JP2003174023A - Composition for forming interlayer insulating film, method of manufacturing interlayer insulating film, and electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composition for forming an interlayer insulating film and so on whereby an insulating film can be formed with high mechanical strength such as sufficient CMP resistance, a low dielectric property, and high adhesion. <P>SOLUTION: The composition for forming an interlayer insulating film of the present invention includes as component (a) a siloxane resin such as alkoxy silane having a carbon content of 10 mass % or less, as component (b) a solvent such an alcohol capable of solving the siloxane resin, and as component (c) a diazabicyclo compound such as 1,8-diazabicyclo[5.4.0]undec-7-ene. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a composition for forming an interlayer insulating film, a method for manufacturing an interlayer insulating film, and an electronic component.

[0002]

2. Description of the Related Art With the miniaturization of wiring due to high integration of LSI, increase in signal delay time due to increase in inter-wiring capacitance has become a problem. In addition to the above, further reduction of the relative dielectric constant and heat treatment process is required.

Generally, the signal propagation velocity (v) of the wiring and the relative permittivity (ε) of the insulating material in contact with the wiring material are represented by the following equation (2): v = k / √ε (2) There is a relationship (k in the formula is a constant). That is, by increasing the frequency range to be used and reducing the relative permittivity (ε) of the insulating material, high speed signal propagation can be achieved. For example, conventionally, the relative dielectric constant is 4.2.
Although a SiO ₂ film formed by the CVD method has been used as a material for forming an interlayer insulating film, a material that exhibits a lower dielectric constant is desired in order to reduce the interwiring capacitance of a device and improve the operation speed of an LSI. Has been done.

On the other hand, as a low dielectric constant material which has been put into practical use at present, there is a SiOF film by a CVD method having a relative dielectric constant of about 3.5. Also, the relative dielectric constant is 2.5 to
As an insulating material of 3.0, organic SOG (Spin
On Glass), organic polymers, and the like. Further, as the insulating material having a relative dielectric constant of 2.5 or less, a porous material having voids in the film is considered to be effective, and L
Research and development for application to the SI interlayer insulating film are being actively conducted.

As a method for forming such a porous material,
JP-A-10-283843, JP-A-11-322
Japanese Patent Application Laid-Open No. 992, Japanese Patent Application Laid-Open No. 11-310411, and the like propose a low dielectric constant of an organic SOG material. This method forms a coating film of a composition containing a polymer having a property of volatilizing or decomposing by heating with a hydrolyzed polycondensation product of a metal alkoxysilane, and forming pores by heating the coating film. Is. On the other hand, Japanese Patent Laid-Open No.
Japanese Patent Laid-Open No. 001-2989 proposes to add a cyclic amine compound to a hydrolyzed polycondensation product of an alkoxysilane having an organic group in order to prevent the film strength from being lowered due to the lowering of the dielectric constant.

[0006]

However, the above-mentioned Japanese Unexamined Patent Application Publication No.
In the method described in Japanese Patent Laid-Open No. 0-283843, the film strength tends to decrease as the dielectric constant of the insulating film decreases, which is a serious problem from the viewpoint of process compatibility.

When the material described in Japanese Patent Laid-Open No. 2001-2989 is applied as an interlayer film material for the Cu-damascene process, CVD used as a cap film.
The adhesiveness (bondability) tends to be weak at the interface between the SiO ₂ film and the SOG film formed by the method. This happens when,
Cu-CMP (Chemical Mechanical) for polishing an excessive Cu film generated when wiring metal is laminated
Interfacial peeling occurs in the (al Polish) step. Furthermore, when a large amount of cyclic amine is added, there is a possibility that the dielectric constant or the desorbed gas may increase due to moisture absorption. These problems are extremely inconvenient from the viewpoint of process compatibility.

Therefore, the present invention has been made in view of the above circumstances and has sufficient mechanical strength, low dielectric properties, and adhesiveness to both a silicon substrate and a SiO ₂ film such as P-TEOS. It is an object of the present invention to provide an interlayer insulating film forming composition capable of forming an insulating film having excellent electrical reliability and improved electrical reliability, a method for producing an interlayer insulating film, and an electronic component having the interlayer insulating film. To do.

[0009]

In order to solve the above problems, the inventors of the present invention have conducted extensive studies from the viewpoint of the constituent components and compositions of insulating film materials, and have found that compositions containing specific components have been The inventors have found that the various problems described above can be solved, and completed the present invention.

That is, the composition for forming an interlayer insulating film according to the present invention is obtained by hydrolyzing and condensing a compound represented by component (a): the following formula (1); R _n SiX _4-n (1) A siloxane resin obtained and having a carbon content of 10 mass% or less;
Component (b): a solvent capable of dissolving component (a) and component (c): a diazabicyclo compound. Here, in the formula, R represents a hydrogen atom or an organic group having 1 to 20 carbon atoms, X represents a hydrolyzable group, n represents an integer of 0 to 2, and when n is 2, each R represents They may be the same or different, and when n is 0 to 2, each X may be the same or different.

An insulating film was formed on a wafer by using the composition having the above structure, and its characteristics were evaluated.
It was confirmed that sufficient elastic modulus and CMP resistance are exhibited, and excellent low dielectric properties are exhibited. Further, if the carbon content in the siloxane resin as the component (a) exceeds 10% by mass, the adhesiveness to other layers and the mechanical strength are undesirably lowered.

Specifically, the concentration of the component (c) is 500 p
It is suitable that it is pm or less. This concentration is 500ppm
If it exceeds, the stability of the composition itself and the film formability as an insulating film tend to be poor.

Further, it is more preferable that the component (d) further contains a thermal decomposition volatile compound which thermally decomposes or volatilizes at a heating temperature of 250 to 500 ° C. This facilitates adjusting the dielectric characteristics of the insulating film. Here, the “pyrolysis” temperature in the present invention means TG-DTA (Thermogravimetry).
-Differential Thermal Analysis). Specifically, a sample of about 10 mg is accurately weighed, and the temperature at which thermal decomposition is started and the temperature at which it is completely decomposed are obtained from the TG curve obtained by measurement with TG / DTA6300 manufactured by Sieko Instruments Inc. Further, "volatile" means that decomposed components are evaporated or vaporized without remaining in the film.

Further, the halogen ion concentration is 10 ppm.
The following is desirable. If the halogen ion concentration exceeds 10 ppm, there is a possibility that residual ions remaining in the obtained insulating film may lead to wiring corrosion.

Furthermore, it is more preferable that the alkali metal ion concentration and the alkaline earth metal ion concentration are each 100 ppb or less. The lower the concentration of these metal ions, the better. If the concentration exceeds 100 ppb, the metal ions will easily flow into the semiconductor element, possibly affecting the device performance.

In the method for producing an interlayer insulating film according to the present invention, the composition for forming an interlayer insulating film according to the present invention is applied onto a substrate to form a film, the solvent contained in the film is removed, and then the film is removed. The coating is baked at a heating temperature of 300 to 500 ° C. When firing is performed in such a temperature range, the film can be sufficiently cured while suppressing the deterioration of the metal wiring layer in the presence of the metal wiring layer, thus improving the ease of manufacturing an insulating film having excellent various characteristics. To be done.

The electronic component according to the present invention has an interlayer insulating film produced by the method for producing an interlayer insulating film of the present invention.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below. As described above, the composition for forming an interlayer insulating film according to the present invention contains the components (a), (b) and (c) as essential components.

<Component (a)> The component (a) in the present invention is a siloxane resin obtained by hydrolyzing and condensing a compound represented by the following formula (1); R _n SiX _4-n (1) Is. Here, in the formula, R represents a hydrogen atom or an organic group having 1 to 20 carbon atoms, X represents a hydrolyzable group, and n
Represents an integer of 0 to 2, and when n is 2, each R may be the same or different, and when n is 0 to 2, each X may be the same or different.

Examples of the hydrolyzable group X include an alkoxy group, a halogen atom, an acetoxy group and an isocyanate group. Among these, an alkoxy group is preferable from the viewpoint of the liquid stability of the composition itself and the coating properties of the coating.

Examples of the compound (alkoxysilane) in which the hydrolyzable group X is an alkoxy group include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-iso-propoxysilane,
Tetra-n-butoxysilane, tetra-sec-butoxysilane, tetra-tert-butoxysilane, tetraphenoxysilane and other tetraalkoxysilanes, trimethoxysilane, triethoxysilane, tripropoxysilane, fluorotrimethoxysilane, fluorotriethoxy. Silane, methyltrimethoxysilane, methyltriethoxysilane, methyltri-n-propoxysilane, methyltri-iso-propoxysilane, methyltri-n
-Butoxysilane, methyltri-iso-butoxysilane, methyltri-tert-butoxysilane, methyltriphenoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltri-n-propoxysilane, ethyltri-iso-propoxysilane, ethyltri-n -Butoxysilane, ethyltri-iso-butoxysilane, ethyltri-tert-butoxysilane,
Ethyltriphenoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-propyltri-n-propoxysilane, n-propyltri-
iso-propoxysilane, n-propyltri-n-butoxysilane, n-propyltri-iso-butoxysilane, n-propyltri-tert-butoxysilane,
n-propyltriphenoxysilane, iso-propyltrimethoxysilane, iso-propyltriethoxysilane, iso-propyltri-n-propoxysilane,
iso-propyltri-iso-propoxysilane, i
so-propyltri-n-butoxysilane, iso-propyltri-iso-butoxysilane, iso-propyltri-tert-butoxysilane, iso-propyltriphenoxysilane, n-butyltrimethoxysilane, n-butyltriethoxysilane , N-butyltri-
n-propoxysilane, n-butyltri-iso-propoxysilane, n-butyltri-n-butoxysilane,
n-butyltri-iso-butoxysilane, n-butyltri-tert-butoxysilane, n-butyltriphenoxysilane, sec-butyltrimethoxysilane, s
ec-butyltriethoxysilane, sec-butyltri-n-propoxysilane, sec-butyltri-iso
-Propoxysilane, sec-butyltri-n-butoxysilane, sec-butyltri-iso-butoxysilane, sec-butyltri-tert-butoxysilane,
sec-butyltriphenoxysilane, t-butyltrimethoxysilane, t-butyltriethoxysilane, t-
Butyltri-n-propoxysilane, t-butyltri-
iso-propoxysilane, t-butyltri-n-butoxysilane, t-butyltri-iso-butoxysilane, t-butyltri-tert-butoxysilane, t-
Butyltriphenoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltri-n
-Propoxysilane, phenyltri-iso-propoxysilane, phenyltri-n-butoxysilane, phenyltri-iso-butoxysilane, phenyltri-te
rt-butoxysilane, phenyltriphenoxysilane, trifluoromethyltrimethoxysilane, pentafluoroethyltrimethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, etc. Trialkoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldi-n-propoxysilane, dimethyldi-iso-propoxysilane, dimethyldi-n-
Butoxysilane, dimethyldi-sec-butoxysilane, dimethyldi-tert-butoxysilane, dimethyldiphenoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diethyldi-n-propoxysilane, diethyldi-iso-propoxysilane, diethyldi-n-butoxysilane. Silane, diethyldi-sec-butoxysilane, diethyldi-tert-butoxysilane,
Diethyldiphenoxysilane, di-n-propyldimethoxysilane, di-n-propyldiethoxysilane, di-
n-propyldi-n-propoxysilane, di-n-propyldi-iso-propoxysilane, di-n-propyldi-n-butoxysilane, di-n-propyldi-sec
-Butoxysilane, di-n-propyldi-tert-butoxysilane, di-n-propyldiphenoxysilane,
Di-iso-propyldimethoxysilane, di-iso-
Propyldiethoxysilane, di-iso-propyldi-
n-propoxysilane, di-iso-propyldi-is
o-propoxysilane, di-iso-propyldi-n-
Butoxysilane, di-iso-propyldi-sec-butoxysilane, di-iso-propyldi-tert-butoxysilane, di-iso-propyldiphenoxysilane, di-n-butyldimethoxysilane, di-n-butyldiethoxysilane , Di-n-butyldi-n-propoxysilane, di-n-butyldi-iso-propoxysilane, di-n-butyldi-n-butoxysilane, di-n-
Butyldi-sec-butoxysilane, di-n-butyldi-tert-butoxysilane, di-n-butyldiphenoxysilane, di-sec-butyldimethoxysilane, di-sec-butyldiethoxysilane, di-sec-butyldi- n-propoxysilane, di-sec-butyldi-
iso-propoxysilane, di-sec-butyldi-n
-Butoxysilane, di-sec-butyldi-sec-butoxysilane, di-sec-butyldi-tert-butoxysilane, di-sec-butyldiphenoxysilane,
Di-tert-butyldimethoxysilane, di-tert
-Butyldiethoxysilane, di-tert-butyldi-
n-propoxysilane, di-tert-butyldi-is
o-propoxysilane, di-tert-butyldi-n-
Butoxysilane, di-tert-butyldi-sec-butoxysilane, di-tert-butyldi-tert-butoxysilane, di-tert-butyldiphenoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, diphenyldi-n-propoxysilane. , Diphenyldi-iso-propoxysilane, diphenyldi-
n-butoxysilane, diphenyldi-sec-butoxysilane, diphenyldi-tert-butoxysilane, diphenyldiphenoxysilane, bis (3,3,3-trifluoropropyl) dimethoxysilane, methyl (3,3
Examples include diorganodialkoxysilanes such as 3,3-trifluoropropyl) dimethoxysilane.

Examples of the compound (halogenated silane) in which the hydrolyzable group X is a halogen atom (halogen group) include those in which the alkoxy group in each of the above alkoxysilane molecules is substituted with a halogen atom. . Furthermore, examples of the compound (acetoxysilane) in which the hydrolyzable group X is an acetoxy group include compounds in which the alkoxy group in each of the above alkoxysilane molecules is substituted with an acetoxy group. Furthermore, examples of the compound (isocyanate silane) in which the hydrolyzable group X is an isocyanate group include those in which the alkoxy group in each of the above alkoxysilane molecules is substituted with an isocyanate group.

The compounds represented by the formula (1) may be used alone or in combination of two or more kinds.

Further, as a catalyst for promoting the hydrolytic condensation reaction in the hydrolytic condensation of the compound represented by the formula (1), formic acid, maleic acid, fumaric acid, acetic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid are used. , Heptanoic acid,
Octanoic acid, nonanoic acid, decanoic acid, oxalic acid, adipic acid, sebacic acid, butyric acid, oleic acid, stearic acid, linoleic acid, linoleic acid, salicylic acid, benzoic acid, p-
Aminobenzoic acid, p-toluenesulfonic acid, phthalic acid,
Organic acids such as sulfonic acid, tartaric acid and trifluoromethanesulfonic acid, and inorganic acids such as hydrochloric acid, phosphoric acid, nitric acid, boric acid, sulfuric acid and hydrofluoric acid can be used.

The amount of this catalyst used is preferably in the range of 0.0001 to 1 mol with respect to 1 mol of the compound represented by the formula (1). If the amount used exceeds 1 mol, gelation tends to be promoted during hydrolysis condensation, and if it is less than 0.0001 mol, the reaction tends to substantially not progress.

Further, in this reaction, alcohol by-produced by hydrolysis may be removed by using an evaporator or the like, if necessary. Furthermore, the amount of water to be present in the hydrolysis-condensation reaction system can be appropriately determined, but is preferably in the range of 0.5 to 20 mol with respect to 1 mol of the compound represented by the formula (1). . This amount of water is 0.5
If the amount is less than 20 moles or more than 20 moles, the film-forming property of the insulating film may be deteriorated and the storage stability of the composition itself may be deteriorated.

Further, the siloxane resin as the component (a) is measured by gel permeation chromatography (GPC) from the viewpoint of solubility in a solvent, mechanical properties, moldability and the like, and a calibration curve of standard polystyrene is used. The mass average molecular weight converted by the above is preferably 500 to 20,000, and more preferably 1,000 to 10,000. If the mass average molecular weight is less than 500, the film forming property of the insulating film tends to be poor. On the other hand, when the mass average molecular weight exceeds 20,000, the compatibility with the solvent tends to decrease.

The carbon content in the siloxane resin in the present invention must be 10% by mass or less, preferably 4 to 10% by mass, more preferably 4 to 9.5% by mass, and particularly preferably 4% by mass. Is 9 mass% or less. If the carbon content exceeds 10% by mass, the adhesiveness to the upper layer film, the mechanical strength of the interlayer insulating film, etc. tend to be significantly deteriorated. Also,
When the carbon content is less than 4% by mass, the electrical characteristics of the interlayer insulating film may be poor.

<Component (b)> The component (b) in the present invention is a solvent capable of dissolving the component (a), that is, the above-mentioned siloxane resin, and is, for example, methanol, ethanol, n.
-Propanol, i-propanol, n-butanol,
i-butanol, sec-butanol, t-butanol, n-pentanol, i-pentanol, 2-methylbutanol, sec-pentanol, t-pentanol, 3-methoxybutanol, n-hexanol, 2-
Methylpentanol, sec-hexanol, 2-ethylbutanol, sec-heptanol, n-octanol, 2-ethylhexanol, sec-octanol,
n-nonyl alcohol, n-decanol, sec-undecyl alcohol, trimethylnonyl alcohol, se
c-tetradecyl alcohol, sec-heptadecyl alcohol, phenol, cyclohexanol, methylcyclohexanol, benzyl alcohol, ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol. , Alcohols such as tripropylene glycol, acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, methyl-i-butyl ketone, methyl-n-
Pentyl ketone, methyl-n-hexyl ketone, diethyl ketone, di-i-butyl ketone, trimethylnonanone, cyclohexanone, cyclopentanone, methylcyclohexanone, 2,4-pentanedione, acetonylacetone, diacetone alcohol, acetophenone, γ −
Ketone-based solvent such as butyrolactone, ethyl ether, i
-Propyl ether, n-butyl ether, n-hexyl ether, 2-ethylhexyl ether, ethylene oxide, 1,2-propylene oxide, dioxolane,
4-methyldioxolane, dioxane, dimethyldioxane, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol diethyl ether, ethylene glycol mono-n-hexyl ether, ethylene glycol monophenyl ether, ethylene glycol mono-2-ethylbutyl ether, Ethylene glycol dibutyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol diethyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol di-n-butyl ether, diethylene glycol mono-n-hexyl ether, ethoxytriglycol, tetraethylene glycol di-n
-Ether solvents such as butyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, tripropylene glycol monomethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran , Methyl acetate, ethyl acetate, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, sec-butyl acetate, n-pentyl acetate, sec-pentyl acetate, 3-methoxybutyl acetate, methyl acetate Pentyl, 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methylcyclohexyl acetate, nonyl acetate,
γ-butyrolactone, γ-valerolactone, methyl acetoacetate, ethyl acetoacetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol mono-n-butyl ether acetate, acetic acid Propylene glycol monoethyl ether, propylene glycol monopropyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, glycol diacetate, methoxytriglycol acetate, ethyl propionate, n-butyl propionate, propionate i -Amyl, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate, n-lactate Examples include ester solvents such as butyl and n-amyl lactate, and solvents such as acetonitrile, N, N-dimethylformamide, N, N-dimethylacetamide and N, N-dimethylsulfoxide. These may be used alone or in combination of two or more.

Regarding the amount of the solvent (that is, the component (b)) used, the amount of the component (a) (siloxane resin) in the mixed solution of the component (a) and the component (b) is 5 to 25% by mass. Such an amount is preferable. When the amount of the solvent is too small and the concentration of the component (a) exceeds 25% by mass, the film forming property of the insulating film is deteriorated and the stability of the composition itself tends to be lowered. On the other hand, when the amount of the solvent is too large and the concentration of the component (a) is less than 5% by mass, it tends to be difficult to form an insulating film having a desired film thickness.

<Component (c)> The component (c) in the present invention is a diazabicyclo compound, such as 1.8-diazabicyclo [5.4.0] undec-7-ene and 1.5-diazabicyclo [4.3.0] nona-5. -Compounds such as ene.

The amount of these diazabicyclo compounds used is 500 with respect to the total amount of the composition for forming an interlayer insulating film.
It is preferably not more than ppm, and 0.01 ppm to 500
More preferably, it is 0.01 ppm-250.
More preferably, it is 0.1 ppm to 100 p.
More preferably, it is pm.

If the amount used exceeds 500 ppm, the film formability of the insulating film and the like tend to deteriorate, and the stability of the composition itself tends to deteriorate, and moreover, the electrical characteristics and process compatibility of the interlayer insulating film tend to deteriorate. Tends to be inferior. If the amount used is less than 0.01 ppm, the electrical properties and mechanical properties of the finally obtained interlayer insulating film tend to deteriorate in some cases. In addition, these diazabicyclo compounds can be added to a desired concentration after being dissolved in water or a solvent, if necessary.

According to the composition for forming an interlayer insulating film having such a component constitution, sufficient mechanical strength and low dielectric property are exhibited, and moreover, a silicon substrate and a SiO ₂ film such as P-TEOS are formed. An insulating film having excellent adhesiveness to both can be formed. Therefore, the electrical reliability can be improved and the CM
In the P step, the conventional problem that interface peeling occurs can be solved. The details of the mechanism by which such an effect that has not been achieved in the past is achieved, though there are still unclear points, but the dehydration condensation reaction is promoted by the diazabicyclo compound and the siloxane bond density is increased,
This is considered to be due to the mechanism that sufficient mechanical strength can be achieved and the residual silanol groups are reduced, so that the dielectric properties are improved. Furthermore, since the carbon content is 10% by mass or less, it is estimated that one of the factors is the high wettability. However, the action is not limited to these.

<Component (d)> The composition for forming an interlayer insulating film of the present invention preferably further contains the component (d). The component (d) is a thermal decomposition volatile compound that thermally decomposes or volatilizes at a heating temperature of 250 to 500 ° C.,
For example, a polymer having a polyalkylene oxide structure, a (meth) acrylate-based polymer, a polyester polymer, a polycarbonate polymer, a polyanhydride polymer, and tetrakissilanes may be mentioned.

Examples of the polyalkylene oxide structure include polyethylene oxide structure, polypropylene oxide structure, polytetramethylene oxide structure, polybutylene oxide structure, and the like. More specifically,
Polyoxyethylene alkyl ether, polyoxyethylene sterol ether, polyoxyethylene lanolin derivative, ethylene oxide derivative of alkylphenol formalin condensate, polyoxyethylene polyoxypropylene block copolymer, ether type compound such as polyoxyethylene polyoxypropylene alkyl ether, Ether ester type compounds such as polyoxyethylene glycerin fatty acid ester, polyoxyethylene sorbitol fatty acid ester, polyoxyethylene fatty acid alkanolamide sulfate, polyethylene glycol fatty acid ester, ethylene glycol fatty acid ester, fatty acid monoglyceride, polyglycerin fatty acid ester, sorbitan fatty acid ester , Ether such as propylene glycol fatty acid ester And the like Le type compound.

As the acrylic acid ester and methacrylic acid ester constituting the (meth) acrylate polymer, alkyl acrylate, methacrylic acid alkyl ester, acrylic acid alkoxyalkyl ester, methacrylic acid alkyl ester, methacrylic acid alkoxyalkyl are used. An ester etc. can be mentioned.

Examples of the alkyl acrylate include carbon acrylate such as methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, pentyl acrylate and hexyl acrylate. An alkyl ester of ~ 6,
Examples of the alkyl methacrylate include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, pentyl methacrylate,
Alkyl esters of 1 to 6 carbon atoms such as hexyl methacrylate, methoxymethyl acrylate and ethoxyethyl acrylate as alkoxyalkyl acrylate, and methoxymethyl methacrylate and ethoxyethyl methacrylate as methacrylic acid alkoxyalkyl ester. Is mentioned.

Furthermore, examples of the polyester include polycondensates of hydroxycarboxylic acids, ring-opening polymers of lactones, and polycondensates of aliphatic polyols with aliphatic polycarboxylic acids.

Further, as the polycarbonate,
Examples thereof include polycondensates of carbonic acid such as polyethylene carbonate, polypropylene carbonate, polytrimethylene carbonate, polytetramethylene carbonate, polypentamethylene carbonate and polyhexamethylene carbonate, and the like.

Further, as polyanhydride, polymalonyl oxide, polyadipoyl oxide,
Examples thereof include polycondensates of dicarboxylic acids such as polypimeyl oxide, polysuberoyl oxide, polyazelayl oxide, and polysebacyl oxide.

In addition, examples of tetrakissilanes include tetrakis (trimethylsiloxy) silane, tetrakis (trimethylsilyl) silane, tetrakis (methoxyethoxy) silane, tetrakis (methoxyethoxyethoxy) silane, and tetrakis (methoxypropoxy) silane. You can

Of these, the alkylene oxide structure is preferred from the viewpoints of compatibility with the siloxane resin of the component (c), solubility of the component (b) in a solvent, mechanical properties of the resulting insulating film, moldability and the like. It is preferable to use the compound, the acrylate polymer, or the tetrakissilanes.
In addition, gel permeation chromatography (GP
The mass average molecular weight measured by C) and converted using a calibration curve of standard polystyrene is 200 to 200,
It is preferably 000, and more preferably 200 to 15,000. This mass average molecular weight is 2000,
If it exceeds 000, the compatibility tends to decrease. On the other hand, when the mass average molecular weight is less than 200, it may be difficult to adjust the dielectric properties of the insulating film.

The amount of the component (d) used is preferably 0 to 200% by mass, more preferably 0 to 100% by mass, based on the siloxane resin contained in the composition. In addition, 0% of the (d) component means that the (d) component is not contained. If the amount used exceeds 200 mass%, the mechanical strength of the insulating film tends to decrease.

Further, if the thermally decomposable volatile compound as the component (d) is thermally decomposed or volatilized at a temperature lower than 250 ° C., it is thermally decomposed and volatilized before the formation of the siloxane skeleton, so that a desired dielectric property is obtained. May not be obtained. On the other hand, if the thermal decomposition volatile compound is thermally decomposed or volatilized at a temperature exceeding 500 ° C., the wiring metal may be deteriorated. Therefore, if it is thermally decomposed or volatilized in such a temperature range, there is an advantage that the dielectric characteristics of the insulating film can be easily adjusted while suppressing the deterioration of the wiring metal.

The composition for forming an interlayer insulating film of the present invention preferably has a halogen ion concentration of 10 ppm or less, more preferably 5 ppm or less. If this concentration exceeds 10 ppm, wiring corrosion may occur due to residual ions remaining in the insulating film.

The composition for forming an interlayer insulating film of the present invention preferably does not contain an alkali metal or an alkaline earth metal, but even when it is contained, the metal ion concentration in the composition is 100 ppb or less. Preferably
It is more preferably 20 ppb or less. If the concentration of these metal ions exceeds 100 ppb, the metal ions may easily flow into the semiconductor element, which may adversely affect the device performance itself. Therefore, it is effective to remove an alkali metal or an alkaline earth metal from the composition by using an ion exchange filter or the like, if necessary.

As a method of forming an interlayer insulating film on a substrate using the composition for forming an interlayer insulating film of the present invention, a spin coating method which is excellent in film forming property and film uniformity of the interlayer insulating film is generally used. Take for example. First, the composition for forming an interlayer insulating film is preferably applied on a substrate such as a silicon wafer at 500 to 5000 revolutions / minute, more preferably 1000 to 5000 rpm.
A coating is formed by spin coating at 3000 rpm. At this time, if the rotation speed is less than 500 rotations / minute, the film uniformity tends to deteriorate, whereas if it exceeds 5000 rotations / minute, the film formability may deteriorate, which is not preferable.

Next, the solvent in the coating is dried on a hot plate or the like at preferably 50 to 300 ° C., more preferably 100 to 250 ° C. If this drying temperature is lower than 50 ° C, the solvent is not sufficiently dried. On the other hand, when the drying temperature exceeds 300 ° C., the pyrolytic volatile compound ((d) component) for forming the pores is pyrolytically volatilized before the siloxane skeleton is formed in the coating film, and the desired low dielectric properties are obtained. It may be difficult to obtain the inter-layer insulating film.

Next, the coating film from which the solvent has been removed is applied to 300 to 5 parts.
Final baking is performed by firing at a heating temperature of 00 ° C. The final curing is preferably carried out in an inert atmosphere of N ₂ , Ar, He or the like, and in this case, the oxygen concentration is preferably 1000 ppm or less. If the heating temperature is less than 300 ° C, sufficient curing tends not to be achieved. On the other hand, if the heating temperature exceeds 500 ° C., the amount of heat input may increase and the wiring metal may deteriorate if there is a metal wiring layer. The heating time at this time is preferably 2 to 60 minutes. If the heating time exceeds 60 minutes, the thermal budget may excessively increase and the wiring metal may deteriorate. Further, as a heating device, a quartz tube furnace or other furnace, a hot plate, a rapid thermal anneal (R
It is preferable to use a heat treatment device such as TA).

The film thickness of the interlayer insulating film thus formed is preferably 0.01 to 40 μm, and more preferably 0.1 to 2.0 μm. When the film thickness exceeds 40 μm, cracks are likely to occur due to stress, while when it is less than 0.01 μm, the leak characteristic between the upper and lower wirings tends to deteriorate.

The electronic component of the present invention having such an interlayer insulating film may be a device having an insulating film such as a semiconductor element or a multilayer wiring board. Specifically, as semiconductor elements, individual semiconductors such as diodes, transistors, compound semiconductors, thermistors, varistors, and thyristors, DRAMs
(Dynamic Random Access Memory), S
RAM (Static Random Access Memory), EPROM (Erasable Programmable Read Only Memory), Mask ROM (Mask
Read only memory), EEPROM (electrical erasable programmable read only memory), memory device such as flash memory, microprocessor, DSP, theoretical circuit device such as ASIC, MMIC (monolithic microwave integrated circuit) Examples thereof include integrated circuit elements such as compound semiconductors, hybrid integrated circuits (hybrid ICs), light emitting diodes, photoelectric conversion elements such as charge-coupled elements, and the like. Examples of the multilayer wiring board include high density wiring boards such as MCM.

By including the interlayer insulating film of the present invention, such an electronic component can achieve high performance such as reduction of signal propagation delay time and at the same time high reliability.

[0054]

EXAMPLES Hereinafter, specific examples according to the present invention will be described, but the present invention is not limited thereto.

Example 1 Tetraethoxysilane 49.
0 g and 47.2 g of methyltriethoxysilane were dissolved in 194.3 g of propylene glycol monopropyl ether, and 28.1 g of water in which 0.26 g of 70% nitric acid was dissolved was added dropwise over 30 minutes with stirring. did. After completion of dropping, reaction was carried out for 5 hours to obtain a polysiloxane solution. To this solution was added 68.4 g of a 20% polymethylmethacrylate / γ-butyrolactone solution, and the produced ethanol was distilled off in a warm bath under reduced pressure to obtain 350 g of a polysiloxane / polymethylmethacrylate solution. The solution was then added with 1.8-diazabicyclo [5.4.0] undec-7-ene 0.0.
35 g was added to prepare an interlayer insulating film forming composition.

Example 2 Tetraethoxysilane 60.
Into a solution prepared by dissolving 5 g and 37.3 g of methyltriethoxysilane in 187.8 g of propylene glycol monopropyl ether, 29.3 g of water in which 0.27 g of 70% nitric acid was dissolved was added dropwise over 30 minutes with stirring. did. After completion of dropping, reaction was carried out for 5 hours to obtain a polysiloxane solution. To this solution was added 67.5 g of a 20% polymethylmethacrylate / γ-butyrolactone solution, and the produced ethanol was distilled off in a warm bath under reduced pressure to obtain 340 g of a polysiloxane / polymethylmethacrylate solution. The solution was then added with 1.8-diazabicyclo [5.4.0] undec-7-ene 0.0.
34 g was added to prepare a composition for forming an interlayer insulating film.

Example 3 Tetraethoxysilane 82.
Into a solution prepared by dissolving 8 g and 18.3 g of methyltriethoxysilane in 175.3 g of propylene glycol monopropyl ether, 30.7 g of water in which 0.29 g of 70% nitric acid was dissolved was added dropwise under stirring over 30 minutes. did. After completion of dropping, reaction was carried out for 5 hours to obtain a polysiloxane solution. To this solution, 65.8 g of a 20% polymethylmethacrylate / γ-butyrolactone solution was added, and the produced ethanol was distilled off in a warm bath under reduced pressure to obtain 330 g of a polysiloxane / polymethylmethacrylate solution. The solution was then added with 1.8-diazabicyclo [5.4.0] undec-7-ene 0.0.
33 g was added to prepare a composition for forming an interlayer insulating film.

Comparative Example 1 Tetraethoxysilane 22.
Into a solution prepared by dissolving 9 g and 69.5 g of methyltriethoxysilane in 208.9 g of propylene glycol monopropyl ether, 26.1 g of water in which 0.24 g of 70% nitric acid was dissolved was added dropwise over 30 minutes under stirring. did. After completion of dropping, reaction was carried out for 5 hours to obtain a polysiloxane solution. To this container was added 70.2 g of a 20% polymethylmethacrylate / γ-butyrolactone solution, and the produced ethanol was distilled off in a warm bath under reduced pressure to obtain 360 g of a polysiloxane / polymethylmethacrylate solution. Then in this solution
1.8-diazabicyclo [5.4.0] undec-7-ene 0.36
g was added to prepare a composition for forming an interlayer insulating film.

[Measurement of Halogen Ion Concentration] Examples 1 to 3
And 50 g of each composition for forming an interlayer insulating film obtained in Comparative Example 1 was taken out into a 100 cc beaker, and a silver nitrate aqueous solution (0.1
%) By the potentiometric titration method.

[Measurement of metallic impurities] AA-6 manufactured by Shimadzu Corporation
650G was used to measure the Na ion and K ion contents in the respective interlayer insulating film forming compositions obtained in Examples 1 to 3 and Comparative Example 1.

<Production of Interlayer Insulating Film> Each of the compositions for forming an interlayer insulating film obtained in Examples 1 to 3 and Comparative Example 1 was rotated at a rotational speed of 150.
A coating was formed by spin coating on a silicon wafer at 0 rpm / 30 seconds. After spin coating, 150 ℃ / 1min + 250 ℃
After removing the solvent in the coating over 1 minute, the O ₂ concentration was 1
The coating film was finally cured in a quartz tube furnace controlled to about 00 ppm at 400 ° C./30 minutes to produce an interlayer insulating film. After the formation, the film thickness of each interlayer insulating film was measured by a spectroscopic ellipsometer (working wavelength: 633 nm).

<Evaluation of Interlayer Insulating Film> The electrical characteristics and film strength of each interlayer insulating film obtained by the above-mentioned <Production of interlayer insulating film> were evaluated by the following methods.

[Measurement of relative permittivity] An aluminum film was formed on each interlayer insulating film to a thickness of 0.1 μm by a vacuum vapor deposition method, and the relative permittivity of this sample was measured with an LF impedance meter at a frequency of 10 kHz.

[Measurement of Elastic Modulus] MT for each interlayer insulating film
A nanoindenter DCM manufactured by S Co. was used to measure the elastic modulus indicating the film strength.

[Single film CMP resistance] For each interlayer insulating film,
CMP polishing was performed under the condition that the interlayer insulating film was not polished. HS-C430 manufactured by Hitachi Chemical Co., Ltd. was used as the slurry, and the applied load was 400 gf / cm ^2.
Polishing was carried out for 1 minute to examine whether or not the insulating film remained. In the case where the insulating film remains, it means that the film has sufficient strength. In Table 1 described later, when there is no problem, "○" is shown and cohesive failure of the insulating film is recognized. The case was judged as'x '.

[Laminated film CMP resistance] C on each interlayer insulating film
After 0.1 μm of P-TEOS film is laminated by VD method, 0.03 μm of Ta metal and 0.2 μm of Cu metal are laminated by sputtering method, and then CMP is performed under the same conditions as the above [single film CMP resistance]. Polished. This is polishing under the condition that only Cu is polished, and when Ta metal remains on the surface of the insulating film after polishing, it indicates that the interfacial peeling between the CVD film / SOG film does not occur. There is. Therefore, in Table 1 to be described later, when the Ta metal surface was obtained on almost the entire surface, "○" was given, and interfacial delamination between the CVD film / SOG film or cohesive failure caused by insufficient film strength was recognized. The case was judged as'x '.

Table 1 summarizes the above measurement results and evaluation results.

[0068]

[Table 1]

[0069]

As described above, according to the composition for forming an interlayer insulating film and the method for manufacturing an interlayer insulating film of the present invention, sufficient mechanical strength, low dielectric property, silicon substrate and P An insulating film having excellent adhesiveness to both SiO ₂ films such as TEOS can be easily formed, and the insulating film and thus the electrical reliability of the device can be improved. Further, as a result, the yield of product production can be improved and the process margin can be increased. Further, according to the electronic component of the present invention, since the insulating film having such excellent characteristics is provided, the electronic component has high density, high quality, and excellent reliability.

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01L 21/768 H01L 21/90 S (72) Inventor Shigeru Nobe 4-13-1, Higashimachi, Hitachi City, Ibaraki Hitachi Seisaku Kogyo Co., Ltd. Yamazaki Plant (72) Inventor Kazuhiro Enomoto 4-13-1, Higashi-cho, Hitachi City, Ibaraki Prefecture Hitachi Chemical Co., Ltd. Yamazaki Plant (72) Inventor, Haraaki Sakurai 4-chome, Higashi-cho, Hitachi City, Ibaraki Prefecture No. 1 Hitachi Chemical Co., Ltd. Yamazaki Works F-term (reference) 4F071 AA33 AA43 AA50 AA51 AA67 AC05 AC06 AC07 AC10 AC12 AE19 AF39 BA02 BB02 BC02 4J002 BG04X BH02X CF00X CG01X CG02X CH02X CP03W EU11 HFD3H01206HFD3H01206FFD3 H01206F3H21H06HFD3H015 QQ48 RR23 RR25 SS22 WW03 WW04 XX12 XX17 XX24 5F058 AA08 AC03 AF04 AG01 AH02

Claims (7)

[Claims] 1. A component (a): the following formula (1); R _n SiX _4-n (1), (wherein R represents a hydrogen atom or an organic group having 1 to 20 carbon atoms, and X represents a hydrolyzed group). Represents a decomposable group, n represents an integer of 0 to 2, when n is 2, each R may be the same or different, and when n is 0 to 2, each X may be the same or different. Good), obtained by hydrolysis and condensation of a compound represented by
A composition for forming an interlayer insulating film, which contains a siloxane resin having a carbon content of 10% by mass or less, a component (b): a solvent capable of dissolving the component (a), and a component (c): a diazabicyclo compound. object. 2. The composition for forming an interlayer insulating film according to claim 1, wherein the concentration of the component (c) is 500 ppm or less. 3. The composition for forming an interlayer insulating film according to claim 1, further comprising a component (d): a thermal decomposition volatile compound which thermally decomposes or volatilizes at a heating temperature of 250 to 500 ° C. 4. The composition for forming an interlayer insulating film according to claim 1, wherein the halogen ion concentration is 10 ppm or less. 5. The composition for forming an interlayer insulating film according to claim 1, wherein the alkali metal ion concentration and the alkaline earth metal ion concentration are each 100 ppb or less. 6. A coating film is formed by applying the composition for forming an interlayer insulating film according to claim 1 on a substrate, removing the solvent contained in the coating film, and then forming the coating film. 30
A method for producing an interlayer insulating film, which comprises firing at a heating temperature of 0 to 500 ° C. 7. An electronic component having an interlayer insulating film manufactured by the method for manufacturing an interlayer insulating film according to claim 6 on a substrate.