JP2002363286A - Method for forming silica membrane, silica membrane, insulating membrane and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a silica membrane expressing a remarkably low dielectric constant of <=2.2 and having little moisture absorption as an interlayer insulation in semiconductor elements and the like. SOLUTION: The method for forming a silica membrane is to treat a membrane containing (A) a siloxane compound and (B) a surfactant in a supercritical medium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a silica film, and more particularly, to a silica film exhibiting a very low dielectric constant of 2.2 or less and having low moisture absorption as interlayer insulation in a semiconductor device or the like. About.

[0002]

2. Description of the Related Art Conventionally, a silica (SiO ₂ ) film formed by a vacuum process such as a CVD method is often used as an interlayer insulating film in a semiconductor device or the like. In recent years, for the purpose of forming a more uniform interlayer insulating film, a coating-type insulating film mainly composed of a hydrolysis product of tetraalkoxylan, which is called an SOG (Spin on Glass) film, may be used. It has become. Also, with the high integration of semiconductor elements and the like, an interlayer insulating film having a low dielectric constant and mainly containing polyorganosiloxane called organic SOG has been developed. However, with higher integration and multilayering of semiconductor devices and the like, an interlayer insulating film having a lower relative dielectric constant and lower moisture absorption has been required.

Therefore, Japanese Patent Application Laid-Open No. 6-181201 discloses an insulating film having a lower dielectric constant as an interlayer insulating film. The purpose of this insulating film is to provide an insulating film of a semiconductor device having low water absorption and excellent crack resistance, and has a structure in which at least one element selected from titanium, zirconium, niobium and tantalum is used. The main component is an oligomer having a number average molecular weight of 500 or more, obtained by polycondensing an organometallic compound containing the compound and an organosilicon compound having at least one alkoxy group in the molecule. However, such a conventional insulating film is still insufficient for application to a semiconductor device having a dielectric constant of 2.5 or more and operating at a high frequency, and a coating film having a lower relative dielectric constant is required.

[0004]

The present invention relates to a method for manufacturing a film for solving the above-mentioned problems, and more particularly, to a method for forming an interlayer insulating film in a semiconductor device or the like.
It is an object of the present invention to provide a method for producing an insulating film having the following relative dielectric constant, more preferably 2.0 or less, particularly preferably 1.9 or less, and having low moisture absorption of a coating film.

[0005]

The present invention provides a method for forming a silica film, which comprises treating a film containing (A) a siloxane compound and (B) a surfactant in a supercritical medium. It is. Next, the present invention provides a silica film obtained by the above forming method. next,
The present invention provides an insulating film using the above silica film. Next, the present invention provides a semiconductor device using the above insulating film.

BEST MODE FOR CARRYING OUT THE INVENTION

In the present invention, first, a film containing (A) a siloxane compound (hereinafter also referred to as “component (A)”) and (B) a surfactant (hereinafter also referred to as “component (B)”) (hereinafter referred to as “component (B)”). Is formed on a substrate. In order to form a coating film, a coating composition obtained by dissolving the components (A) and (B) in an organic solvent (hereinafter, also referred to as “coating composition”) is applied to a substrate, and the organic solvent is removed. . In the present invention, as the component (A), a compound represented by the following general formula (1) (hereinafter, also referred to as “compound (1)”): R ¹ _a Si (OR ² ) _4-a. (1) (R ¹ represents a hydrogen atom, a fluorine atom or a monovalent organic group, R ² represents a monovalent organic group, and a represents an integer of 0 to 3) and the following general formula (2) (Hereinafter also referred to as “compound (2)”) R ³ _b (R ⁴ O) _3-b Si— (R ⁷ ) _d —Si (OR ⁵ ) _3-c R ⁶ _c. (2) (R ³ , R ⁴ , R ⁵ and R ⁶ may be the same or different and each represents a monovalent organic group, and b and c may be the same or different; And R ⁷ represents an oxygen atom or a group represented by — (CH 2) _n —;
Represents 1 to 6, and d represents 0 or 1. Or a hydrolyzate and / or condensate of at least one compound selected from the group consisting of:

In the above general formula (1), R ¹ and R ²
Examples of the monovalent organic group include an alkyl group, an aryl group, an allyl group, and a glycidyl group. Further, in the general formula (1), R ¹ is preferably a monovalent organic group, particularly an alkyl group or a phenyl group. Here, examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group.
And these alkyl groups may be chain-like or branched, and a hydrogen atom may be substituted with a fluorine atom or the like. In the general formula (1), as the aryl group, a phenyl group, a naphthyl group, a methylphenyl group,
Examples thereof include an ethylphenyl group, a chlorophenyl group, a bromophenyl group, and a fluorophenyl group.

Specific examples of the compound represented by the general formula (1) include trimethylmethoxysilane, trimethylethoxysilane, trimethyl-iso-propoxysilane, trimethyl-n-butoxysilane, trimethyl-sec-
Butoxysilane, trimethyl-tert-butoxysilane, trimethylphenoxysilane, triethylmethoxysilane, triethylethoxysilane, triethyl-is
o-propoxysilane, triethyl-n-butoxysilane, triethyl-sec-butoxysilane, triethyl-tert-butoxysilane, triethylphenoxysilane, triphenylmethoxysilane, triphenylethoxysilane, triphenyl-iso-propoxysilane, triphenyl -N-butoxysilane, triphenyl-sec-butoxysilane, triphenyl-tert-
Butoxysilane, triphenylphenoxysilane, trimethoxysilane, triethoxysilane, tri-n-propoxysilane, tri-iso-propoxysilane, tri-n-butoxysilane, tri-sec-butoxysilane, tri-tert-butoxysilane , Triphenoxysilane, fluorotrimethoxysilane, fluorotriethoxysilane, fluorotri-n-propoxysilane,
Fluorotri-iso-propoxysilane, fluorotri-n-butoxysilane, fluorotri-sec-butoxysilane, fluorotri-tert-butoxysilane, fluorotriphenoxysilane, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxy Silane, tetra-iso-propoxysilane, tetra-
n-butoxysilane, tetra-sec-butoxysilane,
Tetra-tert-butoxysilane, tetraphenoxysilane, etc .; methyltrimethoxysilane, methyltriethoxysilane, methyltri-n-propoxysilane, methyltri-iso-propoxysilane, methyltri-n
-Butoxysilane, methyltri-sec-butoxysilane, methyltri-tert-butoxysilane, methyltriphenoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltri-n-propoxysilane, ethyltri-iso-propoxysilane, ethyltri-n -Butoxysilane, ethyltri-sec-butoxysilane, ethyltri-tert-butoxysilane,
Ethyl triphenoxy silane, vinyl trimethoxy silane, vinyl triethoxy silane, vinyl tri-n-propoxy silane, vinyl tri-iso-propoxy silane, vinyl tri-n-butoxy silane, vinyl tri-s
ec-butoxysilane, vinyltri-tert-butoxysilane, vinyltriphenoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-propyltri-n-propoxysilane, n-propyltri-iso-propoxysilane , N-propyltri-n-butoxysilane, n-propyltri-sec
-Butoxysilane, n-propyltri-tert-butoxysilane, n-propyltriphenoxysilane, i-
Propyltrimethoxysilane, i-propyltriethoxysilane, i-propyltri-n-propoxysilane,
i-propyltri-iso-propoxysilane, i-propyltri-n-butoxysilane, i-propyltri-
sec-butoxysilane, i-propyltri-tert
-Butoxysilane, i-propyltriphenoxysilane, n-butyltrimethoxysilane, n-butyltriethoxysilane, n-butyltri-n-propoxysilane, n-butyltri-iso-propoxysilane, n-
Butyltri-n-butoxysilane, n-butyltri-s
ec-butoxysilane, n-butyltri-tert-butoxysilane, n-butyltriphenoxysilane, se
c-butyltrimethoxysilane, sec-butyl-i-
Triethoxysilane, sec-butyl-tri-n-propoxysilane, sec-butyl-tri-iso-propoxysilane, sec-butyl-tri-n-butoxysilane, sec-butyl-tri-sec-butoxysilane,
sec-butyl-tri-tert-butoxysilane, s
ec-butyl-triphenoxysilane, t-butyltrimethoxysilane, t-butyltriethoxysilane, t-butyl
Butyltri-n-propoxysilane, t-butyltri-
iso-propoxysilane, t-butyltri-n-butoxysilane, t-butyltri-sec-butoxysilane, t-butyltri-tert-butoxysilane, t-butyl
Butyltriphenoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltri-n
-Propoxysilane, phenyltri-iso-propoxysilane, phenyltri-n-butoxysilane, phenyltri-sec-butoxysilane, phenyltri-te
rt-butoxysilane, phenyltriphenoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycid Xypropyltriethoxysilane, γ-trifluoropropyltrimethoxysilane, γ-trifluoropropyltriethoxysilane, etc .; dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyl-di-n-propoxysilane, dimethyl-di-iso-propoxy Silane, dimethyl-di-
n-butoxysilane, dimethyl-di-sec-butoxysilane, dimethyl-di-tert-butoxysilane, dimethyldiphenoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diethyl-di-n-propoxysilane, diethyl-di- iso-propoxysilane, diethyl-di-n-butoxysilane, diethyl-
Di-sec-butoxysilane, diethyl-di-tert
-Butoxysilane, diethyldiphenoxysilane, di-
n-propyldimethoxysilane, di-n-propyldiethoxysilane, di-n-propyl-di-n-propoxysilane, di-n-propyl-di-iso-propoxysilane, di-n-propyl-di-n -Butoxysilane, di-n-propyl-di-sec-butoxysilane, di-n
-Propyl-di-tert-butoxysilane, di-n-
Propyl-di-phenoxysilane, di-iso-propyldimethoxysilane, di-iso-propyldiethoxysilane, di-iso-propyl-di-n-propoxysilane, di-iso-propyl-di-iso-propoxysilane, Di-iso-propyl-di-n-butoxysilane, di-iso-propyl-di-sec-butoxysilane, di-iso-propyl-di-tert-butoxysilane, di-iso-propyl-di-phenoxysilane,
Di-n-butyldimethoxysilane, di-n-butyldiethoxysilane, di-n-butyl-di-n-propoxysilane, di-n-butyl-di-iso-propoxysilane, di-n-butyl-di -N-butoxysilane, di-n
-Butyl-di-sec-butoxysilane, di-n-butyl-di-tert-butoxysilane, di-n-butyl-
Di-phenoxysilane, di-sec-butyldimethoxysilane, di-sec-butyldiethoxysilane, di-s
ec-butyl-di-n-propoxysilane, di-sec
-Butyl-di-iso-propoxysilane, di-sec
-Butyl-di-n-butoxysilane, di-sec-butyl-di-sec-butoxysilane, di-sec-butyl-di-tert-butoxysilane, di-sec-butyl-di-phenoxysilane, di-tert -Butyldimethoxysilane, di-tert-butyldiethoxysilane,
Di-tert-butyl-di-n-propoxysilane, di-tert-butyl-di-iso-propoxysilane,
Di-tert-butyl-di-n-butoxysilane, di-
tert-butyl-di-sec-butoxysilane, di-
tert-butyl-di-tert-butoxysilane, di-tert-butyl-di-phenoxysilane, diphenyldimethoxysilane, diphenyl-di-ethoxysilane, diphenyl-di-n-propoxysilane, diphenyl-di-iso-propoxysilane , Diphenyl-di-
n-butoxysilane, diphenyl-di-sec-butoxysilane, diphenyl-di-tert-butoxysilane, diphenyldiphenoxysilane, divinyltrimethoxysilane, γ-aminopropyltrimethoxysilane,
γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-trifluoropropyltrimethoxysilane, γ-trifluoropropyltriethoxysilane, and the like. Can be. Among the above compounds (1), tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-iso
-Propoxysilane, tetraphenoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltri-n-propoxysilane, methyltri-iso-
Propoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane,
Phenyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, trimethylmonomethoxysilane, trimethylmonoethoxysilane, triethylmonomethoxysilane, triethylmonoethoxy Silane, triphenylmonomethoxysilane, triphenylmonoethoxysilane, trimethylmethoxysilane, and trimethylethoxysilane.

In the above formula (2), examples of the monovalent organic group include the same organic groups as those in the above formula (1). Examples of the divalent organic group represented by R ⁷ in the general formula (2) include a methylene group and an alkylene group having 2 to 6 carbon atoms. In the general formula (2), R
Compounds in which ⁷ is an oxygen atom include hexamethoxydisiloxane, hexaethoxydisiloxane, hexaphenoxydisiloxane, 1,1,1,3,3-pentamethoxy-3-methyldisiloxane, 1,1,1,3 , 3-pentaethoxy-3-methyldisiloxane, 1,1,1,
3,3-pentamethoxy-3-phenyldisiloxane,
1,1,1,3,3-pentaethoxy-3-phenyldisiloxane, 1,1,3,3-tetramethoxy-1,3
-Dimethyldisiloxane, 1,1,3,3-tetraethoxy-1,3-dimethyldisiloxane, 1,1,3,3
-Tetramethoxy-1,3-diphenyldisiloxane,
1,1,3,3-tetraethoxy-1,3-diphenyldisiloxane, 1,1,3-trimethoxy-1,3,3
-Trimethyldisiloxane, 1,1,3-triethoxy-1,3,3-trimethyldisiloxane, 1,1,3-
Trimethoxy-1,3,3-triphenyldisiloxane, 1,1,3-triethoxy-1,3,3-triphenyldisiloxane, 1,3-dimethoxy-1,1,3,3
3-tetramethyldisiloxane, 1,3-diethoxy-
1,1,3,3-tetramethyldisiloxane, 1,3-
Examples thereof include dimethoxy-1,1,3,3-tetraphenyldisiloxane and 1,3-diethoxy-1,1,3,3-tetraphenyldisiloxane. Of these, hexamethoxydisiloxane, hexaethoxydisiloxane, 1,1,3,3-tetramethoxy-1,1
3-dimethyldisiloxane, 1,1,3,3-tetraethoxy-1,3-dimethyldisiloxane, 1,1,3,
3-tetramethoxy-1,3-diphenyldisiloxane, 1,3-dimethoxy-1,1,3,3-tetramethyldisiloxane, 1,3-diethoxy-1,1,3,3
-Tetramethyldisiloxane, 1,3-dimethoxy-
1,1,3,3-tetraphenyldisiloxane, 1,3
-Diethoxy-1,1,3,3-tetraphenyldisiloxane and the like can be mentioned as preferred examples.
In the general formula (2), examples of the compound in which d is 0 include hexamethoxydisilane, hexaethoxydisilane, hexaphenixidisilane, 1,1,1,2,2-pentamethoxy-2-methyldisilane, 1,1,1 , 2,2-pentaethoxy-2-methyldisilane, 1,1,1,2,2-
Pentamethoxy-2-phenyldisilane, 1,1,1,
2,2-pentaethoxy-2-phenyldisilane, 1,
1,2,2-tetramethoxy-1,2-dimethyldisilane, 1,1,2,2-tetraethoxy-1,2-dimethyldisilane, 1,1,2,2-tetramethoxy-1,2
-Diphenyldisilane, 1,1,2,2-tetraethoxy-1,2-diphenyldisilane, 1,1,2-trimethoxy-1,2,2-trimethyldisilane, 1,1,2
-Triethoxy-1,2,2-trimethyldisilane,
1,1,2-trimethoxy-1,2,2-triphenyldisilane, 1,1,2-triethoxy-1,2,2-triphenyldisilane, 1,2-dimethoxy-1,1,1
2,2-tetramethyldisilane, 1,2-diethoxy-
1,1,2,2-tetramethyldisilane, 1,2-dimethoxy-1,1,2,2-tetraphenyldisilane,
And 1,2-diethoxy-1,1,2,2-tetraphenyldisilane, R ⁷ in the general formula (2) is - (CH
2) As compounds of the group represented by n-, bis (hexamethoxysilyl) methane, bis (hexaethoxysilyl)
Methane, bis (hexaphenoxysilyl) methane, bis (dimethoxymethylsilyl) methane, bis (diethoxymethylsilyl) methane, bis (dimethoxyphenylsilyl) methane, bis (diethoxyphenylsilyl) methane, bis (methoxydimethylsilyl) Methane, bis (ethoxydimethylsilyl) methane, bis (methoxydiphenylsilyl) methane, bis (ethoxydiphenylsilyl) methane, bis (hexamethoxysilyl) ethane, bis (hexaethoxysilyl) ethane, bis (hexaphenoxysilyl) ethane, Bis (dimethoxymethylsilyl) ethane, bis (diethoxymethylsilyl) ethane,
Bis (dimethoxyphenylsilyl) ethane, bis (diethoxyphenylsilyl) ethane, bis (methoxydimethylsilyl) ethane, bis (ethoxydimethylsilyl) ethane, bis (methoxydiphenylsilyl) ethane, bis (ethoxydiphenylsilyl) ethane, 1 1,3-bis (hexamethoxysilyl) propane, 1,3-bis (hexaethoxysilyl) propane, 1,3-bis (hexaphenoxysilyl) propane, 1,3-bis (dimethoxymethylsilyl) propane, 1,3 -Bis (diethoxymethylsilyl) propane, 1,3-bis (dimethoxyphenylsilyl) propane, 1,3-bis (diethoxyphenylsilyl) propane, 1,3-bis (methoxydimethylsilyl) propane, 1,3 -Bis (ethoxydimethylsilyl) propane 1,3-bis (methoxydiphenylsilyl) propane, 1,3-bis (ethoxydiphenylsilyl) propane can be cited. Of these, hexamethoxydisilane, hexaethoxydisilane, hexaphenixidisilane, 1,1,2,2-tetramethoxy-1,2-dimethyldisilane, 1,1,
2,2-tetraethoxy-1,2-dimethyldisilane,
1,1,2,2-tetramethoxy-1,2-diphenyldisilane, 1,1,2,2-tetraethoxy-1,2-
Diphenyldisilane, 1,2-dimethoxy-1,1,1
2,2-tetramethyldisilane, 1,2-diethoxy-
1,1,2,2-tetramethyldisilane, 1,2-dimethoxy-1,1,2,2-tetraphenyldisilane,
1,2-diethoxy-1,1,2,2-tetraphenyldisilane, bis (hexamethoxysilyl) methane, bis (hexaethoxysilyl) methane, bis (dimethoxymethylsilyl) methane, bis (diethoxymethylsilyl)
Methane, bis (dimethoxyphenylsilyl) methane, bis (diethoxyphenylsilyl) methane, bis (methoxydimethylsilyl) methane, bis (ethoxydimethylsilyl) methane, bis (methoxydiphenylsilyl) methane, bis (ethoxydiphenylsilyl) methane Can be mentioned as a preferable example. In the present invention, two or more compounds (1) and (2) can be used. When the compounds represented by the compound (1) and the compound (2) are hydrolyzed and partially condensed, they are represented by R ² O—, R ⁴ O— and R ⁵ O— in the general formulas (1) and (2). It is preferable to use 0.3 to 20.0 mol of water, and it is particularly preferable to add 0.5 to 20.0 mol of water per 1 mol of the group. The amount of water to add is 0.3-2
If the value is in the range of 0.0 mol, there is no possibility that the uniformity of the coating film is reduced, and the storage stability of the film-forming composition is not likely to be reduced. When the component (A) is a condensate, the weight average molecular weight in terms of polystyrene is preferably from 500 to 2,000,000.

When component (A) is a condensate, a catalyst is used for hydrolysis and condensation of compound (1) and / or compound (2). Examples of the catalyst that can be used at this time include a metal chelate compound, an acid catalyst, and an alkali catalyst. Examples of the metal chelate compound include triethoxy mono (acetylacetonate) titanium, tri-n-propoxy mono (acetylacetonate) titanium, tri-i-propoxy mono (acetylacetonate) titanium, and tri-n- Butoxy mono (acetylacetonate) titanium, tri-sec-butoxy
Mono (acetylacetonato) titanium, tri-t-butoxy mono (acetylacetonato) titanium, diethoxybis (acetylacetonato) titanium, di-n-propoxybis (acetylacetonato) titanium, di-
i-propoxy bis (acetylacetonate) titanium, di-n-butoxy bis (acetylacetonate)
Titanium, di-sec-butoxybis (acetylacetonato) titanium, di-t-butoxybis (acetylacetonato) titanium, monoethoxytris (acetylacetonato) titanium, mono-n-propoxytris (acetyl) Acetonato) titanium, mono-i-propoxy tris (acetylacetonato) titanium, mono-n
-Butoxy-tris (acetylacetonate) titanium,
Mono-sec-butoxy tris (acetylacetonate) titanium, mono-t-butoxy tris (acetylacetonate) titanium, tetrakis (acetylacetonate) titanium, triethoxy mono (ethylacetoacetate) titanium, tri-n- Propoxy mono (ethyl acetoacetate) titanium, tri-i-propoxy mono (ethyl acetoacetate) titanium, tri-n-butoxy mono (ethyl acetoacetate) titanium, tri-s
ec-butoxy mono (ethyl acetoacetate) titanium, tri-t-butoxy mono (ethyl acetoacetate) titanium, diethoxy bis (ethyl acetoacetate) titanium, di-n-propoxy bis (ethyl acetoacetate) titanium, Di-i-propoxy bis (ethyl acetoacetate) titanium, di-n-butoxy bis (ethyl acetoacetate) titanium, di-sec-butoxy bis (ethyl acetoacetate) titanium, di-t
-Butoxy bis (ethyl acetoacetate) titanium,
Monoethoxy tris (ethyl acetoacetate) titanium, mono-n-propoxy tris (ethyl acetoacetate) titanium, mono-i-propoxy tris (ethyl acetoacetate) titanium, mono-n-butoxy tris (ethyl acetoacetate) ) Titanium, mono-sec
-Butoxy-tris (ethylacetoacetate) titanium, mono-t-butoxy-tris (ethylacetoacetate) titanium, tetrakis (ethylacetoacetate)
Titanium chelating compounds such as titanium, mono (acetylacetonate) tris (ethylacetoacetate) titanium, bis (acetylacetonate) bis (ethylacetoacetate) titanium, tris (acetylacetonate) mono (ethylacetoacetate) titanium; triethoxy・ Mono (acetylacetonate) zirconium, tri-
n-propoxy mono (acetylacetonato) zirconium, tri-i-propoxy mono (acetylacetonato) zirconium, tri-n-butoxy mono (acetylacetonato) zirconium, tri-sec-butoxy mono (acetylacetonate) Nart) zirconium,
Tri-t-butoxy mono (acetylacetonate) zirconium, diethoxybis (acetylacetonato) zirconium, di-n-propoxybis (acetylacetonato) zirconium, di-i-propoxy.
Bis (acetylacetonate) zirconium, di-n-
Butoxy bis (acetylacetonate) zirconium, di-sec-butoxy bis (acetylacetonate) zirconium, di-t-butoxybis (acetylacetonate) zirconium, monoethoxy tris (acetylacetonate) zirconium, mono -N-propoxy tris (acetylacetonate) zirconium, mono-i-propoxy tris (acetylacetonate) zirconium, mono-n-butoxy tris (acetylacetonate) zirconium, mono-sec-butoxy tris (acetyl) (Acetonate) zirconium, mono-t-butoxy tris (acetylacetonate) zirconium, tetrakis (acetylacetonate) zirconium, triethoxy mono (ethylacetoacetate) zirconium Tri -n- propoxy mono (ethylacetoacetate) zirconium, tri -i
-Propoxy mono (ethyl acetoacetate) zirconium, tri-n-butoxy mono (ethyl acetoacetate) zirconium, tri-sec-butoxy mono (ethyl acetoacetate) zirconium, tri-t-
Butoxy mono (ethylacetoacetate) zirconium, diethoxybis (ethylacetoacetate) zirconium, di-n-propoxybis (ethylacetoacetate) zirconium, di-i-propoxybis (ethylacetoacetate) zirconium, di- n-butoxybis (ethylacetoacetate) zirconium, di-sec-butoxybis (ethylacetoacetate) zirconium, di-t-butoxybis (ethylacetoacetate) zirconium, monoethoxytris (ethylacetoacetate) zirconium , Mono-n
-Propoxy tris (ethyl acetoacetate) zirconium, mono-i-propoxy tris (ethyl acetoacetate) zirconium, mono-n-butoxy tris (ethyl acetoacetate) zirconium, mono-
sec-butoxy tris (ethyl acetoacetate)
Zirconium, mono-t-butoxy tris (ethylacetoacetate) zirconium, tetrakis (ethylacetoacetate) zirconium, mono (acetylacetonate) tris (ethylacetoacetate) zirconium, bis (acetylacetonate) bis (ethylacetoacetate) Zirconium chelate compounds such as zirconium and tris (acetylacetonate) mono (ethylacetoacetate) zirconium; aluminum chelate compounds such as tris (acetylacetonate) aluminum and tris (ethylacetoacetate) aluminum; Is a chelate compound of titanium and / or aluminum. Particularly preferred is a chelate compound of titanium. One or more of these metal chelate compounds may be used simultaneously.

Examples of the acid catalyst include inorganic acids such as hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid, phosphoric acid, boric acid and oxalic acid;
Acetic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, oxalic acid, maleic acid, methylmalonic acid, adipic acid, sebacic acid, gallic acid, butyric acid, melitic acid, Arachidonic acid, shikimic acid, 2-ethylhexanoic acid, oleic acid, stearic acid, linoleic acid, linoleic acid, salicylic acid,
Benzoic acid, p-aminobenzoic acid, p-toluenesulfonic acid, benzenesulfonic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoroacetic acid, formic acid, malonic acid, sulfonic acid, phthalic acid, fumaric acid, citric acid, tartaric acid And organic acids such as succinic acid, itaconic acid, mesaconic acid, citraconic acid, malic acid, a hydrolyzate of glutaric acid, a hydrolyzate of maleic anhydride, and a hydrolyzate of phthalic anhydride. Is a more preferable example. One or two of these compounds
More than one species may be used simultaneously.

Examples of the alkali catalyst include sodium hydroxide, potassium hydroxide, lithium hydroxide, pyridine, pyrrole, piperazine, pyrrolidine, piperidine,
Picoline, monoethanolamine, diethanolamine, dimethylmonoethanolamine, monomethyldiethanolamine, triethanolamine, diazabicyclooctane, diazabicyclononane, diazabicycloundecene, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium Hydroxide, tetrabutylammonium hydroxide, ammonia,
Methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, pentylamine, octylamine, nonylamine, decylamine,
N, N-dimethylamine, N, N-diethylamine,
N, N-dipropylamine, N, N-dibutylamine,
Trimethylamine, triethylamine, tripropylamine, tributylamine, cyclohexylamine, trimethylimidine, 1-amino-3-methylbutane, dimethylglycine and the like can be mentioned, more preferably organic amines, ammonia, alkylamine and tetramethylamine Ammonium hydroxide is particularly preferred from the viewpoint of the adhesion of the silica-based film to the substrate. One or more of these alkali catalysts may be used simultaneously.

[0013] The amount of the catalyst used is the amount of the compound (1)
R in (4)¹ O-group, R^Two O-group, R ^Three O-group, R^Five 
O-group and R⁶ Per mole of the total amount of the group represented by O-
And usually, 0.00001 to 10 mol, preferably
0.00005 to 5 mol. The amount of catalyst used is within the above range
Within the range, the polymer may precipitate or gel during the reaction.
Less is.

In the above reaction, an organic solvent is generally used. Examples of the organic solvent that can be used at this time include at least one selected from the group consisting of alcohol solvents, ketone solvents, amide solvents, ester solvents, and aprotic solvents. Here, as the alcohol solvent, methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, sec-butanol, t-butanol, n-pentanol, i-pentanol, 2-methyl Butanol, sec-pentanol, t-pentanol, 3-methoxybutanol, n
-Hexanol, 2-methylpentanol, sec-hexanol, 2-ethylbutanol, sec-heptanol, heptanol-3, n-octanol, 2-ethylhexanol, sec-octanol, n-nonyl alcohol, 2,6-dimethylheptanol Nord-4, n-decanol, sec-undecyl alcohol, trimethylnonyl alcohol, sec-tetradecyl alcohol,
sec-heptadecyl alcohol, phenol, cyclohexanol, methylcyclohexanol, 3,3,5
Mono-alcohol solvents such as trimethylcyclohexanol, benzyl alcohol, diacetone alcohol;

Ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, pentanediol-2,4,2-methylpentanediol-2,
4, hexanediol-2,5, heptanediol-
Polyhydric alcohol solvents such as 2,4,2-ethylhexanediol-1,3, diethylene glycol, dipropylene glycol, triethylene glycol, and tripropylene glycol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl Ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monophenyl ether,
Ethylene glycol mono-2-ethyl butyl ether,
Diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether , Dipropylene glycol monoethyl ether,
Polyhydric alcohol partial ether solvents such as dipropylene glycol monopropyl ether; and the like. One or two of these alcohol solvents are used.
More than one species may be used simultaneously.

As the ketone solvent, acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-
n-butyl ketone, diethyl ketone, methyl-i-butyl ketone, methyl-n-pentyl ketone, ethyl-n-
Butyl ketone, methyl-n-hexyl ketone, di-i-
Butyl ketone, trimethylnonanone, cyclohexanone, 2-hexanone, methylcyclohexanone, 2,4
-In addition to pentanedione, acetonylacetone, acetophenone, fenchone, etc., acetylacetone, 2,
4-hexanedione, 2,4-heptanedione, 3,5
-Heptanedione, 2,4-octanedione, 3,5-
Octanedione, 2,4-nonanedione, 3,5-nonanedione, 5-methyl-2,4-hexanedione, 2,
2,6,6-tetramethyl-3,5-heptanedione,
Β-diketones such as 1,1,1,5,5,5-hexafluoro-2,4-heptanedione and the like can be mentioned.
These ketone solvents may be used alone or in combination of two or more.

As amide solvents, formamide, N
-Methylformamide, N, N-dimethylformamide, N-ethylformamide, N, N-diethylformamide, acetamide, N-methylacetamide,
N-dimethylacetamide, N-ethylacetamide,
N, N-diethylacetamide, N-methylpropionamide, N-methylpyrrolidone, N-formylmorpholine, N-formylpiperidine, N-formylpyrrolidine, N-acetylmorpholine, N-acetylpiperidine, N-acetylpyrrolidine and the like. Can be One or two or more of these amide solvents may be used simultaneously.

Examples of the ester solvents include diethyl carbonate, ethylene carbonate, propylene carbonate, diethyl carbonate, methyl acetate, ethyl acetate, γ-butyrolactone, γ
-Valerolactone, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, sec-butyl acetate, n-pentyl acetate, sec-pentyl acetate, 3-methoxybutyl acetate, methylpentyl acetate, acetic acid 2-ethylbutyl, 2-ethylhexyl acetate, benzyl acetate,
Cyclohexyl acetate, methyl cyclohexyl acetate, n-nonyl acetate, methyl acetoacetate, ethyl acetoacetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl acetate, diethylene glycol mono-acetate
n-butyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, glycol diacetate, acetic acid Methoxy triglycol, ethyl propionate, n-butyl propionate, i-amyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate, n-butyl lactate, n-amyl lactate, malonic acid Examples thereof include diethyl, dimethyl phthalate, and diethyl phthalate. These ester solvents include 1
Species or two or more species may be used simultaneously. Examples of aprotic solvents include acetonitrile, dimethyl sulfoxide, N, N, N ', N'-tetraethylsulfamide, hexamethylphosphoric triamide, N-methylmorpholone, N-methylpyrrole, N-ethylpyrrole, −
Methyl-Δ3-pyrroline, N-methylpiperidine, N-
Ethyl piperidine, N, N-dimethylpiperazine, N-
Methylimidazole, N-methyl-4-piperidone, N
-Methyl-2-piperidone, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 1,3
-Dimethyltetrahydro-2 (1H) -pyrimidinone.

Component (B) The component (B) used in the present invention is a surfactant.
And more preferably a nonionic surfactant and / or
Is a cationic surfactant. Such nonionic interface
Examples of the activator include C₁₆H₃₃(OCH_TwoCH_Two)_TwoO
H (hereinafter, such a structure is referred to as C₁₆EO_TwoAbbreviated and described
You. ), C₁₂EO_Two, C₁₂EO_Four, C₁₂EO₆, C₁₂E
O₈, C₁₂EO_Ten, C₁₂EO₂₀, C₁₄EO_Two, C₁₄E
O_Four, C₁₄EO₆, C₁₄EO₈, C₁₄EO_Ten, C₁₄E
O₂₀, C₁₆EO_Four, C₁₆EO₆, C ₁₆EO₈, C₁₆E
O_Ten, C₁₆EO₂₀, C₁₈EO_Two, C₁₈EO_Four, C₁₈E
O₆, C₁₈EO₈, C₁₈EO_Ten, C₁₈EO₂₀Etc.
be able to. In addition, oleic acid,
Fatty acids such as lauric acid, stearic acid and palmitic acid
And various sorbitan fatty acid esters. concrete
Has CH_ThreeC (CH_Three) CH_TwoC (CH_Three)_TwoC₆H_Four(O
CH_TwoCH_Two) XOH (x is an average of 10) Trito
nX-100 (Aldrich), polyethylene oxide
(20) Sorbitan monolaurate (Tween2
0, Aldrich) and polyethylene oxide (2
0) Sorbitan monopalmitate (Tween 40),
Polyethylene oxide (20) sorbitan monostea
, Polyethylene oxide (20) sorbitanmo
Nooriate (Tween 60), sorbitan monopa
Lumitate (Span40) and the like. Polyethylene
One type of nonionic surfactant or two or more types
Combinations of the above can also be used.

Further, a triblock copolymer having three polyalkylene oxide chains can also be used. In particular, a triblock copolymer having a polyethylene oxide chain-polypropylene oxide chain-polyethylene oxide chain can be used. This surfactant has a polypropylene oxide chain in the center,
It has a structure having polyethylene oxide chains on both sides and hydroxyl groups on both ends. The basic structure of this triblock copolymer is represented by (EO) x (PO) y (EO) x
Expressed as x and y are not particularly limited. For example, x = 5
To 110, y = 15 to 70. Preferably, x
= 15-20, y = 50-60. Note that (EO) x () is obtained by combining any X value selected from 15, 19, 18, 19, and 20 and a y value that is any integer included in y = 50 to 60. PO) y (EO) x is the preferred triblock copolymer. Further, a triblock copolymer ((PO) x (EO) y (PO) x) having a polypropylene oxide chain-polyethylene oxide chain-polypropylene oxide chain in which blocks are reversely arranged can also be used. Also for this copolymer, x and y are not particularly limited, but x = 5-110, y = 15
~ 70, more preferably x = 15 ~
20, y = 50-60.

As the triblock copolymer, specifically, EO ₅ PO ₇₀ EO ₅ , EO ₁₃ PO ₃₀ EO ₁₃ , EO ₂₀
PO ₃₀ EO ₂₀ , EO ₂₆ PO ₃₉ EO ₂₆ , EO ₁₇ PO ₅₆ EO
₁₇ , EO ₁₇ PO ₅₈ EO ₁₇ , EO ₂₀ PO ₇₀ EO ₂₀ , EO _{80
PO 30 EO 80, EO 106 PO} 7 0 EO 106, EO 100 PO 39
EO ₁₀₀ , EO ₁₉ PO ₃₃ EO ₁₉ , EO ₂₆ PO ₃₉ EO _{26 and the} like can be used. Preferably, EO ₁₇ PO ₅₆ EO ₁₇ , EO
₁₇ PO ₅₈ EO _{17 and the} like. These triblock copolymers are commercially available from BASF and the like, and it is possible to obtain a triblock copolymer having desired x and y values at a small-scale production level. The triblock copolymer can be used alone or in combination of two or more.

Further, a star diblock copolymer in which two polyethylene oxide chains-polypropylene oxide chains are respectively bonded to two nitrogen atoms of ethylenediamine can also be used. For example, (EO ₁₁₃ P
_{O 22) 2 NCH 2 CH 2} N (PO 22 EO 113) 2, (EO 3 P
O ₁₈ ) ₂ NCH ₂ CH ₂ N (PO ₁₈ EO ₃ ) ₂ , (PO ₁₉ E
O ₁₆ ) ₂ NCH ₂ CH ₂ N (EO ₁₆ PO ₁₉ ) _{2 and the} like. The star diblock copolymer can be used alone or in combination of two or more.

Also, primary alkylamines and the like can be used as the nonionic surfactant. The obtained pore size can be controlled by the type of the surfactant used, specifically, by the length of the hydrophobic portion such as the alkyl chain of the surfactant.

The cationic surfactant is, for example, a long-chain alkyl quaternary ammonium represented by the following general formulas (3) and / or (4). ^{R 8 R 9 R 10 R 11} N + · X - ····· (3) (R 8 ~R 11 are each independently a monovalent hydrocarbon group,
At least one of them is an alkyl group having 10 to 24 carbon atoms. X is an acid anion. R ¹² (N) ⁺ · X ⁻ (4) (R ¹² is an alkyl group having 8 to 24 carbon atoms, (N) represents a pyridine group, and X is an acid anion.)

Such compounds include, for example, alkyltrimethylammonium halide, dialkyldimethylammonium halide, alkyldimethylbenzylammonium halide and the like. Specifically, hexadecyltrimethylammonium chloride, dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride Octadecyltrimethylammonium chloride, decyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, dodecyltrimethylammonium bromide,
Tetradecyl trimethyl ammonium bromide, octadecyl trimethyl ammonium bromide, decyl trimethyl ammonium bromide, hexadecyl trimethyl ammonium iodide, dodecyl trimethyl ammonium iodide, tetradecyl trimethyl ammonium iodide, octadecyl trimethyl ammonium iodide, decyl trimethyl ammonium iodide, hexadecyl Dimethylbenzylammonium chloride, dodecyldimethylbenzylammonium chloride, tetradecyldimethylbenzylammonium chloride, octadecyldimethylbenzylammonium chloride, decyldimethylbenzylammonium chloride, hexadecyldimethylbenzylammonium bromide, Sildimethylbenzylammonium bromide, tetradecyldimethylbenzylammonium bromide, octadecyldimethylbenzylammonium bromide, decyldimethylbenzylammonium bromide, hexadecyldimethylbenzylammonium iodide, dodecyldimethylbenzylammonium iodide, tetradecyldimethylbenzylammonium iodide, octadecyldimethyl Benzylammonium iodide, decyldimethylbenzylammonium iodide; decylpyridinium chloride, dodecylpyridinium chloride, tetradecylpyridinium chloride, hexadecylpyridinium chloride, octadecylpyridinium chloride, decylpyridinium bromide, dodecylpi Dinium bromide, tetradecylpyridinium bromide, hexadecylpyridinium bromide, octadecylpyridinium bromide, decylpyridinium iodide, dodecylpyridinium iodide, tetradecylpyridinium iodide, hexadecylpyridinium iodide, octadecylpyridinium iodide, and the like. . Two or more of these surfactants can be used simultaneously.

In the composition used in the present invention, the hydrolysis and condensation of the component (A) are performed in the presence of the component (B). At this time, the use ratio of the component (B) to the component (A) is as follows:
Component (B) is used in an amount of 5 to 300 parts by weight, more preferably 5 to 250 parts by weight, particularly preferably 10 to 250 parts by weight, based on 100 parts by weight of component (A) (in terms of a completely hydrolyzed condensate). If the component (B) is less than 5 parts by weight, the relative dielectric constant of the silica film will exceed 2.5, and if it exceeds 300 parts by weight, the coating properties of the varnish will be poor.

The composition used in the present invention is as described in the above (A) to
It can be produced by mixing the component (B) and other components as necessary.

Other Additives Components such as colloidal silica, colloidal alumina and a coating improver may be added to the film-forming composition obtained in the present invention. Colloidal silica, for example,
It is a dispersion in which high-purity silicic acid is dispersed in the hydrophilic organic solvent, and usually has an average particle size of 5 to 30 mμ, preferably 10 to 20 mμ, and a solid concentration of about 10 to 40% by weight. . Examples of such colloidal silica include methanol silica sol and isopropanol silica sol manufactured by Nissan Chemical Industry Co., Ltd .; and Oscar manufactured by Catalyst Chemicals Co., Ltd. Examples of the colloidal alumina include alumina sol 5 manufactured by Nissan Chemical Industries, Ltd.
20, 100 and 200; alumina clear sol, alumina sol 10, manufactured by Kawaken Fine Chemical Co., Ltd.
132 and the like. Examples of the coatability improver include a silicone-based surfactant and a poly (meth) acrylate-based surfactant.

The total solid content of the coating composition used in the present invention is preferably 2 to 30% by weight, and is appropriately adjusted according to the purpose of use. The total solid content of the composition is 2-3
When the content is 0% by weight, the thickness of the coating film is in an appropriate range, and the storage stability is more excellent.

In the present invention, the substrate to which the coating composition is applied is a silicon wafer, SiO ₂ wafer, Si
N wafers and the like, and application means such as spin coating, dipping, roll coating, and spraying are used.

In the present invention, the coating film is obtained by applying the above coating composition to a substrate and removing the organic solvent, and the thickness of the coating film is usually 0.05 to 3 μm, preferably 0.1 to 3 μm.
2.5 μm.

In the present invention, the coating film formed as described above is treated in a supercritical medium. As an apparatus used at this time, for example, an apparatus described in JP-A-2001-60575 can be used.

As the supercritical medium, carbon dioxide is preferable, and if necessary, another solvent having excellent compatibility with the component (B) can be added. Examples of other solvents include the organic solvents previously used for the condensation of the component (A). The proportion of the other solvent used is 0 to 50 parts by weight, more preferably 0 to 3 parts by weight, per 100 parts by weight of carbon dioxide.
0 parts by weight.

The conditions for treating the coating composition in a supercritical medium include a temperature of 0 to 200 ° C., and more preferably 20 to 200 ° C.
To 150 ° C., pressure 10 to 200 atm, more preferably 2
0 to 180 atm. The processing time in a supercritical medium is
It is 10 seconds to 2 hours, more preferably 1 minute to 1 hour.

The silica film of the present invention is formed by the above-mentioned method, but the obtained silica film can be washed with a solvent or heat-treated as required. At this time, examples of the solvent used for washing include the organic solvents used for the condensation of the component (A). The heat treatment can be performed at a temperature of about 200 to 500 ° C., usually for about 5 to 240 minutes. As a heating method at this time, a hot plate, an oven, a furnace, or the like can be used. As a heating atmosphere, the heating is performed in the atmosphere, a nitrogen atmosphere, an argon atmosphere, a vacuum, a reduced pressure in which the oxygen concentration is controlled, or the like. Can be.

The film obtained in this manner has a film density of 0.1.
^{3 to} 1.3 g / cm ³ , preferably 0.3 to 1.2 g / cm ³
cm ³ , very low dielectric constant and insulating properties, and excellent surface hardness of the coating film.
I, DRAM, SDRAM, RDRAM, D-RDRA
M, an interlayer insulating film for semiconductor devices such as M, a protective film such as a surface coat film of a semiconductor device, an interlayer insulating film for a multilayer wiring board, a protective film and an insulating preventing film for a liquid crystal display device, a protective film for an electroluminescent display device, and the like. It is useful for applications such as anti-insulation films.

[0037]

The present invention will now be described more specifically with reference to examples. Parts and% in Examples and Comparative Examples are parts by weight and% by weight, respectively, unless otherwise specified. Further, the evaluation of the film-forming composition in the examples was measured as follows. Various evaluations were performed as follows.

An aluminum electrode pattern was formed on the substrate on which a relative dielectric constant film was formed by a vapor deposition method to prepare a sample for measuring the relative dielectric constant. The sample was subjected to CV measurement at a frequency of 100 kHz using a Yokogawa-Hewlett-Packard Co., Ltd. HP16451B electrode and HP4284A precision LCR meter.
The relative dielectric constant of the coating film was measured by the method.

The film-absorbing film-forming substrate was heated to 450 ° C. by using a temperature rising gas analyzer EMD-WA1000S manufactured by Electronic Science Co., Ltd., and the amount of desorbed water was measured. The amount of desorbed water was compared with the SiO ₂ film formed by CVD, and evaluated based on the following criteria. ；: The amount of desorbed water is equal to or less than the SiO ₂ film formed by CVD. ×: The amount of desorbed water exceeds the SiO ₂ film formed by CVD.

Synthesis Example 1 In a quartz separable flask, the formula EO ₁₇ PO ₅₈ EO ₁₇
After dissolving 1.76 g of the nonionic surfactant represented by the formula in 105 g of ion-exchanged water, 20 g of 12N hydrochloric acid was added. This solution was heated to 45 ° C., and 4.73 g of tetraethoxysilane was added to the solution and reacted for 8 hours to obtain a reaction solution.

Synthesis Example 2 The solution obtained in the synthesis example was further reacted at 80 ° C. for 8 hours to obtain a reaction solution.

Synthesis Example 3 In a quartz separable flask, 10 g of tetramethoxysilane, 3.25 g of methyltrimethoxysilane, 3.5 g of hexadecyltrimethylammonium chloride and 100 g of ion-exchanged water were stirred, and then 12 N hydrochloric acid was added. PH was adjusted to 1. The solution was reacted at 20 ° C. for 24 hours to obtain a reaction solution.

Synthesis Example 4 324.40 g of methyltrimethoxysilane, 123.64 g of triethoxysilane, and 125 g of sorbitan monolaurate (Tween 20, Aldrich) were dissolved in 298 g of ethanol, followed by stirring with a three-one motor and a solution temperature of 50. Stabilized to ° C. Next, 254 g of ion-exchanged water in which 0.20 g of maleic acid was dissolved was added to 1
Added to the solution over time. Then, after reacting at 50 ° C. for 3 hours, 502 g of propylene glycol monoethyl ether was added, and the reaction solution was cooled to room temperature. At 50 ° C., a solution containing methanol and ethanol was
g The mixture was removed by evaporation to obtain a reaction solution.

Synthesis Example 5 In a quartz separable flask, 243.30 g of methyltrimethoxysilane and 101.2 g of tetramethoxysilane were used.
After dissolving 4 g, 123.64 g of triethoxysilane, 0.02 g of tetrakis (acetylacetonato) titanium and 50 g of hexadecylpyridinium chloride in 254 g of dipropylene glycol dimethyl ether,
The solution was stirred with a three-one motor to stabilize the solution temperature at 50 ° C. Next, 278 g of ion-exchanged water was added to the solution over 1 hour. Then, after reacting at 50 ° C. for 3 hours, 546 g of dipropylene glycol dimethyl ether was obtained.
Was added and the reaction solution was cooled to room temperature. At 50 ° C., 546 g of a solution containing methanol and ethanol was removed from the reaction solution by evaporation to obtain a reaction solution.

Synthesis Example 6 Distilled ethanol 470. was added to a quartz separable flask.
9 g, ion-exchanged water 226.5 g, C ₁₆ EO ₄ 25 g,
17.2 25% aqueous tetramethylammonium hydroxide solution
g and stirred uniformly. 44.9 g of methyltrimethoxysilane and 68.6 of tetraethoxysilane were added to this solution.
g of the mixture was added over 2 hours. The reaction was carried out for 6 hours while keeping the solution at 58 ° C. To this solution was added 80 g of a 20% aqueous maleic acid solution, and the mixture was sufficiently stirred and then cooled to room temperature. 400 g of propylene glycol monopropyl ether is added to this solution, and then the solution is concentrated to 10% (complete hydrolyzed condensate) using an evaporator at 50 ° C., and then 10% propylene glycol monopropyl maleate is added. 10 g of an ether solution was added to obtain a reaction solution.

Comparative Synthesis Example 1 A reaction solution was obtained in the same manner as in Synthesis Example 1 except that EO ₁₇ PO ₅₈ EO ₁₇ was not added.

Example 1 100 g of the reaction solution obtained in Synthesis Example 1 was filtered through a Teflon (registered trademark) filter having a pore size of 0.2 μm,
A composition sample was applied on an inch silicon wafer by a spin coating method, and the substrate was treated on a hot plate at 90 ° C. for 1 minute and in a nitrogen atmosphere at 200 ° C. for 1 minute. The obtained substrate was put in a closed chamber made of zirconium, and treated with a supercritical medium under the following conditions. Medium: carbon dioxide Temperature: 100 ° C. Pressure: 140 atm Time: 5 minutes The relative dielectric constant of the treated substrate was measured and found to be 2.1.
9, which is a very low value.
O ₂ was less than excellent.

Example 2 The substrate obtained by the supercritical treatment in Example 1 was
Baking was performed on a hot plate in a nitrogen atmosphere at 30 ° C. for 30 minutes. When the relative dielectric constant of this substrate was measured, it was a very low value of 2.06, and the hygroscopicity of the coating film was CVD-SiO ₂
The following was excellent.

Examples 3 to 8 Evaluations were made in the same manner as in Example 2 except that the compositions shown in Table 1 and the treatment were performed under supercritical conditions. The evaluation results are also shown in Table 1.

[0050]

[Table 1]

Comparative Example 1 Evaluation was performed in the same manner as in Example 1 except that the reaction solution obtained in Comparative Synthesis Example 1 was used. The relative dielectric constant of the obtained coating film was as high as 3.12.

Comparative Example 2 Evaluation was performed in the same manner as in Example 1 except that the treatment with the supercritical medium was not performed. The relative permittivity of the coating film was as high as 2.55, and the moisture absorption of the coating film was higher than that of CVD-SiO ₂ .

According to the present invention, a film containing (A) a siloxane compound and (B) a surfactant is treated in a supercritical medium to have a relative dielectric constant of 2.2 or less and a coating film. Can provide a silica film having a low moisture absorption.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C08G 77/48 C08G 77/48 C09D 5/25 C09D 5/25 183/02 183/02 183/04 183/04 183 / 14 183/14 H01L 21/312 H01L 21/312 C 21/316 21/316 G (72) Inventor Kinji Yamada 2-11-11 Tsukiji 2-chome, Chuo-ku, Tokyo F-term (reference) 4D075 BB32Z BB56Z BB68Z CA23 DA06 DB13 DC22 EA05 EB01 4F205 AA33 AB10 AG03 AH33 GA05 GB01 GB11 4J035 BA03 CA162 HA01 HA06 LB20 4J038 DL021 DL031 DL051 DL071 DL081 DL111 HA166 HA446 KA04 KA09 NA04 B04A17 AG21 PB09B BJ02

Claims (12)

[Claims] 1. A siloxane compound and (B)
A method for forming a silica film, comprising treating a film containing a surfactant in a supercritical medium. 2. (A) a siloxane compound represented by the following general formula (1): R ¹ _a Si (OR ² ) _4-a (1) (R ¹ is a hydrogen atom, fluorine A represents an atom or a monovalent organic group, R ² represents a monovalent organic group, a represents an integer of 0 to 3) and a compound represented by the following general formula (2): R ³ _b (R ⁴ _{O) 3-b Si- (R} 7) d -Si (oR 5) 3-c R 6 c ····· (2) (R 3, R 4, R 5 and R ^6, are identical or different Each represents a monovalent organic group, b and c may be the same or different and each represents a number of 0 to 2, and R ⁷ is represented by an oxygen atom or — (CH 2) _n — Represents a group, n
Represents 1 to 6, and d represents 0 or 1. 2. The method for forming a silica film according to claim 1, which is a hydrolyzate and / or a condensate of at least one compound selected from the group consisting of: 3. The method for forming a silica film according to claim 1, wherein the hydrolysis and condensation of the component (A) are performed in the presence of the component (B). 4. The method according to claim 1, wherein the component (B) is at least one selected from the group consisting of a nonionic surfactant and a cationic surfactant. 5. The use ratio of the component (B) to the component (A) is 5 to 300 parts by weight of the component (B) with respect to 100 parts by weight of the component (A) (in terms of a complete hydrolysis condensate). The method for forming a silica film according to claim 1, wherein: 6. The method for forming a silica film according to claim 1, wherein the supercritical medium contains carbon dioxide. 7. The processing conditions in a supercritical medium are as follows:
The method for forming a silica film according to claim 1, wherein the pressure is 200 ° C and the pressure is 10 to 200 atm. 8. A silica film obtained by the method according to claim 1. 9. A method for forming a silica film, comprising subjecting the film obtained by the method according to claim 1 to a heat treatment at 200 to 500 ° C. 10. A silica film obtained by the method according to claim 9. 11. An insulating film comprising the film according to claim 8. 12. A semiconductor device comprising the insulating film according to claim 11.