JP2001262062A - Coating liquid for forming silica coating film, preparation process of silica coating film, silica coating film, semiconductor element using the film and multi-layer wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a silica film-forming coating liquid which shows a high film-forming property and may form a silica film having a low dielectric constant and a preparation process of a silica film using the coating liquid. SOLUTION: Silica coating liquids (II) and (IV) each contains a polysiloxane which is a polymer obtained by hydrolyzing and polycondensing an alkoxysilane of formula (I): R1nSi(OR2)4-n and formula (III): R3nSi(OR4)4-n (wherein R1 and R3 are each a 1-6C alkyl or aryl group, R2 and R4 are each a 1-4C alkyl group; and n is an integer of 0-2), respectively, with a number of carbons per 1 unit silicon of <=0.3 and >=0.6, respectively, and a solvent. A silica coating liquid comprises a combination of there. In the preparation process of the coating film, this liquid is used. A semiconductor element and a multilayer wiring board are prepared using this coating film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating solution for forming a silica-based coating, a method for producing a silica-based coating, a silica-based coating, a semiconductor device using the same, and a multilayer wiring board. The present invention relates to a coating solution for forming a silica-based coating, a method for producing a silica-based coating using the same, a silica-based coating, a semiconductor device, and a multilayer wiring board.

[0002]

2. Description of the Related Art With the miniaturization of wiring due to the high integration of LSIs, an increase in signal delay time due to an increase in capacitance between wirings has become a problem. Conventionally, a SiO ₂ film formed by a CVD method having a relative dielectric constant of about 4.3 has been used as an interlayer insulating film.
In order to improve the operation speed of the device, a film having a lower dielectric constant is required. Low dielectric constant films that are currently in practical use include:
An example is an SiOF film (CVD method) having a relative dielectric constant of about 3.5. As an insulating film having a relative dielectric constant of 3.0 or less, organic SO
G (Spin On Glass) is considered to be influential, and studies for applying it to an interlayer insulating film of LSI are being actively conducted.

The characteristics required for a low dielectric constant film applied to an interlayer insulating film of an LSI include characteristics such as heat resistance, plasma resistance, and adhesion between different types of interlayer insulating films. In a multi-layer wiring process of a miniaturized LSI, a CMP (Chemical Mechanical) is used for global flattening.
An ical polishing process is indispensable, and the adhesiveness between different kinds of interlayer insulating films is a particularly important characteristic. Specifically, when an organic SOG is used as an interlayer insulating film, a stacked structure of a conventional SiO ₂ film and a SiN film is required. Therefore, the adhesion between the insulating film formed by the CVD and the organic SOG is low. is necessary. Relative dielectric constant 3.0
Organic SO which is considered to be effective as the following low dielectric constant film
G denotes an SiO ₂ film formed by conventional CVD, or SiOF
Although the dielectric constant is lower than that of the film, the adhesiveness between different kinds of interlayer insulating films is weak.

[0004] In the CMP process, a characteristic that the adhesion between different kinds of interlayer insulating films has an effect is peeling due to stress in the CMP process. In this regard, in order to achieve high yield and high reliability, adhesiveness between the CVD film and the organic SOG film is strongly desired.

On the other hand, as a method of improving the adhesiveness of an organic SOG film, a method of improving the adhesiveness with a CVD film by making the surface inorganic is described in IEDM Technology D.
egest, 26.3.1 (1999). However, the method of performing the surface treatment is an organic SO
Due to an increase in outgassing due to the decomposition of the organic component of the G film, there arise problems such as an increase in the dielectric constant and a decrease in leak characteristics. Furthermore, the surface treatment method has a problem that there is no margin for peeling between the CVD film and the organic SOG film due to stress during the CMP process. A method of improving adhesion by roughening the surface of an interlayer insulating film layer with an etchant is disclosed in Japanese Patent Application Laid-Open No. 11-679.
Although it is proposed in Japanese Patent Publication No. 00 and the like, peeling may occur between the organic SOG film and the CVD film depending on the load in the CMP process.

[0006]

SUMMARY OF THE INVENTION The present invention eliminates the above-mentioned disadvantages of the prior art and improves the adhesiveness of a coating solution for forming a silica-based film, a method for producing the same, a silica-based film having a low dielectric constant, It is intended to provide a semiconductor device and a multilayer wiring board having high performance.

[0007]

The present invention relates to (A) a compound represented by the general formula (I):

[0008]

Embedded image _{^{R 1 n Si (OR 2)}} 4-n (I)

Wherein R ¹ is an alkyl or aryl group having 1 to 6 carbon atoms, R ² is an alkyl group having 1 to 4 carbon atoms, n
Is an integer of 0 to 2, and a plurality of R ¹ and R ² may be the same or different), and is produced by hydrolytic condensation polymerization of an alkoxysilane represented by
A coating liquid for forming a silica-based film containing a polysiloxane having a carbon number per unit of 0.3 units or less and a solvent (II), and (B) a general formula (III)

[0010]

Embedded image R ³ _n Si (OR ⁴ ) _4-n (III)

Wherein R ³ is an alkyl or aryl group having 1 to 6 carbon atoms, R ⁴ is an alkyl group having 1 to ⁴ carbon atoms, n
Is an integer of 0 to 2, and a plurality of R ³ and R ⁴ may be the same or different.)
The present invention relates to a coating solution for forming a silica-based film, comprising a combination of a coating solution (IV) for forming a silica-based film containing a polysiloxane having a carbon number of 0.6 unit or more per unit and a solvent. In the present invention, the silica-based coating liquid (IV) is coated on a substrate, dried at 50 to 350 ° C., and then coated with a silica-based coating liquid (II).
After drying at 0 to 350 ° C., it is further dried under nitrogen atmosphere for 200 hours.
The present invention relates to a method for producing a silica-based coating which is cured by heating at a temperature of from about 600 ° C. The present invention also relates to a silica-based coating obtained by this method, a semiconductor device and a multilayer wiring board using the silica-based coating. The number of carbon atoms per unit of silicon means the number of carbon atoms per silicon atom in the product polysiloxane.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The alkoxysilane represented by the general formulas (I) and (III) is specifically described below.

[0013]

Embedded image Si (OCH ₃ ) ₄ , Si (OC ₂ H ₅ ) ₄ ,
Si (OC ₃ H ₇ ) ₄ , Si (OC ₄ H ₉ ) ₄

A tetraalkoxysilane such as

[0015]

Embedded image CH ₃ Si (OCH ₃ ) ₃ , C ₂ H ₅ Si (O
CH ₃ ) ₃ , C ₃ H ₇ Si (OCH ₃ ) ₃ , C ₄ H ₉ S
i (OCH ₃ ) ₃ , C ₆ H ₅ Si (OCH ₃ ) ₃ , C ₆
H ₁₁ Si (OCH ₃ ) ₃ , CH ₃ Si (OC
_{2 H 5) 3, C 2} H 5 Si (OC 2 H 5) 3, C 3 H 7
Si (OC ₂ H ₅ ) ₃ , C ₄ H ₉ Si (OC
_{2 H 5) 3, C 6} H 5 Si (OC 2 H 5) 3, C 6 H 11
Si (OC ₂ H ₅ ) ₃ , CH ₃ Si (OC ₃ H ₇ ) ₃ ,
C ₂ H ₅ Si (OC ₃ H ₇ ) ₃ , C ₃ H ₇ Si (OC _{3
H 7) 3, C 4 H} 9 Si (OC 3 H 7) 3, C 6 H 5 S
i (OC ₃ H ₇ ) ₃ , C ₆ H ₁₁ Si (OC ₃ H ₇ ) ₃ ,
CH ₃ Si (OC ₄ H ₉ ) ₃ , C ₂ H ₅ Si (OC ₄ H
_{9) 3, C 3 H 7} Si (OC 4 H 9) 3, C 4 H 9 Si
(OC ₄ H ₉ ) ₃ , C ₆ H ₅ Si (OC ₄ H ₉ ) ₃ , C
₆ H ₁₁ Si (OC ₄ H ₉ ) ₃

A monoorgano trialkoxysilane such as

[0017]

Embedded image (CH ₃ ) ₂ Si (OCH ₃ ) ₂ , (C
_{2 H 5) 2 Si (OCH} 3) 2, (C 3 H 7) 2 Si
(OCH ₃ ) ₂ , (C ₄ H ₉ ) ₂ Si (OCH ₃ ) ₂ ,
(C ₆ H ₅ ) ₂ Si (OCH ₃ ) ₂ , (C ₆ H ₁₁ ) ₂ S
i (OCH ₃ ) ₂ , (CH ₃ ) ₂ Si (OC
_{2 H 5) 2, (C} 2 H 5) 2 Si (OC 2 H 5) 2,
(C ₃ H ₇ ) ₂ Si (OC ₂ H ₅ ) ₂ , (C ₄ H ₉ ) ₂ Si
(OC ₂ H ₅ ) ₂ , (C ₆ H ₅ ) ₂ Si (OC ₂ H ₅ )
₂ , (C ₆ H ₁₁ ) ₂ Si (OC ₂ H ₅ ) ₂ , (CH ₃ )
₂ Si (OC ₃ H ₇ ) ₂ , (C ₂ H ₅ ) ₂ Si (OC _{3
H 7) 2, (C 3} H 7) 2 Si (OC 3 H 7) 2, (C
_{4 H 9) 2 Si (OC} 3 H 7) 2, (C 6 H 5) 2 Si
(OC ₃ H ₇ ) ₂ , (C ₆ H ₁₁ ) ₂ Si (OC ₃ H ₇ )
₂ , (CH ₃ ) ₂ Si (OC ₄ H ₉ ) ₂ , (C ₂ H ₅ )
₂ Si (OC ₄ H ₉ ) ₂ , (C ₃ H ₇ ) ₂ Si (OC _{4
H 9) 2, (C 4} H 9) 2 Si (OC 4 H 9) 2, (C
_{6 H 5) 2 Si (OC} 4 H 9) 2, (C 6 H 11) 2 Si
(OC ₄ H ₉ ) ₂

And the like. One or more of these may be used.

As the alkoxysilane represented by the general formula (I) used in the present invention, the mixing ratio of tetraalkoxysilane, monoorganotrialkoxysilane and diorganodialkoxysilane is expressed by the number of carbon atoms per unit of silicon. In order to reduce the amount to 0.3 units or less, the content of the tetraalkoxysilane needs to be 70% by mole or more, and preferably 90% by mole or more.

As the alkoxysilane represented by the general formula (III) used in the present invention, the mixing ratio of tetraalkoxysilane, monoorganotrialkoxysilane and diorganodialkoxysilane is expressed by the number of carbon atoms per unit of silicon. It must be 0.6 units or more. Further, in order to make the relative dielectric constant 3.0 or less, the mixing ratio of tetraalkoxysilane needs to be 50 mol% or less, and preferably 40 mol% or less. Further, in order to improve the film forming property, the compounding ratio of diorganodialkoxysilane needs to be 50 mol% or less, and preferably 20 mol% or less.

It is preferable to use an organic solvent as a solvent in the coating solution (II) for forming a silica-based film in the present invention. Examples of the organic solvent include alcohols such as methanol, ethanol, propanol and butanol, methyl acetate,
Ethyl acetate, propyl acetate, butyl acetate and other acetic acid ester solvents, ethylene glycol monomethyl acetate, ethylene glycol diacetate and other glycol acetate solvents, glycol ether solvents and the like, and one or more of these solvents are used. . The amount of solvent used is
In order to obtain the function as an adhesive and maintain the dielectric constant, the thickness of the silica-based coating is preferably 100 nm or less, and the amount of the polysiloxane obtained by the above reaction is 1 to 10% by weight. It is preferable that the amount be as follows.

In the present invention, an organic solvent is preferably used as a solvent in the coating solution (IV) for forming a silica-based film. Examples of the organic solvent include alcohols such as methanol, ethanol, propanol and butanol, methyl acetate,
Ethyl acetate, propyl acetate, butyl acetate and other acetic acid ester solvents, ethylene glycol monomethyl acetate, ethylene glycol diacetate and other glycol acetate solvents, glycol ether solvents and the like, and one or more of these solvents are used. . The amount of solvent used is
It is preferable that the amount of the polysiloxane obtained by the above reaction is 5 to 25% by weight. If the amount of the polysiloxane is too large, it is not preferable in terms of stability and film formability. If the amount is too small, it is difficult to obtain a desired film thickness, which is not preferable.

In preparing the silica-based coating liquids (II) and (IV) for use in the present invention, an organic acid such as formic acid, maleic acid, fumaric acid, acetic acid and hydrochloric acid may be used as a catalyst for accelerating the hydrolysis-condensation reaction. And inorganic acids such as phosphoric acid, nitric acid, boric acid and sulfuric acid. This catalyst is used in an appropriate amount depending on the amount of the alkoxysilane compound as a raw material, but is preferably in the range of 0.001 to 1 mol per 1 mol of the alkoxysilane. If the amount is more than the predetermined amount, gelation is promoted, which is not preferable. If the amount is less than the predetermined amount, the polymerization reaction does not proceed, which is not preferable.

In producing the silica-based coating solution (II) or (IV) in the present invention, the amount of water for promoting the hydrolysis-condensation reaction is also determined appropriately. From the viewpoint of storage stability, the amount of water is preferably in the range of 50 to 800 mol% based on the alkoxysilane represented by the general formula (I) or (III).

The coating solution (IV) for forming a silica-based film in the present invention contains a porous material such as polyvinyl acetate, polymethyl methacrylate, or polyacrylic acid in order to realize a low dielectric constant such as a relative dielectric constant of 3.0 or less. A forming material may be contained. The porous forming material is preferably a component which volatilizes in a heating step at 200 to 600 ° C. which is performed in a final step of forming a silica-based coating.

In the present invention, when a silica-based film is formed, spin coating is mainly used in consideration of film forming properties and film uniformity. As a method for forming a silica-based coating using a spin coating method, first, a coating solution for forming a silica-based coating (IV)
On the substrate at 500 to 5000 revolutions / minute, preferably 1
Spin-coat at 000-3000 revolutions / minute. If the number of revolutions in spin coating is too low, the film uniformity tends to decrease, and if it is too high, the film forming properties tend to decrease. Further, the thickness of the film to be formed is preferably 0.2 μm to 2 μm, and it is also possible to perform recoating to a predetermined thickness. If the film thickness is large, it is not preferable because cracks occur in the coating film, and if the film thickness is small, it is not preferable because sufficient dielectric constant characteristics cannot be obtained.

Then, at 50-350 ° C., preferably 150
Dry the solvent on a hot plate at ~ 250 ° C. If the drying temperature is too low, the solvent is not sufficiently dried, which is not preferable. If the drying temperature is too high, the wettability of the coating liquid (II) for forming a silica-based film is unpreferably reduced.

Next, a coating solution for forming a silica-based film (II)
From 500 to 5000 revolutions / minute, preferably from 1000 to
Spin coating is performed at 3000 rpm. If the number of rotations in the spin coating is too low, the film uniformity decreases, and if it is too high, the film-forming properties deteriorate, which is not preferable.

Next, the solvent is dried at 50 to 350 ° C. on a hot plate. If the drying temperature is too low, the solvent is not sufficiently dried, which is not preferable. Further, it is cured by heating at 200 to 600 ° C., preferably 350 to 450 ° C. in a nitrogen atmosphere to produce a silica-based coating. In the case of curing, an apparatus capable of batch processing such as an electric furnace or a vertical furnace is preferable.
If the heat curing temperature is too low, the polymerization of the silica-based coating is not sufficient and dielectric properties cannot be obtained, and if the heat curing temperature is too high, organic components in the silica-based coating are decomposed to increase the dielectric constant and increase the device. Is not preferred because it causes a decrease in the reliability of the device. The oxygen concentration during curing must be 0.1% by volume or less, and preferably 0.01% by volume or less. If the oxygen concentration is high, the organic components contained in the silica-based coating are decomposed, which leads to an increase in the dielectric constant and a decrease in the reliability of the device, which is not preferable.

By adapting the silica-based coating produced according to the present invention as an interlayer insulating film of a semiconductor device and a multilayer wiring board, excellent properties such as a low dielectric constant, preferably a low dielectric constant of 3.5 or less and a high insulation resistance are obtained. High performance such as reduction of electrical characteristics and signal propagation delay time can be achieved.

The semiconductor element in the present invention includes a diode, a transistor, a compound semiconductor, an individual semiconductor such as a thermistor, a varistor, and a thyristor, a DRAM (Dynamic Random Access Memory), an SRAM (Static Random Access Memory), EPR
OM (Erasable Programmable, Read Only Memory), Mask ROM (Mask Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), storage elements such as flash memory, microprocessor, Theoretical circuit elements such as DSP and ASIC,
MMIC (monolithic microwave integrated circuit)
And a photoelectric conversion element such as a light-emitting diode and a charge-coupled device.

The multilayer wiring board in the present invention includes a high-density wiring board such as an MCM. By applying a coating film formed from the composition of the present invention as an interlayer insulating film, high reliability can be achieved at the same time as high performance such as reduction of signal propagation delay time as described above.

[0033]

The present invention will be described below in more detail with reference to Production Examples and Examples. 1. Production of Coating Solution (IV) for Forming Silica-based Film As coating solution (IV) for forming silica-based film, 1 to 5 shown in Table 1 were produced.

[0034]

[Table 1]

The alkoxysilane shown in Table 1 is dissolved in a solvent so as to have a predetermined resin concentration, and ionic water corresponding to the number of moles of the alkoxy group of the alkoxysilane and a catalyst corresponding to 1/200 mole of ionic water are used. Was added dropwise over one hour, and reacted at room temperature for 24 hours to produce a silica-based coating liquid (IV). 2. Manufacture of coating liquid (II) for forming silica-based coating

[0036]

[Table 2]

The alkoxysilane shown in Table 2 was dissolved in a solvent so as to have a predetermined resin concentration, and ionic water corresponding to the number of moles of the alkoxy group of the alkoxysilane and a catalyst corresponding to 1/200 mole of the ionic water were used. After the mixture was added dropwise over 1 hour, the mixture was reacted at room temperature for 24 hours to prepare a coating liquid (II) for forming a silica-based film. 3. Production of silica-based coating film Coating solution 1 for forming a silica-based film thus obtained
5 (IV) was spin-coated on a silicon wafer at 2,000 rpm using a spinner, and the solvent for the silica-based coating was dried on a hot plate at 250 ° C. Next, the coating liquids 1 to 5 (II) for forming a silica-based film were prepared by using a spinner in the same manner as above.
Spin coating was performed at 00 revolutions / minute, and the solvent for the silica-based coating was dried on a hot plate at 250 ° C. Next, it was put into a quartz furnace, heated from room temperature to 400 ° C. in nitrogen at a heating temperature of 30 ° C./min, and baked at the same temperature for 30 minutes. A laminated film was obtained.
When the film thickness of the coating was measured, all of the measured values were 0.4 to 0.6.
μm. 1 μm of aluminum coating on this coating
And the dielectric constant of this sample is set to LF.
Frequency 1 kHz to 100 using an impedance meter
When measured at kHz, the dielectric constants shown in Table 3 were obtained, and all samples showed values of 3.5 or less.

[0038]

[Table 3]

Next, an SiO ₂ coating, which is a polymer of tetraethoxysilane, was formed on the silica coating by a gas phase reaction polymerization method. After making a 3 mm square scratch on the film in a grid pattern, a cellophane tape peeling test was performed. The SiO ₂ film formed by the gas phase reaction polymerization method and the silica-based coating liquid (II) were used. The peeling between the formed silica-based coating and the silica-based coating resulted in the results shown in Table 4. The coating liquid (II) for silica-based coating had a carbon number of 0.3 with respect to 1 unit of silicon.
Peeling was observed in 4 samples exceeding the unit, but peeling at the interface was not observed in other silica-based coatings.

[0040]

[Table 4]

Comparative Example 2 133 g of methyltrimethoxysilane (0.974 mol)
l) was dissolved in 263 g of isopropanol, and a solution of 2.02 g of phosphoric acid dissolved in 51.5 g (2.86 mol) of water was added dropwise to this solution over 30 minutes with stirring. After stirring for 5 hours after the completion of the dropwise addition, a polysiloxane solution was obtained. The coating solution for forming a silica-based film thus obtained is spin-coated on a silicon wafer at 2,000 rpm using a spinner, and then placed in a quartz furnace and heated in nitrogen at 30 ° C./minute. The temperature was raised from room temperature to 400 ° C. at the same temperature, and the mixture was baked at the same temperature for 30 minutes to obtain a colorless, transparent, crack-free silica coating. The thickness of the film was measured and found to be 0.4 μm. The surface of the silica-based coating thus obtained was irradiated with a mercury lamp for 5 minutes to mineralize organic components on the surface. An aluminum coating is placed on this coating.
The thickness of the sample was formed by a sputtering method, and the dielectric constant of this sample was measured with an LF impedance meter at a frequency of 1 kHz to 100 k.
When measured at Hz, the dielectric constant was 4.2.

Comparative Example 3 133 g of methyltrimethoxysilane (0.974 mol)
l) was dissolved in 263 g of isopropanol, and a solution of 2.02 g of phosphoric acid dissolved in 51.5 g (2.86 mol) of water was added dropwise to this solution over 30 minutes with stirring. After stirring for 5 hours after the completion of the dropwise addition, a polysiloxane solution was obtained. The coating solution for forming a silica-based film thus obtained is spin-coated on a silicon wafer at 2,000 rpm using a spinner, and then placed in a quartz furnace and heated in nitrogen at 30 ° C./minute. The temperature was raised from room temperature to 400 ° C. at the same temperature, and the mixture was baked at the same temperature for 30 minutes to obtain a colorless, transparent, crack-free silica coating. The thickness of the film was measured and found to be 0.4 μm. The silica-based coating thus obtained was subjected to a step of surface roughening using an alkali / permanganate type etching solution (potassium permanganate 45 g / liter). An aluminum film was formed on this film to a thickness of 1 μm by sputtering, and the dielectric constant of this sample was measured at a frequency of 1 kHz using an LF impedance meter.
It was 3.3 when measured at z-100kHz.
Next, an SiO ₂ coating, which is a polymer of tetraethoxysilane, was formed on the silica coating by a gas phase reaction polymerization method. After making a 3 mm square scratch on the film in a grid pattern, a cellophane tape peeling test was performed. The SiO ₂ film formed by the gas phase reaction polymerization method and the silica-based coating liquid (II) were used. Peeling from the formed silica-based coating was observed.

[0043]

According to the present invention, it is possible to form a silica-based coating having good film-forming properties and a low dielectric constant. Further, the coating liquid for forming a silica-based film according to the present invention makes it possible to produce a semiconductor element and a multilayer wiring board having excellent dielectric constant and heat-resistant properties and excellent reliability. As a result, the dielectric constant characteristics of the laminated film can be obtained, and it becomes possible to manufacture a semiconductor element and a multilayer wiring board that meet the demand for high-speed operation.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shigeru Nobe 4-3-1 Higashicho, Hitachi City, Ibaraki Prefecture Inside the Hitachi Chemical Co., Ltd. Yamazaki Office (72) Inventor Nobuko Terada 4-chome Higashicho, Hitachi City, Ibaraki Prefecture No. 1 Hitachi Chemical Co., Ltd. Yamazaki Plant F-term (reference) 4D075 AE16 BB24Y BB28Z BB56Z BB93Y BB93Z CA13 CA18 CA21 CA23 DA06 DB11 DC19 DC22 EA07 EB43 EB47 4J038 DL021 DL022 DL031 DL032 JA19 JA25 MA19 PB09 5E346 AA02 AA12 AA26 CC08 CC16 CC43 DD03 EE33 HH06 HH18

Claims (7)

[Claims] (A) R ¹ _n Si (OR ² ) _4-n (I) wherein R ¹ is an alkyl or aryl group having 1 to 6 carbon atoms, ² represents an alkyl group having 1 to 4 carbon atoms, n represents an integer of 0 to 2, and a plurality of R ¹ and R ² may be the same or different.) A coating solution for forming a silica-based film containing a polysiloxane having a carbon number per unit of silicon of 0.3 units or less and a solvent (II), and (B) a general formula (III) R ³ _n Si (OR ⁴ ) _4-n (III) (wherein R ³ is an alkyl group or an aryl group having 1 to 6 carbon atoms, R ⁴ is an alkyl group having 1 to ⁴ carbon atoms, and n is 0) A plurality of R ³ and R ⁴ may be the same or different). A coating solution for forming a silica-based coating film (I) which is produced by decondensation polymerization and contains a polysiloxane having a carbon number of 0.6 unit or more per unit of silicon and a solvent and a solvent.
A coating solution for forming a silica-based film, comprising the combination of V). 2. The silica-based coating formed from the coating liquid (IV) for forming a silica-based coating according to claim 1, having a relative dielectric constant of 3.
A coating liquid for forming a silica-based film, which is 0 or less. 3. A coating solution for forming a silica-based film (IV) according to claim 1, which is coated on a substrate, dried at 50 to 350 ° C., and then coated with a coating solution for forming a silica-based film (II). 50 ~
After drying at 350 ° C., it is further dried under nitrogen atmosphere for 200 to 6 hours.
A method for producing a silica-based coating which is cured by heating at 00 ° C. 4. A method for producing a silica-based coating wherein the relative dielectric constant of the laminated silica-based coating produced in claim 3 is 3.5 or less. 5. A silica-based coating obtained by the production method according to claim 3. 6. A semiconductor device having the silica-based coating according to claim 5. 7. A multilayer wiring board comprising the silica-based coating according to claim 5 as an interlayer insulating film.