JP5095299B2 - Ethinyl group-containing bridged alicyclic compound, insulating film forming material, insulating film and method for producing the same - Google Patents

Description

  The present invention relates to an insulating film for use in the production of a semiconductor, particularly an insulating film having excellent heat resistance and mechanical strength and exhibiting a low relative dielectric constant, a method for producing the same, a polymerizable compound useful for obtaining the insulating film, and an insulating film The present invention relates to a forming material and a polymer having a pore structure.

  2. Description of the Related Art In recent years, in a semiconductor process in which circuit patterns are becoming finer, a lower dielectric constant of an interlayer insulating film is required. It is said that the construction of a hole structure is effective for lowering the dielectric constant of an interlayer insulating film. For silicon oxide-based interlayer insulating films, introduction of a hole structure using a foaming agent or the like has been proposed. . However, although this method can form vacancies, it is difficult to avoid linking of vacancies (continuation of vacancies), so there are difficulties in mechanical strength and thermal stability. The process had serious problems such as film breakage.

  The inventors of the present invention have found that an insulating film having pores at a molecular level formed by polymerization of a polyfunctional crosslinkable monomer can achieve both low dielectric constant and high mechanical strength ( For example, refer to Japanese Patent Application Laid-Open No. 2004-307804). However, the insulating film has a problem in that the dielectric constant tends to vary because many unreacted terminals remain. Further, in the current situation where higher integration of semiconductors is progressing, there is a demand for further reduction in relative dielectric constant.

JP 2004-307804 A

  An object of the present invention is to form a polymer and an insulating film having a high heat resistance and an extremely low relative dielectric constant useful for manufacturing semiconductors, and having a pore structure with little variation in relative dielectric constant, and a method for manufacturing the same. Another object is to provide an insulating film forming material and a polymerizable compound.

  As a result of intensive studies to achieve the above object, the present inventors have found that when an ethynyl group-containing bridged alicyclic compound having a specific structure is polymerized, an insulating film having an extremely low relative permittivity and a small variation in relative permittivity is obtained. The present invention has been completed by finding that it can be obtained well.

（式中、Ｚはアダマンタン−１，３，５，７−テトライル基を示し、Ｘは下記式（３ａ’）〜（３ｖ’）

（式中、Ａは、−ＮＨ−、酸素原子又は硫黄原子を示す。ｓは０〜５の整数を示す）
で表される基、又はこれらが２以上結合した基から選択される基を示し、Ｙは炭素数１〜１０のアルキル基、炭素数６〜２０のアリール基、トリメチルシリル、及びトリエチルシリル基から選択される置換基を有していてもよいエチニル基、又は前記置換基を有していてもよいエチニルフェニル基を示す。Ｒは水素原子、又は炭素数１〜６のアルキル基、炭素数６〜１４の芳香族炭化水素基から選択される炭化水素基を示す。ｍは１〜５の整数、ｎは３又は４を示す。ｎ＋ｋ＝４である。分子内の複数のＸ、Ｙは、それぞれ同一であっても異なっていてもよい）
で表されるエチニル基含有有橋脂環式化合物を提供する。 That is, the present invention provides the following formula (1 ′ )

(In the formula, Z represents an adamantane-1,3,5,7-tetrayl group , and X represents the following formulas (3a ′) to (3v ′)).

(In formula, A shows -NH-, an oxygen atom, or a sulfur atom. S shows the integer of 0-5.)
Or a group selected from a group in which two or more thereof are bonded , and Y is selected from an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, trimethylsilyl, and a triethylsilyl group The ethynyl group which may have a substituent and the ethynylphenyl group which may have the said substituent is shown. R represents a hydrogen atom or a hydrocarbon group selected from an alkyl group having 1 to 6 carbon atoms and an aromatic hydrocarbon group having 6 to 14 carbon atoms . m represents an integer of 1 to 5, and n represents 3 or 4 . n + k = 4 . A plurality of X and Y in the molecule may be the same or different)
An ethynyl group-containing bridged alicyclic compound represented by the formula:

  The present invention also provides an insulating film forming material containing the ethynyl group-containing bridged alicyclic compound.

  This insulating film forming material may contain another ethynyl group-containing compound together with the ethynyl group-containing bridged alicyclic compound.

  The insulating film forming material includes a solution in which an ethynyl group-containing bridged alicyclic compound is dissolved in an organic solvent.

  The present invention further provides a polymer having a pore structure obtained by subjecting the insulating film forming material to a polymerization reaction.

  The present invention further provides an insulating film made of a polymer having the pore structure.

（式中、Ｚは有橋脂環骨格を示し、Ｘは複素環又はその前駆構造を含む２価以上の有機基を示し、Ｙは置換基を有していてもよいエチニル基を含む基を示す。Ｒは水素原子又は炭化水素基を示す。ｍは１〜５の整数、ｎは２〜７の整数、ｋは０〜５の整数を示す。ｎ＋ｋ＝２〜７である。分子内の複数のＸ、Ｙ、及び複数存在する場合のＲは、それぞれ同一であっても異なっていてもよい）
で表されるエチニル基含有有橋脂環式化合物、Ｚにおける有橋脂環骨格に係る有橋脂環が下記式

から選ばれる環、又はこれらが２以上結合した環である前記エチニル基含有有橋脂環式化合物、Ｘにおける複素環又はその前駆構造を含む２価以上の有機基が、イミダゾリル基、ベンズイミダゾリル基、オキサゾリル基、ベンズオキサゾリル基、チアゾリル基、ベンズチアゾリル基、これらの複素環式基の前駆体となる基、前記複素環式基又はその前駆体となる基が２以上結合した基、又は前記複素環式基又はその前駆体となる基の１又は２以上と芳香族炭化水素基が結合した基である前記エチニル基含有有橋脂環式化合物、Ｘにおける複素環又はその前駆構造を含む２価以上の有機基が下記式

（式中、Ａは、−ＮＨ−、酸素原子又は硫黄原子を示す。ｓは０〜５の整数を示す。式中の各環は置換基を有していてもよい）
から選ばれる基、又はこれらが２以上結合した基である前記エチニル基含有有橋脂環式化合物についても記載する。
The present invention also provides a method for producing an insulating film, characterized in that after the insulating film forming material is applied onto a substrate, an insulating film made of a polymer having a pore structure is formed by a polymerization reaction. provide.
In this specification, in addition to the above invention, the following formula (1)

(In the formula, Z represents a bridged alicyclic skeleton, X represents a divalent or higher valent organic group including a heterocyclic ring or a precursor structure thereof, and Y represents a group including an ethynyl group which may have a substituent. R represents a hydrogen atom or a hydrocarbon group, m represents an integer of 1 to 5, n represents an integer of 2 to 7, k represents an integer of 0 to 5. n + k = 2 to 7. A plurality of X, Y, and a plurality of Rs may be the same or different)
The ethynyl group-containing bridged alicyclic compound represented by the formula:

The ethynyl group-containing bridged alicyclic compound, which is a ring selected from the above, or a ring in which two or more of these are bonded, a divalent or higher valent organic group containing a heterocyclic ring or a precursor structure thereof in X is an imidazolyl group or a benzimidazolyl group , An oxazolyl group, a benzoxazolyl group, a thiazolyl group, a benzthiazolyl group, a group that is a precursor of these heterocyclic groups, a group in which two or more of the heterocyclic groups or groups that are precursors thereof are bonded, or The ethynyl group-containing bridged alicyclic compound, which is a group in which an aromatic hydrocarbon group is bonded to one or two or more of a heterocyclic group or a precursor thereof, 2 containing a heterocyclic ring in X or a precursor structure thereof An organic group having a valence greater than

(In the formula, A represents —NH—, an oxygen atom or a sulfur atom. S represents an integer of 0 to 5. Each ring in the formula may have a substituent)
The ethynyl group-containing bridged alicyclic compound which is a group selected from the above or a group in which two or more of these are bonded is also described.

  The ethynyl group-containing bridged alicyclic compound of the present invention has a bridged alicyclic skeleton as a central skeleton, and the group containing an ethynyl group that may have a substituent in the bridged alicyclic skeleton contains a heterocyclic ring. Since it has a structure bonded through an organic group having a valence or higher, a polymer having a pore structure with a low relative dielectric constant and an insulating film can be obtained by polymerization. Further, since the ethynyl group has a property of not lowering the dielectric constant even if it remains unreacted, variation in the relative dielectric constant of the insulating film can be suppressed. The insulating film obtained by polymerizing the ethynyl group-containing bridged alicyclic compound of the present invention has high heat resistance and mechanical strength.

  The ethynyl group-containing bridged alicyclic compound of the present invention is represented by the formula (1). In the formula, Z represents a bridged alicyclic skeleton, X represents a divalent or higher-valent organic group containing a heterocyclic ring or a precursor structure thereof, and Y represents a group containing an ethynyl group which may have a substituent. . R represents a hydrogen atom or a hydrocarbon group.

  Representative examples of the bridged alicyclic skeleton as the central skeleton Z include rings represented by the above formulas (2a) to (2j), or rings in which two or more (for example, 2 to 3) are bonded. .

  Preferred examples of the bridged alicyclic skeleton include an adamantane skeleton (adamantane-1,3,5,7-tetrayl group, etc.), a biadamantane skeleton, a tetraphenyladamantane skeleton, a norbornane skeleton, a tetramethylnorbornane skeleton, a norbornene skeleton, Examples include a tetramethylnorbornene skeleton. The molecular weight of the central skeleton is, for example, about 40 to 1460, preferably about 60 to 500.

  In the divalent or higher valent organic group containing the heterocyclic ring or its precursor structure in X, examples of the heterocyclic ring include an imidazole ring, a benzimidazole ring, an oxazole ring, a benzoxazole ring, a thiazole ring, and a benzthiazole ring. Among these, a benzimidazole ring, a benzoxazole ring, and a benzthiazole ring are preferable in terms of heat resistance.

  X may be composed only of a heterocycle or a precursor structure thereof, or may be composed of a heterocycle or a precursor structure thereof and an aromatic carbocycle. Preferred X is an imidazolyl group, a benzimidazolyl group, an oxazolyl group, a benzoxazolyl group, a thiazolyl group, a benzthiazolyl group, a group that is a precursor of these heterocyclic groups, or the heterocyclic group or a precursor thereof. A group in which two or more groups are bonded, or a group in which an aromatic hydrocarbon group is bonded to one or two or more of the heterocyclic group or a group serving as a precursor thereof is included. X may contain an organic group having 2 to 20 atoms in total (preferably 2 to 10 atoms in total) containing at least an alkylene group or an ether bond, if necessary.

  Representative examples of X include groups represented by the above formulas (3a) to (3v), or groups in which two or more of these are bonded. Formulas (3e), (3i), (3j), (3m), (3o), (3p), (3s), (3t), (3u), and (3v) represent the precursor structure of the benzoxazole ring. It is a group containing. In formula, A shows -NH-, an oxygen atom, or a sulfur atom. s shows the integer of 0-5. Each ring in the formula may have a substituent.

  Examples of the substituent that each ring in the formula may have include, for example, an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, or two or more thereof (for example, 2 to 4). ) May be bonded via an oxygen atom or a sulfur atom or not. The total carbon number of the substituent which each said ring may have is 1-50, for example.

  Examples of the aliphatic hydrocarbon group include 1 to 20 carbon atoms (preferably 1) such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t-butyl, pentyl, hexyl, decyl, and dodecyl groups. -10, more preferably 1-6) linear or branched alkyl group; 2-20 carbon atoms such as vinyl, allyl, 1-butenyl, 3-methyl-4-pentenyl group (preferably 2-2) 10 or more preferably 2 to 5) linear or branched alkenyl group; ethynyl, propynyl, 1-butynyl, 2-butynyl group or the like having 2 to 20 carbon atoms (preferably 2 to 10, more preferably Examples thereof include a linear or branched alkynyl group of about 2 to 5).

  Examples of the alicyclic hydrocarbon group include a cycloalkyl group having about 3 to 20 members (preferably 3 to 15 members, more preferably 3 to 12 members) such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cyclooctyl groups. , Monocyclic alicyclic hydrocarbon groups such as cycloalkenyl groups of about 3 to 20 members (preferably 3 to 15 members, more preferably 3 to 10 members) such as cyclopropenyl, cyclobutenyl, cyclopentenyl and cyclohexenyl groups Adamantane ring, perhydroindene ring, decalin ring, perhydrofluorene ring, perhydroanthracene ring, perhydrophenanthrene ring, tricyclodecane ring, tricycloundecane ring, tetracyclododecane ring, perhydroacenaphthene ring, perhydro Phenalene ring, norbornane ring, norbol Such bridged alicyclic hydrocarbon group having such bridged alicyclic about 2-4 rings such as down ring (bridged ring hydrocarbon group). Examples of the aromatic hydrocarbon group include aromatic hydrocarbon groups having about 6 to 20 carbon atoms (preferably 6 to 14) such as phenyl, biphenyl, naphthyl, anthranyl, phenanthryl, and pyrenyl groups.

The hydrocarbon group in which an aliphatic hydrocarbon group and an alicyclic hydrocarbon group are bonded includes a cycloalkyl-alkyl group such as cyclopentylmethyl, cyclohexylmethyl, 2-cyclohexylethyl group (for example, C _3-20 cycloalkyl- C _1-4 alkyl group, etc.); bridged alicyclic group-alkyl group such as adamantylmethyl, adamantylethyl, norbornylmethyl, norbornylethyl group and the like. The hydrocarbon group in which an aliphatic hydrocarbon group and an aromatic hydrocarbon group are bonded includes, for example, an aralkyl group such as benzyl, 2-phenylethyl, or biphenylmethyl group (for example, a C _7-18 aralkyl group). An alkyl-substituted aryl group (for example, a phenyl group or a naphthyl group substituted with about 1 to 4 C _1-4 alkyl groups) and the like. The aliphatic hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and a group in which these groups are bonded may have a substituent. The substituent is not particularly limited as long as it does not impair the physical properties of the high molecular weight polymer after reaction or polymerization.

  In the group containing an ethynyl group which may have a substituent in Y, examples of the substituent include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, and isobutyl groups (for example, having 1 to 10 carbon atoms). An alkyl group of about a degree; an aryl group such as phenyl or naphthyl group (for example, an aryl group having about 6 to 20 carbon atoms); a substituted silyl group such as trimethylsilyl or triethylsilyl group (for example, a trialkylsilyl group) Is mentioned.

  Preferred Y includes an ethynyl group which may have a substituent, an ethynylphenyl group which may have a substituent, and the like.

（式中、Ｒ′はアルキル基、アリール基又はトリアルキルシリル基を示す） Representative examples of Y include groups represented by the following formulas (4a) to (4d).

(In the formula, R ′ represents an alkyl group, an aryl group or a trialkylsilyl group)

  Examples of the alkyl group in R ′ include alkyl groups having about 1 to 10 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, and isobutyl groups. Examples of the aryl group include aryl groups having about 6 to 20 carbon atoms such as phenyl and naphthyl groups. Examples of the trialkylsilyl group include trimethylsilyl and triethylsilyl groups.

  Examples of the hydrocarbon group for R include an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group in which these are bonded. Examples of the aliphatic hydrocarbon group include 1 to 20 carbon atoms (preferably 1 to 1) such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t-butyl, pentyl, hexyl, decyl, and dodecyl groups. 10 or more preferably 1 to 6) linear or branched alkyl group; 2 to 20 carbon atoms (preferably 2 to 10) such as vinyl, allyl, 1-butenyl, 3-methyl-4-pentenyl group, etc. And more preferably about 2 to 5) linear or branched alkenyl group; ethynyl, propynyl, 1-butynyl, 2-butynyl group and the like having 2 to 20 carbon atoms (preferably 2 to 10, more preferably 2). -5) about a linear or branched alkynyl group.

  Examples of the alicyclic hydrocarbon group include a cycloalkyl group having about 3 to 20 members (preferably 3 to 15 members, more preferably 3 to 12 members) such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cyclooctyl groups. , Monocyclic alicyclic hydrocarbon groups such as cycloalkenyl groups of about 3 to 20 members (preferably 3 to 15 members, more preferably 3 to 10 members) such as cyclopropenyl, cyclobutenyl, cyclopentenyl and cyclohexenyl groups Adamantane ring, perhydroindene ring, decalin ring, perhydrofluorene ring, perhydroanthracene ring, perhydrophenanthrene ring, tricyclodecane ring, tricycloundecane ring, tetracyclododecane ring, perhydroacenaphthene ring, perhydro Phenalene ring, norbornane ring, norbol Such bridged alicyclic hydrocarbon group having such bridged alicyclic about 2-4 rings such as down ring (bridged ring hydrocarbon group). Examples of the aromatic hydrocarbon group include aromatic hydrocarbon groups having about 6 to 20 carbon atoms (preferably 6 to 14) such as phenyl and naphthyl groups.

The hydrocarbon group in which an aliphatic hydrocarbon group and an alicyclic hydrocarbon group are bonded includes a cycloalkyl-alkyl group such as cyclopentylmethyl, cyclohexylmethyl, 2-cyclohexylethyl group (for example, C _3-20 cycloalkyl- C _1-4 alkyl group and the like). The hydrocarbon group in which an aliphatic hydrocarbon group and an aromatic hydrocarbon group are bonded to each other includes an aralkyl group (for example, a C _7-18 aralkyl group) and an alkyl-substituted aryl group (for example, about 1 to about 4). A phenyl group substituted with a C _1-4 alkyl group or a naphthyl group).

  The aliphatic hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and a group in which these groups are bonded may have a substituent. The substituent is not particularly limited as long as it does not impair the physical properties of the crosslinked polymer after reaction or polymerization.

  In formula (1), m represents an integer of 1 to 5. m is preferably 1 or 2, and more preferably 1. n represents an integer of 2 to 7, preferably 3 or 4, and more preferably 4. k represents an integer of 0 to 5. n + k = 2-7. A plurality of X, Y in the molecule and R in the case where a plurality exist may be the same or different.

で表される構造を有する化合物は、末端に下記式（６）

で表される構造を有する対応する化合物を、下記式（７）

で表される化合物と反応させることにより得ることができる。 The compound represented by the formula (1) is a known compound or derivative derived from a known compound using a known reaction as a starting material, such as condensation reaction, substitution reaction, addition reaction, oxidation reaction, cyclization reaction, etc. It can be synthesized using known reactions. For example, among the compounds represented by formula (1), the following formula (5)

The compound having the structure represented by the following formula (6)

A corresponding compound having a structure represented by the following formula (7)

It can obtain by making it react with the compound represented by these.

  The reaction between the compound having the structure represented by the formula (6) and the compound represented by the formula (7) is usually performed in a solvent. Any solvent may be used as long as it dissolves the raw materials and does not inhibit the reaction. Examples thereof include amides such as N, N-dimethylformamide, N, N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone; Cyclic aminoacetals such as imidazolidine and dimethylimidazolidinone (dimethylimidazolidine-dione); Sulfoxides such as dimethyl sulfoxide; Sulfones; Nitriles such as acetonitrile, propionitrile, benzonitrile; Acetone, Methyl ethyl ketone, Diethyl ketone , Ketones such as methyl isobutyl ketone, cyclopentanone, cyclohexanone; formate ester, acetate ester, propionate ester, benzoate ester, γ-butyrolactone, propylene glycol monomethyl ether acetate Esters such as PGMEA); ethers such as dioxane, tetrahydrofuran, diethyl ether, ethylene glycol diethyl ether; halogenated hydrocarbons such as dichloromethane, dichloroethane, chloroform, carbon tetrachloride, chlorobenzene; benzene, toluene, xylene, Examples thereof include aromatic hydrocarbons such as ethylbenzene and mesitylene; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; aliphatic hydrocarbons such as hexane, heptane and octane. These solvents can be used alone or in admixture of two or more.

  Of these, aprotic polar solvents such as amides, cyclic aminoacetals, and sulfones are preferable. Particularly, amides such as N, N-dimethylacetamide (DMAc) and N-methyl-2-pyrrolidone; dimethylimidazolidine Cyclic aminoacetals such as dimethylimidazolidinone (dimethylimidazolidine-dione) are preferably used.

  The reaction is performed in an atmosphere containing oxygen as long as the compound having the structure represented by formula (6) is not oxidized. For example, it can be performed in an atmosphere of a mixed gas obtained by diluting oxygen with an inert gas such as nitrogen or argon.

  The reaction temperature varies depending on the type of raw material and the like, but can generally be appropriately selected within the range of 0 ° C. to 280 ° C., preferably about −30 ° C. to 150 ° C. The reaction temperature may be constant or may be changed continuously or sequentially. The use ratio of the compound having the structure represented by the formula (6) and the compound of the formula (7) can be selected within a wide range. (1 mol of the compound of (7)) may be used, or either one may be used in excess. The amount of the compound having the structure represented by the formula (6) is, for example, 0.1 to 1000 equivalents, preferably 1 to 800 equivalents, more preferably 10 equivalents or more (particularly with respect to the compound of the formula (7)). 10 to 500 equivalents). The reaction can be performed by a conventional method such as a batch system, a semi-batch system, or a continuous system.

  In the reaction, a catalyst (base catalyst, acid catalyst, etc.), a reactive agent, a trapping agent (base, dehydrating agent, etc.), a condensing agent (polyphosphoric acid, etc.), etc. may be used depending on the type of raw material.

In the case of producing the compound represented by the formula (1) or an intermediate material thereof, the heterocyclic ring can be formed as follows. For example, a benzimidazole ring can react a compound having a carboxyl group, a substituted oxycarbonyl group, a formyl group or a haloformyl group with a compound having a 3,4-diaminophenyl group in the presence of oxygen as necessary. Can be formed. The benzoxazole ring can be formed by reacting a compound having a 3-amino-4-hydroxyphenyl group or a 4-amino-3-hydroxyphenyl group in the presence of oxygen as necessary. . Furthermore, the benzthiazole ring can be formed by reacting a compound having a 3-amino-4-mercaptophenyl group or a 4-amino-3-mercaptophenyl group in the presence of oxygen as necessary. . Examples of the substituted oxycarbonyl group include C _1-6 alkoxy-carbonyl groups such as methoxycarbonyl and ethoxycarbonyl.

  The insulating film forming material of the present invention contains at least the ethynyl group-containing bridged alicyclic compound. The insulating film forming material of the present invention may contain another ethynyl group-containing compound together with the ethynyl group-containing bridged alicyclic compound. As other ethynyl group-containing compounds, 2 or more (for example, 2 to 4 ethynyl groups which may have a substituent in the molecule (such as ethynyl group which may have the above-mentioned substituent)) may be contained in the molecule. ) Can be used. Examples of such compounds include 1,3,5,7-tetrakis (4-phenylacetylene) adamantane, 1,3,5-tris (4-phenylacetylene) adamantane, 1,3,5-tris (4- And compounds having two or more ethynyl groups (acetylene groups) such as phenylacetylene) benzene. Moreover, the polymer containing the ethynyl group which may have a substituent in a principal chain or a side chain is mentioned as another ethynyl group containing compound. In the insulating film forming material containing the ethynyl group-containing bridged alicyclic compound and such an ethynyl group-containing polymer, the ethynyl group-containing bridged alicyclic compound functions as a crosslinking agent. For example, after an insulating film forming material (chemical solution) containing the ethynyl group-containing bridged alicyclic compound and ethynyl group-containing polymer is applied to a substrate, it is heated from room temperature to 600 ° C., preferably 400 ° C. Thus, a film having a crosslinked structure and high heat resistance and mechanical strength can be obtained. The ethynyl group-containing bridged alicyclic compound and other ethynyl group-containing compounds can be used alone or in combination of two or more.

  The insulating film forming material of the present invention can be used as a solution in which the ethynyl group-containing bridged alicyclic compound or the ethynyl group-containing bridged alicyclic compound and another ethynyl group-containing compound are dissolved in an organic solvent. .

  Examples of the organic solvent include amides such as N, N-dimethylformamide, N, N-dimethylacetamide, and N-methyl-2-pyrrolidone; dimethylimidazolidine, dimethylimidazolidinone (dimethylimidazolidine-dione), and the like. Cyclic aminoacetals; Sulfoxides such as dimethyl sulfoxide; Sulfones; Nitriles such as acetonitrile, propionitrile and benzonitrile; Ketones such as acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, cyclopentanone and cyclohexanone; Formic acid Esters such as ester, acetate ester, propionate ester, benzoate ester, ethyl lactate, γ-butyrolactone, propylene glycol monomethyl ether acetate (PGMEA); Ethers such as tetrahydrofuran, diethyl ether, ethylene glycol monoethyl ether, ethylene glycol diethyl ether, propylene glycol monomethyl ether (PGME); alcohols such as methanol, ethanol, propanol, butanol, ethylene glycol, propylene glycol; dichloromethane, dichloroethane, Halogenated hydrocarbons such as chloroform, carbon tetrachloride and chlorobenzene; nitro compounds such as nitromethane; aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene and mesitylene; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; hexane, Aliphatic hydrocarbons such as heptane and octane; and mixed solvents thereof.

  The insulating film forming material of the present invention may contain other components as necessary. Examples of such components include the raw material components used for the synthesis of the ethynyl group-containing bridged alicyclic compound. Further, as another additive component, a catalyst for promoting polymerization, cyclization reaction, or the like can be used. Typical examples of the catalyst include acid catalysts such as sulfuric acid, methanesulfonic acid, and p-toluenesulfonic acid, and base catalysts. The usage-amount of a catalyst is 0-10 mol% with respect to the total amount of the said ethynyl group containing bridged alicyclic compound and another ethynyl group containing compound, for example, Preferably it is about 0-5 mol%.

  In order to improve applicability, a thickener that increases the viscosity of the solution may be added to the insulating film forming material of the present invention. Typical examples of the thickener include alkylene glycols such as ethylene glycol, diethylene glycol, triethylene glycol, and polyethylene glycol, and polyalkylene glycols. The usage-amount of a thickener is 0-20 weight% with respect to the whole insulating film forming material, for example, Preferably it is about 0-10 weight%.

  You may add the adhesion promoter for improving the board | substrate adhesiveness of the insulating film formed on a board | substrate to the insulating-film formation material of this invention. Typical examples of the adhesion promoter include trimethoxyvinylsilane, hexamethyldisilazane, γ-aminopropyltriethoxysilane, aluminum monoethylacetoacetate diisopropylate, and the like. The amount of the adhesion promoter used is, for example, 0 to 10% by weight, preferably with respect to the total amount of monomer components (the ethynyl group-containing bridged alicyclic compound and other ethynyl group-containing compounds) constituting the insulating film forming material. Is about 0 to 5% by weight.

  The dissolution of the monomer component and other components in the organic solvent may be performed, for example, in an air atmosphere as long as the monomer component is not oxidized, but is preferably performed in an inert gas atmosphere such as nitrogen or argon. The temperature at which the monomer component and the like are dissolved is not particularly limited, and may be heated according to the solubility and stability of the monomer component and the boiling point of the solvent, for example, 0 to 200 ° C., preferably 10 to 150 ° C. Degree.

  The concentration (total concentration) of the ethynyl group-containing bridged alicyclic compound and other ethynyl group-containing compounds in the insulating film forming material can be appropriately selected in consideration of the solubility, coatability, workability, etc. of the monomer components. For example, it is about 5 to 70% by weight, preferably about 10 to 60% by weight.

  More specifically, for example, the polymer and insulating film having a pore structure of the present invention may be heated (for example, by applying the above-described insulating film forming material as a coating liquid onto a substrate and then subjecting it to a reaction. It can be obtained by polymerization or cyclization reaction such as by baking. Examples of the base material include a silicon wafer, a metal substrate, and a ceramic substrate. The application method is not particularly limited, and conventional methods such as spin coating, dip coating, and spraying can be used.

  The heating temperature is not particularly limited as long as the monomer component can be converted into a high molecular weight polymer, but is generally 25 to 500 ° C (eg 100 to 500 ° C), preferably 25 to 450 ° C (eg 150 to 450 ° C). Degree. Heating may be performed at a constant temperature or a stepped temperature gradient. The heating operation may be performed, for example, in an air atmosphere as long as the performance of the thin film to be formed is not affected, but is preferably performed in an inert gas (nitrogen, argon, etc.) atmosphere or a vacuum atmosphere.

  By heating, the ethynyl groups at the end of the monomer component (the ethynyl group-containing bridged alicyclic compound and the other ethynyl group-containing compounds) react with each other between the molecules to increase the molecular weight, and the corresponding polymer (high molecular weight polymer) Produces. In addition, when the monomer component is a compound having a heterocyclic precursor structure, the polymer component having a desired structure (high molecular weight polymer) is usually progressed along with the increase in the molecular weight of the monomer component and the cyclization reaction or the like. Generate. When the monomer component has a protecting group, usually a high molecular weight or cyclization reaction proceeds with elimination of the protecting group. By the cyclization reaction, an imidazole ring, a benzimidazole ring, an oxazole ring, a benzoxazole ring, a thiazole ring, a benzthiazole ring, or the like is formed from each precursor structure.

  In the present invention, for example, when a tetrafunctional compound [for example, a compound in which n = 4 and m = 1 in the formula (1)] is used as the monomer component, the central skeleton (for example, adamantane skeleton) is apex ( As a crosslinking point, a network polymer film having a structure (a unit in which three hexagons share two sides) crossed in four directions can be formed. When a trifunctional compound [for example, a compound in which n = 3 and m = 1 in the formula (1)] is used as the monomer component, the central skeleton (for example, adamantane skeleton) is used as a vertex (crosslinking point) in three directions A highly cross-linked polymer film having a structure in which three hexagons are shared (units in which three hexagons share two vertices or two sides) is formed. When a bifunctional compound [for example, a compound in which n = 2 and m = 1 in the formula (1)] is used as a monomer component, one polymer molecule is reduced due to an excluded volume effect between segments in the polymer molecular chain. Since the penetration of other molecular chains into the existing region is limited, it is possible to form a polymer film with a high porosity having a sparse packing structure compared with the case of obtaining a high molecular weight polymer directly from a monomer mixture. it can.

  Further, when a tetrafunctional compound or a trifunctional compound and a bifunctional compound are used in combination as a monomer component, a large void is formed with a long distance (side) between adjacent cross-linking points (or nodal points). As a result, a very low dielectric constant can be achieved. More specifically, the tetrafunctional compound forms a crosslinking point having a three-dimensional structure branched in four directions, and the trifunctional compound forms a crosslinking point having a three-dimensional structure branched in three directions. / Or a trifunctional compound and a bifunctional compound can combine to produce a polymer having a sparse pore structure. In addition, when tetrafunctional compound (trifunctional compound) is used alone, many crosslink points are formed at the time of polymerization, so the density is increased, and the degree of molecular freedom is reduced, resulting in uncrosslinked points and increasing the dielectric constant. There is. For this reason, when a tetrafunctional compound and a trifunctional compound are used in combination, a steric hindrance occurs, and a void formed by a polymerization reaction due to a bond with the bifunctional compound is large. This is advantageous in that the polymer has a pore structure.

  In addition, when two kinds of tri- or tetra-functional compounds having functional groups that react with each other are used as monomer components, the density can be prevented from decreasing during the polymerization reaction due to steric hindrance between the monomer components. A polymer having a pore structure of can be obtained. That is, the tri- or tetrafunctional compound used for the monomer component is a tetrahedron (almost regular tetrahedron) centered on a central skeleton (for example, an adamantane skeleton), and has a three-dimensionally bulky structure (a structure with a large volume). It has a large molecule. In the polymerization reaction using these as monomer components, the two tetrahedrons prevent the penetration of each other's tetrahedral structure into the space due to extremely large steric hindrance, and the penetration of the growing oligomers, polymers, etc. is also restricted. The For this reason, the tetrahedral structure inherent to both monomer components is maintained, and a polymer having a low density structure in which pores having a size corresponding to the volume of these tetrahedra are regularly arranged can be formed.

  The insulating film made of the polymer thus formed has a large number of molecular-level vacancies uniformly dispersed therein, and thus has a high porosity and therefore a low dielectric constant. Moreover, it has the advantage that it has sufficient heat resistance and mechanical strength due to cross-linking and has very little copper diffusion from the wiring. In addition, since it has an ethynyl group that does not lower the dielectric constant even if it remains unreacted at the molecular end, there is no variation in relative dielectric constant (K value), and insulation is improved.

  The thickness of the insulating film formed by heating can be appropriately set depending on the application, but is generally 50 nm or more (about 50 to 2000 nm), preferably 100 nm or more (about 100 to 2000 nm), more preferably 300 nm or more (300 About 2000 nm). If the film thickness is less than 50 nm, problems such as adverse effects on electrical characteristics such as the occurrence of leakage current, and difficulty in planarizing the film by chemical mechanical polishing (CMP) in the semiconductor manufacturing process are likely to occur. Particularly, it is not suitable for use as an interlayer insulating film.

  Since the insulating film of the present invention exhibits a low dielectric constant and high heat resistance, it can be used, for example, as an insulating film in electronic material components such as semiconductor devices, and is particularly useful as an interlayer insulating film.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. The film thickness of the polymer film was measured using an ellipsometer. The relative dielectric constant of the polymer film was measured by forming an Al electrode on the surface of the film. Infrared absorption spectrum was measured using a thin film transmission method.

Production Example 1
(Synthesis of amino group-containing adamantane derivatives)

In a reaction vessel (three-necked flask), 77.68 g (0.362 mol) of 3,3′-diaminobenzidine represented by the above formula (B) was added, and 307 g of N, N-dimethylacetamide (DMAc) was added. After dissolution, it was kept below 0 ° C. in an ice bath. A solution prepared by dissolving 10.1 g (0.018 mol) of adamantanetetrakisbenzaldehyde represented by the above formula (A) in 501 g of DMAc was dropped into this reaction vessel at a rate of 6 ml / min using a dropping funnel. During dropping, care was taken that the liquid temperature in the reaction solution did not exceed 0 ° C. After completion of the dropping, the dropping funnel was washed with 105 g of DMAc, and this was also dropped into the reaction vessel. The reaction vessel was heated by an oil bath while introducing a mixed gas of oxygen and nitrogen having an oxygen concentration of 5 mol% using a Teflon (registered trademark) tube, and the reaction temperature was kept at 90 ° C. for 9 hours. . After completion of the reaction, the reaction solution was added dropwise to 9.13 kg of water in another container, and a slurry consisting of a precipitate and a supernatant was stirred for about 1 hour after the completion of the addition. During the stirring, the reaction solution was bubbled with nitrogen to prevent amine oxidation. The produced precipitate was separated by filtration, transferred again to the reaction vessel, 1.83 kg of water was added, and the mixture was heated and refluxed for 30 minutes in a nitrogen atmosphere and washed with hot water. After the temperature was not lowered, the precipitate was filtered off, and the obtained filtrate was dried with a vacuum dryer.
After completion of drying, the obtained precipitate was transferred to a reaction vessel equipped with a reflux tube, tetrahydrofuran (THF) 1.83 kg was added, and the mixture was heated under reflux in a nitrogen atmosphere, and washed with THF. The solid content was again filtered, and the NMR spectrum and infrared absorption spectrum of the product dried by a vacuum dryer were measured. The NMR spectrum data shown in FIG. 1 and the infrared absorption spectrum data shown in FIG. It was confirmed that an amino group-containing adamantane derivative represented by (C) was formed. The yield of the amino group-containing adamantane derivative was 24.5 g, and the yield was 90%.
[NMR spectral data]
¹ H-NMR (DMSO-d6) δ (ppm): 2.32 (12H <—CH ₂ —>), 4.60 (16H <—NH ₂ >), 6.62-6.97 (12H <fragrance) Ring proton>), 7.53-7.78 (12H <aromatic ring proton>), 7.87 (8H), 8.24 (8H) 12.85 (4H)
[Infrared absorption spectrum data (cm ⁻¹ )]
3419 (N—H <stretching vibration>), 2933 (—CH ₂ —C—H <stretching vibration>), 1623 (—C═N— <stretching vibration>), 1420-1520 (aromatic ring <in-plane vibration) >), 1280 (aromatic-NH ₂ <stretching vibration>)

Example 1
(Synthesis of ethynyl group-containing adamantane derivatives)

A solution in which 2.08 g of 4-ethynylbenzaldehyde represented by the above formula (D) is dissolved in 20 g of N, N-dimethylacetamide (DMAc) is placed in a reaction vessel (three-necked flask). Then, a solution prepared by dissolving 2.65 g of an amino group-containing adamantane derivative represented by the above formula (C) in 25 g of DMAc was dropped using a dropping funnel. After completion of dropping, the dropping funnel was washed with 10 g of DMAc, and this was also dropped into the reaction vessel. The reaction vessel was heated with an oil bath while maintaining the liquid temperature at 80 ° C. while introducing a mixed gas of oxygen / nitrogen having an oxygen concentration of 5 mol% using a Teflon (registered trademark) tube, and the reaction was continued for 7 hours. . After completion of the reaction, the reaction solution was added dropwise to 800 g of water in another container, and a slurry consisting of a precipitate and a supernatant was stirred for about 1 hour after the completion of the addition. The produced precipitate was separated by filtration, transferred again to the reaction vessel, added with 400 g of methanol, and stirred for 1 hour. After the precipitate was filtered off, the obtained filtrate was dried with a vacuum dryer. After completion of drying, the resulting precipitate was dissolved in DMAc 50 g and added dropwise to methanol 400 g. The precipitate was filtered off and dried with a vacuum dryer. The NMR spectrum and infrared absorption spectrum of the product were measured, and it was confirmed that the ethynyl group-containing adamantane derivative represented by the above formula (E) was formed. The yield of the ethynyl group-containing adamantane derivative was 3.09 g, and the yield was 87%.
[NMR spectral data]
¹ H-NMR (DMSO-d6) δ (ppm): 2.32 (12H <adamantane-CH _2- >), 4.38 (4H <ethynyl C—H>), 7.54-8.26 (6H <Aromatic ring CH>), 13.05 (4H <imidazole NH)
[Infrared absorption spectrum data (cm ⁻¹ )]
3422 (N—H <stretching vibration>), 2930 (—CH ₂ —CH—stretching vibration>), 2220 (ethynyl group <stretching vibration>, 1620 (—C═N— <stretching vibration>)), 1420-1520 (aromatic ring <in-plane vibration>), 1280 (aromatic-N-H <stretching vibration>), 809 (C-H <out-of-plane variable vibration>

(Preparation of drug solution)
A stirrer was placed in a 30 mL flask equipped with a three-way cock, and while introducing nitrogen into the container, 800 mg of the ethynyl group-containing adamantane derivative obtained above and DMAc and 1,3-dimethyl-2-imidazolidinone ( DMI) mixture (weight ratio 1: 1) was added and stirred at 30 ° C. for 1 hour to obtain a 10 wt% solution of an ethynyl group-containing adamantane derivative. After dissolution, the temperature was returned to room temperature and filtered through 0.2 μm and 0.1 μm Teflon (registered trademark) filters to obtain a chemical solution (insulating film forming material).

(Formation of insulating film)
2 to 3 mL of the chemical solution prepared above was dropped onto a silicon wafer, the rotation speed was adjusted at 1000 to 3000 rpm, and spin coating was performed. Subsequently, the film was obtained by raising the temperature from room temperature to 400 ° C. in a quartz chamber under a nitrogen atmosphere and baking it. The obtained film had a thickness of 267 nm and a relative dielectric constant of 3.0.
[Infrared absorption spectrum data (cm ⁻¹ )]
3422 (N—H <stretching vibration>), 2930 (—CH ₂ —C—H <stretching vibration>), 1620 (—C═N— <stretching vibration>), 1420-1520 (aromatic ring <in-plane vibration) >), 1280 (aromatic-N-H <stretching vibration>), 806 (C-H <out-of-plane variable vibration>

Example 2
(Synthesis of ethynyl group-containing adamantane derivatives)

To a 1000 mL four-necked flask, 9.6 g (72.0 mmol) of 4-ethynyl-1,2-diaminobenzene represented by the above formula (H) was added, and 50 g of N, N-dimethylacetamide (DMAc) was added. Then, using a Teflon (registered trademark) tube, the solution was kept at 25 ° C. while air was blown into the solution. A solution prepared by dissolving 5.0 g (9 mmol) of adamantanetetrakisbenzaldehyde represented by the above formula (A) in 100 g of DMAc was dropped into this mixed solution over 1.5 hours using a dropping funnel. After completion of dropping, the mixture was stirred at 25 ° C. for 1 hour, and then the reaction solution was heated to 80 ° C. and reacted for 24 hours with stirring. After completion of the reaction, the mixture was cooled to 25 ° C., 600 g of pure water was added dropwise, and a slurry consisting of a precipitate and a supernatant was stirred for about 1 hour after the completion of the addition. The produced precipitate was separated by filtration, transferred again to the reaction vessel, added with 600 g of methanol, and stirred for 1 hour. After the precipitate was filtered off, the obtained filtrate was dried with a vacuum dryer. After completion of drying, the resulting precipitate was dissolved in 150 g of DMAc, and 600 g of methanol was added dropwise thereto. After the precipitate was filtered off, the obtained filtrate was dried with a vacuum dryer. The ¹ H-NMR spectrum of the product was measured (see FIG. 3), and it was confirmed that an ethynyl group-containing adamantane derivative represented by the above formula (I) was formed. The yield of the ethynyl group-containing adamantane derivative was 5.4 g, and the yield was 60%.
[NMR spectral data]
¹ H-NMR (DMSO-d6) δ (ppm): 2.1 (12H), 4.0-4.1 (4H), 7.2-8.2 (28H), 13.1 (4H)

(Preparation of drug solution)
The ethynyl group-containing adamantane derivative represented by the formula (I) obtained above is dissolved in a mixed solution (weight ratio 1: 1) of DMAc and 1,3-dimethyl-2-imidazolidinone (DMI) to obtain ethynyl. A 10 wt% solution of the group-containing adamantane derivative was prepared.

(Formation of insulating film)
The chemical solution (insulating film forming material) prepared above was applied onto a silicon wafer using a spin coater. The coated wafer was heated in an electric furnace in a nitrogen atmosphere at 350 ° C. for 1 hour to advance the crosslinking reaction. When the electrical characteristics of the thin film thus obtained (film thickness: 300 nm) were examined, the relative dielectric constant was 3.1. Even when the thin film was left in the air, no increase in current value due to moisture absorption of the thin film was observed.

Comparative Example 1
(Preparation of drug solution)
While introducing a stirring bar into a 30 mL flask equipped with a three-way cock and introducing nitrogen into the container, 255 mg of a carboxylic acid compound represented by the following formula (F), 550 mg of an amine compound represented by the following formula (G), A mixture of DMAc and DMI (weight ratio 1: 1) was added and stirred at 30 ° C. for 1 hour to obtain a 10 wt% (total concentration) solution of the two compounds. After dissolution, the temperature was returned to room temperature and filtered through 0.2 μm and 0.1 μm Teflon (registered trademark) filters to obtain a chemical solution (insulating film forming material).

(Formation of insulating film)
2 to 3 mL of the chemical solution prepared above was dropped onto a silicon wafer, the rotation speed was adjusted at 1000 to 3000 rpm, and spin coating was performed. Subsequently, the film was obtained by raising the temperature from room temperature to 400 ° C. in a quartz chamber under a nitrogen atmosphere and baking it. The obtained film had a thickness of 260 nm and a relative dielectric constant of 3.5.
[Infrared absorption spectrum data (cm ⁻¹ )]
3419 (N—H <stretching vibration>), 2933 (—CH ₂ —C—H <stretching vibration>), 1626 (—C═N— <stretching vibration>), 1420-1520 (aromatic ring <in-plane vibration) >), 1282 (aromatic-N-H <stretching vibration>), 806 (C-H <out-of-plane angular vibration>

Evaluation Test About the insulating films obtained in Example 1, Example 2 and Comparative Example 1, the relative dielectric constant was measured by a probe method at a frequency of 1 kHz to 1 MHz. The relative dielectric constant of the film produced in Comparative Example 1 is 3.5, whereas the dielectric constants of the films produced in Example 1 and Example 2 (ethynyl type) are 3.0 and 3.1, respectively. there were. In Examples, since there was no unreacted terminal having high polarity, a film having a low relative dielectric constant was obtained, and the effect of reducing the dielectric constant of a low polarity ethynyl group was confirmed.

2 is an NMR spectrum of an amino group-containing adamantane derivative obtained in Production Example 1. 2 is an infrared absorption spectrum of an amino group-containing adamantane derivative obtained in Production Example 1. 2 is an NMR spectrum of the ethynyl group-containing adamantane derivative obtained in Example 2.

Claims (7)

The following formula (1 ' )

(In the formula, Z represents an adamantane-1,3,5,7-tetrayl group , and X represents the following formulas (3a ′) to (3v ′)).

(In formula, A shows -NH-, an oxygen atom, or a sulfur atom. S shows the integer of 0-5.)
Or a group selected from a group in which two or more thereof are bonded , and Y is selected from an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, trimethylsilyl, and a triethylsilyl group The ethynyl group which may have a substituent and the ethynylphenyl group which may have the said substituent is shown. R represents a hydrogen atom or a hydrocarbon group selected from an alkyl group having 1 to 6 carbon atoms and an aromatic hydrocarbon group having 6 to 14 carbon atoms . m represents an integer of 1 to 5, and n represents 3 or 4 . n + k = 4 . A plurality of X and Y in the molecule may be the same or different)
An ethynyl group-containing bridged alicyclic compound represented by: An insulating film forming material comprising the ethynyl group-containing bridged alicyclic compound according to claim 1 . Insulating film-forming material according to claim 2 together with an ethynyl group-containing bridged alicyclic compounds described, other ethynyl group-containing compound in claim 1. Insulating film-forming material according to claim 2 or 3, wherein ethynyl group-containing bridged alicyclic compound is a solution in an organic solvent. A polymer having a pore structure obtained by subjecting the insulating film forming material according to any one of claims 2 to 4 to a polymerization reaction. An insulating film comprising a polymer having a pore structure according to claim 5 . A method for producing an insulating film, comprising: applying an insulating film forming material according to claim 4 on a substrate; and subjecting the material to a polymerization reaction to form an insulating film made of a polymer having a pore structure.

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