JP2007077276A - Composition for forming film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composition for forming an insulating film usable for electronic devices, having good film properties such as permittivity and mechanical strength, to provide an insulating film obtained by using the composition, and to provide electronic devices comprising the insulating film. <P>SOLUTION: The composition for forming films comprises a compound having an alicyclic hydrocarbon structure and Si atom, wherein the compound having the alicyclic hydrocarbon structure and the Si atom has a particle shape of 2-15 nm particle diameter. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a film-forming composition, and more particularly, to an insulating film-forming composition having good film properties such as dielectric constant and mechanical strength used for electronic devices, and further, an insulation obtained using the composition. The present invention relates to a film and an electronic device having the 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.

Polybenzoxazole and polyimide are widely known as highly heat-resistant insulating films, but because they contain highly polar N atoms, they are satisfactory in terms of low dielectric properties, low water absorption, durability, and hydrolysis resistance. Nothing has been obtained.
In addition, many organic polymers are generally poorly soluble in organic solvents, and it is an important issue to suppress precipitation in coating solutions and the generation of bumps in insulating films. Therefore, if the polymer main chain is bent to have a bent structure, the glass transition point and the heat resistance are adversely affected, and it is not easy to achieve both.
Further, a highly heat-resistant resin having a polyarylene ether as a basic main chain is known (Patent Document 1), and the dielectric constant is in the range of 2.6 to 2.7. However, in order to realize a high-speed device, further reduction of the dielectric constant is desired, and the dielectric constant is preferably 2.6 or less, more preferably 2.5 or less.

  However, since it is very difficult to reduce the relative dielectric constant below 2.5 in an organic-containing silicon oxide film, an insulating film in which holes are introduced inside the film, that is, a so-called porous film is necessary. come.

Patent Document 2 introduces two porous films.
In the first example, a porous film is formed by firing a thin film formed of a solution containing a silicon resin and an organic solvent. According to this, continuous pores are randomly formed at the trace where the organic solvent is vaporized and disappears during the firing of the thin film. In this case, the organic solvent has both a function as a solvent and a function for forming pores. In general, a spin coating method is used to form a thin film by applying a solution on a substrate, and a hot plate and a furnace (electric furnace) are used for baking the thin film.

  In the second example, a porous film is formed by baking a thin film formed of a solution in which porogen made of an organic substance is added in addition to a silicon resin and an organic solvent. According to this, it is possible to form not only continuous holes but also independent holes by selecting the porogen. In this case, of course, the porogen vaporizes from the film and disappears.

In the first and second conventional examples, since continuous holes are formed at random, in order to realize a low dielectric constant film having a relative dielectric constant k = 2.2 to 2.3, an empty space of 30% or more is used. The porosity (percentage of pores per unit volume) is required. For this reason, problems such as damage due to a wet process in wiring processing of an insulating film or migration of wiring metal atoms have occurred. In the first or second conventional example, if the relative permittivity is to be lowered, the porosity increases, so the problem becomes more serious.
Further, although a porous insulating film using fine particles is introduced in Cited Document 3, further improvement in relative permittivity and mechanical strength has been desired.
US Pat. No. 6,509,415 JP 2001-294815 A JP 2004-253626 A

  The present invention relates to a film-forming composition for solving the above-mentioned problems, more specifically to a composition for forming an insulating film having good film properties such as dielectric constant and mechanical strength used for electronic devices, etc. The present invention relates to an insulating film obtained using the composition and an electronic device having the insulating film.

It has been found that the above problems are solved by the following configuration.
<1>
A film-forming composition comprising a compound having an alicyclic hydrocarbon structure and a Si atom, wherein the compound having a cycloaliphatic hydrocarbon structure and a Si atom has a particle shape having a particle size of 2 nm to 15 nm. A film forming composition.
<2>
The film-forming composition as described in <1>, wherein the alicyclic hydrocarbon structure is a cage structure.
<3>
The film-forming composition as described in <2>, wherein the cage structure is a saturated hydrocarbon structure.
<4>
<2> or <3>, wherein the ratio of the total number of carbon atoms of the cage structure to the total number of carbon atoms in the total solid content contained in the film-forming composition is 30% or more A film forming composition.
<5>
The film-forming composition according to any one of <2> to <4>, wherein the cage structure is an adamantane structure.
<6>
The film-forming composition according to any one of <2> to <4>, wherein the cage structure is a diamantane structure.
<7>
The film-forming composition as described in <6>, wherein the compound having a cage structure is a hydrolytic condensate of at least one compound represented by any of the following formulas (1) to (3): .

In the formulas (1) to (3),
Each R independently represents an alkyl group, an alkenyl group, an alkynyl group, or an aryl group.
m1 to m6 each independently represents an integer of 1 to 14.
Each X independently represents a halogen atom, an alkyl group, an alkenyl group, an aryl group, or a silyl group.
Each L independently represents a divalent linking group represented by —CH═CH— or —C≡C—.
n1 to n6 each independently represents an integer of 0 to 13.
Moreover, the compound represented by Formula (1)-(3) may couple | bond together two or more by the single bond or the coupling group.
<8>
The film-forming composition according to any one of <1> to <7>, wherein the compound having an alicyclic hydrocarbon structure and a Si atom is a compound composed of a constituent element excluding a nitrogen atom.
<9>
Furthermore, the organic solvent is contained, The composition for film formation in any one of <1>-<8> characterized by the above-mentioned.
<10>
A porous insulating film formed using the film forming composition according to any one of <1> to <9>.
<11>
An electronic device having the insulating film according to <10>.

  The insulating film formed from the film-forming composition of the present invention has good film properties such as dielectric constant and mechanical strength, and therefore can be used as an interlayer insulating film in electronic devices and the like.

  Hereinafter, the present invention will be described in detail.

<Compound having alicyclic hydrocarbon structure and Si atom>
The film forming composition of the present invention contains a compound having an alicyclic hydrocarbon structure and a Si atom. Having an alicyclic hydrocarbon structure is preferable from the viewpoint of hygroscopicity and heat resistance.
The alicyclic hydrocarbon structure may be monocyclic or polycyclic, and may have a hetero atom in the alicyclic ring. Specific examples include groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms. The carbon number is preferably 6-30, and particularly preferably 7-25. These alicyclic hydrocarbon groups may have a substituent.
Below, the structural example of an alicyclic part is shown among alicyclic hydrocarbon groups.

Examples of the substituent that the alicyclic hydrocarbon group may have include an oxy group, an alkyl group, a halogen atom, a hydroxyl group, an alkoxy group, a carboxyl group, and an alkoxycarbonyl group.
The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group, and more preferably a substituent selected from the group consisting of a methyl group, an ethyl group, a propyl group, and an isopropyl group. To express. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.
The alkyl group, alkoxy group, and alkoxycarbonyl group may further have a substituent. Examples of such a substituent include an alkoxy group having 1 to 4 carbon atoms (methoxy group, ethoxy group, butoxy group). Group), hydroxy group, oxo group, alkylcarbonyl group (preferably 2 to 5 carbon atoms), alkylcarbonyloxy group (preferably 2 to 5 carbon atoms), alkyloxycarbonyl group (preferably 2 to 5 carbon atoms) And halogen atoms (chlorine atom, bromine atom, fluorine atom, etc.).
As the alicyclic hydrocarbon structure, a cage structure is preferable.

  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 the single bridged cyclic compound does not define volume.

The total carbon number of the cage structure is preferably 10 to 30, more preferably 11 to 18, and particularly preferably 14 carbon atoms.
The carbon atom here does not include a linking group substituted with a cage structure or a carbon atom of the substituent. For example, 1-methyladamantane is composed of 10 carbon atoms, and 1-ethyldiamantane is composed of 14 carbon atoms.

  The cage structure is preferably a saturated hydrocarbon structure, and preferred examples include diamond-like structures such as adamantane, diamantane, triamantane, tetramantane, dodecahedran, and the like because they have high heat resistance. Examples include adamantane, diamantane, and triamantane, and particularly preferred examples include diamantane in that a lower dielectric constant is obtained and synthesis is easy.

  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.), C6-C20 aryloxy groups (phenoxy etc.) ), Arylsulfonyl groups having 6 to 20 carbon atoms (such as phenylsulfonyl), nitro groups, cyano groups, silyl groups (triethoxysilyl, methyldiethoxysilyl, Vinylsilyl etc.) and the like. Among these, preferred substituents are a fluorine atom, a bromine atom, a linear, branched or cyclic alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, an alkynyl group having 2 to 5 carbon atoms, and a silyl group. is there. These substituents may be further substituted with another substituent.

  The cage structure in the present invention is preferably 1 to 4 valent, more preferably 2 to 3 valent, and particularly preferably 2 valent. 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 compound having an alicyclic hydrocarbon structure and Si atom of the present invention is a polymer compound (for example, a polymer). In this case, the weight average molecular weight may be any value as long as it satisfies the preferable range of the particle diameter.

  In the present invention, the cage structure may be incorporated into the polymer main chain as a monovalent or higher pendant group. Preferable polymer main chains to which the cage structure is bonded include, for example, linear or branched polysiloxane, ladder-type polysiloxane, cage-type polysiloxane, network-type polysiloxane, and the like. Among these, network type polysiloxane and branched type polysiloxane are preferable from the viewpoint of good heat resistance.

In the present invention, the cage structure is also preferably a part of the polymer main chain. That is, when it is a part of the polymer main chain, it means that the polymer chain is cleaved when the cage structure is removed from the polymer. In this form, the cage structures are directly single-bonded between the cage structures or linked by a suitable divalent or higher 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, R11 to R17 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or an alkoxy 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 -CH = CH-, -C≡C-, -O-, -Si (R ₁₆ ) (R ₁₇ )-or a combination thereof.

  The compound having an alicyclic hydrocarbon structure and a Si atom of the present invention may contain one or more cage structures in the molecule.

Specific examples of the compound having an alicyclic hydrocarbon structure and a Si atom of the present invention are shown below, but the present invention is not limited to these.
[Si (O _0.5 ) ₄ ] _{m on the} right side of the structural formula indicates a three-dimensional structure in which Si and O are alternately arranged and that there are m Si.
Here, m and n represent a composition ratio (mol%), and m + n = 100.

  The compound having an alicyclic hydrocarbon structure and an Si atom of the present invention is more preferably a hydrolytic condensate of at least one compound represented by any one of the following formulas (1) to (3). More preferably, it is a hydrolysis-condensation product of at least one compound represented by 1).

In the formulas (1) to (3),
Each R independently represents an alkyl group, an alkenyl group, an alkynyl group, or an aryl group.
m1 to m6 each independently represents an integer of 1 to 14.
Each X independently represents a halogen atom, an alkyl group, an alkenyl group, an aryl group, or a silyl group.
Each L independently represents a divalent linking group represented by —CH═CH— or —C≡C—.
n1 to n6 each independently represents an integer of 0 to 13.
Moreover, the compound represented by Formula (1)-(3) may couple | bond together two or more by the single bond or the coupling group.

R preferably represents 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, or an aryl group having 6 to 20 carbon atoms, and R represents a further substituent. May be substituted. Examples of the substituent include a halogen atom (fluorine atom, chloro atom, bromine atom, or iodine atom), alkyl group, alkenyl group, alkynyl group, aryl group, acyl group, aryloxy group, arylsulfonyl group, nitro group, cyano group. And a silyl group. R is more preferably a hydrogen atom, 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, more preferably a hydrogen atom or 0 to 10 carbon atoms. Represents a silyl group.
m1 to m6 are preferably integers of 1 to 4, more preferably an integer of 1 to 3, and particularly preferably 2 or 3.
X is preferably a halogen atom, an alkyl group (preferably 1 to 10 carbon atoms), an alkenyl group (preferably 2 to 10 carbon atoms), an aryl group (preferably 6 to 20 carbon atoms), a silyl group (preferably a carbon number). 0-20), X may be further substituted with another substituent, and examples of the substituent include those described above. X is more preferably a fluorine atom, a chlorine atom, a bromine atom, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or a silyl group having 0 to 20 carbon atoms, more preferably a bromine atom, An alkenyl group having 2 to 4 carbon atoms and a silyl group having 0 to 10 carbon atoms are represented.
n1 to n6 are preferably an integer of 0 to 3, more preferably an integer of 0 to 2, and particularly preferably 0 or 1.

  A compound represented by any one of formulas (1) to (3), or a compound in which the compounds represented by formulas (1) to (3) are bonded by a single bond or a linking group ((D-9) Specific examples of (D-10 ′)) are shown. The present invention is not limited to these.

  The compound of the present invention preferably has a reactive group that forms a covalent bond with other molecules by heat. Such a reactive group is not particularly limited, and for example, a substituent that causes a cycloaddition reaction or a radical polymerization reaction can be preferably used. For example, a group having a double bond (vinyl group, allyl group, etc.), a group having a triple bond (ethynyl group, phenylethynyl group, etc.), a combination of a diene group or a dienophile group for causing a Diels-Alder reaction is effective. In particular, an ethynyl group and a phenylethynyl group are effective.

  Further, the compound of the present invention preferably does not contain a nitrogen atom that increases the molar polarizability or causes the hygroscopicity of the insulating film to increase the dielectric constant. In particular, since a sufficiently low dielectric constant cannot be obtained with a polyimide compound, the compound having a cage structure of the present application is preferably a compound other than polyimide, that is, a compound having no polyimide bond or amide bond.

  From the viewpoint of imparting good characteristics (dielectric constant, mechanical strength) to the insulating film formed from the composition of the present invention, the total of the cage structure occupying the total number of carbons in the total solid content contained in the film-forming composition. The carbon number ratio is preferably 30% or more, more preferably 50 to 95%, and still more preferably 60% to 90%. Here, the total solid content contained in the film-forming composition corresponds to the total solid content constituting the insulating film obtained by this coating solution. In addition, what does not remain in an insulating film after insulating film formation like a foaming agent is not included in solid content.

<Cage structure of film forming composition and particles of compound having Si atom>
The compound having a cage structure and a Si atom in the film-forming composition of the present invention has a particle shape with a particle size of 2 nm to 15 nm, and the particle shape may be spherical or polyhedral, preferably a particle with a particle size of 3 nm to 10 nm. It is a shape, More preferably, it is a particle shape with a particle size of 3 nm-8 nm.

  As long as the average particle size is in such a range, it may be a uniform particle size or a mixture of two or more particles having different particle sizes, that is, even if the particle size distribution is sharp, it is broad. Or it may be bimodal. A sharp particle size distribution is preferred. The coefficient of variation in particle size is preferably 15% or less, more preferably 10% or less, and even more preferably 5% or less.

  As a method for forming particles, a known method can be applied, and a method using hydrolysis and condensation of alkoxysilane with a base catalyst such as Sto-ber method (J. Colloid Interface Sci., 26, 62 (1968), J. Colloid Interface Sci., 128, 121 (1989)) and microemulsion polymerization of alkoxysilane (Adv. Mater., 12, 955 (1997)). In addition, the bulk fired body once formed may be crushed and taken out and classified. Examples of the classification include a centrifugal separation method, a solubility separation method, and a physical sieving method. Among these, the centrifugal separation method is most preferable in consideration of the ease of operation and the yield of fine particles. Centrifugation can be performed using, for example, KUBOTA 7930 manufactured by KUBOTA. The temperature of the rotor used for the separation is usually 0 ° C. to 100 ° C., preferably 0 ° C. to 50 ° C., the rotor rotation speed is 1000 to 30000 rpm, and the separation time is preferably 5 minutes to 24 hours. The obtained particles are usually used after being redispersed in water or an organic solvent. In addition, any method such as a mechanochemical method, a mechanical alloying method, a gas phase method, other ultrasonic chemistry, and a fine particle generation method using a supercritical fluid can be applied.

  As a particle formation method by hydrolysis condensation, hydrolysis condensation using a base catalyst in an appropriate organic solvent in the presence of water can be mentioned. As the basic catalyst, basic compounds such as amines, alkali metal hydrides, quaternary ammonium compounds, and amine coupling agents can be used. Specific examples include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and ammonia. Among them, tetrapropylammonium hydroxide is particularly preferable. The addition amount of the base catalyst is 0.01 to 5 mol, preferably 0.1 to 2 mol, more preferably 0.2 to 0.6 mol with respect to 1 mol of alkoxysilane.

  The alkoxysilane constituting the particles may be added to the mixture consisting of the alkoxysilane for particles and a base catalyst, water and / or an organic solvent before the reaction, or may be added step by step. .

  Examples of the organic solvent include alcohols, ketones, ethers, esters and the like. More specifically, for example, alcohols such as methanol, ethanol, propanol and butanol, ketones such as methyl ethyl ketone and methyl isobutyl ketone, Glycol ethers such as methyl cellosolve, ethyl cellosolve and propylene glycol monopropyl ether, glycols such as ethylene glycol, propylene glycol and hexylene glycol, and esters such as methyl acetate, ethyl acetate, methyl lactate and ethyl lactate are used.

  The water necessary for the hydrolysis of the alkoxysilane is generally added as a liquid or as an aqueous solution of alcohol or the like, but it may be added in the form of water vapor. If water is added rapidly, depending on the type of alkoxysilane, hydrolysis and condensation may be too fast and precipitation may occur, so it is preferable to take sufficient time to add water. Therefore, when adding in a liquid, it is preferable to use a method such as coexistence of a solvent such as alcohol or addition at a low temperature so that the alkoxysilane uniformly contacts water.

  The amount of water added is preferably in the range of 0.1 mol to 50 mol, more preferably 1 to 20 mol, per mol of the alkoxysilane group charged as a raw material. It is preferable that the amount of water added be in this range since the following reaction proceeds smoothly. The reaction temperature for obtaining the particles is preferably 0 to 150 ° C., more preferably 20 to 150 ° C., particularly preferably 20 to 100 ° C. in view of the densification and hydrolysis progress of the particles and the controllability of the particle size. It is. Although depending on the reaction temperature, the reaction time is usually 1 hour to 10 days, preferably 4 hours to 10 days, more preferably 1 day to 5 days.

  Alternatively, the initial reaction can be allowed to proceed at a low temperature, and aging can be performed at a high temperature in the later stage. The aging temperature is preferably 180 ° C. or higher.

  The above production conditions include siloxane compounds that do not grow into fine particles in addition to the intended particles, as well as partial hydrolysates and partial condensates containing unreacted alkoxysilane. It is preferable to separate the target particles. This can be achieved using the same technique as the classification of the previously crushed product.

  In microemulsion polymerization, a microemulsion microemulsion is prepared from a transparent liquid of an organic group-containing alkoxysilane of about several nm to several tens of nm in water, where hydrolysis condensation can be performed. A system in which an anionic surfactant AOT (dioctyl sulfosuccinate sodium salt) is mixed with water and oil is known and well studied as a typical microemulsion system. AOT dissociates cations from hydrophilic groups by hydration. For this reason, it is known that the electrostatic repulsion between hydrophilic groups increases as the temperature rises, the spontaneous curvature of the surfactant film changes, and phase transitions between various structures are observed. For this reason, it is preferable to set reaction conditions, such as temperature, appropriately.

  Surfactants for nanoparticle growth, ie surface ligands, include long-chain alkylamines that are linear or branched organic moieties containing 4 to 18 carbon atoms; 4 to 18 carbon atoms ( Linear, branched, cyclic or aromatic organic chain containing long chain alcohols; linear or branched containing 4 to 18 carbon atoms and further containing a cyclic structure or aromatic ring A long-chain phosphonic acid that is an organic moiety that may be linear or branched and contains 4 to 18 carbon atoms and may further contain a cyclic structure or an aromatic ring Acids; long chain carboxylic acids that are linear or branched organic moieties containing 4 to 18 carbon atoms. Of these, long-chain carboxylic acids are preferred. A nonionic surfactant having a long chain alkyl group and a polyethylene oxide group is also preferably used.

  A small amount of an organic solvent can also be added as a dispersant. The organic solvent is preferably 10 wt% or less of water, and more preferably 5 wt% or less. More preferably, it is 1 wt% or less.

  Organic solvents to be added include alcohols (such as methanol, ethanol, propanol and butanol), alkanes (such as butane, pentane, hexane, heptane, octane, nonane, decane and dodecane, and crude fractions such as petroleum ether or kerosene), Ketones (including but not limited to acetone and methyl ethyl ketone), ethers (such as ethyl ether, propyl ether, butyl ether, pentyl ether, hexyl ether, heptyl ether, octyl ether, phenyl ether, and methyl phenyl ether (anisole)) , Aromatic compounds (such as benzene, toluene, xylene, and mesitylene), and carboxylic acids (such as acetic acid, propionic acid, butyric acid). Among these solvents, hexane, toluene, ethanol, acetone, methyl ethyl ketone, octyl ether, and phenyl ether are usually used depending on the combination of their effectiveness and cost, and hexane, acetone, and ethanol have low boiling points. Most preferred.

  A preferred combination of the organic solvent to be added and the surfactant is octyl ether or phenyl ether and oleic acid. Another example is a 25 mol polyethylene oxide adduct of alcohol and nonylphenol.

  The particles thus obtained may be deionized with an ion exchange resin by replacing the dispersion medium with water. The heat resistance of the formed porous insulating film may be improved by the treatment.

The film-forming composition of the present invention can contain an organic solvent and can be used as a coating solution.
Examples of suitable solvents that can be used in the present invention include, but are not limited to, alcohol solvents such as 1-methoxy-2-propanol, 1-butanol, 2-ethoxymethanol, and 3-methoxypropanol; acetylacetone Ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, 2-pentanone, 3-pentanone, 2-heptanone, 3-heptanone, cyclohexanone; propyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, ethyl propionate, propyl propionate, Ester solvents such as butyl propionate, isobutyl propionate, propylene glycol monomethyl ether acetate, methyl lactate, ethyl lactate, γ-butyrolactone; diisopropyl ether, dibutyl ether, ethyl propyl ether Ether solvents such as tellurium, anisole, phenetol, veratrol; aromatic hydrocarbon solvents such as mesitylene, ethylbenzene, diethylbenzene, propylbenzene, 1,2-dichlorobenzene, and the like. You may mix and use.

  More preferred solvents are 1-methoxy-2-propanol, cyclohexanone, propylene glycol monomethyl ether acetate, ethyl lactate, γ-butyrolactone, anisole and mesitylene.

  The solid content concentration of the coating liquid of the present invention is preferably 3 to 50% by mass, more preferably 5 to 35% by mass, and particularly preferably 7 to 20% by mass.

Furthermore, the composition for forming a film of the present invention includes a radical generator, a nonionic surfactant, and the like within a range that does not impair various properties of the insulating film (heat resistance, dielectric constant, mechanical strength, coatability, adhesion, etc.). You may add additives, such as a fluorine-type nonionic surfactant and a silane coupling agent.
As fluorine-based and / or silicon-based surfactants (fluorine-based surfactants and silicon-based surfactants, surfactants containing both fluorine atoms and silicon atoms), for example, JP-A-62-36663, JP-A-61-226746, JP-A-61-226745, JP-A-62-170950, JP-A-63-34540, JP-A-7-230165, JP-A-8-62834 JP-A-9-54432, JP-A-9-5988, JP-A 2002-277862, US Pat. Nos. 5,405,720, 5,360,692, 5,529,881, and 5,296,330. , 5436098, 5,576,143, 5,294,511, and 5,824,451. Can be mentioned surfactants, the following commercially available surfactants can be used as it is.

  Examples of commercially available surfactants that can be used include F-top EF301, EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176, F189, R08 (Dainippon Ink Chemical Co., Ltd.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (Asahi Glass Co., Ltd.), Troisol S-366 (Troy Chemical Co., Ltd.), etc. Fluorine type surfactant or silicon type surfactant can be mentioned. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

  In addition to the known surfactants described above, the surfactant is derived from a fluoroaliphatic compound produced by a telomerization method (also called telomer method) or an oligomerization method (also called oligomer method). A surfactant using a polymer having a fluoroaliphatic group can be used. The fluoroaliphatic compound can be synthesized by the method described in JP-A-2002-90991.

  As the polymer having a fluoroaliphatic group, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate and / or (poly (oxyalkylene)) methacrylate is preferable and distributed irregularly. Or may be block copolymerized. Examples of the poly (oxyalkylene) group include a poly (oxyethylene) group, a poly (oxypropylene) group, a poly (oxybutylene) group, and the like, and a poly (oxyethylene, oxypropylene, and oxyethylene group). A unit having different chain lengths in the same chain length, such as a block link) or poly (block link of oxyethylene and oxypropylene) may be used. Furthermore, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer but also a monomer having two or more different fluoroaliphatic groups, Further, it may be a ternary or higher copolymer obtained by simultaneously copolymerizing two or more different (poly (oxyalkylene)) acrylates (or methacrylates).

Examples of commercially available surfactants include Megafac F178, F-470, F-473, F-475, F-476, and F-472 (Dainippon Ink Chemical Co., Ltd.). Further, a copolymer of an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxyalkylene)) acrylate (or methacrylate), an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxy) (Ethylene)) acrylate (or methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate) copolymer, acrylate (or methacrylate) and (poly (oxyalkylene)) acrylate having C ₈ F ₁₇ groups (or Copolymer of acrylate (or methacrylate), (poly (oxyethylene)) acrylate (or methacrylate), and (poly (oxypropylene)) acrylate (or methacrylate) having a C ₈ F ₁₇ group Coalesce, etc. Can.

Examples of the radical generator include t-butyl peroxide, pentyl peroxide, hexyl peroxide, lauroyl peroxide, benzoyl peroxide, azobisisobutyronitrile, and the like. Examples of the nonionic surfactant include octyl polyethylene oxide, decyl polyethylene oxide, dodecyl polyethylene oxide, octyl polypropylene oxide, decyl polypropylene oxide, dodecyl polypropylene oxide, and the like.
Examples of the silane coupling agent include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, allyltrimethoxysilane, allyltriethoxysilane, divinyldiethoxysilane, trivinylethoxysilane, hydrolysates thereof, or The dehydration condensate of this thing etc. are mentioned.
The addition amount of these additives has an appropriate range depending on the use of the additive or the solid content concentration of the coating liquid, but generally 0.001% to 10% by mass% in the coating liquid, More preferably, it is 0.01% to 5%, and particularly preferably 0.05% to 2%.

  The insulating film can be formed by applying the coating solution of the present invention to the substrate by any method such as spin coating, roller coating, dip coating, or scanning, and then removing the solvent by heat treatment. . The method of the heat treatment is not particularly limited, but the generally used hot plate heating, a method using a furnace, light irradiation heating using a xenon lamp by RTP (Rapid Thermal Processor), etc. are applied. Can do.

  The film obtained by using the coating liquid of the present invention is suitable as an insulating film in electronic components such as semiconductor devices and multichip module multilayer wiring boards, and other than semiconductor interlayer insulating films, surface protective films, and buffer coat films. It can be used as a passivation film in an LSI, an α-ray blocking film, a flexographic printing plate cover lay film, an overcoat film, a flexible copper clad plate cover coat, a solder resist film, a liquid crystal alignment film, and the like. In addition, it can also be used for various applications such as filtration membranes for water treatment, soil modifier carriers, photocatalyst carriers for environmental purification, and building materials.

  Although there is no restriction | limiting in particular in the film thickness of this coating film, it is preferable that it is 0.001-100 micrometers, It is more preferable that it is 0.01-10 micrometers, It is especially preferable that it is 0.1-1 micrometers.

  The compounds of the present invention are preferably cross-linked by heating after coating to form an insulating film having excellent mechanical strength and heat resistance. The optimum conditions for this heat treatment are preferably a heating temperature of 200 to 450 ° C, more preferably 300 to 420 ° C, particularly preferably 350 to 400 ° C, and a heating time of preferably 1 minute to 2 hours, more The time is preferably 10 minutes to 1.5 hours, particularly preferably 30 minutes to 1 hour. The heat treatment may be performed in several stages.

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

<Synthesis Example 1>
Synthesis of hydrolysis condensate (D-1-P-1) 10 g of the compound (D-1) having the following structure was dissolved in 20 g of methyl isobutyl ketone, and 400 ppm of nitric acid was added dropwise over 10 minutes. Thereafter, an aging reaction was carried out at 180 ° C. for 2 hours in an autoclave. Subsequently, 2 g of magnesium nitrate was added to remove excess water. The reaction solution was removed using a rotary evaporator, and freeze-dried using 1,4-dioxane. The obtained compound (D-1-P-1) was dispersed in tetrahydrofuran (THF), and the particle size of the particles was measured by a dynamic light dispersion method. The average particle size was 5 nm. With the standard deviation σ shown, 3σ was about 5% of the average particle size.

<Example 1>
BYK-306 (manufactured by Bicchemi) 0.1% as a dispersant in a mixed solvent of 5.0 ml of cyclohexanone and 5.0 ml of propylene glycol monomethyl ether with 1.0 g of the above compound (D-1-P-1) particles. The dispersion was used (to the particle weight) to prepare a coating solution. This solution was filtered through a 0.1 micron tetrafluoroethylene filter, spin-coated on a silicon wafer, this coating was heated on a hot plate at 150 ° C. for 60 seconds under a nitrogen stream, and further heated in a 400 ° C. oven. Heated in for 60 minutes. The relative dielectric constant of the obtained insulating film having a thickness of 0.5 microns was calculated from the capacitance value at 1 MHz by using a mercury probe manufactured by Four Dimensions and a HP4285ALCR meter manufactured by Yokogawa Hewlett-Packard. Moreover, it was 6.9 GPa when the Young's modulus was measured using nano indenter SA2 by MTS.
This wafer was immersed in boiling water at 100 ° C. for 1 hour, dried in vacuum at 200 ° C. for 12 hours, and then measured for a dielectric constant of 2.05.

<Synthesis Example 2>
Synthesis of Hydrolyzed Condensate (D-1-P-2) 1.0 g of the compound (D-1) having the above structure was dissolved in 2 g of propylene glycol monomethyl ether acetate and dissolved in 100 g of water having an oleic acid concentration of 2%. It was dripped over 60 minutes. Simultaneously, 10 g of nitric acid having a concentration of 400 ppm was dropped over 60 minutes, and after completion of the dropping, an aging reaction was carried out at 180 ° C. for 2 hours in an autoclave. Subsequently, using a rotary evaporator, the reaction solvent was removed and lyophilization was performed. The obtained compound (D-1-P-2) was dispersed in tetrahydrofuran (THF) and the particle size of the particles was measured by a dynamic light dispersion method. The average particle size was 8 nm, and the particle size distribution was With the standard deviation σ shown, 3σ was about 10% of the average particle size.
<Example 2>
BYK-306 (Bikchemi) 0.1% (vs. particle weight) in a mixed solvent of 5.0 ml of cyclohexanone and 5.0 ml of propylene glycol monomethyl ether, 1.0 g of particles of the above compound (D-1-P-2) ) To prepare a coating solution. This solution was filtered through a 0.1 micron tetrafluoroethylene filter, spin-coated on a silicon wafer, this coating was heated on a hot plate at 180 ° C. for 60 seconds under a nitrogen stream, and further heated in an oven at 400 ° C. Heated in for 60 minutes. The relative dielectric constant of the obtained insulating film having a thickness of 0.5 microns was 2.05. The Young's modulus was 6.0 GPa.
This wafer was immersed in boiling water at 100 ° C. for 1 hour, dried in vacuum at 200 ° C. for 12 hours, and the relative dielectric constant measured by the above method was 2.06.

<Comparative Synthesis Example 1>
Synthesis of hydrolyzed condensate (BP-1) 10 g of the compound (B) having the following structure was dissolved in 20 g of methyl isobutyl ketone, and nitric acid having a concentration of 400 ppm was added dropwise over 10 minutes. The aging reaction was performed at 180 ° C. for 2 hours. Subsequently, 2 g of magnesium nitrate was added to remove excess water. The reaction solution was removed using a rotary evaporator, and freeze-dried using 1,4-dioxane. The obtained compound (B-P-1) was dispersed in tetrahydrofuran (THF), and the particle size of the particles was measured by a dynamic light dispersion method. As a result, the average particle size was 20 nm. With a deviation σ, 3σ was about 20% of the average particle size.

<Comparative Example 1>
Using 1.0% of BYK-306 (by Big Chemi) 0.1% (vs. particle weight) in a mixed solvent of 5.0 ml of cyclohexanone and 5.0 ml of propylene glycol monomethyl ether, 1.0 g of particles of the above compound (BP-1). Dispersed to prepare a coating solution. This solution was filtered through a 0.1 micron tetrafluoroethylene filter, spin-coated on a silicon wafer, this coating was heated on a hot plate at 180 ° C. for 60 seconds under a nitrogen stream, and further heated in an oven at 400 ° C. Heated in for 60 minutes. The dielectric constant of the obtained insulating film having a thickness of 0.5 microns was 2.40. The Young's modulus was 4.0 GPa.
This wafer was immersed in boiling water at 100 ° C. for 1 hour, dried in vacuum at 200 ° C. for 12 hours, and the relative dielectric constant was measured by the above method to be 2.80.

<Comparative Synthesis Example 2>
Synthesis of hydrolyzed condensate (D-1-L-3) 5 g of the compound (D-1) having the above structure was dissolved in 20 g of diethylene glycol dimethyl ether, and nitric acid with a concentration of 400 ppm was added dropwise over 1 minute at 40 ° C. It was allowed to react at 3 o'clock. Subsequently, ethanol and water were removed using a rotary evaporator. When the obtained solution was diluted with tetrahydrofuran (THF) and measured by gel permeation chromatography (GPC), the weight average molecular weight of the obtained compound (D-1-L-3) was 2,000. Met. When the particle size was measured by the dynamic light dispersion method, the average particle size was about 1 nm, and 3σ was about 20% of the average particle size with a standard deviation σ indicating the particle size distribution.

<Comparative example 2>
The equivalent of 1.0 g of (D-1-L-3) above is diluted with 5.0 ml of propylene glycol monomethyl ether, and further 0.5 g of polypropylene glycol (Aldrich), BYK-306 (Bicchemi) 0.1% Compound weight was used to prepare a coating solution. This solution was filtered through a 0.1 micron tetrafluoroethylene filter, spin-coated on a silicon wafer, this coating was heated on a hot plate at 180 ° C. for 60 seconds under a nitrogen stream, and further heated in an oven at 400 ° C. Heated in for 60 minutes. The dielectric constant of the obtained insulating film having a thickness of 0.5 microns was 2.10. The Young's modulus was 3.0 GPa.
This wafer was immersed in boiling water at 100 ° C. for 1 hour, dried in vacuum at 200 ° C. for 12 hours, and the relative dielectric constant was measured by the above method to be 2.70.

Claims (11)

  A film-forming composition comprising a compound having an alicyclic hydrocarbon structure and a Si atom, wherein the compound having a cycloaliphatic hydrocarbon structure and a Si atom has a particle shape having a particle size of 2 nm to 15 nm. A film forming composition.   The film-forming composition according to claim 1, wherein the alicyclic hydrocarbon structure is a cage structure.   The film-forming composition according to claim 2, wherein the cage structure is a saturated hydrocarbon structure.   4. The film according to claim 2, wherein the ratio of the total carbon number of the cage structure to the total carbon number in the total solid content contained in the film-forming composition is 30% or more. Forming composition.   The film-forming composition according to any one of claims 2 to 4, wherein the cage structure is an adamantane structure.   The film-forming composition according to any one of claims 2 to 4, wherein the cage structure is a diamantane structure. The film-forming composition according to claim 6, wherein the compound having a cage structure is a hydrolytic condensate of at least one compound represented by any one of the following formulas (1) to (3): .

In the formulas (1) to (3),
Each R independently represents an alkyl group, an alkenyl group, an alkynyl group, or an aryl group.
m1 to m6 each independently represents an integer of 1 to 14.
Each X independently represents a halogen atom, an alkyl group, an alkenyl group, an aryl group, or a silyl group.
L each independently represents a divalent linking group represented by —CH═CH— or —C≡C—.
n1 to n6 each independently represents an integer of 0 to 13.
Moreover, the compound represented by Formula (1)-(3) may couple | bond together two or more by the single bond or the coupling group.   The film-forming composition according to any one of claims 1 to 7, wherein the compound having an alicyclic hydrocarbon structure and a Si atom comprises a constituent element excluding a nitrogen atom.   Furthermore, the organic solvent is included, The composition for film formation in any one of Claims 1-8 characterized by the above-mentioned.   A porous insulating film formed using the film-forming composition according to claim 1.   An electronic device having the insulating film according to claim 10.