present invention, ring Z 1 and ring Z 2 Examples of arene rings represented by include monocyclic arene rings such as benzene rings and polycyclic arene rings; examples of polycyclic arene rings include fused polycyclic arene rings (fused polycyclic aromatic hydrocarbon rings) and ring aggregate arene rings (ring aggregate polycyclic aromatic hydrocarbon rings). Examples of fused polycyclic arene rings include fused bicyclic or tetracyclic arene rings; examples of fused bicyclic arene rings include naphthalene rings and indene rings. 10-16 Examples include arene rings, and fused tricyclic arene rings include anthracene rings and phenanthrene rings. 14-20 Examples include arene rings. Ring-assembly arene rings include biphenyl rings, f Examples include bialene rings such as phenylnaphthalene rings and binaphthyl rings; and telarene rings such as terphenyl rings. Preferred ring-assembled arene rings include C such as biphenyl rings. 12-18 It is a Bialen ring.

[0028] A preferred arene ring is C 6-14 C such as an arene ring, preferably a benzene ring, naphthalene ring, or biphenyl ring. 6-12 C such as an arene ring, more preferably a benzene ring, naphthalene ring, etc. 6-10 An arene ring, particularly a naphthalene ring. Particularly preferred arene rings are fused polycyclic arene rings, preferably fused polycyclic C11 rings. 10-14 It is an arene ring, and more preferably a naphthalene ring. Note that ring Z 1 and ring Z 2 The types may be the same or different from each other, and are preferably the same.

[0029] R 1 and R 2 Substituents represented by include halogen atoms; hydrocarbon groups such as alkyl groups, cycloalkyl groups, aryl groups, and aralkyl groups; alkoxy groups; acyl groups; nitro groups; cyano groups; and substituted amino groups.

[0030] Examples of halogen atoms include fluorine, chlorine, and bromine atoms. Examples of alkyl groups include linear or branched C groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, and t-butyl groups. 1-6 Examples include alkyl groups. Cycloalkyl groups include cyclopentyl groups, cyclohexyl groups, and other C groups. 5-8 Examples include cycloalkyl groups. Aralkyl groups include C such as the benzyl group. 6-10 Aryl-C 1-4 Examples include alkyl groups. Aryl groups include C such as phenyl groups. 6-10 Examples include aryl groups. Examples of alkoxy groups include linear or branched C groups such as methoxy groups. 1-10 Examples include alkoxy groups. Acyl groups include acetyl groups and other C groups. 1-6Examples include acyl groups. Substituted amino groups include dialkylamino groups and diacylamino groups, and dialkylamino groups include diC such as dimethylamino groups. 1-4 Examples include alkylamino groups, and diacylamino groups include diacetylamino groups and other diC groups. 1-4 An example is the acylamino group. 1 and R 2 The substituents represented by may be the same or different, and are preferably the same.

[0031] Preferred R 1 and R 2 C is linear or branched C 1-4 C such as alkyl groups and cyclohexyl groups 5-8 Cycloalkyl groups, C 6-14 Linear or branched carbon atoms such as aryl groups and methoxy groups 1-4 Alkoxy groups; more preferably linear or branched C such as methyl or ethyl groups. 1-3 Alkyl groups; especially C such as methyl groups. 1-2 It is an alkyl group. 1 and R 2 The types may be the same or different from each other, and are preferably the same. 1 or R 2 When is an aryl group, the bonded ring Z 1 , Z 2 Together, they form the aforementioned ring-assembled arene ring.

[0032] R 1 and R 2 The number of substitutions m and n can be 0 or integers greater than or equal to 1, for example, integers from 0 to 8, preferably in the following increments: 0 to 6, 0 to 4, 0 to 3, 0 to 2, 0 or 1, and especially 0. Note that the number of substitutions m and n may be the same or different from each other. If the number of substitutions m or n is 2 or more, then 2 or more R 1 or R 2 The types may be the same or different from each other.

[0033] Ar 1 and Ar 2Examples of arene rings (aromatic hydrocarbon rings) represented by this formula include monocyclic arene rings such as benzene rings, fused polycyclic arene rings, and ring-aggregated arene rings.

[0034] As for condensed polycyclic arene rings, ring Z 1 and ring Z 2 Similar condensed polycyclic C 10-14 Examples include arene rings. A preferred condensed polycyclic arene ring is the naphthalene ring.

[0035] Examples of ring-assembled arene rings include biphenyl rings, binaphthyl rings, and phenylnaphthalene rings. B C 6-12 An example is the arene ring. A preferred ring assembly of arene rings is the biphenyl ring.

[0036] Note that Ar 1 and Ar 2 The types may be the same or different from each other, and are preferably the same. 1 and Ar 2 The preferred arene ring represented by is a benzene ring, a biphenyl ring, or a naphthalene ring.

[0037] Ar 1 and Ar 2 When is a benzene ring, ring Z at position 9 of the fluorene ring. 1 and ring Z 2 The bonding (or substitution) position is not particularly limited, ring Z 1 and ring Z 2 When is a biphenyl ring, it may be at the 3rd or 4th position of the biphenyl ring, preferably at the 3rd position of the biphenyl ring; ring Z 1 and ring Z 2 When is a naphthalene ring, it may be at position 1 or 2 of the naphthalene ring, preferably at position 2 of the naphthalene ring (or in a 2-naphthyl relationship).

[0038] R 3 and R 4 Examples of substituents represented by include halogen atoms, alkyl groups, aryl groups, and cyano groups.

[0039] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, etc. Examples of the alkyl group include linear or branched C 1-6 alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, t-butyl group, etc. Examples of the aryl group include C 6-10 aryl groups such as phenyl group, etc. Incidentally, R 3 and R 4 The substituents represented by may be the same or different.

[0040] Preferred R 3 and R 4 are a halogen atom, a linear or branched C 1-4 alkyl group, a cyano group, more preferably a linear or branched C 1-3 alkyl group such as methyl group, ethyl group, etc., particularly a C 1-2 alkyl group such as methyl group. R 3 and R 4 The types of may be the same as or different from each other, and are preferably the same. <00​​​​​​​​​​​​​​​​​​​​​​​​​​​​2 When is a naphthalene ring, then is a fluorene ring (Ar 1 and Ar 2 The substitution is at one of the positions 5 to 8 of the naphthyl group bonded to the 9th position of the benzene ring at position 1 or 2, and the substitution is at position 1 or 2 of the naphthalene ring to the 9th position of the fluorene ring (substitution in the relationship of 1-naphthyl or 2-naphthyl), and it is preferable that the substitution is at positions 1,5 or 2,6, with substitution at positions 2,6 being particularly preferable.

[0043] Examples of compounds represented by formula (1) include 9,9-bis(cyanatophenyl)fluorene such as 9,9-bis(4-cyanatophenyl)fluorene; 9,9-bis(4-cyanato-3-methylphenyl)fluorene, 9,9-bis(4-cyanato-3,5-dimethylphenyl)fluorene such as 9,9-bis(cyanato-C 1-4 Alkylphenyl)fluorene; 9,9-bis(cyanato-biphenyl)fluorene such as 9,9-bis(4-cyanato-3-phenylphenyl)fluorene; 9,9-bis(5-cyanato-1-naphthyl), 9,9-bis(6-cyanato-2-naphthyl)fluorene, etc., 9,9-bis[cyanato-C 6-12 [Ayl] Fluorene can be used as an example.

[0044] The preferred compound represented by formula (1) is the fluorene ring (Z) represented by formula (1a) below. 1 and Z 2 The naphthalene ring is Ar 1 and Ar 2 Compounds having a benzofluorene ring (Z) represented by the following formula (1b); 1 and Z 2 The naphthalene ring is Ar 1 and Ar 2 Compounds having a dibenzofluorene ring (Z) represented by the following formulas (1c)(1d); and compounds having a dibenzofluorene ring (Z) represented by the following formulas (1c)(1d). 1 and Z 2 The naphthalene ring is Ar 1 and Ar 2It is a compound having a naphthalene ring.

[0045] [ka]

[0046] (In the formula, R 1 , R 2 , R 3 and R 4 (and m, n, p, and q are the same as in formula (1) above) In addition, in formulas (1a), (1b), (1c), and (1d) above, the fluorene ring and the ring corresponding to the fluorene ring are assigned position numbers.

[0047] Examples of such compounds include 9,9-bis(cyanatonaphthyl)fluorene represented by formula (1a), 11,11-bis(cyanatonaphthyl)-2,3-benzofluorene (11,11-bis(cyanatonaphthyl)-11H-benzo[b]fluorene) represented by formula (1b), 13,13-bis(cyanatonaphthyl)-2,3,6,7-dibenzofluorene (13,13-bis(cyanatonaphthyl)-13H-dibenzo[b,h]fluorene) represented by formula (1c), and 13,13-bis(cyanatonaphthyl)-1,2,7,8-dibenzofluorene (13,13-bis(cyanatonaphthyl)-13H-dibenzo[a,i]fluorene) represented by formula (1d). Furthermore, it is preferable that the naphthalene ring is bonded to the fluorene ring and the cyanate group in a 1,5-diyl, 2,6-diyl bond relationship.

[0048] Further preferred compounds include compounds represented by the following formula (1a) (in formula (1) above, Z 1 and Z 2 The naphthalene ring is Ar 1 and Ar 2 This includes compounds in which the ring is a benzene ring.

[0049] [ka]

[0050] (In the formula, R 1 , R 2 , R 3 and R 4 (and m, n, p, and q are the same as in formula (1) above)

[0051] In such compounds, preferred values ​​of m, n, p, and q are all 0. Therefore, preferred cyanate esters include 9,9-bis(cyanatonaphthyl)fluorenes. Examples of the 9,9-bis(cyanatonaphthyl)fluorenes include 9,9-bis(6-cyanato-2-naphthyl)fluorene and 9,9-bis(5-cyanato-1-naphthyl)fluorene. Of these compounds, 9,9-bis(6-cyanato-2-naphthyl)fluorene is particularly preferred.

[0052] Such cyanate esters may be in liquid form at room temperature (20°C), but are preferably in crystalline form. Cyanate esters in crystalline form are easy to handle and are industrially advantageous. For example, in formula (1) above, the ring Ar 1 Ar 2 , Z 1 , and Z 1 The melting point of cyanate esters in which the ring is Ar is 130-170°C, preferably 140-160°C, and particularly 145-150°C. 1 Ar 2 The ring is a benzene ring, and the ring is Z. 1 , and Z 1 The melting point of cyanate esters in which ring Z is a naphthalene ring is 200-240°C, preferably 210-235°C, and particularly 220-230°C. Therefore, ring Z 1 , and Z 1 However, polycyclic arene rings, particularly cyanate esters which are condensed polycyclic arene rings, are suitable for forming highly heat-resistant and etching-resistant films.

[0053] [Method for producing cyanate esters] The cyanate ester represented by formula (1) can be prepared by conventional methods, for example, by reacting a compound represented by formula (2) below with a cyanide halide represented by formula (3) below in a solvent in the presence of a basic compound (such as a tertiary amine like a trialkylamine). The reaction may be carried out in the presence of water and a liquid-liquid-liquid-free solvent. Alternatively, as described in Patent Document 2, the compound represented by formula (2) below and a cyanide halide may be reacted in a two-phase solvent system of water and an organic solvent under acidic conditions in the presence of a tertiary amine.

[0054] [ka]

[0055] (In the formula, X represents a halogen atom, Z 1 , Z 2 Ar 1 Ar 2 , R 1 , R 2 , R 3 and R 4 (and m, n, p, and q are the same as in formula (1) above)

[0056] Examples of cyanogen halides represented by formula (3) above include cyanogen chloride and cyanogen bromide. The amount of cyanogen halide used is 1 mole of hydroxyl groups of the compound represented by formula (2). The amount is 0.7 to 5 moles, preferably 1 to 3.5 moles, and more preferably 1.2 to 3 moles.

[0057] The basic compound may be either an organic base or an inorganic base. Examples of organic bases include trialkylamines such as trimethylamine, triethylamine, and tri-n-butylamine; N,N-dialkylanilines such as N,N-dimethylaniline; aromatic heterocyclic amines such as pyridine; and aliphatic heterocyclic amines such as 1,4-diazabicyclo[2.2.2]octane, 1,8-diazabicyclo[5.4.0]-7-undecene, and 1,5-diazabicyclo[4.3.0]-5-nonene. Preferred organic bases include tri-C15 amines such as trimethylamine, triethylamine, tri-n-butylamine, and diisopropylethylamine. 1-4 It is an alkylamine. The amount of organic base used is 1 to 8 moles, preferably 1.2 to 3.5 moles, per mole of hydroxyl groups of the compound represented by formula (2).

[0058] Examples of inorganic bases include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide; and alkali metal carbonates. A preferred inorganic base is sodium hydroxide. The amount of inorganic base used is 1 to 5 moles, preferably 1.2 to 3.5 moles, per mole of hydroxyl groups of the compound represented by formula (2).

[0059] Examples of solvents include hydrocarbons, halogenated hydrocarbons, ethers, ketones, esters, amides, sulfoxides, and nitriles. These solvents can also be used as mixed solvents, and a mixture of water and a liquid-liquid solvent (a two-phase solvent system of water and an organic solvent) can be used as such.

[0060] Hydrocarbons include aliphatic hydrocarbons such as n-hexane and octane, alicyclic hydrocarbons such as cyclohexane, and aromatic hydrocarbons such as benzene, toluene, and xylene. Halogenated hydrocarbons include dichloromethane, chloroform, carbon tetrachloride, dichloroethane, trichloroethane, chlorobenzene, and bromobenzene. Ethers include diethyl ether, dimethyl cellulose, diglyme, dioxane, and tetrahydrofuran; ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; esters include methyl acetate and ethyl acetate; amides include N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone; sulfoxides include dimethyl sulfoxide; and nitriles include acetonitrile and benzonitrile.

[0061] The reaction can be carried out under atmospheric pressure or under pressure, with a reaction temperature of -20°C to 50°C, preferably -15°C to 25°C, and more preferably -10°C to 15°C. The reaction may also be carried out in an atmosphere of an inert gas such as nitrogen gas or argon gas.

[0062] After the reaction is complete, the cyanate ester (1) can be separated and purified from the reaction mixture by conventional separation methods, such as filtration, washing, concentration, extraction, crystallization, recrystallization, column chromatography, or a combination thereof. For example, the reaction mixture may be concentrated as needed, the precipitate may be filtered off, washed and dried, or the precipitate may be crystallized.

[0063] [Uses of cyanate esters] The compound represented by formula (1) (cyanate ester) has film-forming properties on its own and exhibits higher solubility in organic solvents compared to novolac resins and other materials used as resist underlayers. In particular, it has a high glass transition temperature (heat resistance) and chemical resistance, excellent electrical insulation properties, and forms a cured film with a low dielectric constant and small dielectric loss tangent. Therefore, the cyanate ester may be combined with a resin component to form a resin composition. The resin component is a polyolefin-based resin. Examples of resin components include thermoplastic resins such as lipids, polystyrene resins, polyester resins, polycarbonate resins, polyphenylene ether resins, and polyethersulfone resins, as well as thermosetting resins such as epoxy resins, vinyl ester resins, phenolic resins, bismaleimide resins, oxetane resins, and benzoxazine compounds. These resin components can be used individually or in combination of two or more. Preferred resin components are polyphenylene ether resins, epoxy resins, phenolic resins, and bismaleimide resins.

[0064] Examples of epoxy resins include glycidyl ether type epoxy resins, glycidyl ester type epoxy resins, glycidylamine type epoxy resins, and alicyclic epoxy resins in which a cyclohexene ring is epoxidized. Examples of glycidyl ether type epoxy resins include bisphenol type epoxy resins, novolac type epoxy resins, and naphthalene type epoxy resins.

[0065] Examples of bisphenol-type epoxy resins include biphenyl-type epoxy resins, bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol S-type epoxy resins, bisphenol E-type epoxy resins, bisphenol Z-type epoxy resins, and fluorene-type epoxy resins (9,9-bis(glycidyloxy C 6-10 Examples include aryl fluorenes, etc., and the bisphenol-type epoxy resin may be a phenoxy-type epoxy resin with a large molecular weight. Examples of novolac-type epoxy resins include phenol novolac-type epoxy resins and cresol novolac epoxy resins.

[0066] Examples of phenolic resins include novolac-type phenolic resins and resol-type phenolic resins. The preferred phenolic resin is the novolac-type phenolic resin.

[0067] The content of the compound represented by formula (1) (cyanate ester) is 10 to 120 parts by mass, preferably 20 to 100 parts by mass, and more preferably 25 to 75 parts by mass, per 100 parts by mass of the resin component.

[0068] The resin composition may contain an elastomer and additives. Examples of elastomers include styrene-based elastomers such as styrene-butadiene block copolymer, styrene-isoprene block copolymer, and styrene-hydrogenated butadiene block copolymer; olefin-based elastomers such as ethylene-propylene-based elastomers; polyamide-based elastomers; and polyester-based elastomers. The elastomer content is 0 to 30 parts by mass, preferably 1 to 25 parts by mass, and more preferably 5 to 20 parts by mass, based on 100 parts by mass of the total amount of the cyanate ester and resin components.

[0069] Examples of additives include fillers, silane coupling agents, stabilizers (antioxidants, UV absorbers, preservatives, etc.), curing agents depending on the thermosetting resin, antistatic agents, flame retardants, defoamers, leveling agents, and colorants.

[0070] Examples of fillers include inorganic fillers such as carbon black, silica, titanium dioxide, aluminum oxide, zirconium oxide, zinc oxide, barium sulfate, clay, kaolin, and talc, as well as fibrous fillers such as glass fibers and carbon fibers. The amount of filler used is 10 to 250 parts by mass, preferably 25 to 200 parts by mass, and more preferably 50 to 150 parts by mass, per 100 parts by mass of the total amount of the cyanate ester and resin components.

[0071] Silane coupling agents include epoxy group-containing silane coupling agents such as 3-glycidyloxypropyltrimethoxysilane and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; vinyl-containing silane coupling agents such as 3-(meth)acryloyloxypropyltrimethoxysilane, vinyltrimethoxysilane, and vinyl-tri(2-methoxyethoxy)silane. Silane coupling agents containing amino groups; examples include amino group-containing silane coupling agents such as 3-aminopropyltriethoxysilane, 3-(2-aminoethylamino)propyldimethoxymethylsilane, and N-2-(aminoethyl)-3-aminopropyltrimethoxylane. These silane coupling agents can be used alone or in combination of two or more.

[0072] The amount of silane coupling agent used is 0.1 to 30 parts by mass, preferably 0.5 to 20 parts by mass, and more preferably 1 to 10 parts by mass, based on 100 parts by mass of the total amount of the cyanate ester and resin components.

[0073] Such resin compositions can be effectively used as prepregs, laminates (including metal foil-clad laminates), printed circuit boards (including multilayer printed circuit boards), sealants, and the like.

[0074] [Resist material] Furthermore, the cyanate ester forms a cured film (resistance film) with high etching resistance (or radiation resistance, high-energy ray resistance), and this cured film also has anti-reflective properties. Therefore, the cyanate ester is suitable as a resist material, particularly as a material for forming a protective film, such as a resist underlayer film and / or an anti-reflective film (at least one resistance film selected from the resist underlayer film and the resist anti-reflective film), in pattern formation where a predetermined pattern (or circuit pattern) is formed by lithography.

[0075] The resist material (composition) of the present invention may contain at least a cyanate ester represented by formula (1) (first cyanate ester), and may also contain a second cyanate ester if necessary. Examples of the second cyanate ester include biphenyl-type dicyanate ester, cyanate ester having a bisphenol fluorene skeleton, cyanate ester having a bisphenol alkane skeleton, cyanate ester having a triphenol alkane skeleton, and novolac-type cyanate ester.

[0076] Examples of cyanate esters having a bisphenol fluorene skeleton include 9,9-bis(4-cyanatophenyl)-9H-fluorene, 9,9-bis(3-methyl-4-cyanatophenyl)-9H-fluorene, 9,9-bis(3,5-dimethyl-4-cyanatophenyl)-9H-fluorene, and 9,9-bis[4-cyanato-3-phenylphenyl]fluorene. Examples of cyanate esters having a bisphenol alkane skeleton include bisphenol A-type dicyanate, bisphenol AP-type dicyanate, bisphenol B-type dicyanate, bisphenol C-type dicyanate, bisphenol E-type dicyanate, bisphenol F-type dicyanate, bisphenol AD-type dicyanate, bisphenol S-type dicyanate, and bisphenol Z-type dicyanate. Examples of cyanate esters having a triphenol alkane skeleton include tris(4-cyanatophenyl)methane and tris(4-cyanatophenyl)ethane, while examples of novolac-type cyanate esters include phenol novolac-type cyanate esters and cresol novolac-type cyanate esters.

[0077] The amount of the second cyanate ester used can be selected from the range of 0 to 100 parts by mass per 100 parts by mass of the first cyanate ester, and is preferably 2 to 75 parts by mass, preferably 5 to 60 parts by mass, and more preferably 10 to 50 parts by mass.

[0078] A cyanate ester containing at least the first cyanate ester may be used as is as a resist material. A preferred resist material (composition) contains an organic solvent in addition to the cyanate ester.

[0079] The organic solvent may be a hydrocarbon solvent, a ketone solvent, an ester solvent, or a cellosolve solvent. Examples of hydrocarbon solvents include alicyclic hydrocarbon solvents such as cyclohexane, and aromatic hydrocarbon solvents such as toluene and xylene. Examples of ketone solvents include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Examples of ester solvents include methyl acetate, ethyl acetate, butyl acetate, isoamyl acetate, and ethyl lactate. Examples of cellosolve-based solvents include cellosolves such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve; cellosolve acetates such as ethyl cellosolve acetate and butyl cellosolve acetate; carbitols such as methyl carbitol and ethyl carbitol; carbitol acetates such as methyl carbitol acetate, ethyl carbitol acetate, and butyl carbitol acetate; and propylene glycol monomethyl ether, propylene glycol monoethyl ether (1-ethoxy-2-propanol), propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate. Organic solvents can be used alone or in combination of two or more.

[0080] The compound represented by formula (1) (cyanate ester) is curable by heating. Therefore, although not strictly necessary, the resist material may contain an acid catalyst (acid generator), a crosslinking agent, etc.

[0081] The acid generator accelerates the curing of the cyanate ester and may be either a photoacid generator or a thermoacid generator. Examples of acid generators include onium salts, diazomethane derivatives, glyoxime derivatives, and sulfonic acid esters.

[0082] Examples of onium salts include sulfonium trifluoromethanesulfonate salt and sulfonium p-toluenesulfonate salt. Examples of sulfonium trifluoromethanesulfonate salts include triphenylsulfonium, (pt-butoxyphenyl)diphenylsulfonium trifluoromethanesulfonate, tris(pt-butoxyphenyl)sulfonium trifluoromethanesulfonate, trinaphthylsulfonium trifluoromethanesulfonate, cyclohexylmethyl(2-oxocyclohexyl)sulfonium trifluoromethanesulfonate, and (2-norbonyl)methyl(2-oxocyclohexyl)sulfonium trifluoromethanesulfonate; examples of sulfonium p-toluenesulfonate salts include triphenylsulfonium p-toluenesulfonate, (pt-butoxyphenyl)diphenylsulfonium p-toluenesulfonate, and tris(pt-butoxyphenyl)sulfonium p-toluenesulfonate. Examples of diazomethane derivatives include bis(benzenesulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(naphthalenesulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(n-butylsulfonyl)diazomethane, bis(isobutylsulfonyl)diazomethane, bis(isopropylsulfonyl)diazomethane, and bis(t-butylsulfonyl)diazomethane.

[0083] Examples of glyoxime derivatives include bis-(p-toluenesulfonyl)-α-dimethylglyoxime and bis-(n-butanesulfonyl)-α-dimethylglyoxime. Examples of sulfonic acid esters include sulfonic acid ester derivatives of N-hydroxyimide compounds such as N-hydroxysuccinidomidemethanesulfonic acid, N-hydroxysuccinidomidetrifluoromethanesulfonic acid, N-hydroxysuccinidomide 1-propanesulfonic acid, N-hydroxysuccinidomide 2-propanesulfonic acid, N-hydroxysuccinidomide 1-pentanesulfonic acid, N-hydroxysuccinidomidep-toluenesulfonic acid, N-hydroxynaphthalimidemethanesulfonic acid, and N-hydroxynaphthalimidebenzenesulfonic acid; and nitrobenzyl sulfonates such as p-toluenesulfonic acid 2,6-dinitrobenzyl. Examples of trissulfonyloxybenzenes include 1,2,3-tris(methanesulfonyloxy)benzene, 1,2,3-tris(trifluoromethanesulfonyloxy)benzene, and 1,2,3-tris(p-toluenesulfonyloxy)benzene.

[0084] The acid generator content is 0 to 50 parts by mass, preferably 1 to 30 parts by mass, and more preferably 2 to 15 parts by mass, per 100 parts by mass of cyanate ester.

[0085] Furthermore, the resist material containing the acid generator may also contain a basic compound to improve storage stability. This basic compound acts as a quencher, capturing trace amounts of acid generated from the acid generator, and is effective in improving the crosslinking reaction.

[0086] The basic compound may be either an organic base or an inorganic base, and the organic base may be any of the amines (primary amines, secondary amines, or tertiary amines). Preferred basic compounds are organic bases, especially tertiary amines. Examples of amines including tertiary amines include trimethylamine and triethylamine. 1-10Alkylamines; such as N,N,N',N'-tetramethylethylenediamine and other tetra-C 1-4 Alkylalkylenediamines; alkanolamines such as triethanolamine and dimethylaminoethanol; N,N-diC2s such as N,N-dimethylaniline 1-4 Alkyl C 6-10 DiC such as allenes and benzyldimethylamine. 1-4 Alkylamino C 1-4 Alkyl C 6-10 Examples of heterocyclic amines include arenes, morpholine, N-methylmorpholine, N-methylpiperidine, pyridine, 4-dimethylaminopyridine, N-methylpyrrolidone, 1,4-diazabicyclo[2.2.2]octane (DABCO), diazabicycloundecene (DBU), and diazabicyclononene (DBN).

[0087] The basic compound content is 0 to 2 parts by mass, preferably 0 to 1 part by mass, per 100 parts by mass of the resist material.

[0088] Examples of crosslinking agents include melamines, guanamines (benzoguanamines), ureas, epoxy compounds, vinyl ethers, and azides.

[0089] Examples of melamines include hexamethylolmelamine and hexamethoxymethylmelamine; examples of guanamines include tetramethylolguanamine and tetramethoxymethylguanamine; and examples of ureas include tetramethylolurea and tetramethoxymethylurea. Epoxy compounds include compounds having 2 or more, preferably 3 to 6, epoxy groups. Examples of such compounds include ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, glycerin triglycidyl ether, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, and tris(2,3-epoxypropyl) triisocyanurate. Vinyl ethers include compounds having two or more, preferably three to six, vinyl ether groups in one molecule. Examples of such compounds include ethylene glycol divinyl ether, triethylene glycol divinyl ether, propylene glycol divinyl ether, butanediol divinyl ether, neopentyl glycol divinyl ether, trimethylolpropane trivinyl ether, 1,4-cyclohexanediol divinyl ether, and pentaerythritol tetravinyl ether.

[0090] The crosslinking agent content is 0 to 50 parts by mass, preferably 1 to 30 parts by mass, and more preferably 3 to 15 parts by mass, per 100 parts by mass of cyanate ester.

[0091] The resist material may contain additives as needed. Such additives include stabilizers (antioxidants, preservatives, etc.), UV absorbers, surfactants, and antistatic agents. Examples include flame retardants and colorants.

[0092] A resist film can be formed by applying a resist material directly or indirectly to a substrate (or base material) in a conventional manner, and then heating or baking the resulting coating film, which may be cured. More specifically, a resist pattern can be formed by applying the resist material to a substrate to form an underlayer film (or coating film), forming at least one photoresist layer on this underlayer film, exposing or irradiating this photoresist layer with energy rays or radiation of a predetermined wavelength in a predetermined pattern, and then developing it to form a predetermined resist pattern (or circuit pattern).

[0093] Furthermore, the resist film or underlying film has the property of absorbing the energy rays or radiation, and also functions as an anti-reflective film. Therefore, the resist material is suitable for forming the underlying film and / or anti-reflective film.

[0094] As the substrate (or base material), any known substrate can be used, and examples include substrates made of silicon, silicon nitride, titanium nitride, aluminum, etc. The substrate may also be a laminate in which the film to be processed is laminated on a base material (support).

[0095] An adhesion layer may be formed on the surface of the substrate (or base material) to enhance adhesion with the resist film. For applying the resist material to the substrate (or base material), coating methods such as spin coating and printing methods such as screen printing can be used.

[0096] The underlayer film (or coating film) is preferably formed by applying a resist material to the substrate (or base material), removing the solvent by drying, and then heating or baking to cure it. The heating or baking temperature can be selected from the range of 80 to 400°C, preferably 100 to 300°C, and more preferably 150 to 250°C. The thickness of the underlayer film is 10 nm to 10 μm, preferably 20 to 1000 nm, and more preferably 50 to 800 nm.

[0097] The intermediate layer may be formed with a resist containing a polysilsesquioxane derivative to enhance oxygen gas etching resistance, or it may be formed using PVD (physical vapor deposition) or CVD (chemical vapor deposition). Furthermore, forming a silicon-containing film such as silicon oxide, silicon nitride, or a SiON film as the intermediate layer can increase the absorbance of light of a predetermined wavelength and also provide anti-reflective properties.

[0098] The photoresist layer can utilize conventional photoresists (positive or negative type photoresists), and for fine pattern formation, positive type photoresists, particularly chemically amplified positive type photoresists, can be used. The photoresist can be made of a material that is photosensitive to high-energy rays with wavelengths of 300 nm or less. Specifically, materials that are photosensitive to excimer lasers at 248 nm, 193 nm, and 157 nm, soft X-rays at 3 to 20 nm, electron beams, and X-rays can be used. Typical photoresists contain organic solvents, acid generators, and especially photoacid generators, as described above.

[0099] The photoresist layer can be formed by applying a photoresist material to a lower or intermediate layer using a wet method such as spin coating or screen printing, as described above, and then pre-baking (PAB) at 80-180°C. The thickness of the coating layer is 20-500 nm, preferably 50-300 nm. A resist pattern can be formed by pattern exposure of the coating layer, post-exposure baking (PEB), and development.

[0100] Furthermore, when etching using a resist pattern as a mask, etching gas can be used. Examples of etching gases include inert gases such as oxygen, helium, and argon, as well as hydrogen, nitrogen, carbon monoxide, carbon dioxide, ammonia, nitrogen dioxide, and sulfur dioxide. These etching gases can also be used as mixed gases. The preferred etching gas is oxygen. [Examples]

[0101] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples. The evaluation methods in the examples and comparative examples are as follows.

[0102] 1 ¹H-NMR: Using a nuclear magnetic resonance spectrometer (BRUKER ADVANCE III HD), with tetramethylsilane as the internal standard and CDCl3 as the solvent, 1 The 1H-NMR spectrum was measured.

[0103] Melting point: The melting point was measured using a differential scanning calorimeter (EXSTAR DSC6200, manufactured by SII Nanotechnology Co., Ltd.) under a nitrogen atmosphere, with a measurement temperature of 30-300°C and a heating rate of 10°C / min. From the obtained DSC chart (DSC curve), the temperature at the peak of the endothermic peak due to melting was determined as the melting point.

[0104] (Heat resistance (weight loss temperature)) The 5% and 10% weight loss temperatures were measured using a differential thermogravimetric analyzer (Hitachi High-Tech Science, Ltd., "TG / DTA6200") under the following conditions.

[0105] Measurement temperature range: 30~520℃ Temperature increase: 10℃ / min Gas atmosphere: Under a nitrogen atmosphere.

[0106] (heated residue) The sample was heated to 180°C, and the weight loss was measured after it had stopped changing weight and was left standing for 1 minute.

[0107] (purity) Liquid chromatography (LC, Shimadzu Corporation, "LC-2010A") was used, and the elutions were measured using acetonitrile / water (volume ratio) = 70 / 30 → 95 / 5 → 70 / 30.

[0108] (Refractive index) The refractive index was measured using a refractometer (ATAGO DR-M2) at a measurement temperature of 25°C and a wavelength of 589 nm.

[0109] Synthesis Example 1 (Synthesis of 9,9-bis(6-cyanato-2-naphthyl)fluorene) In a reactor equipped with a stirrer, dropping funnel, thermometer, and three-way stopcock, 284 g (0.63 mol) of 9,9-bis(6-hydroxy-2-naphthyl)fluorene (BNF) (manufactured by Osaka Gas Chemical Co., Ltd.) was charged, the mixture was purged with nitrogen gas, and then 2000 ml of tetrahydrofuran was added and dissolved. The mixture was then cooled to an internal temperature of 5°C or below.

[0110] 276 g (2.52 mol) of bromosyanide was added in portions over 5 minutes and dissolved. The internal temperature was then cooled to below 0°C. While maintaining the internal temperature at 0-10°C, 350 ml (2.52 mol) of triethylamine was added over 150 minutes. The temperature was then raised to room temperature, and the reaction was continued for 45 hours. The reaction solution was analyzed by high-performance liquid chromatography (HPLC) to confirm that the starting materials had disappeared.

[0111] The precipitate was filtered off, washed with tetrahydrofuran, and the filtrate and washing solution were collected and concentrated under reduced pressure and heated to obtain 273 g of yellowish-brown mud (crude product yield 86.6%).

[0112] Next, 273 g of the yellowish-brown muddy substance was dissolved in 1000 ml of chloroform at 65°C, then 600 ml of ethyl acetate was added, and the mixture was cooled to room temperature for 60 minutes under stirring. After standing at 0°C for 30 minutes, it was left to stand overnight at -20°C. The precipitate was filtered off, washed with a chloroform / ethyl acetate / 0.6 L (volume ratio 1:1) mixture cooled to -20°C, and then dried under reduced pressure to obtain 9,9-bis(6-cyanato-2-naphthyl)fluorene (BNF cyanate ester), represented by the following formula, as crystals.

[0113] [ka]

[0114] NMR: 1H-NMR (CDCl3, 300MHz) δ (ppm): 7.3 (m, 2H), 7.5 (d, 6H), 7.6 (d, 2H), 7.7 (s, 2H), 8.0 (m, 8H) Melting point: 224°C.

[0115] Synthesis Example 2 (Synthesis of 9,9-bis(4-cyanatophenyl)fluorene) Except for using 9,9-bis(4-hydroxyphenyl)fluorene (BPF, manufactured by Osaka Gas Chemical Co., Ltd.) instead of 9,9-bis(6-hydroxy-2-naphthyl)fluorene (BNF), 9,9-bis(4-hydroxyphenyl)fluorene (BPF cyanate ester), represented by the following formula, was obtained as crystals in the same manner as in Synthesis Example 1.

[0116] [ka]

[0117] NMR: 1 H-NMR (CDCl3, 300MHz) δ (ppm): 7.2-7.4 (m, 14H), 7.9 (d, 2H) Melting point: 147°C.

[0118] [Examples 1 and 2 and Comparative Examples 1 and 2] Each resist composition with the following composition was applied to a silicon substrate using a spin coater, and then heated (pre-baked; PAB) for a predetermined temperature and time as described below to form a cured film of a predetermined thickness.

[0119] Example 1: Cyclohexanone solution containing 10% by mass of the BNF cyanate ester from Synthesis Example 1 (cured film thickness: 400 nm, PAB: 200°C / 90 seconds) Example 2: Cyclohexa containing the BPF cyanate ester from Synthesis Example 2 at a concentration of 10% by mass. Non-solution (cured film thickness: 250 nm, PAB: 120°C / 90 seconds) Comparative Example 1: BisA cyanate ester: 2,2-bis(4-cyanatophenyl)propane (Kanto Chemical Co., Ltd.) Comparative Example 2: ArF resist (TArF-P6111, polymer having an acrylic lactone skeleton: Tokyo Ohka Kogyo Co., Ltd.) (Cured film thickness: 260 nm, PAB: 130°C / 60 seconds)

[0120] In Comparative Example 1, attempts were made to cure BisA cyanate ester under various temperature conditions, but it did not cure. Instead, it melted, crystallized, and sublimated upon heating, making it difficult to form a cured film on its own. In contrast, cyanate esters having a fluorene skeleton (BNF cyanate ester and BPF cyanate ester) readily formed a cured film upon heating.

[0121] Reactive ion etching (RIE) test Then, reactive ion etching (RIE) tests were performed under the following conditions, and the etching rates of the cyanate esters in Examples 1 and 2 were evaluated, with the etching rate of Comparative Example 2 (ArF resist) set to "1". Specifically, three silicon wafers with cured films of each resist composition formed on them were prepared as described above, and test pieces were made by applying masking tape across the center of each silicon wafer. All test pieces were placed in the chamber of the reactive ion etching (RIE) apparatus, and reactive ion etching was performed under the following conditions. In Example 1 and Comparative Example 2, one test piece was removed sequentially for each resist composition's cured film after 30 seconds, 60 seconds, and 120 seconds from the start of etching. In Example 2, one test piece was removed after 60 seconds, 90 seconds, and 120 seconds from the start of etching. The test was terminated by visually confirming whether the bottom of the chamber was discolored or whether the cured film had disappeared and the silicon substrate was exposed. This procedure was repeated four times.

[0122] [RIE Dry Etching Conditions] Gas types: CF4 = 100 ml / min, O2 = 2 ml / min RF output: 150W Pressure: 10 Pa Time: 30 seconds → 60 seconds → 120 seconds

[0123] Film thickness T (nm) and etching time ET The etching rate formula was derived from the relationship with (seconds). Figure 1 shows the relationship between etching time (processing time) and film thickness.

[0124] The etching rate formula and etching rate were as follows. Example 1 (BNF cyanate ester): T = -0.848 × E T +400 Etching speed: 0.848 nm / second Example 2 (BPF cyanate ester): T = -1.08 × E T +254 Etching speed: 1.08 nm / second Comparative Example 2 (ArF resist): T = -1.50 × E T +269 Etching speed: 1.50 nm / second

[0125] When the etching rate of Comparative Example 2 (ArF resist) was set to "1.0", the etching rate ratio of Example 1 (BNF cyanate ester) and Example 2 (BPF cyanate ester) was as follows.

[0126] Comparative Example 2 (ArF resist) / Example 2 (BPF cyanate ester) / Example 1 (BNF cyanate ester) = 1.0 / 0.72 / 0.56

[0127] As is clear from this etching rate ratio and the slope of the graph in Figure 1, Example 2 (BPF cyanate ester) showed higher etching resistance compared to Comparative Example 2 (ArF resist), and in particular, Example 1 (BNF cyanate ester) was confirmed to have high etching resistance. [Industrial applicability]

[0128] The cyanate ester of the present invention forms a cured film with high heat resistance and chemical resistance. Therefore, the cyanate ester can be used as a modifier for various thermosetting resins. It can also be used in combination with epoxy resins, phenolic resins, bismaleimide resins, etc., as paints, inks, adhesives, etc., and is suitable for forming resin compositions (including flame-retardant resin compositions) suitable for structural materials. In particular, because it has high electrical insulation properties and a low dielectric loss tangent in dielectric constant, the cyanate ester and resin compositions are suitable as electrical and electronic materials, and compositions containing the cyanate ester can be used as prepregs, composite materials, molding materials, printed circuit boards, and encapsulants for electronic components. Furthermore, it can form a cured film with high etching resistance. Therefore, the cyanate ester can be used as a component of resist materials (compositions), and is advantageous for forming resistant films such as underlayer films (protective films) and anti-reflective films in the manufacture of semiconductor devices in which microfabrication or predetermined patterns (circuit patterns) are formed by lithography using photoresist materials.

Claims

1. A resist material containing a cyanate ester represented by the following formula (1). 【Chemistry 1】 (In the formula, Z １ and Z ２ Each of these represents a benzene ring, and Ar １ and Ar ２ Each of these represents the same or different arene ring, R １ , R ２ , R ３ and R ４ (Each of the ampersands represents the same or different substituents, m and n represent integers of 0 or 1 or greater, and p and q represent integers from 0 to 4.)

2. The resist material according to claim 1, wherein the cyanate ester is in crystalline form.

3. The resist material according to claim 1 or 2, which is at least one selected from a resist underlayer material and a resist anti-reflective coating material.

4. Furthermore, the resist material according to any one of claims 1 to 3, further comprising an organic solvent.

5. A resistance film formed from the resist material described in any one of claims 1 to 4, wherein at least one resistance film is selected from a resist underlayer film and a resist anti-reflective film.

6. A method for forming a base layer film and / or anti-reflective film by directly or indirectly applying a resist material according to any one of claims 1 to 4 to a substrate and heating it.

7. A semiconductor element comprising a substrate, an underlayer film and / or anti-reflective film directly or indirectly formed on the substrate, and at least one photoresist layer formed on the underlayer film and / or anti-reflective film, wherein at least the photoresist layer is formed in a predetermined pattern, and the underlayer film and / or anti-reflective film is formed of a resist material according to any one of claims 1 to 4.

8. A pattern forming method comprising: directly or indirectly forming an underlayer film and / or anti-reflective film on a substrate; forming at least one photoresist layer on the underlayer film and / or anti-reflective film; and developing the photoresist layer by irradiating it with energy rays in a predetermined pattern, wherein the underlayer film and / or anti-reflective film is formed of a resist material according to any one of claims 1 to 4.

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