JP2010070618A - Composition for forming insulating film, the insulating film, and electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composition for forming an insulating film capable of obtaining a polyphenylene organic insulating film that has effectiveness to sharply improve film mechanical strength by EB cure, inhibits pore failure upon making fine pores within the film using a pore forming agent, and exhibits a low dielectric constant and high mechanical strength, and to provide the insulating film produced using the composition, and an electronic device having the insulating film. <P>SOLUTION: This composition for forming the insulating film includes polyphenylene formed by the Diels-Alder reaction of a compound having at least one cyclopentadienone group with a compound having at least one acetylene group, wherein the polyphenylene has a substituent which contains a secondary carbon atom. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an insulating film forming composition capable of forming an insulating film having good film characteristics such as dielectric constant and mechanical strength used for electronic devices and the like, and an insulating film obtained using the insulating film forming composition And an electronic device having an insulating film.

  As semiconductor integrated circuits (ICs) have become more highly integrated, multifunctional, and higher in performance in recent years, circuit resistance and inter-wiring capacitance have increased, leading to increased power consumption and delay time. In particular, an increase in the delay time causes a decrease in signal speed and crosstalk in the semiconductor integrated circuit. Therefore, in order to reduce the delay time and increase the speed of the semiconductor integrated circuit, it is required to reduce wiring resistance and parasitic capacitance. As a specific measure for reducing the parasitic capacitance, an attempt is made to cover the periphery of the wiring with a low dielectric insulating film. Further, the insulating film is required to have excellent heat resistance that can withstand a subsequent process such as a thin film formation process, chip connection, and pinning when manufacturing a mounting substrate, and chemical resistance that can withstand a wet process. Furthermore, in recent years, low resistance Cu wiring is being introduced from Al wiring, and along with this, planarization by CMP (Chemical Mechanical Polishing) has become common, and high mechanical strength that can withstand this process is required. Yes.

Conventionally, silicon dioxide (SiO ₂ , k = 3.9) has been applied as an insulating film covering the periphery of such wiring. However, in recent years, in order to further reduce the dielectric constant of the insulating film, the application of a coating type insulating film that is easy to reduce the dielectric constant by controlling the film structure is being studied.
For example, Patent Document 1 discloses a coating-type low dielectric constant insulating film forming material mainly composed of a polyphenylene organic polymer. Furthermore, in recent years, an attempt to use a pore forming agent (porogen) has been proposed in order to further reduce the dielectric constant of an insulating film made of a polyphenylene organic polymer.

  For example, the pore-forming agent forms a domain (discrete region) in a dielectric matrix material such as a polyphenylene-based organic polymer, and is thermally or radiation (electromagnetic radiation, electron beam) at a temperature near the curing temperature of the matrix material. Refers to a material that decomposes and vaporizes under the influence of, and forms pores in the matrix. Since the dielectric constant of the vacancies formed in the matrix by decomposition and vaporization of the vacancy forming agent is about 1 (corresponding to the dielectric constant in vacuum), the dielectric constant of the entire insulating film can be greatly reduced. Become. Patent Documents 2 and 3 and the like are disclosed as examples of a technique for reducing the dielectric constant of an insulating film mainly composed of a polyphenylene organic polymer by using a pore forming agent.

  On the other hand, in recent years, as a curing method for curing a coating film obtained by coating from a coating type low dielectric constant insulating film forming composition, an acceleration voltage of about several keV to several tens keV while heating the coating film is used. A so-called electron beam cure (EB cure) in which an electron beam with energy is applied has been studied, and a specific disclosure example can be seen in Patent Document 4 and the like. Compared with general heat curing (curing method in which the coating film is cured only by heat), the time until the coating film curing is completed can be greatly shortened by applying EB curing. Furthermore, it is known that a film having higher mechanical strength than a general thermal cure can be obtained by applying EB cure to the organic silicon oxide film.

JP 2000-191752 A Special Table 2002-530505 gazette JP 2005-517785 Gazette Japanese Patent No. 3530165

  On the other hand, when the present inventors have examined the prior art, when EB cure is applied to a low dielectric constant insulating film mainly composed of a polyphenylene organic polymer described in Patent Document 1, the above organic silicon is used. It has been found that the effect of improving the mechanical strength of the film tends to be difficult to obtain as compared with the oxide film.

  In addition, in the technique for reducing the dielectric constant of an insulating film using a pore forming agent (porogen) described in Patent Documents 2 and 3, the size of the holes formed in the insulating film by decomposition and vaporization of the porogen It is necessary to make (the pore diameter) as small as possible, and attempts have been made to control the size to less than a few nm. However, since the mechanical strength of the dielectric matrix materials described in Patent Documents 2 and 3 is not sufficient, small voids formed in processes such as high-temperature heat treatment and CMP treatment performed many times during the manufacturing process of semiconductor devices. There was a problem that the holes were easily collapsed.

  In view of the above circumstances, the present inventors have obtained an effect of significantly improving the mechanical strength of a film by EB curing, and in forming fine holes in a film using a hole forming agent, A composition for forming an insulating film from which a polyphenylene-based organic insulating film exhibiting low dielectric constant and high mechanical strength can be obtained, an insulating film obtained from the composition for forming an insulating film, and an electronic device having the insulating film The purpose is to provide.

  As a result of intensive studies by the present inventors, the mechanical strength and dielectric constant of the film obtained from the composition can be increased by using a composition containing a polyphenylene-based material having a substituent containing a secondary carbon atom. I found it to be improved.

（一般式（ａ）中、Ｒ^１は、水素原子、芳香族基、または第２級炭素原子を含有する置換基を有する芳香族基を表す。Ａｒ^１は、ベンゼン基、ナフタレン基、ビフェニル基、９，９−ジフェニルフルオレン基、または一般式（ｂ）で表される基を表す。
一般式（ｃ）中、Ｒ^２は、水素原子、芳香族基、または第２級炭素原子を含有する置換基を有する芳香族基を表す。Ａｒ^３は、ベンゼン基、ナフタレン基、ビフェニル基、９，９−ジフェニルフルオレン基、または一般式（ｂ）で表される基を表す。ｙは、３〜６の整数を表す。
一般式（ｄ）中、Ｒ^２は、水素原子、芳香族基、または第２級炭素原子を含有する置換基を有する芳香族基を表す。Ａｒ^２は、ベンゼン基、ナフタレン基、ビフェニル基、９，９−ジフェニルフルオレン基、または一般式（ｂ）で表される基を表す。
一般式（ｅ）中、Ｒ^１およびＲ^２は、それぞれ独立して、水素原子、芳香族基、または第２級炭素原子を含有する置換基を有する芳香族基を表す。Ａｒ^４は、ベンゼン基、ナフタレン基、ビフェニル基、９，９−ジフェニルフルオレン基、または一般式（ｂ）で表される基を表す。なお、Ｒ^１とＲ^２の少なくとも一方は、第２級炭素原子を含有する置換基を有する芳香族基を表す。
一般式（ｆ）中、Ｒ^１およびＲ^２は、それぞれ独立して、水素原子、芳香族基、または第２級炭素原子を含有する置換基を有する芳香族基を表す。Ａｒ^４は、ベンゼン基、ナフタレン基、ビフェニル基、９，９−ジフェニルフルオレン基、または一般式（ｂ）で表される基を表す。なお、Ｒ^１とＲ^２の少なくとも一方は、第２級炭素原子を含有する置換基を有する芳香族基を表す。）

（一般式（ｂ）中、Ｚは−Ｏ−、−Ｓ−、アルキレン、−Ｏ−ＣＦ_２−、ペルフルオロアルキレン、またはアリーレン基を表す。）
＜４＞ 前記ポリフェニレンが、少なくとも１種の前記一般式（ａ）で表される化合物と、少なくとも１種の前記一般式（ｃ）で表される化合物とを含む出発原料から合成されたポリフェニレンである＜３＞に記載の絶縁膜形成用組成物。
＜５＞ ＜１＞〜＜４＞のいずれかに記載の絶縁膜形成用組成物を基板上に塗布して、塗膜を得る膜形成工程と、膜形成工程で得られた前記塗膜に電子線を照射して、前記塗膜を硬化させる硬化工程とを含む絶縁膜の製造方法。
＜６＞ ＜５＞に記載の製造方法より得られる絶縁膜を有する電子デバイス。 That is, the present inventors have found that the above problem is solved by the following <1> to <6> configurations.
<1> A composition for forming an insulating film containing polyphenylene formed by a Diels-Alder reaction between a compound having at least one cyclopentadienone group and a compound having at least one acetylene group, wherein the polyphenylene is An insulating film-forming composition having a substituent containing a secondary carbon atom.
<2> The composition for forming an insulating film according to <1>, wherein the substituent containing the secondary carbon atom is a branched alkyl group having 3 to 12 carbon atoms or a polycyclic cycloalkyl group.
<3> The compound represented by the compound represented by the general formula (a), the compound represented by the general formula (c), the compound represented by the general formula (d), or the general formula (e). And the composition for forming an insulating film according to <1> or <2>, which is polyphenylene synthesized from a starting material containing at least one selected from the group consisting of compounds represented by formula (f).

(In General Formula (a), R ¹ represents a hydrogen atom, an aromatic group, or an aromatic group having a substituent containing a secondary carbon atom. Ar ¹ represents a benzene group, a naphthalene group, or a biphenyl group. , 9,9-diphenylfluorene group or a group represented by the general formula (b).
In general formula (c), R ² represents a hydrogen atom, an aromatic group, or an aromatic group having a substituent containing a secondary carbon atom. Ar ³ represents a benzene group, a naphthalene group, a biphenyl group, a 9,9-diphenylfluorene group, or a group represented by the general formula (b). y represents an integer of 3 to 6.
In general formula (d), R ² represents a hydrogen atom, an aromatic group, or an aromatic group having a substituent containing a secondary carbon atom. Ar ² represents a benzene group, a naphthalene group, a biphenyl group, a 9,9-diphenylfluorene group, or a group represented by the general formula (b).
In general formula (e), R ¹ and R ² each independently represents a hydrogen atom, an aromatic group, or an aromatic group having a substituent containing a secondary carbon atom. Ar ⁴ represents a benzene group, a naphthalene group, a biphenyl group, a 9,9-diphenylfluorene group, or a group represented by the general formula (b). Note that at least one of R ¹ and R ² represents an aromatic group having a substituent containing a secondary carbon atom.
In General Formula (f), R ¹ and R ² each independently represent a hydrogen atom, an aromatic group, or an aromatic group having a substituent containing a secondary carbon atom. Ar ⁴ represents a benzene group, a naphthalene group, a biphenyl group, a 9,9-diphenylfluorene group, or a group represented by the general formula (b). Note that at least one of R ¹ and R ² represents an aromatic group having a substituent containing a secondary carbon atom. )

(In the general formula (b), Z represents —O—, —S—, alkylene, —O—CF ₂ —, perfluoroalkylene, or an arylene group.)
<4> The polyphenylene is a polyphenylene synthesized from a starting material containing at least one compound represented by the general formula (a) and at least one compound represented by the general formula (c). The composition for forming an insulating film according to <3>.
<5> A film forming step of applying a composition for forming an insulating film according to any one of <1> to <4> on a substrate to obtain a coating film, and the coating film obtained in the film forming step. A method for producing an insulating film, comprising: a curing step of irradiating an electron beam to cure the coating film.
<6> An electronic device having an insulating film obtained by the production method according to <5>.

  According to the present invention, the effect of significantly improving the mechanical strength of the film by EB curing is obtained, and in forming fine vacancies in the film using the vacancy forming agent, the collapse of the vacancies is suppressed, and low It is possible to provide an insulating film forming composition from which a polyphenylene-based organic insulating film exhibiting a dielectric constant and high mechanical strength is obtained, an insulating film obtained from the insulating film forming composition, and an electronic device having the insulating film.

Below, the composition for insulating film formation which concerns on this invention, the insulating film obtained from the composition for insulating film formation, and the manufacturing method of an insulating film are demonstrated in detail.
First, polyphenylene contained in the composition for forming an insulating film will be described.

The polyphenylene contained in the composition of the present invention is a polyphenylene formed by a Diels-Alder reaction between a compound having at least one cyclopentadienone group and a compound having at least one acetylene group. It has a substituent containing a carbon atom. More specifically, the aromatic ring group constituting polyphenylene has a substituent containing a secondary carbon atom.
Substituents containing secondary carbon atoms are generally inert to thermal cure, but under electron beam irradiation, radicals are generated at secondary carbon atom sites, and the generated radicals are coupled to each other. It is thought that a crosslinked structure is formed. That is, when polyphenylene has a substituent containing secondary carbon atoms, the substituents containing secondary carbon atoms undergo a crosslinking reaction during electron beam curing, and the crosslinking density of the film is improved. It is estimated that the effects of the present invention can be obtained.

<Compound having at least one cyclopentadienone group>
First, the compound having at least one cyclopentadienone group used in the present invention will be described. This compound is one of the starting materials for polyphenylene obtained by Diels-Alder reaction.
This compound only needs to have at least one cyclopentadienone group. The structure of the compound is not particularly limited as long as the product obtained by Diels-Alder reaction using this compound is polyphenylene.

  This compound has at least one cyclopentadienone group. Among them, the number of cyclopentadienone groups is preferably 2 or more, and more preferably 2 to 4 in that the heat resistance and mechanical strength of the insulating film obtained using this compound are excellent.

  The molecular weight of the compound having at least one cyclopentadienone group is not particularly limited as long as the effects of the present invention are not impaired. Especially, 500-5000 are preferable from the point of ease of handling, such as solubility, and 700-3000 are more preferable.

  One preferred example of the compound having at least one cyclopentadienone group is a compound represented by the general formula (a).

(In General Formula (a), R ¹ represents a hydrogen atom, an aromatic group, or an aromatic group having a substituent containing a secondary carbon atom. Ar ¹ represents a benzene group, a naphthalene group, or a biphenyl group. , 9,9-diphenylfluorene group, or a group represented by the general formula (b).

(In the general formula (b), Z represents —O—, —S—, alkylene, —O—CF ₂ —, perfluoroalkylene, or an arylene group.)

In general formula (a), R ¹ represents a hydrogen atom, an aromatic group, or an aromatic group having a substituent containing a secondary carbon atom. In general formula (a), R ¹ may be the same or different. At least one (preferably 2 to 4) of R ¹ is preferably an aromatic group having a substituent containing a secondary carbon atom.
The aromatic group is not particularly limited as long as it is aromatic, and examples thereof include an aromatic heterocyclic group and an aromatic hydrocarbon group. From the viewpoint of low dielectric properties, an aromatic hydrocarbon group is preferred. Especially, C6-C18 is preferable and C6-C10 is more preferable. Specific examples include a phenyl group and a naphthyl group.
Moreover, the aromatic group may have a substituent. Of these, an inert substituent is preferable. An inert substituent is essentially inert to the Diels-Alder reaction of a cyclopentadienone group and an acetylene group, and is the use condition of a polymer cured in a microelectronic device, in an environment such as water. A group that does not react easily with other substances. _{Specifically, F, Cl, Br, -CF} 3, -OCH 3, -OCF 3, -OPh, alkyl group having 1 to 8 carbon atoms, and a cycloalkyl group having 3 to 8 carbon atoms.

The substituent containing a secondary carbon atom in the aromatic group having a substituent containing a secondary carbon atom is not particularly limited as long as it has a secondary carbon atom. Of these, a branched alkyl group or a polycyclic cycloalkyl group is preferred from the viewpoint of low dielectric properties.
As a branched alkyl group, C3-C12 is preferable and C3-C6 is more preferable. Specific examples include isopropyl, isobutyl, isopentyl, 2-methylbutyl, 2-methylpentyl, 2-ethylbutyl, 2-ethylhexyl, 2,6-dimethyl-4-heptyl, trimethylnonyl and the like.
The polycyclic cycloalkyl group preferably has 6 to 14 carbon atoms, and more preferably has 7 to 10 carbon atoms. Specific examples include an adamantyl group, an isobornyl group, a norbornyl group, a diamantyl group, and the like. Among these, an isopropyl group or an adamantyl group is preferably mentioned as a substituent containing a secondary carbon atom.

The aromatic group in the aromatic group having a substituent containing a secondary carbon atom has the same meaning as the aromatic group represented by R ¹ described above, and the preferred range is also the same.

In addition, specific examples of the aromatic group having a substituent containing a secondary carbon atom include, for example, a benzene ring group or a naphthalene ring group having an isopropyl group or an adamantyl group.
The number of substituents containing secondary carbon atoms in the aromatic group having a substituent containing secondary carbon atoms is not particularly limited, and is preferably 1 or 2 from the viewpoint of easy synthesis.

In General Formula (a), Ar ¹ represents a divalent benzene group, naphthalene group, biphenyl group, 9,9-diphenylfluorene group, or a group represented by General Formula (b). Among these groups, a benzene group, a biphenyl group, a 9,9-diphenylfluorene group, and a diphenyl ether group are preferable from the viewpoint of low dielectric properties. In addition, a cyclopentadienone group is bonded to any two positions on the benzene ring group in each of these groups.
Examples of Ar ¹ include groups represented by general formula (W-1) to general formula (W-4). In addition, * in each formula represents a bonding position.

In the general formula (W-4), Z is —O—, —S—, alkylene (preferably having 1 to 3 carbon atoms, more preferably 1 carbon atom), —O—CF ₂ —, perfluoroalkylene, Or represents an arylene group or the like.

Specific examples of the group represented by Ar ¹ are shown below, but the present invention is not limited thereto.

In the general formula (b), Z is -O -, - represents a, or an arylene group S-, alkylene, -O-CF ₂ - -, perfluoroalkylene (e.g., _-CF 2).

<Compound having at least one acetylene group>
Next, the compound having at least one acetylene group used in the present invention will be described. This compound is one of the starting materials for polyphenylene obtained by Diels-Alder reaction.
The compound only needs to have at least one acetylene group. The structure of the compound is not particularly limited as long as the product obtained by Diels-Alder reaction using this compound is polyphenylene.

  This compound has at least one acetylene group. Among them, the number of acetylene groups is preferably 2 or more, more preferably 3 to 6 in that the heat resistance and mechanical strength of the insulating film obtained using this compound are excellent.

  The molecular weight of the compound having at least one acetylene group is not particularly limited as long as the effects of the present invention are not impaired. Especially, 200-4000 are preferable from the point of ease of handling, such as solubility, and 250-2000 are more preferable.

  Preferable examples of the compound having at least one acetylene group include compounds represented by general formula (c).

(In General Formula (c), R ² represents a hydrogen atom, an aromatic group, or an aromatic group having a substituent containing a secondary carbon atom. Ar ³ represents a benzene group, a naphthalene group, or a biphenyl group. , 9,9-diphenylfluorene group, or a group represented by the general formula (b), y represents an integer of 3 to 6.)

(In the general formula (b), Z represents —O—, —S—, alkylene, —O—CF ₂ —, perfluoroalkylene, or an arylene group.)

In general formula (c), R ² represents a hydrogen atom, an aromatic group, or an aromatic group having a substituent containing a secondary carbon atom. The aromatic group represented by R ² and the aromatic group having a substituent containing a secondary carbon atom include the aromatic group represented by R ¹ and the secondary carbon atom in the general formula (a). It is synonymous with the aromatic group which has a substituent to contain, respectively, and its preferable range is also the same.
In addition, R < ² > in general formula (c) may be the same, or may differ. It is preferable that at least one of R ² is an aromatic group having a substituent containing a secondary carbon atom.

In General Formula (c), Ar ³ represents a y-valent benzene group, naphthalene group, biphenyl group, 9,9-diphenylfluorene group, or a group represented by General Formula (b). Y groups each containing R ² and an acetylene group are bonded to any position on the benzene ring group in each of these groups.
Of these, a benzene group, a biphenyl group, a 9,9-diphenylfluorene group, a diphenyl ether group, and the like are preferable in that the obtained insulating film exhibits lower dielectric constant.

Specific examples of the group represented by Ar ³ are shown below, but the present invention is not limited thereto.

  In general formula (c), y represents an integer of 3 to 6, preferably an integer of 3 to 5, and more preferably an integer of 3 to 4.

  The group represented by general formula (b) in general formula (c) is synonymous with the group represented by general formula (b) in general formula (a).

  Other preferable examples of the compound having at least one acetylene group include compounds represented by the general formula (d).

(In general formula (d), R ² represents a hydrogen atom, an aromatic group, or an aromatic group having a substituent containing a secondary carbon atom. Ar ² represents a divalent benzene group or naphthalene. A group, a biphenyl group, a 9,9-diphenylfluorene group, or a group represented by the general formula (b).)

(In the general formula (b), Z represents —O—, —S—, alkylene, —O—CF ₂ —, perfluoroalkylene, or an arylene group.)

In general formula (d), R ² represents a hydrogen atom, an aromatic group, or an aromatic group having a substituent containing a secondary carbon atom. The aromatic group represented by R ² and the aromatic group having a substituent containing a secondary carbon atom are synonymous with R ² in the general formula (c), and the preferred range is also the same. In addition, it is preferable that at least one of R ² is an aromatic group having a substituent containing a secondary carbon atom.

In General Formula (d), Ar ² represents a divalent benzene group, naphthalene group, biphenyl group, 9,9-diphenylfluorene group, or a group represented by General Formula (b). Each group represented by Ar ² in the general formula (d) has the same meaning as each group represented by Ar ¹ in the general formula (a).
A group containing R ² and an acetylene group is bonded to any two positions on the benzene ring group in each of these groups.

When the compound represented by the general formula (a) described above is reacted with the compound represented by the general formula (c) and / or the compound represented by the general formula (d), the compound represented by the general formula (a) At least one of R ² in R ¹ and the general formula (c) and the general formula (d) of represents an aromatic group having a substituent containing a secondary carbon atom.

<Compound having a cyclopentadienone group and an acetylene group>
In synthesizing the polyphenylene of the present invention, a compound having both a cyclopentadienone group and an acetylene group may be used.
Specifically, the compound represented by the following general formula (e) is mentioned.

(In General Formula (e), R ¹ and R ² each independently represents a hydrogen atom, an aromatic group, or an aromatic group having a substituent containing a secondary carbon atom. Ar ⁴ is A benzene group, a naphthalene group, a biphenyl group, a 9,9-diphenylfluorene group, or a group represented by the general formula (b), wherein at least one of R ¹ and R ² contains a secondary carbon atom. Represents an aromatic group having a substituent.

(In the general formula (b), Z represents —O—, —S—, alkylene, —O—CF ₂ —, perfluoroalkylene, or an arylene group.)

In general formula (e), R ¹ and R ² each independently represents a hydrogen atom, an aromatic group, or an aromatic group having a substituent containing a secondary carbon atom. R ¹ and R ² have the same meanings as R ¹ and R ² represented by the general formula (a) and the general formula (c), respectively.

In general formula (e), Ar ⁴ represents a divalent benzene group, naphthalene group, biphenyl group, 9,9-diphenylfluorene group, or a group represented by general formula (b). Each group represented by Ar ⁴ in the general formula (e) has the same meaning as each group represented by Ar ¹ in the general formula (a). Specific examples of Ar ⁴ include specific examples of the group represented by Ar ¹ in the general formula (a).
A group containing R ² and an acetylene group and a cyclopentadienone group are bonded to any two positions on the benzene ring group in each of these groups.

  Another preferred example of the compound having a cyclopentadienone group and an acetylene group is a compound represented by the general formula (f).

(In General Formula (f), R ¹ and R ² each independently represents a hydrogen atom, an aromatic group, or an aromatic group having a substituent containing a secondary carbon atom. Ar ⁴ is A benzene group, a naphthalene group, a biphenyl group, a 9,9-diphenylfluorene group, or a group represented by the general formula (b), wherein at least one of R ¹ and R ² contains a secondary carbon atom. Represents an aromatic group having a substituent.

(In the general formula (b), Z represents —O—, —S—, alkylene, —O—CF ₂ —, perfluoroalkylene, or an arylene group.)

In General Formula (f), R ¹ and R ² each independently represent a hydrogen atom, an aromatic group, or an aromatic group having a substituent containing a secondary carbon atom. R ¹ and R ² have the same meanings as R ¹ and R ² represented by the general formula (a) and the general formula (c), respectively.

In General Formula (f), Ar ⁴ represents a divalent benzene group, naphthalene group, biphenyl group, 9,9-diphenylfluorene group, or a group represented by General Formula (b). Each group represented by Ar ⁴ in the general formula (f) has the same meaning as the groups represented by Ar ⁴ in the general formula (e).
A group containing R ² and an acetylene group and a cyclopentadienone group are bonded to any two positions on the benzene ring group in each of these groups.

<Polyphenylene>
The polyphenylene formed by the Diels-Alder reaction between the compounds described above has a substituent containing a secondary carbon atom. More specifically, a part of the aromatic ring group constituting polyphenylene has a substituent containing a secondary carbon atom.
The polyphenylene used in the present invention refers to a polymer composed of a phenylene skeleton (benzene ring group) as a main component. The polyphenylene of the present invention may have —O—, —S—, alkylene, —O—CF ₂ —, perfluoroalkylene, or the like as part of its polymer skeleton.

  The weight average molecular weight (Mw) of the obtained polyphenylene is not particularly limited and can be adjusted as appropriate. Of these, the weight average molecular weight is preferably from 2,000 to 300,000, more preferably from 5,000 to 100,000, from the viewpoint of ease of handling such as solubility in a solvent and uniform coatability.

The substituent containing a secondary carbon atom, which the polyphenylene of the present invention has, has the same meaning as the “substituent containing a secondary carbon atom” described for R ¹ in the general formula (a).
Polyphenylene may have a substituent containing a secondary carbon atom in either the side chain or the terminal.

Preferable examples of the polyphenylene of the present invention include oligomers or polymers represented by general formula (I) to general formula (IV).
Here, the oligomer refers to a compound having a weight average molecular weight of less than 4,000, and the polymer refers to a compound having a weight average molecular weight of 4,000 or more.
Below, each formula is explained.

<Oligomer or polymer represented by formula (I)>
One preferred example of the polyphenylene of the present invention is an oligomer or polymer represented by the general formula (I): [A] _W [B] _T [E] _V.
A in the general formula (I) represents a repeating unit represented by the following general formula (I-1). B in the general formula (I) represents a repeating unit represented by the following general formula (I-2).

  E in the general formula (I) represents a repeating unit represented by the following general formula (I-3) to general formula (I-8).

The oligomer or polymer represented by the general formula (I) is represented by the above-described compound represented by the general formula (a), the compound represented by the general formula (c), and / or the general formula (d). It can synthesize | combine using a compound.
Ar ¹ , Ar ² , Ar ³ , R ¹ , R ² and y in the general formula (I) are the groups represented by the general formula (a), the general formula (c) and the general formula (d). It is synonymous.

In general formula (I), M represents a single bond. p is the number of unreacted acetylene groups in the monomer unit, r is one less than the number of reacted acetylene groups in the monomer unit, and satisfies the relational expression of p + r = y−1.
W is an integer of 0 to 1,000, T is an integer of 0 to 1,000, and V is an integer of 2 or more.

<Oligomer or polymer represented by general formula (II-1) to general formula (II-3)>
As a preferable example of the polyphenylene of this invention, the oligomer or polymer represented by general formula (II-1)-general formula (II-3) is mentioned.

The oligomer or polymer represented by the general formula (II-1) to the general formula (II-3) includes the compound represented by the general formula (a) and the compound represented by the general formula (d). Can be synthesized.
The reaction ratio (weight ratio) between the compound represented by the general formula (a) and the compound represented by the general formula (d) is preferably 1: 1 to 1: 3, more preferably 1: 1-1: 2.
In general formula (II-1) to general formula (II-3), R ¹ , R ² , Ar ¹ and Ar ² are the groups represented by general formula (a) and general formula (d) It is synonymous.

  In General Formula (II-1) to General Formula (II-3), X represents an integer of 1 to 1000, preferably an integer of 1 to 50, and more preferably an integer of 1 to 10.

<Oligomer or polymer represented by general formula (III)>
One preferred example of the polyphenylene of the present invention is an oligomer or polymer represented by the general formula (III).

The oligomer or polymer represented by the general formula (III) can be synthesized by reacting the compounds represented by the general formula (e) described above.
R ¹ , R ² , and Ar ⁴ in the general formula (III) have the same meanings as the groups represented in the general formula (e).

  In general formula (III), X represents an integer of 1 to 1000, preferably an integer of 1 to 50, and more preferably an integer of 1 to 10.

<Oligomer or polymer represented by general formula (IV)>
One preferred example of the polyphenylene of the present invention is an oligomer or polymer represented by the general formula (IV).

The oligomer or polymer represented by the general formula (IV) can be synthesized by reacting the compounds represented by the general formula (f) described above.
R ¹ , R ² , and Ar ⁴ in the general formula (IV) have the same meanings as the groups represented in the general formula (f).

  In general formula (III), X represents an integer of 1 to 1000, preferably an integer of 1 to 50, and more preferably an integer of 1 to 10.

<Synthesis method>
A compound represented by the general formula (a), which is a precursor of polyphenylene described in the general formula (I), the general formula (II), the general formula (III), and the general formula (IV), the general formula (e ), A compound having a cyclopentadienone group, such as a compound represented by the general formula (f), can be synthesized using a conventionally known method. For example, it can be produced by condensation of benzyls (oxalyl compounds such as Ph-CO-CO-Ph) and benzyl ketones. As more specific methods, Kumar et al., Macromolecules, 1995 (year), vol. 28, pp. 124-130, Ogliaruso et al., J. Org. Chem., 1965 (year), vol. 30, pp. 3354, Examples include the methods described in Ogliaruso et al., J. Org. Chem., 1963 (year), vol. 28, pp. 2725 and US Pat. No. 4,400,540.

  A compound represented by general formula (c), which is a precursor of polyphenylene described in the above formula (I), formula (II), formula (III) and formula (IV), represented by general formula (d) A compound containing an acetylene group such as a compound, a compound represented by the general formula (e) and a compound represented by the general formula (f) can be produced by a conventionally known method. Specifically, the desired aromatic acetylene is obtained by halogenating an aromatic compound and then reacting an appropriate substituted acetylene with the halogenated aromatic compound in the presence of an aryl ethynylation catalyst typified by a palladium complex. Compounds containing groups can be obtained.

  Next, a generally known reaction mechanism for a reaction in which a compound having a cyclopentadienone group as a precursor and a compound having an acetylene group are polymerized to produce polyphenylene will be described below. For example, in the case of the oligomer or polymer represented by the general formula (II) described above, it is generally considered that the production process proceeds according to the following reaction scheme.

  Although not shown in the above reaction scheme, depending on the type of polyphenylene precursor used and the reaction conditions, a carbonyl-crosslinked substance may be included in the formed oligomer or polymer of the polyphenylene of the present invention. In this case, upon further heating, it is believed that essentially all of this carbonyl bridged material is converted to an aromatic ring. When one or more acetylene-containing monomers are used, the reaction formula shown suggests that a repeating unit corresponding to each acetylene-containing monomer is generated, and the formed oligomer and polymer are random copolymers composed of each repeating unit. It is considered to be. It is thought that a Diels-Alder reaction occurs between the cyclopentadienone group and the acetylene group, and forms a para bond or a meta bond in the phenylated ring.

  The content of the above-described polyphenylene in the composition of the present invention is preferably 50 to 100% by mass, and preferably 70 to 100% by mass with respect to the total solid components contained in the composition of the present invention. More preferably, it is more preferably 80 to 100% by mass. In the present specification, the total solid component contained in the composition of the present invention refers to all components excluding organic solvents.

<Void forming agent>
Next, other components that may be contained in the composition for forming an insulating film of the present invention will be described.
The composition for forming an insulating film of the present invention may contain a pore forming agent.
The pore-forming agent is a substance having a function of forming pores in the above-described film mainly composed of polyphenylene. For example, by heating a film obtained using a composition containing a pore-forming agent, pores formed by the pore-forming agent are formed in the film, and a membrane containing pores can be obtained.

The pore forming agent is not particularly limited, but various polymers can be used.
The polymer as the pore-forming agent is one that thermally decomposes at a temperature lower than the thermal decomposition temperature of polyphenylene.

Examples of the polymer that can be used as a pore-forming agent include polyvinyl aromatic compounds (polystyrene, polyvinyl pyridine, halogenated polyvinyl aromatic compounds, polyacenaphthylene, etc.), polyacrylonitrile, polyalkylene oxide (polyethylene oxide, polypropylene oxide, etc.). ), Polyethylene, polylactic acid, polysiloxane, polycaprolactone, polycaprolactam, polyurethane, polymethacrylate (such as polymethyl methacrylate) or polymethacrylic acid, polyacrylate (such as polymethyl acrylate) and polyacrylic acid, polydiene (polybutadiene, polyisoprene) Etc.), polyvinyl chloride, polyacetal, and amine capped alkylene oxide (from Huntsman Corp.). effamineTM commercially available as polyether amines), and the like.
In addition, polyphenylene oxide, poly (dimethylsiloxane), polytetrahydrofuran, polycyclohexylethylene, polyethyloxazoline, polyvinylpyridine, and the like may be used.

  The polymer described as an example of the pore forming agent may be any of a homopolymer, a block copolymer, a random copolymer, and the like. Moreover, these mixtures may be sufficient. The shape of the polymer is not particularly limited, and may be, for example, linear, branched, hyperbranched, dendritic or star-like.

The most preferred polymer as a pore-forming agent contained in the composition of the present invention is polystyrene. Examples of polystyrene include anionic polymerized polystyrene, syndiotactic polystyrene, unsubstituted and substituted polystyrene (eg, poly (α-methylstyrene)), and unsubstituted polystyrene is particularly preferable.
Polystyrene decomposes in a polyphenylene-based matrix at a high temperature (for example, about 420 ° C. to 450 ° C.) at which polyphenylene does not decompose and is mainly decomposed into monomers. It is preferable because it is released into

The molecular weight of a polymer suitable as a pore-forming agent can be appropriately selected depending on various factors such as compatibility with polyphenylene and a matrix obtained by polymerization and curing of the polymer, and the size of pores in the insulating film. In general, the number average molecular weight (Mn) of the pore forming agent is preferably 2000 to 100,000, more preferably 5000 to 50,000, and even more preferably 5000 to 35,000.
A polymer having a narrow molecular weight distribution (Mw / Mn: 1.01 to 1.5) is preferable.

  The pore forming agent may be a granular material having a size corresponding to the size of the pores generated in the insulating film. Such a substance is preferably a substance having an average diameter of 0.5 to 50 nm, more preferably 0.5 to 20 nm. There is no restriction | limiting in the material of this substance, etc., As an example, a hyperbranched polymer like a dendrimer and latex particle, especially crosslinked polystyrene containing latex are mentioned preferably.

  Examples of these materials include Dendritech, Inc. Also available through Polymer J. (Tokyo), Vol. 17, 117 (1985), described by Tomalia et al., Polyamidoamine (PAMAM) dendrimer, polypropyleneimine polyamine (DAB-Am) dendrimer available from DSM Corporation, Flechette type polyether dendrimer (J. Am. Chem. Soc., Vol. 112, 7638 (1990), Vol. 113, 4252 (1991) by Frechet et al.), Parsec type liquid crystal monodendrons, dendronized polymers and their self-assembled polymers (Nature, Vol. 391, 161 (1998), J. Am. Chem. Soc., Vol. 119, 1539 (1997) by Percec et al.), Boltlon H series dendritic polyester. (Commercially available from PerstorpAB).

  In the system of the matrix, that is, the solid content derived from the polyphenylene compound and the various pore forming agents as described above, for example, when removing the pore forming agent by heating, Selecting the pore-forming agent such that the matrix is formed before the forming agent is diffused or decomposed, and the pore-forming agent is preferably completely diffused or decomposed before the matrix is diffused or decomposed. Is preferred. A large difference between the temperature at which the matrix is crosslinked and the temperature at which the pore-forming agent is diffused or decomposed is preferable in that the range of selection of the pore-forming agent is widened.

  The pore forming agent shown above can be added in the form of graft copolymerization or block copolymerization with respect to polyphenylene in advance, instead of being added as a separate component to polyphenylene. By pre-grafting or block-copolymerizing polyphenylene, the pore-forming agent is microphase-separated in polyphenylene, preventing the formation of inappropriately large voids in the film. There is a tendency to be able to. By introducing a dienophile group such as an acetylene group or vinyl group into a part of the pore forming agent and mixing it appropriately with the Diels-Alder reaction, which is a synthesis reaction of polyphenylene, the pore forming agent is graft copolymerized with polyphenylene. Alternatively, block copolymerization can be performed.

<Organic solvent>
The composition for forming an insulating film of the present invention may contain an organic solvent that dissolves all solid components including polyphenylene.
Examples of the organic solvent include 1-methoxy-2-propanol, propanol, acetylacetone, cyclohexanone, propylene glycol monomethyl ether acetate, butyl acetate, methyl lactate, ethyl lactate, γ-butyrolactone, anisole, mesitylene, and t-butylbenzene. Particularly preferred are 1-methoxy-2-propanol, cyclohexanone, propylene glycol monomethyl ether acetate, ethyl lactate, γ-butyrolactone, t-butylbenzene, anisole and the like. These may be used alone or in combination of two or more.

  The solid content concentration when the composition for forming an insulating film of the present invention contains the above organic solvent is preferably 1 to 50% by mass, more preferably 2 to 15% by mass, and particularly preferably 3 to 10%. % By mass. Here, the solid content is a component corresponding to all components constituting a film obtained using this composition, and does not include an organic solvent.

  In addition, the polyphenylene contained in the composition of the present invention can be synthesized by adding a polyphenylene precursor to an inert organic solvent described later and heating. In that case, the above-mentioned organic solvent may be sufficient as the inert organic solvent in the solution after a synthesis | combination. Further, a solution obtained by adding a polyphenylene precursor to an inert organic solvent and heating or the like contains the polyphenylene of the present invention, but at least a part of the polyphenylene of the present invention is dissolved in the inert organic solvent.

<Adhesion aid>
The composition for forming an insulating film of the present invention may further contain an adhesion assistant.
In particular, the organic polymer insulating film formed from the composition mainly composed of polyphenylene of the present invention is used in the production of semiconductor devices. Silicon dioxide (SiO ₂ ), organic silicon (SiOC), silicon carbide nitride (SiCN) ), And is often provided in an upper layer of an inorganic material such as silicon carbide (SiC). Such an inorganic material layer and an organic polymer layer tend to have basically weak adhesion at the interface. If the adhesion between the inorganic material layer and the organic polymer layer is weak, peeling occurs from the interface during the subsequent CMP polishing process, which becomes a significant obstacle in manufacturing a semiconductor device. In order to avoid this, it is preferable to add an adhesion assistant that improves the interfacial adhesion between the inorganic material layer and the organic polymer layer.

Representative examples of adhesion aids used in the compositions of the present invention are silane compounds, preferably alkoxysilanes (eg, trimethoxyvinylsilane, triethoxyvinylsilane, tetraethoxysilane, phenyltrimethoxysilane, allyltrimethoxysilane, Organosilane such as divinyldiethoxysilane), acetoxysilane (for example, vinyltriacetoxysilane, 3-aminopropyltrimethoxysilane), and hydrolyzates or dehydrated condensates thereof, hexamethyldisilazane [(CH ₃ ) _{3 -Si-NH-Si (CH 3} ) 3], or aminosilane couplers, for example, γ- aminopropyltriethoxysilane or chelating (e.g., from the viewpoint of forming aluminum oxide, aluminum monoethyl acetoacetate diisopropylate, Preparative _{[((iso-C 3 H} 7 O) 2 Al (OCOC 2 H 5 CHCOCH 3))], aluminum alkoxide), and the like. You may mix and use these materials. Moreover, you may use what is marketed as an adhesion promoter.

  The content of the adhesion assistant in the composition for forming an insulating film of the present invention is not particularly limited, but is generally preferably 0.05 to 10% by mass with respect to the total solid content, and preferably 0.1 to 5%. 0.0 mass% is more preferable, and 1-3.0 mass% is more preferable. Note that the total solid component refers to all components excluding the organic solvent from the composition as described above.

<Surfactant>
The composition for forming an insulating film of the present invention may further contain a surfactant. When the surfactant is contained in the composition, it becomes easy to uniformly adjust the film thickness of the insulating film formed by the insulating film forming composition of the present invention.
Examples of the surfactant include nonionic surfactants, anionic surfactants, cationic surfactants, silicone surfactants, fluorine-containing surfactants, polyalkylene oxide surfactants, and acrylic interfaces. An active agent etc. are mentioned. Only one type of such surfactant may be used, or two or more types may be used in combination. Among these, silicone surfactants, nonionic surfactants, fluorine-containing surfactants, and acrylic surfactants can be preferably used, and silicone surfactants can be more preferably used.

  Here, the silicone-based surfactant means a surfactant containing at least one Si atom. The composition for forming an insulating film of the present invention preferably contains a silicone-based surfactant, and more preferably has a structure containing alkylene oxide and dimethylsiloxane. Specifically, the structure represented by the general formula (g) is more preferable.

  In general formula (g), R is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, x is an integer of 1 to 20, and m and n are each independently an integer of 2 to 100. A plurality of R may be the same or different.

  The content of the surfactant in the composition for forming an insulating film of the present invention is not particularly limited, but is preferably 0.1 to 10% by mass with respect to the total solid components contained in the composition, 1.0-5.0 mass% is more preferable. The total solid component refers to all components excluding the organic solvent from the composition as described above.

Moreover, the composition for forming an insulating film of the present invention may further contain additives such as a radical generator and colloidal silica.
The content of these additives in the composition for forming an insulating film is not particularly limited as long as the properties (heat resistance, etc.) of the obtained insulating film are not impaired, but the total solid contained in the composition of the present invention. It is preferable that it is 50 mass% or less with respect to a component, and it is more preferable that it is 30 mass% or less.

The composition for forming an insulating film of the present invention preferably has a sufficiently low metal content as an impurity.
The content of the transition metal in the composition for forming an insulating film of the present invention is preferably 10 ppm or less, preferably 1 ppm or less, and 100 ppb or less, as measured by ICP-MS method. Further preferred. Transition metals have a high catalytic ability to promote oxidation. For this reason, if a large amount of transition metal is contained, an oxidation reaction occurs in the pre-baking and thermosetting processes, which may increase the dielectric constant of the insulating film formed from the insulating film forming composition.
Further, the metal content other than the transition metal in the composition for forming an insulating film of the present invention is preferably 30 ppm or less, more preferably 3 ppm or less, when measured by the ICP-MS method, and 300 ppb. More preferably, it is as follows.

<Method for producing composition for forming insulating film>
Next, the manufacturing method of the composition for insulating film formation of this invention is demonstrated.
The polyphenylene contained in the composition for forming an insulating film of the present invention is produced using a compound having at least one cyclopentadienone group and a compound having at least one acetylene group as starting materials. Examples of the starting material include compounds represented by the above general formula (a) to general formula (f). Such starting materials are also referred to herein as “polyphenylene precursors”.

The polyphenylene precursor is preferably sufficiently purified. In particular, it is preferable to contain as little metal and ionic substances as possible.
For example, if the polyfunctional compound containing an aromatic acetylene group contains a residual ethynylation catalyst, it is washed with water and contacted with an aliphatic hydrocarbon solvent. The polyfunctional compound is then dissolved in an aromatic solvent and then filtered through pure silica gel to remove the residual ethynylation catalyst from the polyfunctional compound. If further recrystallization is performed, the residual ethynylation catalyst can be further removed.

  The method for synthesizing polyphenylene from the polyphenylene precursor is not particularly limited, but the polyphenylene precursor is dissolved in an inert organic solvent and heated to an appropriate polymerization temperature under atmospheric pressure, reduced pressure or increased pressure. A method of synthesizing polyphenylene is preferred. Under these conditions, it is easy to obtain polyphenylene having a uniform molecular weight, and the heat generated by the reaction can be reduced. Moreover, since the obtained solution containing polyphenylene is the composition for forming an insulating film of the present invention, an operation such as adding polyphenylene to an organic solvent becomes unnecessary.

  Examples of the inert organic solvent include mesitylene, pyridine, triethylamine, N-methylpyrrolidone (NMP), methylbenzoate, ethylbenzoate, butylbenzoate, cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, cyclohexylpyrrolidinone, ether Or a hydroxy ether (eg, dibenzyl ether, diglyme, triglyme, diethylene glycol ethyl ether, diethylene glycol methyl ether, dipropylene glycol methyl ether, dipropylene glycol dimethyl ether, propylene glycol phenyl ether, propylene glycol methyl ether, tripropylene glycol methyl ether), Toluene, xylene, benzene, dipropylene glycol Ether acetate, dichlorobenzene, propylene carbonate, naphthalene, diphenyl ether, butyrolactone, dimethylacetamide, dimethylformamide, and mixtures thereof. Preferred inert organic solvents include mesitylene, N-methylpyrrolidone (NMP), γ-butyrolactone, diphenyl ether, and mixtures thereof.

Reaction conditions such as reaction temperature and reaction time at which the polymerization reaction of the polyphenylene precursor is most advantageously carried out vary depending on various factors such as the type of polyphenylene precursor and the type of inert organic solvent.
For example, an oligomer can be synthesized from a polyphenylene precursor at atmospheric pressure with a reaction temperature of 100 ° C. to 475 ° C. and a reaction time of 1 minute to 48 hours. The reaction temperature is preferably 150 ° C to 450 ° C, more preferably 200 ° C to 250 ° C. The reaction time is preferably 60 minutes to 48 hours, more preferably 1 minute to 10 hours, and further preferably 1 minute to 1 hour. Furthermore, chain extension (advancement) may be performed.
The polymerization reaction of the polyphenylene precursor can also be performed in a non-oxidizing atmosphere, for example, nitrogen or other inert gas.

<Insulating film manufacturing method>
The method for producing an insulating film using the above-described composition for forming an insulating film is not particularly limited, and various methods can be carried out. The manufacturing method mainly includes a film forming process for producing a film using the above-described composition and a curing process for curing the obtained film. Below, each process is described.

<Film formation process>
In the film forming step, the composition for forming an insulating film of the present invention is applied to a substrate by any method such as a spin coating method, a roller coating method, a dip coating method, or a scanning method, and if necessary, by a heat treatment or the like. In this step, the organic solvent is removed to obtain a coating film.
As a method of applying to the substrate, a spin coating method or a scanning method is preferable, and a spin coating method is more preferable. In the spin coating method, a commercially available apparatus can be used. For example, the clean track series (manufactured by Tokyo Electron), D-spin series (manufactured by Dainippon Screen), SS series or CS series (manufactured by Tokyo Ohka Kogyo Co., Ltd.) can be preferably used.
The spin coating conditions may be any rotational speed, but for example, a rotational speed of about 1300 rpm is preferable for a 300 mm silicon substrate. With this rotation speed, the in-plane uniformity of the insulating film to be formed becomes better. In addition, it does not specifically limit as a board | substrate used, For example, a silicon wafer, a SiN wafer, a glass substrate, a ceramic substrate, a plastic substrate etc. are selected according to a use purpose.

  Also, the method for discharging the composition for forming an insulating film of the present invention includes a dynamic discharge for discharging the composition for forming an insulating film onto a rotating substrate and a static discharge for discharging the composition for forming an insulating film onto a stationary substrate. Any of the discharges may be used, but dynamic discharge is preferable from the viewpoint of in-plane uniformity of the insulating film to be formed. In addition, from the viewpoint of reducing the consumption of the insulating film forming composition, only the organic solvent preliminarily contained in the insulating film forming composition is ejected onto the substrate to form a liquid film, and then the insulating film is insulated from above. A method of discharging a film forming composition can also be used. Here, when two or more kinds of organic solvents are contained in the composition for forming an insulating film, the liquid film may be formed using only the one having a higher content. The spin coating time is not particularly limited, but is preferably within 180 seconds from the viewpoint of throughput. Further, from the viewpoint of transporting the substrate, it is also preferable to perform processing (edge rinse, back rinse) so as not to leave the film at the edge portion of the substrate.

The method of heat treatment for removing the solvent is not particularly limited, however, generally used hot plate heating, heating method using a furnace, light irradiation heating using a xenon lamp by RTP (Rapid Thermal Processor), etc. Etc. can be applied. Preferred are hot plate heating and a heating method using a furnace.
Commercially available equipment can be preferably used as the hot plate, for example, the clean track series (Tokyo Electron), D-Spin series (Dainippon Screen), SS series or CS series (Tokyo Ohka Kogyo). Can be mentioned. As the furnace, the α series (manufactured by Tokyo Electron) and the like are preferably mentioned.

<Curing process>
A hardening process is a process of hardening the coating film obtained at the film formation process by the irradiation process and / or heat processing of a high energy ray (an electron beam, an ultraviolet-ray, etc.). The high energy ray irradiation treatment or the heat treatment may be performed a plurality of times. It is preferable that the irradiation process of high energy rays (such as an electron beam and ultraviolet rays) and the heat treatment are performed in parallel. By performing irradiation treatment of high energy rays (electron beam, ultraviolet ray, etc.) and heat treatment at the same time, the throughput of the curing process can be improved and the mechanical strength of the film obtained can be improved compared to each treatment alone. It is easy to obtain advantages such as improvement.
As the curing step, it is preferable to cure the coating film by irradiation with an electron beam, and the coating film is cured while being irradiated with an electron beam under heat treatment (preferably 200 to 400 ° C., more preferably 300 to 350 ° C.). It is more preferable. By performing electron beam irradiation under heat treatment, substituents containing secondary carbon atoms substituted on a part or all of the aromatic ring constituting polyphenylene cause a crosslinking reaction, and the effect of the present invention is achieved. It becomes easy to obtain.

In the case of curing by irradiating with a high energy beam, examples of the high energy beam include an electron beam, an ultraviolet ray, and an X-ray, and it is particularly preferable to use an electron beam.
As an energy at the time of using an electron beam as a high energy ray, 0.05-50 keV is preferable, 0.10-30 keV is more preferable, 0.50-20 keV is further more preferable. The total dose of the electron beam is preferably 0 to 5.0 μC / cm ² , more preferably 0 to 2.0 μC / cm ² , and still more preferably 0 to 1.0 μC / cm ² . The substrate temperature when irradiating the electron beam is preferably 0 to 450 ° C, more preferably 100 to 400 ° C, and further preferably 150 to 350 ° C. The atmospheric pressure when irradiating the electron beam is preferably 0 to 133 kPa, more preferably 0 to 60 kPa, and still more preferably 0 to 20 kPa.
Further, from the viewpoint of preventing the oxidation of polyphenylene contained in the composition for forming an insulating film of the present invention, it is preferable to use an inert gas atmosphere such as Ar, He, or nitrogen as the atmosphere when irradiating the electron beam. Further, for the purpose of reaction with plasma, electromagnetic waves, and chemical species generated by interaction with an electron beam, a gas such as oxygen, hydrocarbon, or ammonia may be added.
The electron beam irradiation may be performed a plurality of times. In this case, the electron beam irradiation conditions need not be the same each time, and may be performed under different conditions each time.

Ultraviolet rays may be used as the high energy rays irradiated when the coating film is cured. The irradiation wavelength region when ultraviolet rays are used is preferably 160 to 400 nm, and the output is preferably 0.1 to 2000 mWcm ⁻² immediately above the substrate. The substrate temperature at the time of ultraviolet irradiation is preferably 250 to 450 ° C, more preferably 250 to 400 ° C, and further preferably 250 to 350 ° C.
From the viewpoint of preventing the oxidation of polyphenylene contained in the composition for forming an insulating film of the present invention, it is preferable to use an inert atmosphere such as Ar, He, or nitrogen as the atmosphere around the substrate at the time of ultraviolet irradiation. Moreover, the pressure at the time of ultraviolet irradiation has preferable 0-133 kPa.

Moreover, in this invention, you may make it harden | cure by heat processing instead of irradiating a high energy ray. For example, the carbon-carbon triple bond or carbon-carbon double bond remaining in the polyphenylene contained in the composition for forming an insulating film of the present invention is polymerized during the heat treatment to increase the strength of the formed insulating film. be able to. The conditions for this heat treatment are preferably 100 to 450 ° C, more preferably 200 to 420 ° C, and still more preferably 350 ° C to 400 ° C. Moreover, Preferably it is 1 minute-2 hours, More preferably, it is 10 minutes-1.5 hours, More preferably, it is 30 minutes-1 hour.
The heat treatment may be performed in several times. In addition, this heat treatment is preferably performed in a nitrogen atmosphere in order to prevent thermal oxidation by oxygen.

<Insulating film>
The thickness of the insulating film of the present invention is not particularly limited, but is preferably 0.01 to 10 μm, more preferably 0.02 to 5.0 μm, and 0.03 to 1.0 μm. Is more preferable.
Here, the thickness of the insulating film of the present invention means a simple average value when three or more arbitrary positions are measured with an optical interference film thickness measuring instrument.

<Application>
The insulating film obtained using the composition for forming an insulating film of the present invention can be suitably used for an interlayer insulating film for a semiconductor or the like. The insulating film of the present invention can be suitably used for electronic devices and the like. An electronic device means a wide range of electronic equipment including a semiconductor device (semiconductor device) and a magnetic recording head.
For example, when used as an interlayer insulating film for a semiconductor, in the wiring structure, there may be a barrier layer on the side surface of the wiring to prevent metal migration, and CMP (chemical In addition to the cap layer and interlayer adhesion layer that prevent peeling in mechanical and mechanical polishing, there may be an etching stopper layer, etc. Furthermore, the interlayer insulating film layer may be divided into multiple layers with other materials as required. Also good.

  As the CMP slurry (chemical solution), a commercially available slurry (for example, manufactured by Fujimi, manufactured by Rodel Nitta, manufactured by JSR, manufactured by Hitachi Chemical Co., Ltd.) can be used as appropriate. Moreover, as a CMP apparatus, a commercially available apparatus (Applied Materials, Ebara Corporation, etc.) can be used as appropriate. Further, cleaning can be performed to remove slurry residues after CMP.

  The insulating film of the present invention can be etched for copper wiring or other purposes. Etching may be either wet etching or dry etching, but dry etching is preferred. For dry etching, either ammonia-based plasma or fluorocarbon-based plasma can be used as appropriate. For these plasmas, not only Ar but also gas such as oxygen, nitrogen, hydrogen, or helium can be used. In addition, ashing can be performed for the purpose of removing the photoresist or the like used for the processing after the etching processing, and further, cleaning can be performed to remove a residue at the time of ashing.

  The insulating film of the present invention can be used for various purposes. For example, it is suitable as an insulating film in semiconductor devices such as LSI, system LSI, DRAM, SDRAM, RDRAM, and D-RDRAM, and electronic parts such as multichip module multilayer wiring boards, semiconductor interlayer insulating film, etching stopper film, surface In addition to protective films and buffer coat films, it is used as LSI passivation films, alpha ray blocking films, flexographic printing plate cover lay films, overcoat films, flexible copper-clad cover coats, solder resist films, liquid crystal alignment films, etc. be able to.

  EXAMPLES The present invention will be described in more detail with reference to the following examples, but the present invention is not limited by these examples.

  The following GPC measurements were performed using Waters 2695 and Shodex GPC column KF-805L at a column temperature of 40 ° C. with tetrahydrofuran as the elution solvent at a flow rate of 1 ml / min. The weight average molecular weight (Mw) was standard polystyrene. Calculation was performed using a calibration curve prepared by using the calibration curve.

(Synthesis Example 1: Synthesis of 1-ethynyl-4-isopropylbenzene (Compound (A)))
1-ethynyl-4-isopropylbenzene was synthesized according to the following scheme.

  To a 300 ml eggplant flask, 6.0 g of isopropylbenzene and 100 ml of carbon tetrachloride were added, and 50 ml of bromine was slowly added while stirring at room temperature. After stirring at room temperature for 4 hours, the reaction solution was slowly poured into a saturated sodium bisulfite solution containing ice to remove excess bromine. The separated aqueous phase was extracted with chloroform three times, and the resulting organic phase was washed with water and dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, and the resulting oil was dissolved in a small amount of dichloromethane, packed in silica gel chromatography, and column purification was performed using hexane as an eluent. The solvent of the solution obtained by column purification was distilled off under reduced pressure to obtain 9.8 g of 1-bromo-4-isopropylbenzene (yield: 99%).

  Subsequently, 8.9 g of 1-bromo-4-isopropylbenzene, 0.94 g of dichlorobis (triphenylphosphene) palladium, 0.43 g of copper iodide, diisopropyl were added to a 200 ml three-necked flask equipped with a nitrogen introduction tube and a stirring device. 60 ml of amine was added, and 4.88 g of 3-methyl-1-butyn-3-ol was added while stirring under a nitrogen stream. Thereafter, the mixture was stirred at 60 ° C. for 10 hours, and the deposited salt was filtered and concentrated under reduced pressure. The obtained solid was dissolved in a small amount of ethyl acetate, packed in silica gel chromatography, and column purification was performed using hexane / ethyl acetate as an eluent. The solvent of the solution obtained by column purification was distilled off under reduced pressure to give 7.5 g of 4- (4-isopropylphenyl) -2-methylbut-3-yn-2-ol as a white solid (yield: 83% )Obtained.

  Next, 6.9 g of 4- (4-isopropylphenyl) -2-methylbut-3-yn-2-ol, 13.6 g of crushed sodium hydroxide, 100 ml of toluene in a 200 ml eggplant flask equipped with a Dean Stark and stirring device. The mixture was heated to reflux to remove water generated in the system by azeotropy. After the reaction solution was cooled to room temperature, sodium hydroxide was removed by filtration and concentrated under reduced pressure. The obtained oil was dissolved in a small amount of ethyl acetate, packed in silica gel chromatography, and column purification was performed using hexane / ethyl acetate as an eluent. The solvent of the solution obtained by column purification was distilled off under reduced pressure to obtain 4.3 g (yield: 87%) of 1-ethynyl-4-isopropylbenzene (compound (A)) as a colorless oil.

(Synthesis Example 2: Synthesis of 1- (4-ethynylphenyl) adamantane (Compound (B)))
1- (4-ethynylphenyl) adamantane was synthesized according to the following scheme.

  To a 300 ml three-necked flask equipped with a condenser tube, 7.22 g of magnesium, 0.5 g of 1,2-dibromoethane, and 20 ml of diethyl ether were added, and the atmosphere was replaced with nitrogen. While stirring at room temperature, 28.5 g of bromobenzene in 100 ml of diethyl ether Was slowly added dropwise. After completion of the dropwise addition, the mixture was stirred at room temperature for 1 hour, the Grignard reagent prepared to remove residual magnesium was transferred to another 300 ml three-necked flask, and the Grignard reagent was concentrated under vacuum to obtain a white solid. Under nitrogen, 12.9 g of 1-bromoadamantane and 140 ml of dry dichloromethane were added to the solid Grignard reagent, and the mixture was heated to reflux for 24 hours. After cooling the reaction solution to room temperature, the reaction solution was added to 2N hydrochloric acid at 0 ° C., and the separated aqueous layer was extracted with dichloromethane three times. The obtained organic layer was washed with water and dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, and the resulting solid was dissolved in a small amount of dichloromethane, packed in silica gel chromatography, and column purification was performed using hexane as an eluent. The solvent of the solution obtained by column purification was distilled off under reduced pressure to obtain 11.7 g (yield: 92%) of 1-phenyladamantane as a white solid.

  Next, 10.6 g of 1-phenyladamantane and 100 ml of carbon tetrachloride were added to a 300 ml eggplant flask, and 50 ml of bromine was slowly added while stirring at room temperature. After stirring at room temperature for 4 hours, the reaction solution was slowly poured into a saturated sodium hydrogen sulfite solution containing ice to remove excess bromine. The separated aqueous layer was extracted with chloroform three times, and the resulting organic layer was washed with water and dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, and the resulting solid was dissolved in a small amount of dichloromethane, packed in silica gel chromatography, and column purification was performed using hexane as an eluent. The solvent of the obtained solution was distilled off under reduced pressure to obtain 14.4 g (yield: 99%) of 1- (4-bromophenyl) adamantane as a white solid.

  Next, in a 200 ml three-necked flask equipped with a nitrogen introduction tube and a stirring device, 13.0 g of 1- (4-bromophenyl) adamantane, 0.94 g of dichlorobis (triphenylphosphene) palladium, 0.43 g of copper iodide, 60 ml of diisopropylamine was added, and 4.88 g of 3-methyl-1-butyn-3-ol was added while stirring under a nitrogen stream. The mixture was stirred at 60 ° C. for 10 hours, the precipitated salt was filtered, and concentrated under reduced pressure. The obtained solid was dissolved in a small amount of ethyl acetate, packed in silica gel chromatography, and column purification was performed using hexane / ethyl acetate as an eluent. The solvent of the solution obtained by column purification was distilled off under reduced pressure to give 10.9 g of 1-((4-adamantyl) phenyl) -3-methyl-1-butyn-3-ol as a white solid (yield: 83%).

  Next, Dean Stark, 1-((4-adamantyl) phenyl) -3-methyl-1-butyn-3-ol 10.0 g, 13.6 g of crushed sodium hydroxide in a 200 ml eggplant flask equipped with a stirrer, 100 ml of toluene was added, and the mixture was heated to reflux to remove water generated in the system by azeotropic distillation. After the reaction solution was cooled to room temperature, sodium hydroxide was removed by filtration and concentrated under reduced pressure. The obtained solid was dissolved in a small amount of ethyl acetate, packed in silica gel chromatography, and column purification was performed using hexane / ethyl acetate as an eluent. The solvent of the solution obtained by column purification was distilled off under reduced pressure to obtain 6.98 g (yield: 87%) of 1- (4-ethynylphenyl) adamantane (compound (B)) as a white solid.

(Synthesis Example 3: Synthesis of 1,3,5-tris (2- (4-isopropylphenyl) ethynyl) benzene (Compound (C)))
A 200 ml three-necked flask equipped with a nitrogen inlet tube and a stirrer was charged with 3.15 g of 1,3,5-tribromobenzene, 0.7 g of dichlorobis (triphenylphosphene) palladium, 0.29 g of copper iodide and 50 ml of triethylamine. In addition, 5.6 g of the compound (A) obtained in Synthesis Example 1 was added while stirring under a nitrogen stream. After stirring the reaction mixture at 80 ° C. for 10 hours, the reaction mixture was cooled to room temperature and the precipitated salt was filtered. Pure water was added to the obtained filtrate to precipitate a crude product. The precipitated crude product was collected by filtration and washed 3 times with pure water and once with hexane. Furthermore, the crude product was dissolved in a small amount of toluene, packed in silica gel chromatography, and column purification was performed using hexane / ethyl acetate as an eluent. The solvent of the solution obtained by column purification was distilled off under reduced pressure to obtain 3.7 g of 1,3,5-tris (2- (4-isopropylphenyl) ethynyl) benzene (compound (C)) as a white solid ( Yield: 73%).

(Synthesis Example 4: Synthesis of Compound (D))
The following compound (D) was synthesized by the method described in Synthesis Example 3 except that the compound (B) synthesized in Synthesis Example 2 was used instead of the compound (A).

(Synthesis Example 5: Synthesis of Compound (E))
Moreover, the following compound (E) was synthesize | combined by the method of the synthesis example 3 except having used commercially available phenylethynylbenzene instead of the compound (A).

(Synthesis Example 6: 3,3 ′-(oxydi-1,4-phenylene) bis (2,4,5-triphenylcyclopentadienone) and 1,3,5-tris (2- (4-isopropylphenyl) Synthesis of polyphenylene, Diels-Alder product, with) ethynyl) benzene (compound (C))
7.83 g of 3,3 ′-(oxydi-1,4-phenylene) bis (2,4,5-triphenylcyclopentadienone) synthesized with reference to Japanese Patent Laid-Open No. 2000-191752, and the above synthesis example 3.36 g of 1,3,5-tris (2- (4-isopropylphenyl) ethynyl) benzene (compound (C)) obtained in 3 was dissolved in 100 ml of diphenyl ether, and the resulting solution was placed in a flask. added. The inside of the flask was purged with nitrogen, and the solution was heated and stirred at 200 ° C. After heating for 8 hours, the solution cooled to room temperature was added to 50 ml of ethanol. As a powdered solid obtained by precipitation at this time, 3,3 ′-(oxydi-1,4-phenylene) bis (2,4,5-triphenylcyclopentadienone) and 1,3,5-tris ( Polyphenylene (A-1) was obtained as a Diels-Alder product with 2- (4-isopropylphenyl) ethynyl) benzene (compound (C)). The weight average molecular weight of polyphenylene (A-1) determined by GPC (gel permeation chromatography) in terms of polystyrene standard was 13,200.

(Synthesis Example 7: Polyphenylene as a Diels-Alder product of 3,3 ′-(oxydi-1,4-phenylene) bis (2,4,5-triphenylcyclopentadienone) and compound (D) Synthesis)
Polyphenylene (A-2) was obtained in the same manner as in Synthesis Example 6 except that the compound (D) described in Synthesis Example 4 was used instead of the compound (C). The weight average molecular weight of polyphenylene (A-2) determined by GPC (gel permeation chromatography) in terms of polystyrene standard was 8,700.

(Synthesis Example 8: Polyphenylene as a Diels-Alder product of 3,3 ′-(oxydi-1,4-phenylene) bis (2,4,5-triphenylcyclopentadienone) and compound (E) Synthesis)
Polyphenylene (A-3) was obtained in the same manner as in Synthesis Example 6 except that the compound (E) described in Synthesis Example 5 was used instead of the compound (C). The weight average molecular weight of polyphenylene (A-3) determined by GPC (gel permeation chromatography) in terms of polystyrene standard was 36,500.

Synthesis Example 9 Synthesis of 1,3-bis [(4-adamantyl) phenyl] -2-propanone (Compound (F))
1,3-bis [(4-adamantyl) phenyl] -2-propanone was synthesized according to the following scheme.

  To a 200 ml three-necked flask equipped with a nitrogen introduction tube and a stirring device, 10 g of 1,3-diphenyl-2-propanone, 20.5 g of 1-bromoadamantane, and 100 g of 1,2-dichloroethane were added, and the mixture was stirred while stirring under a nitrogen stream. The reaction solution was cooled to ° C. Iron (III) chloride 0.771g was added, and it stirred at room temperature for 8 hours. 100 g of water was added to the reaction solution, and the mixture was stirred at room temperature for 1 hour, and then the separated aqueous layer was extracted with dichloromethane. The obtained organic layer was washed twice with water and dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, and the resulting solid was recrystallized from methanol to give 1,3-bis [(4-adamantyl) phenyl] -2-propanone (compound (F)) as a white solid. 0.7 g was obtained (yield 82%).

(Synthesis Example 10: Synthesis Example of Compound (H))
Compound (H) was synthesized according to the following scheme.

  6.51 g of 4,4′-bis (phenylglyoxaloyl) diphenyl ether (compound (G)) and 1,3-bis [(4-adamantyl) phenyl] -2-propanone obtained in Synthesis Example 9 ( 14.7 g of Compound (F)) and 100 ml of degassed ethanol were added to a 300 ml flask equipped with a reflux condenser having a nitrogen inlet and a stirrer. The mixture was heated to reflux to obtain a homogeneous solution, and the flask was purged with nitrogen for 1 hour. Subsequently, while heating the solution to 70 ° C., a solution prepared by dissolving 0.84 g of potassium hydroxide in 10 ml of ethanol and 1 ml of water was added dropwise over 20 minutes. After completion of the dropwise addition, the reaction solution was heated to reflux for an additional hour to produce the target compound (H), which gradually appeared in the reaction solution as a solid suspension. After the reaction solution was cooled to room temperature, 1.0 g of glacial acetic acid was added and stirred for 20 minutes to neutralize the remaining potassium hydroxide. The solid floating in the reaction solution was collected by filtration, and washed with 50 ml of pure water and 100 ml of ethanol in a funnel to obtain a crude product of compound (H). The obtained crude product was recrystallized from methanol to obtain 27.6 g of the target compound (H) (yield 70%).

(Synthesis Example 11: Synthesis of Polyphenylene as Diels-Alder Product of Compound (H) and Compound (D))
13.2 g of the compound (H) obtained in Synthesis Example 10 and 5.21 g of the compound (D) obtained in Synthesis Example 4 are dissolved in 120 ml of diphenyl ether, and the obtained solution is added to the flask. It was. The flask was purged with nitrogen, and the solution was heated to reflux with stirring. After heating under reflux for 24 hours, the reaction solution was cooled to room temperature and added to 200 ml of ethanol. At this time, polyphenylene (A-4) which is a Diels-Alder reactant of the compound (H) and the compound (D) was obtained as a powdery solid obtained by precipitation. The weight average molecular weight of polyphenylene (A-4) obtained by GPC (gel permeation chromatography) in terms of polystyrene standard was 8,000.

(Synthesis Example 12: Synthesis of terminal acrylic ester polystyrene (compound (I)) used as a macromonomer for graft polymerization)
A glass polymerization reaction vessel cleaned with refluxing toluene and dried under vacuum was charged with 700 mL of cyclohexane (dehydrated with activated alumina). While maintaining this reaction vessel at 55 ° C., 50.31 g of styrene distilled and purified on calcium hydride was added. Furthermore, the heptane solution of sec-butyllithium was added so that the addition amount of sec-butyllithium was equivalent to 3 mol% with respect to styrene, and styrene anion polymerization was performed. After stirring the reaction solution for 1 hour, 0.6 g of ethylene oxide dried over calcium hydride was added. After 30 minutes, 0.31 g of acrylic acid chloride dissolved in 10 mL of tetrahydrofuran dehydrated with activated alumina was added. After another 30 minutes, the solution was cooled to room temperature and added to 1 L of methanol to obtain the desired terminal acrylate polystyrene (compound (I)). The weight average molecular weight (Mw) of the obtained compound (I) determined by GPC (gel permeation chromatography) in terms of polystyrene standard was 3,800, and the number average molecular weight (Mn) was 3,600.

(Synthesis Example 13: 3,3 ′-(oxydi-1,4-phenylene) bis (2,4,5-triphenylcyclopentadienone) and 1,3,5-tris (2- (4-isopropylphenyl) Synthesis of polyphenylene compound (A-5) obtained by graft polymerization of polystyrene as a pore-generating agent to Diels-Alder product with) ethynyl) benzene (compound (C))
7.83 g of 3,3 ′-(oxydi-1,4-phenylene) bis (2,4,5-triphenylcyclopentadienone) and 1,3,5-tris obtained in Synthesis Example 3 ( 2.95 g of 2- (4-isopropylphenyl) ethynyl) benzene (compound (C)) and 4.62 g of the terminal acrylate ester polystyrene (compound (I)) obtained in Synthesis Example 12 were added to 50 ml of γ-butyrolactone. The resulting solution was added to the flask. The atmosphere in the flask was replaced with nitrogen, and the solution was heated and stirred at 200 ° C. After heating for 12 hours, the solution cooled to room temperature was added to 50 ml of ethanol. As a powdered solid obtained by precipitation at this time, 3,3 ′-(oxydi-1,4-phenylene) bis (2,4,5-triphenylcyclopentadienone) and 1,3,5-tris ( Polyphenylene (A-5) in which polystyrene was graft-polymerized to a Diels-Alder product with 2- (4-isopropylphenyl) ethynyl) benzene (compound (C)) was obtained. The weight average molecular weight of polyphenylene (A-5) obtained by GPC (gel permeation chromatography) in terms of polystyrene standard was 39,300.

(Synthesis Example 14: For a Diels-Alder product of 3,3 ′-(oxydi-1,4-phenylene) bis (2,4,5-triphenylcyclopentadienone) and compound (D), Synthesis of polyphenylene compound (A-6) obtained by graft polymerization of polystyrene as a pore-forming agent)
Polyphenylene (A-6) was obtained in the same manner as in Synthesis Example 13, except that the compound (D) described in Synthesis Example 3 was used instead of the compound (C). The weight average molecular weight of polyphenylene (A-6) determined by GPC (gel permeation chromatography) in terms of polystyrene standard was 23,600.

(Synthesis Example 15: For a Diels-Alder product of 3,3 ′-(oxydi-1,4-phenylene) bis (2,4,5-triphenylcyclopentadienone) and compound (E), (Synthesis of polyphenylene compound (A-7) obtained by graft polymerization of polystyrene as a pore-forming agent)
Polyphenylene (A-7) was obtained in the same manner as in Synthesis Example 13, except that the compound (E) described in Synthesis Example 3 was used instead of the compound (C). The weight average molecular weight of polyphenylene (A-7) determined by GPC (gel permeation chromatography) in terms of polystyrene standard was 38,600.

(Synthesis Example 16: Synthesis of polyphenylene compound (A-8) obtained by graft-polymerizing polystyrene as a pore-generating agent to a Diels-Alder product of compound (H) and compound (D))
13.20 g of the compound (H) obtained in Synthesis Example 10, 4.57 g of the compound (D) obtained in Synthesis Example 3, and the terminal acrylate ester polystyrene obtained in Synthesis Example 12 (Compound (I)) ) 4.62 g was dissolved in 100 ml of γ-butyrolactone and the resulting solution was added to the flask. The inside of the flask was purged with nitrogen, and the solution was heated and stirred at 220 ° C. After heating for 24 hours, the solution cooled to room temperature was added to 200 ml of ethanol. As a pulverulent solid obtained by precipitation at this time, polyphenylene (A-8) in which polystyrene was graft-polymerized to the Diels-Alder product of the compound (H) and the compound (D) was obtained. The weight average molecular weight of polyphenylene (A-8) determined by GPC (gel permeation chromatography) in terms of polystyrene standard was 29,300.

<Preparation of composition for insulating film formation>
1.0 g of various polyphenylene compounds (A-1) to (A-8) obtained in the above synthesis examples, and vinyl triacetoxysilane oligomer (weight average molecular weight: 360) as an adhesion assistant for all solid components The composition for forming an insulating film was prepared by adding to a solvent (11 g) so as to be 3.0% by mass and completely dissolving it. Table 1 summarizes the types of polyphenylene compound and solvent used in the preparation of the insulating film forming composition, the mixing ratio (mass ratio) of the solvent, and the like.
The oligomer of vinyltriacetoxysilane is obtained by mixing 23.2 g of vinyltriacetoxysilane (manufactured by Toray Dow Corning, Z-6075) with 5.4 g of deionized water having a resistivity of 18.3 MΩ. The mixture was stirred at room temperature for 45 minutes and synthesized by hydrolyzing vinyltriacetoxysilane.

<Production of wafer with coating film for evaluation>
Each insulating film forming coating solution prepared as described above was spin-coated on an 8-inch bare silicon wafer having a substrate resistance of 7 Ω / cm using a spin coater ACT-8 SOD manufactured by Tokyo Electron. The coated film was baked at 110 ° C. for 60 seconds, followed by 200 ° C. for 60 seconds. About the obtained wafer with a coating film, it cured by the method shown in Table 1, and produced the wafer for evaluation.
Of the curing methods described in Table 1, furnace curing is a curing method in which a wafer with a film is exposed for one hour in a 400 ° C. clean oven purged with nitrogen. Electron beam curing is a method of curing for 50 seconds while irradiating an electron beam with an acceleration voltage of 13 keV on a 350 ° C. hot plate installed in a vacuum chamber adjusted to a vacuum degree of 10 Torr in a helium gas atmosphere. . Furthermore, the porogen desorption process is a pore forming agent polystyrene by exposing the film cured by performing the above-described furnace cure or electron beam cure to a nitrogen-substituted 420 ° C. clean oven for 1 hour. This is a step of decomposing and removing pores to form pores in the film.

<Measurement of film dielectric constant>
The relative dielectric constant of the film obtained as described above was calculated from the capacitance value at 1 MHz using a mercury probe manufactured by Four Dimensions and a HP4285A LCR meter manufactured by Yokogawa Hewlett-Packard. The results are summarized in Table 1.

<Mechanical strength (Young's modulus)>
As the mechanical strength of the film obtained in the above manner, Young's modulus (25 ° C.) was measured using a nanoindenter SA2 manufactured by MTS. The results are summarized in Table 1.

Abbreviations of solvents in Table 1 mean the following solvents, respectively.
(D-1): Cyclohexanone (D-2): 2-heptanone (D-3): γ-butyrolactone

In Table 1 above, Comparative Examples 1 and 2 show a performance comparison when performing a furnace cure and an electron beam cure on a film obtained from a composition not including the present invention containing polyphenylene (A-3). Yes. In this case, it was found that there was no significant difference in the Young's modulus of the film between the furnace cure and the electron beam cure.
On the other hand, Examples 1-12 are the evaluation result regarding the coating film obtained from the composition applicable to this invention containing polyphenylene (A-1), (A-2) or (A-4). is there. In this case, it was found that each example showed better film dielectric constant and Young's modulus than the comparative example. Further, in the performance comparison between the furnace cure and the electron beam cure, it was found that the Young's modulus of the film was dramatically improved by applying the electron beam cure in comparison with the furnace cure.

Further, Comparative Examples 3 and 4 are examples of coatings obtained from compositions that do not fall under the composition of the present invention, including polyphenylene (A-7) in which a pore-forming agent (polystyrene) is graft-copolymerized. The performance comparison when performing curing and electron beam curing is shown. In this case, although the pore forming agent was contained, the dielectric constant of the film was hardly reduced. This is presumably because after the polystyrene as the pore forming agent was decomposed and vaporized, the domains occupied by the polystyrene could not remain as pores in the insulating film but disappeared.
On the other hand, Examples 13-24 correspond to this invention containing the polyphenylene (A-5), (A-6), or (A-8) by which the void | hole formation agent (polystyrene) was graft-polymerized. It is an evaluation result regarding the coating film obtained from the composition. In this case, each example showed good film dielectric constant and Young's modulus, and it was found that the dielectric constant was greatly reduced especially for the film subjected to electron beam curing.

Claims (6)

  An insulating film forming composition comprising polyphenylene formed by a Diels-Alder reaction between a compound having at least one cyclopentadienone group and a compound having at least one acetylene group, wherein the polyphenylene is a secondary compound A composition for forming an insulating film, which has a substituent containing a carbon atom.   The composition for forming an insulating film according to claim 1, wherein the substituent containing the secondary carbon atom is a branched alkyl group having 3 to 12 carbon atoms or a polycyclic cycloalkyl group. The polyphenylene is a compound represented by general formula (a), a compound represented by general formula (c), a compound represented by general formula (d), a compound represented by general formula (e), and general The composition for forming an insulating film according to claim 1 or 2, wherein the composition is polyphenylene synthesized from a starting material containing at least one selected from the group consisting of compounds represented by formula (f).

(In General Formula (a), R ¹ represents a hydrogen atom, an aromatic group, or an aromatic group having a substituent containing a secondary carbon atom. Ar ¹ represents a benzene group, a naphthalene group, or a biphenyl group. , 9,9-diphenylfluorene group or a group represented by the general formula (b).
In general formula (c), R ² represents a hydrogen atom, an aromatic group, or an aromatic group having a substituent containing a secondary carbon atom. Ar ³ represents a benzene group, a naphthalene group, a biphenyl group, a 9,9-diphenylfluorene group, or a group represented by the general formula (b). y represents an integer of 3 to 6.
In general formula (d), R ² represents a hydrogen atom, an aromatic group, or an aromatic group having a substituent containing a secondary carbon atom. Ar ² represents a benzene group, a naphthalene group, a biphenyl group, a 9,9-diphenylfluorene group, or a group represented by the general formula (b).
In general formula (e), R ¹ and R ² each independently represents a hydrogen atom, an aromatic group, or an aromatic group having a substituent containing a secondary carbon atom. Ar ⁴ represents a benzene group, a naphthalene group, a biphenyl group, a 9,9-diphenylfluorene group, or a group represented by the general formula (b). Note that at least one of R ¹ and R ² represents an aromatic group having a substituent containing a secondary carbon atom.
In General Formula (f), R ¹ and R ² each independently represent a hydrogen atom, an aromatic group, or an aromatic group having a substituent containing a secondary carbon atom. Ar ⁴ represents a benzene group, a naphthalene group, a biphenyl group, a 9,9-diphenylfluorene group, or a group represented by the general formula (b). Note that at least one of R ¹ and R ² represents an aromatic group having a substituent containing a secondary carbon atom. )

(In the general formula (b), Z represents —O—, —S—, alkylene, —O—CF ₂ —, perfluoroalkylene, or an arylene group.)   The polyphenylene is a polyphenylene synthesized from a starting material containing at least one compound represented by the general formula (a) and at least one compound represented by the general formula (c). 3. The composition for forming an insulating film according to 3.   A composition for forming an insulating film according to any one of claims 1 to 4 is applied on a substrate to obtain a coating film, and the coating film obtained in the film forming process is irradiated with an electron beam. And a method for producing an insulating film, comprising: a curing step for curing the coating film.   An electronic device having an insulating film obtained by the manufacturing method according to claim 5.