JP2007161784A - Insulating film, compound, film-forming composition and electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an insulating film having good film properties such as dielectric constant and mechanical strength and usable in electronic devices, etc., a film-forming composition for forming the insulating film, and electronic devices, etc., having the insulating film. <P>SOLUTION: The insulating film is formed by using a film-forming composition containing a compound having a cage structure and an organic solvent and has a glass transition temperature of ≥300°C. The invention further relates to an electronic device having the insulating film, a compound composed of a polymer of a monomer having a cage structure and having a glass transition temperature of ≥200°C, a film-forming composition containing the compound and an organic solvent, an insulating film formed by using the film-forming composition and having a glass transition temperature of ≥300°C, and an electronic device having the insulating film. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an insulating film, and more particularly to an insulating film having good film properties such as dielectric constant, mechanical strength, heat resistance, etc. used in electronic devices, a film-forming composition used for the formation thereof, and a compound. The present invention relates to an electronic device having an insulating film.

  In recent years, in the field of electronic materials, with the progress of higher integration, more functions, and higher performance, circuit resistance and capacitor capacity between wirings have increased, leading to an increase in power consumption and delay time. In particular, an increase in delay time is a major factor in reducing the signal speed of the device and the occurrence of crosstalk. Therefore, in order to reduce the delay time and speed up the device, it is necessary to reduce parasitic resistance and parasitic capacitance. It has been. As a specific measure for reducing this parasitic capacitance, an attempt has been made to cover the periphery of the wiring with a low dielectric interlayer insulating film. In addition, the interlayer insulating film is required to have excellent heat resistance that can withstand post-processes such as a thin film forming 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 high. It has been demanded.

For a long time, polybenzoxazole and polyimide have been widely known as high heat-resistant insulating films. In addition, a highly heat-resistant insulating film made of polyarylene ether is disclosed. However, in order to realize a high-speed device, there is a strong demand for further reduction of the dielectric constant.
Polymers based on saturated hydrocarbons such as polyethylene are characterized by a low dielectric constant due to their low electronic polarization, but are generally composed of carbon-carbon single bonds with low bond dissociation energy. The problem is that the heat resistance is low.

US Pat. No. 6,380,347 US Pat. No. 5,965,679

  The present invention is an insulating film for solving the above problems, more specifically, an insulating film having good film characteristics such as dielectric constant and mechanical strength used for electronic devices, and further for forming a film used for forming the insulating film. Provided are a composition and an electronic device having the insulating film.

It has been found that the above problems are solved by the following configurations (1) to (18).
(1) An insulating film formed using a film-forming composition containing a compound having a cage structure and an organic solvent, and having a glass transition temperature of 300 ° C. or higher.
(2) The insulating film according to (1), wherein the compound having a cage structure is a polymer of a monomer having a cage structure.
(3) The insulating film according to (1) or (2), wherein the compound having a cage structure has a glass transition temperature of 200 ° C. or higher.
(4) The insulating film according to (2), wherein the monomer having a cage structure has a carbon-carbon double bond or a carbon-carbon triple bond.
(5) The insulating film according to any one of (1) to (4), wherein the cage structure is selected from adamantane, biadamantane, diamantane, triamantane, and tetramantane.

(6) The insulating film according to any one of (2) to (5), wherein the monomer having a cage structure is selected from the group of the following formulas (I) to (VI).

In formulas (I) to (VI),
X _{1 to} X ₈ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a silyl group, an acyl group, an alkoxycarbonyl group, a carbamoyl group, or the like.
Y _{1 to} Y ₈ each independently represents a halogen atom, an alkyl group, a C 6 -aryl group or a silyl group.
m ₁ and m ₅ each independently represents an integer of ₁ to 16, and n ₁ and n ₅ each independently represents an integer of 0 to 15.
m ₂ , m ₃ , m ₆ and m ₇ each independently represent an integer of 1 to 15, and n ₂ , n ₃ , n ₆ and n ₇ each independently represents an integer of 0 to 14.
m ₄ and m ₈ each independently represents an integer of 1 to 20, and n ₄ and n ₈ each independently represents an integer of 0 to 19.

(7) Any of (1) to (6), wherein the compound having a cage structure is obtained by polymerizing a monomer having a cage structure in the presence of a transition metal catalyst or a radical initiator The insulating film as described in 2.
(8) The insulating film according to any one of (1) to (7), wherein the compound having a cage structure is dissolved in cyclohexanone or anisole at 3% by mass or more at 25 ° C.
(9) An electronic device having the insulating film according to any one of (1) to (8).

(10) A compound having a cage structure and a glass transition temperature of 200 ° C. or higher.
(11) The compound according to (10), wherein the monomer having a cage structure has a carbon-carbon double bond or a carbon-carbon triple bond.
(12) The compound according to (10) or (11), wherein the cage structure is selected from adamantane, biadamantane, diamantane, triamantane, and tetramantane.

(13) The compound according to any one of (10) to (12), wherein the monomer having a cage structure is selected from the group of the following formulas (I) to (VI).

In formulas (I) to (VI),
X _{1 to} X ₈ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a silyl group, an acyl group, an alkoxycarbonyl group, a carbamoyl group, or the like.
Y _{1 to} Y ₈ each independently represents a halogen atom, an alkyl group, a C 6 -aryl group or a silyl group.
m ₁ and m ₅ each independently represents an integer of ₁ to 16, and n ₁ and n ₅ each independently represents an integer of 0 to 15.
m ₂ , m ₃ , m ₆ and m ₇ each independently represent an integer of 1 to 15, and n ₂ , n ₃ , n ₆ and n ₇ each independently represents an integer of 0 to 14.
m ₄ and m ₈ each independently represents an integer of 1 to 20, and n ₄ and n ₈ each independently represents an integer of 0 to 19.

(14) The compound according to any one of (10) to (13), which is obtained by polymerizing a monomer having a cage structure in the presence of a transition metal catalyst or a radical initiator.
(15) The compound according to any one of (10) to (14), which is dissolved in cyclohexanone or anisole at 3% by mass or more at 25 ° C.
(16) A film-forming composition comprising the compound according to any one of (10) to (15) and an organic solvent.
(17) An insulating film having a glass transition temperature of 300 ° C. or higher, formed using the film forming composition according to (16).
(18) An electronic device having the insulating film according to (17).

  Since the insulating film of the present invention has a low dielectric constant, a good surface shape, and a high glass transition temperature, it has excellent heat resistance and can be used as an interlayer insulating film in electronic devices and the like.

Hereinafter, the present invention will be described in detail.
The insulating film of the present invention is formed using a film-forming composition containing a polymer of a monomer having a cage structure and an organic solvent, and has a glass transition temperature of 300 ° C. or higher, preferably 400 ° C. or higher. It has a low dielectric constant, good surface shape, and high heat resistance.
In the insulating film of the present invention, the glass transition temperature is not particularly limited in order to make the glass transition temperature 300 ° C. or higher, but the film forming composition uses a polymer having a glass transition temperature of 200 ° C. or higher as the polymer to be used. Further, there may be mentioned techniques such as using a material to which a cross-linking agent is added, increasing the temperature in firing stepwise after the film-forming composition is applied to the substrate and dried.

Further, as a polymer advantageous for use in the formation of the insulating film of the present invention, a compound (polymer) having a glass transition temperature of 200 ° C. or higher is mentioned. This polymer further has a cage structure. It is a polymer of a monomer and is dissolved in a solvent such as cyclohexanone at 25 ° C. at 3% by mass or more.
Normally, a polymer having a glass transition temperature of 200 ° C. or higher is not soluble in a solvent. Surprisingly, the polymer (compound) having a cage structure according to the present invention has a glass transition temperature of 200 ° C. In spite of the above, it was a solvent-soluble one that dissolved 3% by mass or more in a solvent such as cyclohexanone at 25 ° C.

  In addition, when a film-forming composition to which a crosslinking agent is added is used, the crosslinking agent to be used is not particularly limited. For example, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, penta Erythritol tetraacrylate, dipentaerythritol hexaacrylate, trimethylolpropane benzoic acid, trimethylolpropane triglycidyl ether, phenylglycidyl ether acrylate hexamethylene diisocyanate urethane prepolymer, phenylglycidyl ether acrylate tridiisocyanate urethane prepolymer, pentaerythritol triacrylate Hexamethylene diisocyanate urethane prepolymer, pe Taerythritol triacrylate isophorodiisocyanate urethane prepolymer, dipentaerythritol pentaacrylate hexamethylene diisocyanate urethane prepolymer, α-methylstyrene dimer, polydicyclopentadiene, polysilsesquioxane, polynorbornadiene, polynorbornadiene epoxide, cis-1, 4-polyisoprene, 1,4-polybutadiene, 1,2-polybutadiene, urea resin, melamine resin, benzoguanamine resin, nylon, methyltrivinylsilane, tetravinylsilane, divinylmethylphenylsilane, diphenylmethylvinylsilane, diphenyldivinylsilane, and the following Although the compound represented by a formula can be mentioned, it is not limited to these. In the following formula, n represents a positive number.

  In addition, regarding the method of stepwise raising the temperature in firing after applying and drying the above-mentioned film-forming composition on a substrate, usually heating and firing at a constant temperature for a certain time, stepwise firing It is. For example, what is baked at 400 ° C. for 1 hour may be heated at 100 ° C., 200 ° C., 300 ° C., 400 ° C. for 15 minutes, or at 300 ° C., 450 ° C. for 30 minutes.

  The “cage structure” described in the present invention is such that the volume is determined by a plurality of rings formed of covalently bonded atoms, and points located within the volume cannot be separated from the volume without passing through the ring. Refers to a molecule. For example, an adamantane structure is considered a cage structure. In contrast, a cyclic structure having a single bridge such as norbornane (bicyclo [2,2,1] heptane) is not considered a cage structure because the ring of a single bridged cyclic compound does not define volume. .

  The cage structure of the present invention may contain either a saturated or unsaturated bond and may contain a heteroatom such as oxygen, nitrogen or sulfur, but a saturated hydrocarbon is preferred from the viewpoint of low dielectric constant.

  The cage structure of the present invention is preferably adamantane, biadamantane, diamantane, triamantane, tetramantane, dodekahedran, more preferably adamantane, biadamantane, diamantane, and particularly beadamantane in that it has a low dielectric constant. Diamantane is preferred.

  The cage structure in the present invention may have one or more substituents. Examples of the substituent include a halogen atom (a fluorine atom, a chloro atom, a bromine atom, or an iodine atom), a carbon number of 1 to 10. Linear, branched and cyclic alkyl groups (methyl, t-butyl, cyclopentyl, cyclohexyl, etc.), alkenyl groups having 2 to 10 carbon atoms (vinyl, propenyl, etc.), alkynyl groups having 2 to 10 carbon atoms (ethynyl, phenyl) Ethynyl, etc.), C6-C20 aryl groups (phenyl, 1-naphthyl, 2-naphthyl, etc.), C2-C10 acyl groups (benzoyl, etc.), C2-C10 alkoxycarbonyl groups (methoxycarbonyl) Etc.), a carbamoyl group having 1 to 10 carbon atoms (N, N-diethylcarbamoyl etc.), an aryloxy group having 6 to 20 carbon atoms (phenoxy etc.), 6 carbon atoms 20 arylsulfonyl group (phenylsulfonyl, etc.), a nitro group, a cyano group, a silyl group (triethoxysilyl, methyldiethoxysilyl, trivinylsilyl or the like) and the like.

  The cage structure in the present invention is preferably divalent to tetravalent. At this time, the group bonded to the cage structure may be a monovalent or higher valent substituent or a divalent or higher linking group. The cage structure is preferably divalent or trivalent, particularly preferably divalent.

  The compound having a cage structure used for forming the insulating film of the present invention is preferably a polymer of a monomer having a cage structure. Here, the term “monomer” refers to a monomer that is polymerized to be a dimer or higher polymer. This polymer may be a homopolymer or a copolymer.

  The polymerization reaction of the monomer is caused by the polymerizable group substituted for the monomer. Here, the polymerizable group refers to a reactive substituent that polymerizes the monomer. The polymerization reaction may be any polymerization reaction, and examples thereof include radical polymerization, cationic polymerization, anionic polymerization, ring-opening polymerization, polycondensation, polyaddition, addition condensation, and transition metal catalyst polymerization.

The polymerization reaction of the monomer of the present invention is preferably performed in the presence of a nonmetallic polymerization initiator. For example, a monomer having a polymerizable carbon-carbon triple bond can be polymerized in the presence of a polymerization initiator that exhibits activity by generating free radicals such as carbon radicals and oxygen radicals by heating.
As the polymerization initiator, an organic peroxide or an organic azo compound is preferably used, and an organic peroxide is particularly preferable.

  Examples of the organic peroxide include ketone peroxides such as perhexa H, peroxyketals such as perhexa TMH, hydroperoxides such as perbutyl H-69, park mill D, and perbutyl C, which are commercially available from Nippon Oil & Fats Co., Ltd. , Dialkyl peroxides such as perbutyl D, diacyl peroxides such as niper BW, peroxyesters such as perbutyl Z and perbutyl L, peroxydicarbonates such as perroyl TCP, diisobutyryl peroxide, cumylperoxyneodeca Noate, di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, di-sec-butyl peroxydicarbonate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, di (4 -T-Buchi Chlohexyl) peroxydicarbonate, di (2-ethylhexyl) peroxydicarbonate, t-hexylperoxyneodecanoate, t-butylperoxyneodecanoate, t-butylperoxyneoheptanoate, t- Hexyl peroxypivalate, t-butyl peroxypivalate, di (3,5,5-trimethylhexanoyl) peroxide, dilauroyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2- Ethylhexanoate, disuccinic acid peroxide, 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane, t-hexylperoxy-2-ethylhexanoate, di (4-methyl Benzoyl) peroxide, t-butylperoxy-2-ethylhexanoe Di (3-methylbenzoyl) peroxide, benzoyl (3-methylbenzoyl) peroxide, dibenzoyl peroxide, dibenzoyl peroxide, 1,1-di (t-butylperoxy) -2-methylcyclohexane, 1,1-di (t-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1-di (t-hexylperoxy) cyclohexane, 1,1-di (t-butylperoxy) cyclohexane, 2,2-di (4,4-di- (t-butylperoxy) cyclohexyl) propane, t-hexylperoxyisopropyl monocarbonate, t-butylperoxymaleic acid, t-butylperoxy-3,5 5, -trimethylhexanoate, t-butyl peroxylaurate, t-butyl peroxyiso Propyl monocarbonate, t-butylperoxy 2-ethylhexyl monocarbonate, t-hexylperoxybenzoate, 2,5-di-methyl-2,5-di (benzoylperoxy) hexane, t-butylperoxyacetate, 2,2-di- (t-butylperoxy) butane, t-butylperoxybenzoate, n-butyl 4,4-di-t-butylperoxyvalerate, di (2-t-butylperoxyisopropyl) Benzene, dicumyl peroxide, di-t-hexyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, t-butylcumyl peroxide, di-t-butyl peroxide , P-methane hydroperoxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hex -3, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide, 2,3-dimethyl-2,3-diphenylbutane, 2,4-dichlorobenzoyl peroxide, o-chlorobenzoyl peroxide, p-chlorobenzoyl peroxide, tris- (t-butylperoxy) triazine, 2,4,4-trimethylpentylperoxyneodecanoate, α -Cumylperoxyneodecanoate, t-amylperoxy 2-ethylhexanoate, t-butylperoxyisobutyrate, di-t-butylperoxyhexahydroterephthalate, di-t-butylperoxytrimethyladipate Di-3-methoxybuty Peroxydicarbonate, di-isopropylperoxydicarbonate, t-butylperoxyisopropylcarbonate, 1,6-bis (t-butylperoxycarbonyloxy) hexane, diethylene glycol bis (t-butylperoxycarbonate), t- Hexyl peroxyneodecanoate or the like is preferably used.

  As organic azo compounds, azonitrile compounds such as V-30, V-40, V-59, V-60, V-65, and V-70, which are commercially available from Wako Pure Chemical Industries, Ltd., VA-080, Azoamide compounds such as VA-085, VA-086, VF-096, VAm-110, and VAm-111, cyclic azoamidine compounds such as VA-044 and VA-061, and azoamidine compounds such as V-50 and VA-057 2,2-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2-azobis (2,4-dimethylvaleronitrile), 2,2-azobis (2-methylpropionitrile), 2,2-azobis (2,4-dimethylbutyronitrile), 1,1-azobis (cyclohexane-1-carbonitrile), 1-[(1-cyano-1-methylethyl) a Zo] formamide, 2,2-azobis {2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] propionamide}, 2,2-azobis [2-methyl-N- (2 -Hydroxybutyl) propionamide], 2,2-azobis [N- (2-propenyl) -2-methylpropionamide], 2,2-azobis (N-butyl-2-methylpropionamide), 2,2- Azobis (N-cyclohexyl-2-methylpropioamide), 2,2-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, 2,2-azobis [2- (2-imidazoline-2) -Yl) propane] disulfate dihydrate, 2,2-azobis {2- [1- (2-hydroxyethyl) -2-imidazolin-2-yl] propane} Hydrochloride, 2,2-azobis [2- [2-imidazolin-2-yl] propane], 2,2-azobis (1-imino-1-pyrrolidino-2-methylpropane) dihydrochloride, 2,2-azobis (2-methylpropionamidine) dihydrochloride, 2,2-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] tetrahydrate, dimethyl 2,2-azobis (2-methylpropionate), 4,4-azobis (4-cyanovaleric acid), 2,2-azobis (2,4,4-trimethylpentane) and the like are preferably used.

The polymerization initiator of the present invention may be used alone or in combination of two or more.
The amount of the polymerization initiator used in the present invention is preferably 0.001 to 2 mol, more preferably 0.01 to 1 mol, and particularly preferably 0.05 to 0.5 mol with respect to 1 mol of the monomer.

The polymerization reaction of the monomer of the present invention is also preferably performed in the presence of a transition metal catalyst. For example, a monomer having a polymerizable carbon-carbon double bond or carbon-carbon triple bond may be a Pd-based catalyst such as Pd (PPh ₃ ) ₄ , Pd (OAc) ₂ , Ziegler-Natta catalyst, nickel acetylacetonate, etc. polymerized using a Ni-based catalyst, W-based catalyst such as WCl _6, Mo-based catalysts such as MoCl _5, Ta catalysts such as TaCl _5, Nb-based catalyst such as NbCl _5, Rh-based catalyst, a Pt-based catalyst and the like It is preferable.

The transition metal catalyst of the present invention may be used alone or in combination of two or more.
The amount of the transition metal catalyst used in the present invention is preferably 0.001 to 2 mol, more preferably 0.01 to 1 mol, particularly preferably 0.05 to 0.5 mol, relative to 1 mol of the monomer.

The cage structure in the present invention may be substituted as a pendant group in the polymer and may be a part of the polymer main chain, but a form that is a part of the polymer main chain is more preferable. Here, the form which is a part of the polymer main chain means that the polymer chain is cleaved when the cage structure is removed from the polymer. In this form, the cage structure is directly single-bonded or connected by an appropriate divalent linking group. Examples of the linking group include, for example, —C (R ₁₁ ) (R ₁₂ ) —, —C (R ₁₃ ) ═C (R ₁₄ ) —, —C≡C—, arylene group, —CO—, —O—. , —SO ₂ —, —N (R ₁₅ ) —, —Si (R ₁₆ ) (R ₁₇ ) —, or a combination thereof. Here, R _{11 to} R ₁₇ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group or an aryl group. These linking groups may be substituted with a substituent, and for example, the above-described substituents are preferable examples.
Among these, more preferred linking groups are —C (R ₁₁ ) (R ₁₂ ) —, —CH═CH—, —C≡C—, arylene group, —O—, —Si (R ₁₆ ) (R ₁₇ ). — Or a combination thereof, and particularly preferred are —C (R ₁₁ ) (R ₁₂ ) — and —CH═CH— from the viewpoint of low dielectric constant.

  The compound having a cage structure of the present invention may be a low molecular compound or a high molecular compound (for example, a polymer), but a polymer is preferable. When the compound having a cage structure is a polymer, the weight average molecular weight is preferably 1000 to 500000, more preferably 3000 to 300000, and particularly preferably 5000 to 200000. The polymer having a cage structure may be contained in the insulating film forming coating solution as a resin composition having a molecular weight distribution. When the compound having a cage structure is a low molecular compound, the molecular weight is preferably 150 to 3000, more preferably 200 to 2000, and particularly preferably 220 to 1000.

  The compound having a cage structure of the present invention is preferably a polymer of a monomer having a polymerizable carbon-carbon triple bond. Furthermore, a polymer of a compound represented by the following formulas (I) to (IV) is more preferable.

In formulas (I) to (VI),
X _{1 to} X ₈ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, or a carbon number. A silyl group having 0 to 20 carbon atoms, an acyl group having 2 to 10 carbon atoms, an alkoxycarbonyl group having 2 to 10 carbon atoms, a carbamoyl group having 1 to 20 carbon atoms and the like are represented. Among these, Preferably a hydrogen atom, a C1-C10 alkyl group, a C6-C20 aryl group, a C0-C20 silyl group, a C2-C10 acyl group, C2-C10 An alkoxycarbonyl group and a carbamoyl group having 1 to 20 carbon atoms, more preferably a hydrogen atom and an aryl group having 6 to 20 carbon atoms, and particularly preferably a hydrogen atom.
Y _{1 to} Y ₈ each independently represent a halogen atom (fluorine, chlorine, bromine, etc.), an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, or a silyl group having 0 to 20 carbon atoms; Preferably they are a C1-C10 alkyl group and C6-C20 aryl group which may have a substituent, Especially preferably, they are an alkyl group (methyl group etc.).
X _{1 to} X ₈ and Y _{1 to} Y ₈ may be further substituted with another substituent.
m ₁ and m ₅ each independently represents an integer of 1 to 16, preferably 1 to 4, more preferably 1 to 3, and particularly preferably 2.
n ₁ and n ₅ each independently represents an integer of 0 to 15, preferably 0 to 4, more preferably 0 or 1, and particularly preferably 0.
m ₂ , m ₃ , m ₆ and m ₇ each independently represents an integer of 1 to 15, preferably 1 to 4, more preferably 1 to 3, and particularly preferably 2.
n ₂ , n ₃ , n ₆ and n ₇ each independently represents an integer of 0 to 14, preferably 0 to 4, more preferably 0 or 1, particularly preferably 0.
m ₄ and m ₈ each independently represents an integer of 1 to 20, preferably 1 to 4, more preferably 1 to 3, and particularly preferably 2.
n ₄ and n ₈ each independently represents an integer of 0 to 19, preferably 0 to 4, more preferably 0 or 1, and particularly preferably 0.

  The monomer having a cage structure of the present invention is preferably a compound represented by the above formula (II) or (III), more preferably a compound represented by the above formula (III).

  Two or more compounds having the cage structure of the present invention may be used in combination, or two or more monomers having the cage structure of the present invention may be copolymerized.

  The compound having a cage structure of the present invention preferably has sufficient solubility in an organic solvent. The solubility is preferably 3% by mass or more, more preferably 5% by mass or more, and particularly preferably 10% by mass or more in cyclohexanone or anisole at 25 ° C.

  Examples of the compound having a cage structure of the present invention include polybenzoxazoles described in JP-A Nos. 11-322929, 2003-12802, and 2004-18593, and quinoline resins described in JP-A-2001-2899. Special table 2003-530464, Special table 2004-535497, Special table 2004-504424, Special table 2004-504455, Special table 2005-501131, Special table 2005-516382, Special table 2005-514479, JP-A-2005-522528, JP-A-2000-100808, US Pat. No. 6,509,415, polyaryl resins, JP-A-11-214382, JP-A-2001-332542, JP-A-2003-252882, JP-A-2003-292878 No., JP2004-2787 , JP 2004-67877, poly adamantane described in JP 2004-59444, JP 2003-252992, polyimides and the like described in JP 2004-26850.

  Specific examples of the monomer having a cage structure that can be used in the present invention are described below, but the present invention is not limited thereto.

As the solvent used in the polymerization reaction, any solvent may be used as long as the raw material monomer can be dissolved at a necessary concentration and does not adversely affect the characteristics of the film formed from the obtained polymer. . For example, alcohol solvents such as water, methanol, ethanol and propanol, alcohol solvents such as alcohol acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, acetophenone, ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, γ-butyrolactone, methyl benzoate Ester solvents such as dibutyl ether, anisole, etc., aromatic hydrocarbon solvents such as toluene, xylene, mesitylene, t-butylbenzene, 1,3,5-triisopropylbenzene, N-methylpyrrolidinone, Amide solvents such as dimethylacetamide, carbon tetrachloride, dichloromethane, chloroform, 1,2-dichloroethane, chlorobenzene, 1,2-dichlorobenzene, 1,2,4-trichloro Halogen-based solvents such as benzene, hexane, heptane, octane, and aliphatic hydrocarbon solvents such as cyclohexane can be used. Among these, preferred solvents are acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, acetophenone, ethyl acetate, propylene glycol monomethyl ether acetate, γ-butyrolactone, anisole, tetrahydrofuran, toluene, xylene, mesitylene, t-butylbenzene, 1,3. , 5-triisopropylbenzene, 1,2-dichloroethane, chlorobenzene, 1,2-dichlorobenzene, 1,2,4-trichlorobenzene, more preferably tetrahydrofuran, γ-butyrolactone, anisole, toluene, xylene, mesitylene, t-butylbenzene, 1,3,5-triisopropylbenzene, 1,2-dichloroethane, chlorobenzene, 1,2-dichlorobenzene, 1,2,4-trichloroben A down, particularly preferably γ- butyrolactone, anisole, mesitylene, t- butyl, 1,3,5-triisopropylbenzene, 1,2-dichlorobenzene, 1,2,4-trichlorobenzene. These may be used alone or in admixture of two or more.
The concentration of the monomer in the reaction solution is preferably 1 to 50% by mass, more preferably 5 to 30% by mass, and particularly preferably 10 to 20% by mass.

Optimum conditions for the polymerization reaction in the present invention vary depending on the polymerization initiator, monomer, solvent type, concentration, and the like, but preferably the internal temperature is 0 ° C to 200 ° C, more preferably 50 ° C to 170 ° C, and particularly preferably 100. C. to 150.degree. C., preferably 1 to 50 hours, more preferably 2 to 20 hours, and particularly preferably 3 to 10 hours.
Moreover, in order to suppress the inactivation of the polymerization initiator by oxygen, it is preferable to make it react under inert gas atmosphere (for example, nitrogen, argon, etc.). The oxygen concentration during the reaction is preferably 100 ppm or less, more preferably 50 ppm or less, and particularly preferably 20 ppm or less.
The preferable range of the weight average molecular weight of the polymer obtained by polymerization is 1000 to 500000, more preferably 3000 to 300000, and particularly preferably 5000 to 200000.

The monomer having a cage structure according to the present invention is prepared, for example, by using commercially available diamantane as a raw material and reacting with bromine in the presence or absence of an aluminum bromide catalyst to introduce a bromine atom at a desired position, followed by aluminum bromide, Synthesis by introducing 2,2-dibromoethyl group by reaction with vinyl bromide and Friedel-Crafts in the presence of Lewis acids such as aluminum chloride and iron chloride, followed by dehydrobration with strong base and conversion to ethynyl group can do. Specifically, Macromolecules, 1991, 24, 5266-5268, 1995, 28, 5554-5560, Journal of Organic Chemistry, 39, 2995-3003 (1974) ) And the like.
Moreover, an alkyl group or a silyl group can be introduced by anionizing a hydrogen atom of a terminal acetylene group with butyllithium or the like and reacting this with an alkyl halide or a silyl halide.

  The polymer of this invention may be used individually or may be used in mixture of 2 or more types.

Although the coating solvent used in the present invention is not particularly limited, for example, alcohol solvents such as methanol, ethanol, 2-propanol, 1-butanol, 2-ethoxymethanol, 3-methoxypropanol, 1-methoxy-2-propanol, Ketone solvents such as acetone, acetylacetone, methyl ethyl ketone, methyl isobutyl ketone, 2-pentanone, 3-pentanone, 2-heptanone, 3-heptanone, cyclopentanone, cyclohexanone, ethyl acetate, propyl acetate, butyl acetate, isobutyl acetate, acetic acid Esters such as pentyl, ethyl propionate, propyl propionate, butyl propionate, isobutyl propionate, propylene glycol monomethyl ether acetate, methyl lactate, ethyl lactate, and γ-butyrolactone , Ether solvents such as diisopropyl ether, dibutyl ether, ethyl propyl ether, anisole, phenetol, veratrol, aromatic hydrocarbon solvents such as mesitylene, ethylbenzene, diethylbenzene, propylbenzene, t-butylbenzene, N-methylpyrrolidinone, dimethyl Examples include amide solvents such as acetamide, and these may be used alone or in admixture of two or more.
More preferred coating solvents are 1-methoxy-2-propanol, propanol, acetylacetone, cyclohexanone, propylene glycol monomethyl ether acetate, butyl acetate, methyl lactate, ethyl lactate, γ-butyrolactone, anisole, mesitylene, t-butylbenzene, Particularly preferred are 1-methoxy-2-propanol, cyclohexanone, propylene glycol monomethyl ether acetate, ethyl lactate, γ-butyrolactone, t-butylbenzene and anisole.
The solid content concentration of the film-forming composition of the present invention is preferably 1 to 50% by mass, more preferably 2 to 15% by mass, and particularly preferably 3 to 10% by mass.

  The film-forming composition of the present invention preferably has a sufficiently low metal content as an impurity. The metal concentration of the film-forming composition can be measured with high sensitivity by the ICP-MS method. In that case, the metal content other than the transition metal is preferably 30 ppm or less, more preferably 3 ppm or less, particularly preferably 300 ppb or less. It is. In addition, the transition metal has a high catalytic ability to promote oxidation, and from the viewpoint of increasing the dielectric constant of the film obtained in the present invention by an oxidation reaction in the prebaking and thermosetting processes, the content is preferably smaller. Preferably it is 10 ppm or less, More preferably, it is 1 ppm or less, Most preferably, it is 100 ppb or less.

The metal concentration of the film forming composition can also be evaluated by performing total reflection X-ray fluorescence measurement on the film obtained using the film forming composition of the present invention. When W-ray is used as the X-ray source, K, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Pd can be observed as metal elements, and each of them can be 100 × 10 ¹⁰ atom · cm ^{−. 2} or less is preferable, more preferably 50 × 10 ¹⁰ atom · cm ⁻² or less, and particularly preferably 10 × 10 ¹⁰ atom · cm ⁻² or less.

Moreover, Br which is halogen is also observable, and the residual amount is preferably 10000 × 10 ¹⁰ atom · cm ⁻² or less, more preferably 1000 × 10 ¹⁰ atom · cm ⁻² or less, particularly preferably 400 × 10 ¹⁰ atom. ^-It is cm- ² or less.
Further, although Cl can be observed as a halogen, the remaining amount is preferably 100 × 10 ¹⁰ atom · cm ⁻² or less, more preferably 50 × 10 ¹⁰ atom ·· from the viewpoint of damaging a CVD apparatus, an etching apparatus, or the like. cm ⁻² or less, particularly preferably 10 × 10 ¹⁰ atom · cm ⁻² or less.

  Furthermore, the composition for forming a film of the present invention includes a radical generator, colloidal silica, and the like within a range that does not impair the properties of the obtained insulating film (heat resistance, dielectric constant, mechanical strength, coatability, adhesion, etc.). You may add additives, such as surfactant, a silane coupling agent, and an adhesive agent.

  Any colloidal silica may be used in the present invention. For example, a dispersion in which high-purity silicic acid is dispersed in a hydrophilic organic solvent or water, usually having an average particle size of 5 to 30 nm, preferably 10 to 20 nm, and a solid content concentration of about 5 to 40% by mass It is.

  Any surfactant may be used in the present invention, and examples thereof include nonionic surfactants, anionic surfactants, cationic surfactants, silicone surfactants, and fluorine-containing interfaces. Activators, polyalkylene oxide surfactants, acrylic surfactants and the like can be mentioned. The surfactant used in the present invention may be one type or two or more types. As the surfactant, silicone surfactants, nonionic surfactants, fluorine-containing surfactants, and acrylic surfactants are preferable, and silicone surfactants are particularly preferable.

  The addition amount of the surfactant used in the present invention is preferably 0.01% by mass or more and 1% by mass or less, and 0.1% by mass or more and 0.5% by mass or less with respect to the total amount of the film-forming coating solution. More preferably.

  In the present invention, the silicon-based surfactant is a surfactant containing at least one Si atom. The silicon-based surfactant used in the present invention may be any silicon-based surfactant, and preferably has a structure containing alkylene oxide and dimethylsiloxane. A structure including the following chemical formula is more preferable.

  In the formula, R is a hydrogen atom or an alkyl group (preferably 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 x and R may be the same or different.

  Examples of the silicon-based surfactant used in the present invention include BYK306, BYK307 (manufactured by Big Chemie), SH7PA, SH21PA, SH28PA, SH30PA (manufactured by Toray Dow Corning Silicone), Troysol S366 (manufactured by Troy Chemical). Can be mentioned.

  Any nonionic surfactant may be used as the nonionic surfactant used in the present invention. For example, polyoxyethylene alkyl ethers, polyoxyethylene aryl ethers, polyoxyethylene dialkyl esters, sorbitan fatty acid esters, fatty acid-modified polyoxyethylenes, polyoxyethylene-polyoxypropylene block copolymers, etc. Can do.

  As the fluorine-containing surfactant used in the present invention, any fluorine-containing surfactant may be used. For example, perfluorooctyl polyethylene oxide, perfluorodecyl polyethylene oxide, perfluorodecyl polyethylene oxide and the like can be mentioned.

  The acrylic surfactant used in the present invention may be any acrylic surfactant. For example, a (meth) acrylic acid type copolymer etc. are mentioned.

  Any silane coupling agent may be used in the present invention. For example, 3-glycidyloxypropyltrimethoxysilane, 3-aminoglycidyloxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3- Glycidyloxypropylmethyldimethoxysilane, 1-methacryloxypropylmethyldimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N -(2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-triethoxysilylpropyltriethylenetriamine, 10- Trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6 -Diazanonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyl Triethoxysilane, - bis (oxyethylene) -3-aminopropyl trimethoxysilane, N- bis (oxyethylene) -3-aminopropyltriethoxysilane and the like. The silane coupling agent used in the present invention may be one type or two or more types.

  Any adhesion promoter may be used in the present invention. For example, trimethoxysilylbenzoic acid, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane , Γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, trimethoxyvinylsilane, γ-aminopropyltriethoxysilane, aluminum monoethylacetoacetate diisopropylate, vinyltris (2 -Methoxyethoxy) silane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane , 3-chloropropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, trimethylchlorosilane, dimethylvinylchlorosilane, methyldiphenylchlorosilane, chloromethyldimethylchlorosilane, trimethylmethoxysilane, dimethyldiethoxy Silane, methyldimethoxysilane, dimethylvinylethoxysilane, diphenyldimethoxysilane, phenyltriethoxysilane, hexamethyldisilazane, N, N'-bis (trimethylsilyl) urea, dimethyltrimethylsilylamine, trimethylsilylimidazole, vinyltrichlorosilane, benzotriazole, Benzimidazole, indazole, imidazole, 2-mercaptobenzimidazole, 2 Mercaptobenzothiazole, 2-mercaptobenzoxazole, urazole, thiouracil, mercaptoimidazole, mercaptopyrimidine, 1,1-dimethylurea, 1,3-dimethylurea, may be mentioned thiourea compounds. Functional silane coupling agents are preferred as adhesion promoters. The preferable use amount of the adhesion promoter is preferably 10 parts by mass or less, particularly 0.05 to 5 parts by mass with respect to 100 parts by mass of the total solid content.

In the composition for forming a film of the present invention, a pore forming factor can be used within the range allowed by the mechanical strength of the film to make the film porous and to reduce the dielectric constant.
The pore-forming factor as an additive that becomes a pore-forming agent is not particularly limited, but a non-metallic compound is preferably used, and the solubility in a solvent used in a coating solution for film formation, the polymer of the present invention. It is necessary to satisfy the compatibility with. Moreover, the boiling point or decomposition temperature of the pore-forming agent is preferably 100 to 500 ° C, more preferably 200 to 450 ° C, and particularly preferably 250 to 400 ° C. As molecular weight, it is preferable that it is 200-50000, More preferably, it is 300-10000, Most preferably, it is 400-5000. The addition amount is preferably 0.5 to 75%, more preferably 0.5 to 30%, and particularly preferably 1% to 20% by mass% with respect to the polymer forming the film. The polymer may contain a decomposable group as a pore-forming factor, and the decomposition temperature is preferably 100 to 500 ° C, more preferably 200 to 450 ° C, and particularly preferably 250 to 400 ° C. is there. The content of the decomposable group is 0.5 to 75%, more preferably 0.5 to 30%, and particularly preferably 1 to 20% in terms of mol% with respect to the polymer forming the film.

  Examples of the polymer that can be used as the pore-forming agent include polyvinyl aromatic compounds (polystyrene, polyvinyl pyridine, halogenated polyvinyl aromatic compounds, etc.), polyacrylonitrile, polyalkylene oxide (polyethylene oxide, polypropylene oxide, etc.), polyethylene, poly Lactic acid, polysiloxane, polycaprolactone, polycaprolactam, polyurethane, polymethacrylate (such as polymethyl methacrylate) or polymethacrylic acid, polyacrylate (such as polymethyl acrylate) and polyacrylic acid, polydiene (such as polybutadiene and polyisoprene), polyvinyl chloride , Polyacetals, and amine-capped alkylene oxides

In addition, polyphenylene oxide, poly (dimethylsiloxane), polytetrahydrofuran, polycyclohexylethylene, polyethyloxazoline, polyvinylpyridine, polycaprolactone, and the like may be used.
In particular, polystyrene can be suitably used as a pore forming agent. Examples of polystyrene include anionic polymerized polystyrene, syndiotactic polystyrene, unsubstituted and substituted polystyrene (for example, poly (α-methylstyrene)), and unsubstituted polystyrene is preferred.
Examples of thermoplastic pore forming polymers include polyacrylate, polymethacrylate, polybutadiene, polyisoprene, polyphenylene oxide, polypropylene oxide, polyethylene oxide, poly (dimethylsiloxane), polytetrahydrofuran, polyethylene, polycyclohexylethylene, polyethyloxazoline. , Polycaprolactone, polylactic acid, polyvinyl pyridine and the like.

  The insulating film of the present invention is formed by applying a film-forming composition to a substrate by any method such as spin coating, roller coating, dip coating, or scanning, and then removing the solvent by heat treatment. be able to. As a method of applying to the substrate, a spin coating method or a scanning method is preferable. Particularly preferred is the spin coating method. For spin coating, commercially available equipment can be used. For example, a clean track series (manufactured by Tokyo Electron), a D-spin series (manufactured by Dainippon Screen), an SS series or a CS series (manufactured by Tokyo Ohka Kogyo Co., Ltd.) can be preferably used. The spin coating conditions may be any rotational speed, but a rotational speed of about 1300 rpm is preferable for a 300 mm silicon substrate from the viewpoint of in-plane uniformity of the film.

  In addition, the method for discharging the composition solution may be either dynamic discharge for discharging the composition solution onto a rotating substrate or static discharge for discharging the composition solution onto a stationary substrate. From the viewpoint of performance, dynamic ejection is preferable. In addition, from the viewpoint of suppressing the consumption of the composition, it is also possible to use a method in which only the main solvent of the composition is preliminarily discharged onto the substrate to form a liquid film, and then the composition is discharged from there. it can. 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 is not particularly limited, but it is possible to apply commonly used hot plate heating, heating method using a furnace, light irradiation heating using a xenon lamp by RTP (Rapid Thermal Processor), etc. Can do. A heating method using hot plate heating or furnace is preferable. A commercially available apparatus can be preferably used as the hot plate, and a 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. As the furnace, α series (manufactured by Tokyo Electron) and the like can be preferably used.

The polymer of the present invention is particularly preferably cured (baked) by applying heat treatment after coating on the substrate. For example, a polymerization reaction during post-heating of the carbon triple bond remaining in the polymer can be used. The conditions for this post-heat treatment are preferably 100 to 450 ° C., more preferably 200 to 420 ° C., particularly preferably 350 to 400 ° C., preferably 1 minute to 2 hours, more preferably 10 minutes to 1.5 ° C. Time, particularly preferably in the range of 30 minutes to 1 hour. The post-heating treatment may be performed in several times. Further, this post-heating is particularly preferably performed in a nitrogen atmosphere in order to prevent thermal oxidation by oxygen.
Moreover, in this invention, you may make it harden | cure (baking) by causing the polymerization reaction of the carbon triple bond which remains in a polymer by irradiating a high energy ray instead of heat processing. Examples of high energy rays include electron beams, ultraviolet rays, and X-rays, but are not particularly limited to these methods.

The energy when an electron beam is used as the high energy beam is preferably 50 keV or less, more preferably 30 keV or less, and particularly preferably 20 keV or less. The total dose of the electron beam is preferably 5 μC / cm ² or less, more preferably ² μC / cm ² or less. Particularly preferably, it is 1 μC / cm ² or less. The substrate temperature at the time of irradiation with an electron beam is preferably 0 to 450 ° C, more preferably 0 to 400 ° C, and particularly preferably 0 to 350 ° C. The pressure is preferably 0 to 133 kPa, more preferably 0 to 60 kPa, and particularly preferably 0 to 20 kPa. From the viewpoint of preventing oxidation of the polymer of the present invention, the atmosphere around the substrate is preferably an inert atmosphere such as Ar, He, or nitrogen. Further, a gas such as oxygen, hydrocarbon, or ammonia may be added for the purpose of reaction with plasma, electromagnetic waves, or chemical species generated by interaction with an electron beam. The electron beam irradiation in the present invention 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. The irradiation wavelength region when using ultraviolet rays is preferably 190 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 particularly preferably 250 to 350 ° C. From the viewpoint of preventing oxidation of the polymer of the present invention, the atmosphere around the substrate is preferably an inert atmosphere such as Ar, He, or nitrogen. Further, the pressure at that time is preferably 0 to 133 kPa.

  When the insulating film of the present invention is used as an interlayer insulating film for a semiconductor, in the wiring structure, there may be a barrier layer for preventing metal migration on the side surface of the wiring. There may be an etching stopper layer, etc., in addition to a cap layer and interlayer adhesion layer that prevent separation by CMP, and further, the interlayer insulating film layer may be divided into multiple layers with other kinds of materials as necessary. .

  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. These plasmas can use not only Ar but also oxygen, or gases such as nitrogen, hydrogen, and helium. In addition, after the etching process, ashing can be performed for the purpose of removing the photoresist or the like used for the 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 subjected to CMP (Chemical Mechanical Polishing) in order to flatten the copper plating portion after the copper wiring processing. As the CMP slurry (chemical solution), commercially available slurries (for example, manufactured by Fujimi, manufactured by Rodel Nitta, manufactured by JSR, manufactured by Hitachi Chemical, etc.) can be used as appropriate. Moreover, as a CMP apparatus, a commercially available apparatus (Applied Materials Co., Ltd., Ebara Corporation, etc.) can be used suitably. Furthermore, it can be washed to remove the slurry residue after CMP.

The insulating film of the present invention can be used for various purposes. For example, it is suitable as an insulating film for semiconductor devices such as LSI, system LSI, DRAM, SDRAM, RDRAM, and D-RDRAM, and electronic parts such as multichip module multilayer wiring boards, interlayer insulating film for semiconductor, etching stopper film, surface protection In addition to films, buffer coat films, 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. I can do it.
Further, as another application, the film of the present invention can be provided with conductivity by doping with an electron donor or acceptor and used as a conductive film.

  The following examples illustrate the invention and are not intended to limit its scope.

<Example 1>
4,9-diethynyldiamantane was synthesized according to the synthesis method described in Macromolecules, 5266 (1991). Next, 2 g of 4,9-diethynyldiamantane, 0.4 g of dicumyl peroxide (park mill D, manufactured by NOF Corporation) and 10 ml of t-butylbenzene were stirred and polymerized at an internal temperature of 150 ° C. for 5 hours under a nitrogen stream. . After the reaction solution was brought to room temperature, it was added to 100 ml of methanol, and the precipitated solid was filtered and washed with methanol. 1.0 g of polymer (A) having a weight average molecular weight of about 14,000 and a glass transition temperature of 450 ° C. or higher was obtained.
The solubility of the polymer (A) in cyclohexanone was 20% by mass or more at 25 ° C.
A coating solution was prepared by completely dissolving 1.0 g of the polymer (A) in 10 g of cyclohexanone. The solution was filtered through a 0.1 micron tetrafluoroethylene filter, spin-coated on a silicon wafer, the coating was heated on a hot plate at 250 ° C. for 60 seconds under a nitrogen stream, and further purged with nitrogen. As a result of baking in an oven at 400 ° C. for 30 minutes and further in an oven at 450 ° C. for 30 minutes, a uniform film having a thickness of 0.5 μm and no defects was obtained. The relative dielectric constant of the film (measured temperature: 25 ° C., the same applies hereinafter) was calculated from the capacitance value at 1 MHz using a mercury probe manufactured by Four Dimensions and an HP4285ALCR meter manufactured by Yokogawa Hewlett-Packard. The Young's modulus (measurement temperature: 25 ° C., the same applies hereinafter) was measured using a nanoindenter SA2 manufactured by MTS, and the glass transition temperature of the insulating film after thermal crosslinking was 450 ° C. or higher. Met. In addition, the measurement temperature of Young's modulus is 25 degreeC, and it is the same also in a following example and a comparative example.

<Example 2>
2 g of 1,6-diethynyldiamantane, 0.8 g of 1,1′-azobis (cyclohexane-1-carbonitrile) (V-40, manufactured by Wako Pure Chemical Industries, Ltd.) and 10 ml of t-butylbenzene under nitrogen flow The mixture was stirred and polymerized at a temperature of 120 ° C. for 8 hours. The reaction solution was brought to room temperature and then added to 100 ml of methanol. The precipitated solid was filtered and washed with methanol. 1.0 g of polymer (B) having a weight average molecular weight of about 10,000 and a glass transition temperature of 450 ° C. or higher was obtained.
The solubility of the polymer (B) in cyclohexanone was 15% by mass or more at 25 ° C.
A coating solution was prepared by completely dissolving 1.0 g of the polymer (B) in 10 g of cyclohexanone. The solution was filtered through a 0.1 micron tetrafluoroethylene filter, spin-coated on a silicon wafer, the coating was heated on a hot plate at 250 ° C. for 60 seconds under a nitrogen stream, and further purged with nitrogen. As a result of baking in an oven at 400 ° C. for 30 minutes and further in an oven at 450 ° C. for 30 minutes, a uniform film having a thickness of 0.5 μm and no defects was obtained. The relative dielectric constant of the film was 2.40. The Young's modulus was 7.8 GPa, and the glass transition temperature of the insulating film after thermal crosslinking was 450 ° C. or higher.

<Example 3>
1.0 g of the polymer (C) was synthesized in the same manner as in Example 1 except that 1,3-diethynyladamantane was used instead of 4,9-diethynyldiamantane. As a result of GPC measurement, the weight average molecular weight was about 20,000, and the glass transition temperature of the polymer was measured by DSC Q1000 manufactured by TA Instruments.
The solubility of the polymer (C) in cyclohexanone was 15% by mass or more at 25 ° C.
A 10% by mass solution of a polymer cyclohexanone was prepared and filtered through a 0.2 micron TFE filter, and then spin-coated on a silicon wafer. This coating film was baked in a furnace purged with nitrogen at 400 ° C. for 30 minutes and further at 450 ° C. for 30 minutes. A uniform film having a thickness of 0.5 microns was obtained.
The relative dielectric constant of the obtained film was 2.37. The Young's modulus was 7.6 GPa, and the glass transition temperature of the insulating film after thermal crosslinking was 400 ° C. or higher.

<Example 4>
To a 500 mL flask, 50 g of commercially available triethynylbenzene, 0.1 g of t-butylperoxypivalate (manufactured by Arkema Yoshitomi: Lupazole 11) and 200 mL of orthodichlorobenzene were added and stirred at an internal temperature of 75 ° C. for 5 hours. After cooling at room temperature for 1 hour, the polymer (D) from which insoluble components were removed was obtained by passing through a column.
A coating solution was prepared by completely dissolving 0.9 g of the polymer (A) and 0.1 g of the polymer (D) in 10 g of cyclohexanone. The solution was filtered through a 0.1 micron tetrafluoroethylene filter, spin-coated on a silicon wafer, the coating was heated on a hot plate at 250 ° C. for 60 seconds under a nitrogen stream, and further purged with nitrogen. As a result of baking in an oven at 400 ° C. for 60 minutes, a uniform film having a thickness of 0.5 μm and no defects was obtained. The relative dielectric constant of the obtained film was 2.40. The Young's modulus was 10.4 GPa, and the glass transition temperature of the insulating film after thermal crosslinking was 480 ° C. or higher.

<Comparative Example 1>
0.7 g of the polymer (D) was synthesized in the same manner as in Example 1 except that 5-vinyl-2-norbornane was used in place of 4,9-diethynyldiamantane. As a result of GPC measurement, the weight average molecular weight was about 20,000, and the solubility in cyclohexanone was 20% by mass or more at 25 ° C.
A film was prepared using the polymer (D) according to the method of Example 1. The obtained film had a relative dielectric constant of 2.55 and a Young's modulus of 3.5 GPa, but a glass transition temperature of less than 200 ° C.

  It can be seen that the insulating film of the present invention is superior in Young's modulus and relative dielectric constant, and particularly excellent in heat resistance, as compared with the comparative example.

Claims (18)

  An insulating film formed using a film-forming composition containing a compound having a cage structure and an organic solvent, and having a glass transition temperature of 300 ° C. or higher.   2. The insulating film according to claim 1, wherein the compound having a cage structure is a polymer of a monomer having a cage structure.   The insulating film according to claim 1 or 2, wherein the compound having a cage structure has a glass transition temperature of 200 ° C or higher.   The insulating film according to claim 2, wherein the monomer having a cage structure has a carbon-carbon double bond or a carbon-carbon triple bond.   5. The insulating film according to claim 1, wherein the cage structure is selected from adamantane, biadamantane, diamantane, triamantane, and tetramantane. 6. The insulating film according to claim 2, wherein the monomer having a cage structure is selected from the group of the following formulas (I) to (VI).

In formulas (I) to (VI),
X _{1 to} X ₈ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a silyl group, an acyl group, an alkoxycarbonyl group, a carbamoyl group, or the like.
Y _{1 to} Y ₈ each independently represents a halogen atom, an alkyl group, a C 6 -aryl group or a silyl group.
m ₁ and m ₅ each independently represents an integer of ₁ to 16, and n ₁ and n ₅ each independently represents an integer of 0 to 15.
m ₂ , m ₃ , m ₆ and m ₇ each independently represent an integer of 1 to 15, and n ₂ , n ₃ , n ₆ and n ₇ each independently represents an integer of 0 to 14.
m ₄ and m ₈ each independently represents an integer of 1 to 20, and n ₄ and n ₈ each independently represents an integer of 0 to 19.   The insulating film according to any one of claims 1 to 6, wherein the compound having a cage structure is obtained by polymerizing a monomer having a cage structure in the presence of a transition metal catalyst or in the presence of a radical initiator. .   The insulating film according to claim 1, wherein the compound having a cage structure is dissolved in cyclohexanone or anisole at 3% by mass or more at 25 ° C.   An electronic device having the insulating film according to claim 1.   A compound of a monomer having a cage structure and having a glass transition temperature of 200 ° C. or higher.   11. The compound according to claim 10, wherein the monomer having a cage structure has a carbon-carbon double bond or a carbon-carbon triple bond.   12. The compound according to claim 10 or 11, wherein the cage structure is selected from adamantane, biadamantane, diamantane, triamantane, and tetramantane. The compound according to any one of claims 10 to 12, wherein the monomer having a cage structure is selected from the group of the following formulas (I) to (VI).

In formulas (I) to (VI),
X _{1 to} X ₈ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a silyl group, an acyl group, an alkoxycarbonyl group, a carbamoyl group, or the like.
Y _{1 to} Y ₈ each independently represents a halogen atom, an alkyl group, a C 6 -aryl group or a silyl group.
m ₁ and m ₅ each independently represents an integer of ₁ to 16, and n ₁ and n ₅ each independently represents an integer of 0 to 15.
m ₂ , m ₃ , m ₆ and m ₇ each independently represent an integer of 1 to 15, and n ₂ , n ₃ , n ₆ and n ₇ each independently represents an integer of 0 to 14.
m ₄ and m ₈ each independently represents an integer of 1 to 20, and n ₄ and n ₈ each independently represents an integer of 0 to 19.   The compound according to any one of claims 10 to 13, which is obtained by polymerizing a monomer having a cage structure in the presence of a transition metal catalyst or in the presence of a radical initiator.   The compound according to any one of claims 10 to 14, wherein the compound is dissolved in cyclohexanone or anisole at 3% by mass or more at 25 ° C.   The composition for film formation containing the compound and organic solvent in any one of Claims 10-15.   An insulating film having a glass transition temperature of 300 ° C. or higher formed using the film forming composition according to claim 16.   An electronic device having the insulating film according to claim 17.