JP5341944B2 - Method of forming insulating film for trench filling using polysiloxane condensation reaction product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solution of a condensation reaction product which: is particularly suitable for filling up trench that is formed in a substrate and has a narrow opening and a high aspect ratio; has a long pot life; has good trench filling property; has a small curing shrinkage when burned and converted to a silicon oxide; and is excellent in crack resistance and HF resistance. <P>SOLUTION: The solution of a condensation reaction product comprises (I) the condensation reaction product and (II) a solvent, wherein the condensation reaction product is obtained by the condensation reaction of a condensation ingredient that contains at least (i) a polysiloxane compound of 40 mass% or more and 99 mass% or less in terms of condensation weight and (ii) a silica particle of 1 mass% or more and 60 mass% or less; and the polysiloxane compound is derived from silane compounds represented by formula (1): R<SP>1</SP><SB>n</SB>SiX<SP>1</SP><SB>4-n</SB>which are two or more kinds of silane compounds containing at least a four-functional silane compound and a three-functional silane compound. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a polysiloxane condensation reaction solution, and more particularly to a polysiloxane condensation reaction solution suitable for filling a trench formed in a semiconductor device, and more particularly to a trench filling suitable for an insulating protective film. Relates to a polysiloxane condensation reaction product solution. The present invention also relates to a method for producing the above polysiloxane condensation reaction product solution, a use of the polysiloxane condensation reaction solution, and more particularly, a method for forming an insulating film for trench filling.

  In recent years, in order to increase the degree of memory integration, many semiconductor memory devices in which memory cells are arranged three-dimensionally have been proposed. In such a semiconductor device, it is necessary to perform electrical isolation between the memory cells and between the circuit elements by forming a trench in a portion corresponding to the gap between the memory cell and the circuit element and embedding an insulating material in the trench. . As the degree of integration of the memory increases, the opening width of the trench is narrowed, and the aspect ratio of the trench (that is, the value obtained by dividing the depth of the trench by the opening width of the trench) tends to increase. Furthermore, a three-dimensional semiconductor memory device is required to have a thicker crack resistance when fired at a high temperature of 700 ° C. or higher.

  As a material for filling the trench, silicon oxide is widely and preferably used because it requires high electrical insulation.

  As means for embedding silicon oxide in the trench, a silicon oxide film is conventionally formed on a silicon substrate having a trench by a CVD method. However, with the recent miniaturization of semiconductor elements, the opening width tends to become narrower and the aspect ratio tends to increase. Therefore, when silicon oxide is buried in a trench having an opening width of 0.2 μm or less and an aspect ratio of 2 or more by CVD, voids (unfilled portions) or seams (seam-like unfilled portions) are formed in the trenches. ) Is likely to occur.

  As a method other than the CVD method, a method of embedding a fine groove by a coating method and forming a silica film by baking in an oxidizing atmosphere is known. As materials used in this method, polysilazane materials, polysilane materials, and silicone materials are known.

  Among the polysilazane materials, hydrogenated polysilazane has been reported to have good trench embedding properties and low curing shrinkage during conversion to a silicon oxide film (for example, Patent Document 1). However, since hydrogenated polysilazane requires firing by steam oxidation, there is a problem that the substrate is easily oxidized. Furthermore, in recent years, the trench width is narrower and the trench depth tends to be deeper, so that there is a problem of insufficient embedding property, a problem of cracking in a thick film, and a danger of ammonia gas being generated during firing. There was a problem.

  In addition, the polysilane material has a problem that the applied polysilane compound easily evaporates and cracks occur in a thick film (for example, Patent Document 2).

  Since the silicone material is accompanied by dehydration and dealcoholization condensation reactions when the coating film is baked, there is a problem that voids and cracks are generated in the obtained silicon oxide film. In addition, there is a problem that the density becomes non-uniform from the film surface toward the bottom of the trench because of the large shrinkage during conversion from the silicone material to the silicon oxide.

As a method for avoiding the occurrence of voids and cracks using a silicone material, a composition comprising silica particles and a polysiloxane compound has been proposed (for example, Patent Document 3).
However, since the silica particles defined as the silicon oxide particles in Patent Document 3 and the polysiloxane compound defined as the silicon atom binder are only mixed, the pot life (storage stability at room temperature) of the solution is increased. There is a problem that it is bad, and there is a problem that voids are generated due to poor embedding in trenches having an opening width of 30 nm or less and an aspect ratio of 15 or more.

  For example, Patent Documents 4 to 6 describe materials obtained by condensation reaction of silica particles and a polysiloxane compound. However, the materials described in Patent Documents 4 to 6 are materials designed for use as an interlayer insulating film. Since the embedding property in the trench is not required for the interlayer insulating film, these documents do not describe the embedding property in the trench.

JP 2001-308090 A JP 2003-31568 A JP 2006-310448 A Japanese Patent No. 3320440 Japanese Patent No. 2851915 Japanese Patent No. 3163579

  Furthermore, when the present inventors conducted a follow-up experiment, when the ratio of the component derived from the tetrafunctional silane compound in the polysiloxane compound defined as a hydrolyzate in Patent Documents 4 to 6 is 100 mol%, crack resistance It has been found that there is a problem that a thick film having a thickness of 1 μm or more is not formed and a problem that HF resistance is poor. Moreover, when the ratio of the component originating in the trifunctional silane compound in a polysiloxane compound is 100 mol%, it discovered that there existed a problem that film-forming property, the adhesiveness to a board | substrate, and the embedding property to a trench were bad. Furthermore, regarding the polysiloxane compound composed of a tetrafunctional silane compound and a trifunctional silane compound, in Patent Documents 4 to 6, there is an example of a compound having a silica particle ratio of 70% by mass or more defined as silica sol. Since the particle ratio is high, it has been found that there is a problem that crack resistance and embedding in a trench are poor.

  An object of the present invention is to provide a condensation reaction product having a long pot life, a low curing shrinkage when fired to form silicon oxide, and excellent crack resistance and HF resistance. The present invention further provides a condensation reaction product that can be suitably used for embedding in a trench having a narrow opening width and a high aspect formed in the substrate, and has a long pot life and good film formability and adhesion to the substrate. Therefore, it is possible to provide a condensation reaction product that has good embedding property in a trench when used for trench embedding, has a small shrinkage in curing when fired into silicon oxide, and is excellent in crack resistance and HF resistance. Objective.

  As a result of intensive studies to develop a method for achieving the above object, the present inventors have found that the condensation reaction product solution shown below has a long pot life and a small shrinkage in curing when baked into silicon oxide. The present inventors have found out that they are excellent in crack resistance and HF resistance, and in particular, found that they are useful as a composition for filling a trench due to good filling properties in the trench. That is, the present invention is as follows.

[1] A method of forming an insulating film for trench embedding formed in a semiconductor element,
(I) (i) The following general formula (1):
R ¹ _n SiX ¹ _4-n (1)
{In the formula, n is an integer of 0 to 3, R ¹ is a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and X ¹ is a halogen atom, an alkoxy group having 1 to 6 carbon atoms or An acetoxy group. }
Condensation reaction of a condensation component containing at least 40% by mass to 99% by mass of a polysiloxane compound derived from the silane compound represented by formula (ii) and 1% by mass to 60% by mass of silica particles. And (II) a solvent,
The silane compound represented by the general formula (1) contains at least a tetrafunctional silane compound in which n is 0 in the general formula (1) and a trifunctional silane compound in which n is 1 in the general formula (1). An application step of applying a condensation reaction product solution, which is two or more types of silane compounds, onto a substrate to obtain a coated substrate;
A baking step of heating the coated substrate obtained in the coating step;
A method for forming an insulating film for filling a trench, comprising:
[2] The condensation component contains a condensation conversion amount of the polysiloxane compound of 50% by mass to 90% by mass and 10% by mass to 50% by mass of the silica particles,
The following general formula (2) in the polysiloxane compound:
SiX ² ₄ (2)
{In the formula, X ² represents a halogen atom, an alkoxy group having 1 to 6 carbon atoms or an acetoxy group. }
The method for forming an insulating film for filling a trench according to the above [1], wherein the ratio of the component derived from the tetrafunctional silane compound represented by the formula is 5 mol% or more and 40 mol% or less.
[3] The following general formula (3) in the polysiloxane compound:
R ² SiX ³ ₃ (3)
{In the formula, R ² represents a hydrocarbon group having 1 to 10 carbon atoms, and X ³ represents a halogen atom, an alkoxy group having 1 to 6 carbon atoms, or an acetoxy group. }
The method for forming an insulating film for filling a trench according to the above [1] or [2], wherein the ratio of the component derived from the trifunctional silane compound represented by the formula is 60 mol% or more and 95 mol% or less.
[4] In ²⁹ Si NMR analysis, the peak intensity (A) of all tetrafunctional siloxane components in the condensation reaction product and the peak intensity (B) of the component corresponding to the number of siloxane bonds in the condensation reaction product are 4 {(B) / (A)} ≧ 0.50
The method for forming an insulating film for filling a trench according to any one of the above [1] to [3], which satisfies the above relationship.
[5] The method for forming an insulating film for filling a trench according to any one of [1] to [4], wherein the condensation reaction product has a weight average molecular weight of 1,000 or more and 20,000 or less.
[6] A condensation reaction product solution for forming an insulating film for filling a trench formed in a semiconductor element,
(I) (i) The following general formula (1):
R ¹ _n SiX ¹ _4-n (1)
{In the formula, n is an integer of 0 to 3, R ¹ is a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and X ¹ is a halogen atom, an alkoxy group having 1 to 6 carbon atoms or An acetoxy group. }
Condensation reaction of a condensation component containing at least 40% by mass to 99% by mass of a polysiloxane compound derived from the silane compound represented by formula (ii) and 1% by mass to 60% by mass of silica particles. And (II) a solvent,
The silane compound represented by the general formula (1) contains at least a tetrafunctional silane compound in which n is 0 in the general formula (1) and a trifunctional silane compound in which n is 1 in the general formula (1). A condensation reaction product solution for forming an insulating film for trench embedding, which is two or more kinds of silane compounds.

  The condensation reaction product solution of the present invention has a long pot life, a small shrinkage in curing when fired into silicon oxide, excellent crack resistance and HF resistance, and when used for trench filling, into the trench. Excellent embeddability. Therefore, the condensation reaction product solution of the present invention is particularly suitable for embedding in a trench having a narrow opening width and a high aspect ratio formed in the substrate.

It is a ²⁹ SiNMR spectrum of Example 1 of the present invention. It is a ²⁹ SiNMR spectrum of Comparative Example 3 of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail.

[Condensation reaction product solution]
The present invention relates to (i) the following general formula (1):
R ¹ _n SiX ¹ _4-n (1)
{In the formula, n is an integer of 0 to 3, R ¹ is a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and X ¹ is a halogen atom, an alkoxy group having 1 to 6 carbon atoms or An acetoxy group. } The condensation component of the polysiloxane compound derived from the silane compound represented by the formula (ii) is condensed with a condensation component containing at least 40% by mass to 99% by mass and (ii) 1% by mass to 60% by mass of silica particles. A silane compound represented by the general formula (1) containing a condensation reaction product obtained by reaction and (II) a solvent, a tetrafunctional silane compound in which n in the general formula (1) is 0, and the general formula (1) Provided is a condensation reaction product solution that is two or more types of silane compounds containing at least a trifunctional silane compound in which n is 1. In addition, content in the condensation component described in this specification is when the total mass of all components in the condensation component (however, the amount of the polysiloxane compound and any silane compound is replaced with a condensation conversion amount) is 100% by mass. Is the amount.

  In the present invention, as described above, a condensation reaction in which a ratio of silica particles and a polysiloxane compound derived from two or more kinds of silane compounds is optimized is allowed to cause a thickening and an opening width. Narrow and high aspect ratio trench filling is possible. In the present invention, it has been found that optimization of the composition of the condensation reaction product is effective for embedding the condensation reaction product without generating voids and seams in the trench, and more preferably, the viscosity of the condensation reaction product is reduced. We found that the reduction was effective. It was found that the viscosity can be lowered by optimizing the molecular weight of the condensation reaction product and the silanol group ratio of the Q structure.

<Condensation product>
The condensation reaction product is represented by the above general formula (1), and a polysiloxane compound derived from two or more kinds of silane compounds containing at least a tetrafunctional silane compound and a trifunctional silane compound, and silica particles, have a predetermined composition. It is obtained by subjecting a condensation component contained in

(Polysiloxane compound)
The polysiloxane compound used in the present invention is derived from the silane compound represented by the general formula (1). More specifically, the polysiloxane compound is a polycondensate of a silane compound represented by the general formula (1). Furthermore, the silane compound represented by the general formula (1) used in the present invention is a tetrafunctional silane compound in which n in the general formula (1) is 0 and n in the general formula (1) is 1. Two or more silane compounds containing at least a functional silane compound.

Specific examples of R ^{1 in} the general formula (1) include: methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, t-butyl, n-pentyl, iso-pentyl, neopentyl, cyclopentyl, Acyclic such as n-hexyl, iso-hexyl, cyclohexyl, n-heptyl, iso-heptyl, n-octyl, iso-octyl, t-octyl, n-nonyl, iso-nonyl, n-decyl, iso-decyl Or a cyclic aliphatic hydrocarbon group; acyclic and cyclic such as vinyl, propenyl, butenyl, pentenyl, hexenyl, cyclohexenyl, cyclohexenylethyl, norbornenylethyl, heptenyl, octenyl, nonenyl, decenyl, styryl Alkenyl group; benzyl, phenethyl, 2-methylbenzyl, 3-methylbenzene Jill, aralkyl groups such as 4-methylbenzyl; PhCH = CH- Araarukeniru group such group; and the like are; phenyl, tolyl, xylyl, or similar aryl groups. Further, a specific example of R ¹ includes a hydrogen atom. Among these, R ¹ is preferably a hydrogen atom, a methyl group or an ethyl group in that a condensation reaction product having a small weight loss and a small shrinkage rate can be provided upon conversion to silicon oxide during firing. More preferably a methyl group.

Specific examples of X ^{1 in} the general formula (1) include, for example: halogen atoms such as chlorine, bromine and iodine; methoxy group, ethoxy group, n-propyloxy group, iso-propyloxy group, n-butyloxy group , T-butyloxy group, n-hexyloxy group, cyclohexyloxy group and other alkoxy groups; acetoxy group; and the like. Among these, halogen atoms such as chlorine, bromine and iodine, alkoxy groups such as methoxy group and ethoxy group, and acetoxy group are preferable because of high reactivity of the condensation reaction.

  When the polysiloxane compound contains a component derived from a tetrafunctional silane compound in which n in the general formula (1) is 0, film formability and adhesion to the substrate are improved, and the general formula (1) By including a component derived from a trifunctional silane compound in which n is 1, crack resistance and HF resistance are improved, and embedding is further improved. In the present invention, by using a polysiloxane compound derived from two or more kinds of silane compounds having the above specific composition, a condensation reaction having both film formability, adhesion to a substrate, crack resistance and HF resistance, and embedding properties. A product solution is obtained. Below, the more preferable aspect of a tetrafunctional silane compound and a trifunctional silane compound is demonstrated.

In the polysiloxane compound used in the present invention, the following general formula (2):
SiX ² ₄ (2)
{In the formula, X ² represents a halogen atom, an alkoxy group having 1 to 6 carbon atoms or an acetoxy group. }
It is preferable that the ratio of the component originating in the tetrafunctional silane compound represented by these is 5 mol% or more and 40 mol% or less. The structure of X ^{2 in} the general formula (2) corresponds to the structure of X ^{1 in} the general formula (1), and the structure of the general formula (2) is a part of the structure of the general formula (1). Represents. When the proportion of the component derived from the tetrafunctional silane compound represented by the general formula (2) in the polysiloxane compound is 5 mol% or more, it is preferable because the film formability and the adhesion to the substrate are good, The ratio is more preferably 10 mol% or more. On the other hand, when the ratio is 40 mol% or less, it is preferable because HF resistance is good, and the ratio is more preferably 35 mol% or less, and still more preferably 30 mol% or less.

Specific examples of X ^{2 in} the general formula (2) include: halogen atoms such as chlorine, bromine and iodine; methoxy group, ethoxy group, n-propyloxy group, iso-propyloxy group, n-butyloxy group , T-butyloxy group, n-hexyloxy group, alkoxy group such as cyclohexyloxy group; acetoxy group and the like. Among these, halogen atoms such as chlorine, bromine and iodine, alkoxy groups such as methoxy group and ethoxy group, and acetoxy group are preferable because of high reactivity of the condensation reaction.

  Among them, the condensation component used in the present invention contains a condensation conversion amount of the polysiloxane compound represented by the general formula (1) of 50% by mass to 90% by mass and 10% by mass to 50% by mass of silica particles. And the aspect whose ratio of the component originating in the tetrafunctional silane compound represented by the said General formula (2) in this polysiloxane compound is 5 mol% or more and 40 mol% or less is especially preferable.

In the polysiloxane compound used in the present invention, the following general formula (3):
R ² SiX ³ ₃ (3)
{In the formula, R ² represents a hydrocarbon group having 1 to 10 carbon atoms, and X ³ represents a halogen atom, an alkoxy group having 1 to 6 carbon atoms, or an acetoxy group. }
It is preferable that the ratio of the component originating in the trifunctional silane compound represented by these is 60 mol% or more and 95 mol% or less. The structure of X ^{3 in} the general formula (3) corresponds to X ¹ in the general formula (1), and the structure of R ^{2 in} the general formula (3) is the same as that in the general formula (1). 2 represents a part of R ¹ . That is, the structure of the general formula (3) represents a part of the structure of the general formula (1). When the proportion of the component derived from the trifunctional silane compound represented by the general formula (3) in the polysiloxane compound is 60 mol% or more, the HF resistance and crack resistance are good and the embedding property is good. Preferably, the ratio is more preferably 65 mol% or more, still more preferably 70 mol% or more. On the other hand, when the ratio is 95 mol% or less, it is preferable because the film formability and the adhesion to the substrate are good, and the ratio is more preferably 90 mol% or less.

The presence and content of the structure of the polysiloxane compound, particularly the structures represented by the above general formulas (1), (2) and (3), can be confirmed by ²⁹ Si NMR analysis.

Specific examples of R ^{2 in} the general formula (3) include: methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, t-butyl, n-pentyl, iso-pentyl, neopentyl, cyclopentyl, Acyclic such as n-hexyl, iso-hexyl, cyclohexyl, n-heptyl, iso-heptyl, n-octyl, iso-octyl, t-octyl, n-nonyl, iso-nonyl, n-decyl, iso-decyl Or a cyclic aliphatic hydrocarbon group; acyclic and cyclic such as vinyl, propenyl, butenyl, pentenyl, hexenyl, cyclohexenyl, cyclohexenylethyl, norbornenylethyl, heptenyl, octenyl, nonenyl, decenyl, styryl Alkenyl group; benzyl, phenethyl, 2-methylbenzyl, 3-methylbenzene Jill, aralkyl groups such as 4-methylbenzyl; PhCH = CH- Araarukeniru group such group; and the like are; phenyl, tolyl, xylyl, or similar aryl groups. Among these, R ² is preferably a methyl group or an ethyl group in that a condensation reaction product having a small weight loss and a small shrinkage rate can be provided upon conversion to silicon oxide during firing. A methyl group is preferred.

Specific examples of X ^{3 in} the general formula (3) include, for example: halogen atoms such as chlorine, bromine and iodine; methoxy group, ethoxy group, n-propyloxy group, iso-propyloxy group, n-butyloxy group , T-butyloxy group, n-hexyloxy group, cyclohexyloxy group and other alkoxy groups; acetoxy group; and the like. Among these, halogen atoms such as chlorine, bromine and iodine, alkoxy groups such as methoxy group and ethoxy group, and acetoxy group are preferable because of high reactivity of the condensation reaction.

(Manufacture of polysiloxane compounds)
The polysiloxane compound can be produced, for example, by a method of polycondensing the above silane compound in the presence of water. At this time, it is preferably 0.1 equivalents or more and 10 equivalents or less, more preferably 0.4 equivalents or more, based on the number of X ¹ contained in the silane compound represented by the general formula (1) in an acidic atmosphere. Polycondensation is carried out in the presence of water in the range of 8 equivalents or less. When the amount of water is within the above range, it is preferable because the pot life of the condensation reaction product solution can be lengthened and the crack resistance after film formation can be improved.

When the silane compound used for producing the polysiloxane compound contains a halogen atom or an acetoxy group as X ¹ in the general formula (1), the reaction system is acidic by adding water for the condensation reaction. In order to show this, it does not matter whether or not an acid catalyst is used in addition to the silane compound. On the other hand, when X ¹ in the general formula (1) is an alkoxy group, it is preferable to add an acid catalyst.

  Examples of the acid catalyst include inorganic acids and organic acids. Examples of the inorganic acid include hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid, phosphoric acid, and boric acid. Examples of the organic acid include acetic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, oxalic acid, maleic acid, methylmalonic acid, benzoic acid, and p-aminobenzoic acid. Examples include acid, p-toluenesulfonic acid, benzenesulfonic acid, trifluoroacetic acid, formic acid, malonic acid, sulfonic acid, phthalic acid, fumaric acid, citric acid, tartaric acid, citraconic acid, malic acid, glutaric acid and the like.

  Said inorganic acid and organic acid can be used 1 type or in mixture of 2 or more types. The amount of the acid catalyst used is an amount that adjusts the pH of the reaction system when producing the polysiloxane compound to a range of 0.01 to 7.0, preferably 5.0 to 7.0. preferable. In this case, the weight average molecular weight of the polysiloxane compound can be controlled well.

  The polysiloxane compound can be produced in an organic solvent or a mixed solvent of water and an organic solvent. Examples of the organic solvent include alcohols, esters, ketones, ethers, aliphatic hydrocarbons, aromatic hydrocarbon compounds, amide compounds, and the like.

  Examples of the alcohols include: monohydric alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, and butyl alcohol; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, glycerin, trimethylolpropane, and hexanetriol; ethylene glycol monomethyl Ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene Glycol monopropyl ether, mono ethers of polyhydric alcohols such as propylene glycol monobutyl ether; and the like.

  Examples of the esters include methyl acetate, ethyl acetate, butyl acetate and the like.

  Examples of the ketones include acetone, methyl ethyl ketone, and methyl isoamyl ketone.

  As the ethers, in addition to the monoethers of the above polyhydric alcohols, for example: ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dipropyl ether, ethylene glycol dibutyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, Polyhydric alcohol ethers obtained by alkyl etherifying all hydroxyl groups of polyhydric alcohols such as propylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, and diethylene glycol diethyl ether; tetrahydrofuran, 1,4-dioxane, anisole and the like.

  Examples of the aliphatic hydrocarbons include hexane, heptane, octane, nonane, decane and the like.

  Examples of the aromatic hydrocarbons include benzene, toluene, xylene and the like.

  Examples of the amide compounds include dimethylformamide, dimethylacetamide, N-methylpyrrolidone and the like.

  Among these solvents, alcohol solvents such as methanol, ethanol, isopropanol, butanol, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, ethylene glycol monomethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl Ether solvents such as ether and amide compound solvents such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone are preferred because they are easy to mix with water and disperse silica particles.

  In a preferred embodiment, the polysiloxane compound can be produced by hydrolysis polycondensation in an aqueous alcohol solution under weakly acidic conditions of pH 5 or more and less than 7.

  These solvents may be used alone or in combination of a plurality of solvents. Moreover, you may react in a bulk, without using the said solvent.

  The reaction temperature for producing the polysiloxane compound is not particularly limited, but it is preferably -50 ° C or higher and 200 ° C or lower, more preferably 0 ° C or higher and 150 ° C or lower. By performing the reaction in the above temperature range, the molecular weight of the polysiloxane compound can be easily controlled.

The content of the polysiloxane compound in the condensation component is set to be 40% by mass or more and 99% by mass or less in terms of the condensation conversion amount of the polysiloxane compound. In the present specification, the polycondensation amount of the polysiloxane compound means that X ¹ remaining in the polysiloxane compound (X ¹ is as defined above for the general formula (1)) is ½ It means the amount obtained by replacing with oxygen atoms. The condensation conversion amount of 40% by mass or more is preferable from the viewpoint of good film formability and trench embeddability. The condensation conversion amount is more preferably 50% by mass or more, and still more preferably 55% by mass or more. On the other hand, it is preferable that the amount in terms of condensation is 99% by mass or less because a low shrinkage rate and good crack resistance can be obtained. The condensation conversion amount is more preferably 90% by mass or less, and still more preferably 85% by mass or less.

(Silica particles)
Examples of the silica particles used in the present invention include fumed silica and colloidal silica.

  The fumed silica can be obtained by reacting a compound containing a silicon atom with oxygen and hydrogen in a gas phase. Examples of the silicon compound used as a raw material include silicon halide (for example, silicon chloride).

  The colloidal silica can be synthesized by a sol-gel method in which a raw material compound is hydrolyzed and condensed. Examples of the raw material compound for colloidal silica include alkoxy silicon (for example, tetraethoxysilane) and halogenated silane compounds (for example, diphenyldichlorosilane). Especially, since it is preferable that there are few impurities, such as a metal and a halogen, the colloidal silica obtained from the alkoxy silicon is more preferable.

  The average primary particle diameter of the silica particles is preferably 1 nm or more and 120 nm or less, more preferably 40 nm or less, still more preferably 20 nm or less, and most preferably 15 nm or less. When the average primary particle size is 1 nm or more, the crack resistance is good, and when it is 120 nm or less, the embedding property in the trench is good.

  The average secondary particle diameter of the silica particles is preferably 2 nm or more and 250 nm or less, more preferably 80 nm or less, still more preferably 40 nm or less, and most preferably 30 nm or less. When the average secondary particle size is 2 nm or more, the crack resistance is good, and when the average secondary particle size is 250 nm or less, the embedding property in the trench is good.

  In addition, the average secondary particle diameter of the silica particles is within the above range and 0.1 to 3 times the minimum opening width among the trenches formed in the substrate, the embedding property in the trenches is It is preferable in terms of goodness, and more preferably 0.1 to 2 times the minimum opening width.

  The average primary particle diameter is a value obtained by calculation from the specific surface area of BET, and the average secondary particle diameter is a value measured with a dynamic light scattering photometer.

  The shape of the silica particles can be spherical, rod-shaped, plate-shaped, fibrous, or a shape in which two or more of these are combined, but is preferably spherical. The term “spherical” as used herein includes not only true spheres, but also spheres such as spheroids and ovals.

The specific surface area of the silica particles is preferably a BET specific surface area of 25 m ² / g or more, more preferably 70 m ² / g or more, still more preferably 140 m ² / g or more, in view of good HF resistance. Preferably it is 180 m ² / g or more. The BET specific surface area is a value measured by a method calculated from the pressure of N ₂ molecules and the gas adsorption amount.

  The silica particles are not limited as long as they meet the above requirements, and commercially available products can also be used.

  Commercially available products include colloidal silica such as LEVASIL series (manufactured by HC Starck Co., Ltd.), methanol silica sol, IPA-ST, MEK-ST, NBA-ST, XBA-ST, DMAC-ST, ST-UP. , ST-OUP, ST-20, ST-40, ST-C, ST-N, ST-O, ST-50, ST-OL (manufactured by Nissan Chemical Industries, Ltd.), Quatlon PL series (Fuso Chemical Co., Ltd.), OSCAL series (Catalyst Kasei Kogyo Co., Ltd.), etc .; As powdered silica particles, for example, Aerosil 130, 300, 380, TT600, OX50 (above, Nippon Aerosil Co., Ltd.) ), Sildex H31, H32, H51, H52, H121, H122 (above, manufactured by Asahi Glass Co., Ltd.), E220A, E2 0 (manufactured by Nippon Silica Industrial (Ltd.)), SYLYSIA470 (manufactured by Fuji Silysia Chemical (Co., Ltd.)), SG Flake (manufactured by Nippon Sheet Glass Co., Ltd.), and the like, respectively. Silica particles can also be used in a form dispersed in a dispersion medium. The content in that case is calculated using a value obtained by multiplying the mass of the net silica particles, that is, the mass of the dispersion by the concentration of the silica particles.

  Content of the silica particle in a condensation component is 1 mass% or more and 60 mass% or less. The content of 1% by mass or more is preferable in that a low shrinkage rate and good crack resistance can be obtained. The content is more preferably 10% by mass or more, and still more preferably 15% by mass or more. On the other hand, the content of 60% by mass or less is preferable from the viewpoint of good film formability and trench embeddability. The content is more preferably 50% by mass or less, and still more preferably 45% by mass or less.

(Silane compound)
The condensation component used in the production of the condensation reaction product used in the present invention can be composed of the above polysiloxane compound and silica particles, or can contain other components. As the other component, for example, a silane compound represented by the general formula (1) can be used. In this case, for example, the following two-stage condensation reaction can be employed. That is, a polysiloxane compound and silica particles are first subjected to a condensation reaction by a method of adding a polysiloxane compound solution to a dispersion in which silica particles are dispersed in a solvent to cause a condensation reaction (first step). Next, the silane compound represented by the general formula (1) is further reacted with the obtained reaction solution (second stage). The silane compound represented by the general formula (1) used as the condensation component may be one kind or plural kinds. When using a plurality of types of silane compounds, for example, in the second stage, they may be added to the reaction system one by one sequentially, or after mixing a plurality of types of silane compounds into the reaction system. Also good.

When the silane compound represented by the general formula (1) is used as the condensation component, the content of the silane compound in the condensation component is more than 0% by mass and 40% by mass or less in terms of the condensation conversion amount of the silane compound. It is preferable to set so. Here, the condensation conversion amount of the silane compound means an amount obtained by substituting X ¹ in the general formula (1) with 1/2 oxygen atom. It is preferable that the condensation conversion amount exceeds 0% by mass because the pot life of the condensation reaction product solution is long. The condensation conversion amount is more preferably 0.01% by mass or more, and still more preferably 0.03% by mass or more. On the other hand, it is preferable that the condensation conversion amount is 40% by mass or less from the viewpoint of good crack resistance. The condensation conversion amount is more preferably 30% by mass or less, and still more preferably 20% by mass or less.

(Characteristics of condensation reaction product)
Among the silane compounds represented by the silica particles and the general formula (1), a tetrafunctional siloxane component derived from a tetrafunctional silane compound with n = 0 (that is, represented by the general formula (2)) is defined as a Q component. Then, Q0 to Q4 component amounts corresponding to 0 to 4 siloxane bonds can be obtained from a solution or solid ²⁹ Si NMR analysis. In the present invention, in the ²⁹ Si NMR analysis, all tetrafunctional siloxane components in the condensation reaction product (that is, a component having a siloxane bond number of 0 (Q0 component), a component having a siloxane bond number of 1 (Q1 component) ), A component corresponding to two siloxane bonds (Q2 component), a component corresponding to three siloxane bonds (Q3 component), and a component corresponding to four siloxane bonds (Q4 component)) The ratio of the peak intensity (A) to the peak intensity (B) of the component corresponding to four siloxane bonds in the condensation reaction product (ie, Q4 component) is {(B) / (A)} ≧ 0 It is preferable to satisfy the relationship of .50. The ratio is more preferably {(B) / (A)} ≧ 0.6, and further preferably {(B) / (A)} ≧ 0.7. When the ratio is within the above range, the condensation reaction product has few terminal groups such as silanol groups and alkoxy groups, so that the curing shrinkage ratio is small, the trench embedding property is good, and the pot life of the condensation reaction product solution is Long preferred. The peak intensity of each Q component is calculated from the peak area.

The weight average molecular weight of the condensation reaction product is preferably 1,000 or more and 20,000 or less, and more preferably 1,000 or more and 10,000 or less. When the condensation reaction product has a weight average molecular weight of 1,000 or more, the film formability and crack resistance are good, and when the weight average molecular weight is 20,000 or less, the trench embedding property is good, and the condensation reaction product. The pot life of the solution is long and preferable. The weight average molecular weight is a value calculated using gel permeation chromatography and calculated in terms of standard polymethyl methacrylate. The molecular weight can be measured, for example, by using a gel permeation chromatography (GPC), HLC-8220, TSKgelGMH _HR- M column manufactured by Tosoh, and using a 1% by mass solution of the condensation reaction product in an acetone solvent. Differential refraction A weight average molecular weight (Mw) in terms of standard polymethyl methacrylate can be determined by a rate meter (RI).

(solvent)
The condensation reaction product solution of the present invention contains a solvent. Examples of the solvent include at least one solvent selected from alcohols, ketones, esters, ethers, and hydrocarbon solvents, and esters, ethers, and hydrocarbon solvents are more preferable. Moreover, it is preferable that the boiling point of these solvents is 100 degreeC or more and 200 degrees C or less. The content of the solvent in the condensation reaction product solution of the present invention is preferably 100 parts by mass or more and 1900 parts by mass or less, more preferably 150 parts by mass or more and 900 parts by mass or less with respect to 100 parts by mass of the condensation reaction product. When the content of the solvent is 100 parts by mass or more, the pot life of the condensation reaction product solution is long, and when it is 1900 parts by mass or less, the trench embedding property is favorable, which is preferable.

  Specific examples of the alcohol, ketone, ester, ether, and hydrocarbon solvent include butanol, pentanol, hexanol, octanol, methoxyethanol, ethoxyethanol, propylene glycol monomethoxy ether, propylene glycol monoethoxy ether, and the like. Alcohol solvents, methyl ethyl ketone, methyl isobutyl ketone, isoamyl ketone, ethyl hexyl ketone, cyclopentanone, cyclohexanone, γ-butyrolactone and other ketone solvents, butyl acetate, pentyl acetate, hexyl acetate, propyl propionate, butyl propionate, Ester solvents such as pentyl propionate, hexyl propionate, propylene glycol monomethyl ether acetate, ethyl lactate, butyl ethyl Ether solvents such as ether, butyl propyl ether, dibutyl ether, anisole, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol diethyl ether, hydrocarbon solvents such as toluene, xylene, etc. Can be mentioned.

  In the present invention, at least one solvent selected from alcohols, ketones, esters, ethers and hydrocarbon solvents having a boiling point of 100 ° C. or more and 200 ° C. or less is 50 mass of the total solvent contained in the condensation reaction product solution. % Or more is preferable. In this case, a solvent having a boiling point of 100 ° C. or lower may be mixed in the condensation reaction product solution. When one or more solvents selected from alcohols, ketones, esters, ethers and hydrocarbon solvents having a boiling point of 100 ° C. or higher and 200 ° C. or lower constitute 50% by mass or more of the total solvent, the pot life of the condensation reaction product solution Is preferable because the film thickness is long and the film formability is good.

(Production of condensation reaction product solution)
A preferred method for producing the above-described condensation reaction product solution of the present invention will be described below.
Another aspect of the present invention is a method for producing the condensation reaction product solution of the present invention described above,
The following general formula (1):
R ¹ _n SiX ¹ _4-n (1)
{In the formula, n is an integer of 0 to 3, R ¹ is a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and X ¹ is a halogen atom, an alkoxy group having 1 to 6 carbon atoms or An acetoxy group. }
Two types of silane compounds represented by general formula (1) containing at least a tetrafunctional silane compound in which n is 0 and a trifunctional silane compound in which n is 1 in general formula (1) A first step of hydrolyzing and polycondensing the above silane compound to obtain a polysiloxane compound;
A condensation reaction of at least a condensation component containing at least 40% by mass to 99% by mass of the polysiloxane compound obtained in the first step and 1% by mass to 60% by mass of silica particles; And the process of
A method comprising:

  The solvent can be added or present in the reaction system at any timing in either or both of the first step and the second step. Further, after the second step, a third step of further adding a solvent can be optionally included. In the third step, after the addition of the solvent, for example, a solvent replacement treatment for removing a solvent having a boiling point of 100 ° C. or lower and water may be performed.

In a preferred embodiment, in the first step, as the silane compound represented by the general formula (1),
The following general formula (2):
SiX ² ₄ (2)
{In the formula, X ² represents a halogen atom, an alkoxy group having 1 to 6 carbon atoms or an acetoxy group. }
5 mol% or more and 40 mol% or less of a tetrafunctional silane compound represented by the following general formula (3):
R ² SiX ³ ₃ (3)
{In the formula, R ² represents a hydrocarbon group having 1 to 10 carbon atoms, and X ³ represents a halogen atom, an alkoxy group having 1 to 6 carbon atoms, or an acetoxy group. }
A silane compound in combination with 60 to 95 mol% of the trifunctional silane compound represented by the formula can be used.

  The first step can be carried out by the method described in detail in the section on the production of the polysiloxane compound.

  In the second step, when the silica particles are subjected to a condensation reaction with the polysiloxane compound, the reaction can be advanced using silica particles dispersed in a solvent. This solvent can be water or an organic solvent or a mixed solvent thereof. The type of organic solvent present in the reaction system during the condensation reaction varies depending on the dispersion medium in which the silica particles used are dispersed. When the dispersion medium of silica particles used is aqueous, the aqueous dispersion obtained by adding water and / or alcohol solvent to the silica particles may be reacted with the polysiloxane compound, or the aqueous dispersion of silica particles The alcohol-based dispersion of the silica particles may be reacted with the polysiloxane compound after the water contained in is once substituted with an alcohol-based solvent. The alcohol solvent that can be used is preferably an alcohol solvent having 1 to 4 carbon atoms, and examples thereof include methanol, ethanol, n-propanol, 2-propanol, n-butanol, methoxyethanol, and ethoxyethanol. These are preferable because they can be easily mixed with water.

  When the silica particle dispersion medium used is a solvent such as alcohol, ketone, ester, or hydrocarbon, water or a solvent such as alcohol, ether, ketone, or ester is used as a solvent to be present in the reaction system during the condensation reaction. Can be used. Examples of the alcohol include methanol, ethanol, n-propanol, 2-propanol, and n-butanol. Examples of the ether include dimethoxyethane. Examples of the ketone include acetone, methyl ethyl ketone, and methyl isobutyl ketone. Examples of the ester include methyl acetate, ethyl acetate, propyl acetate, ethyl formate, propyl formate and the like.

  In a preferred embodiment, the second step can be performed in an aqueous alcohol solution having 1 to 4 carbon atoms.

  The pH of the reaction system when the polysiloxane compound and the silica particles are subjected to a condensation reaction is preferably adjusted in the range of pH = 4 to 9, more preferably pH = 5 to 8, particularly preferably pH = 6 to 8. To do. The pH within the above range is preferable because the weight average molecular weight of the condensation reaction product and the silanol group ratio of the Q component can be easily controlled.

  The condensation reaction between the polysiloxane compound and the silica particles is usually performed in the presence of an acid catalyst. As an acid catalyst, the same acid catalyst as mentioned above as what is used for manufacture of a polysiloxane compound can be mentioned. When removing the acid catalyst after the production of the polysiloxane compound, it is usually necessary to add the acid catalyst again when reacting the polysiloxane compound and the silica particles, but the acid catalyst is not removed after the production of the polysiloxane compound. When the silica particles are reacted as they are, the polysiloxane compound and the silica particles can be reacted with the acid catalyst used when the polysiloxane compound is reacted without adding the acid catalyst again. However, in this case, an acid catalyst may be added again during the reaction between the polysiloxane compound and the silica particles.

  The reaction temperature between the polysiloxane compound and the silica particles is preferably 0 ° C. or higher and 200 ° C. or lower, more preferably 50 ° C. or higher and 150 ° C. or lower. When the reaction temperature is within the above range, it is preferable because the weight average molecular weight of the condensation reaction product and the silanol group ratio of the Q component can be easily controlled.

  In a particularly preferred embodiment, the condensation reaction between the polysiloxane compound and the silica particles is carried out in an aqueous alcohol solution having 1 to 4 carbon atoms at a temperature of 50 ° C. or higher under conditions of pH 6 to 8.

  When the silane compound represented by the general formula (1) is used as the condensation component, in the second step, after the condensation reaction (first stage) between the polysiloxane compound and the silica particles, the condensation reaction is generated. The product can be further reacted with a silane compound (second stage). The silane compound may be added neat or once diluted with a solvent. As the solvent for dilution, for example, alcohol-based, ether-based, ketone-based, ester-based, hydrocarbon-based, halogenated solvent and the like are used.

  In the second step, the silane compound represented by the general formula (1) is preferably added to the reaction system in a concentration range of 1% by mass to 100% by mass (100% by mass in the case of neat), The concentration is more preferably 3% by mass or more and 50% by mass or less. When the concentration is within the above range, it is preferable because the amount of solvent used in the production of the condensation reaction product is small.

  In a typical embodiment, a reaction product of a polysiloxane compound and silica particles is formed in the first stage, and subsequently, in the second stage, the silane compound represented by the general formula (1) is introduced into the reaction system. It is preferably added and reacted in the range of −50 ° C. to 200 ° C. for 1 minute to 100 hours. By controlling the reaction temperature and the reaction time, it is possible to control the viscosity of the condensation reaction product solution when forming the condensation reaction product, and when the reaction temperature and the reaction time are within the above ranges, The viscosity can be controlled within a particularly suitable range for film formation.

  The pH of the reaction solution after the condensation reaction (reaction of polysiloxane compound and silica particles, or reaction of polysiloxane compound, silica particles and silane compound) is preferably adjusted to 6 or more and 8 or less. The pH can be adjusted, for example, by removing the acid by distillation after the condensation reaction. When the pH of the reaction solution is within the above range, the pot life of the condensation reaction product solution is preferably long.

  A solvent selected from alcohols, ketones, esters, ethers and hydrocarbon solvents (preferably having a boiling point of 100 ° C. or higher and 200 ° C. or lower) is subjected to a condensation reaction (reaction between a polysiloxane compound and silica particles, or a polysiloxane compound. Or the silica particles and the silane compound) may be added in advance, or after the condensation reaction, the third step may be provided or added at the timing of the both. May be.

  In the case of providing the third step after forming the condensation reaction product, alcohol, ketone, ester, ether, and carbonization are added to the concentrate obtained by removing the solvent used in the condensation reaction by a method such as distillation. A solvent having a boiling point of 100 ° C. or higher and 200 ° C. or lower selected from hydrogen-based solvents may be further added.

  Solvent (especially organic solvent) used in the condensation reaction in the second step (reaction of polysiloxane compound and silica particles, or reaction of polysiloxane compound, silica particles and silane compound), and When the alcohol produced at this time has a boiling point lower than a solvent having a boiling point of 100 ° C. or more and 200 ° C. or less selected from the group consisting of alcohol, ketone, ester, ether and hydrocarbon solvent, during the condensation reaction or after the condensation reaction It is preferable to add a solvent having a boiling point of 100 ° C. or higher and 200 ° C. or lower selected from alcohols, ketones, esters, ethers and hydrocarbon solvents, and then remove the low boiling point solvent by a method such as distillation. In this case, it is preferable in that the pot life of the condensation reaction product solution can be increased.

  In a particularly preferred embodiment, in the third step, the reaction solution after the condensation reaction has at least one boiling point of 100 ° C. or more and 200 ° C. or less selected from the group consisting of alcohols, ketones, esters, ethers and hydrocarbon solvents. After adding the solvent, components having a boiling point of 100 ° C. or lower are distilled off. As a result, solvent replacement with a high boiling point solvent can be performed. As a component having a boiling point of 100 ° C. or lower, for example, when the first step and / or the second step are performed in a hydroalcoholic aqueous solution or in an alcohol having a boiling point of 100 ° C. or lower, water, or a boiling point of 100 ° C. or lower And alcohol.

  More specifically, when water and alcohol are used in the condensation reaction (reaction between polysiloxane compound and silica particles, or reaction between polysiloxane compound, silica particles and silane compound), the above-mentioned after the condensation reaction. After adding the solvent in the manner as described above, water and alcohol having a boiling point of 100 ° C. or lower are removed by a method such as distillation, and components having a boiling point of 100 ° C. or lower in the condensation reaction product solution (that is, water and alcohol having a boiling point of 100 ° C. or lower) The content of is preferably 1% by mass or less. When the content is in the above range, the pot life of the condensation reaction product solution is preferably long.

  After obtaining the condensation reaction product solution by the procedure as described above, purification may be performed to remove ions. Examples of the method for removing ions include ion exchange with an ion exchange resin, ultrafiltration, and distillation.

A preferred embodiment of the present invention is a method for producing the condensation reaction product solution of the present invention, comprising:
The following general formula (2):
SiX ² ₄ (2)
{In the formula, X ² represents a halogen atom, an alkoxy group having 1 to 6 carbon atoms or an acetoxy group. }
5 mol% or more and 40 mol% or less of a tetrafunctional silane compound represented by the following general formula (3):
R ² SiX ³ ₃ (3)
{In the formula, R ² represents a hydrocarbon group having 1 to 10 carbon atoms, and X ³ represents a halogen atom, an alkoxy group having 1 to 6 carbon atoms, or an acetoxy group. }
A first step of obtaining a polysiloxane compound by hydrolytic polycondensation of a trifunctional silane compound represented by the formula: 60 mol% or more and 95 mol% or less in an aqueous alcohol solution under weakly acidic conditions of pH 5 or more and less than 7. When,
A condensation component consisting of 40% by mass to 99% by mass of the polysiloxane compound obtained in the first step and 1% by mass to 60% by mass of silica particles is obtained by using a C 1-4 alcohol. A second step of carrying out a condensation reaction at a temperature of 50 ° C. or higher in an aqueous solution at a pH of 6 to 8, and obtaining a reaction solution;
After adding at least one solvent having a boiling point of 100 ° C. or more and 200 ° C. or less selected from the group consisting of alcohol, ketone, ester, ether and hydrocarbon solvent to the reaction solution obtained in the second step, distillation is performed. And a third step of obtaining a condensation reaction product solution by distilling off components having a boiling point of 100 ° C. or lower.

(Characteristics of condensation reaction product solution)
In order to embed the condensation reaction product solution in a trench having a narrow opening width and a high aspect ratio, it is preferable that the fluidity of the condensation reaction solution is low. In the present invention, the low fluidity is evaluated by the viscosity at 25 ° C. at a solid content concentration of 50 mass% of the condensation reaction product solution.

  In the present specification, the solid content concentration of the condensation reaction product solution means the concentration of the compound having Si atoms present in the solution. The solid content concentration can be measured by a method of measuring the weight before and after baking the condensation reaction product solution at 600 ° C. in a nitrogen atmosphere. The viscosity value at 25 ° C. means a value when the viscosity value is stabilized (variation is 2% or less) using an E-type viscometer. In the present invention, the viscosity at 25 ° C. when the solid content concentration of the condensation reaction product solution is 50% by mass is preferably 500 mPa · s or less. The viscosity is more preferably 200 mPa · s or less, still more preferably 100 mPa · s or less, and particularly preferably 70 mPa · s or less. When the viscosity is in the above range, the filling property into the trench is good, which is preferable. For example, in the case of a trench having an opening width of 25 nm or less and an aspect ratio of 40 or more, the viscosity is preferably 70 mPa · s or less.

  The condensation reaction product solution of the present invention is suitably used for, for example, filling a trench formed in a semiconductor element.

<Method for forming insulating film>
Another aspect of the present invention includes an application step of applying the above-described condensation reaction product solution of the present invention onto a substrate to obtain a coated substrate, and a baking step of heating the coated substrate obtained in the coating step. A method for forming a film is provided. The condensation reaction product solution produced by the method as described above can be applied on the substrate by a usual method. Examples of the coating method include spin coating, dip coating, roller blade coating, and spray coating. Among them, the spin coating method is preferable in that the coating thickness during film formation is uniform.

  An example of the substrate is a silicon (Si) substrate. The substrate may have a trench structure. In the coating process, when the condensation reaction product solution is applied to a substrate having a trench structure by, for example, a spin coating method, it may be applied at a single rotational speed or a combination of multiple rotational speeds. In particular, it is preferable to set the rotational speed of at least the first stage to a low speed and to increase the speed of the second and subsequent stages. This is because the condensation reaction product can be spread over the entire surface of the substrate (for example, a silicon substrate) by rotating at a low speed in the first stage, and the embedding property is improved. The number of times of application of the condensation reaction product may be one or more, but it is more preferable to apply it once from the viewpoint of good film formability and manufacturing cost. For example, a coated substrate can be obtained by the procedure as described above.

  Next, the coated substrate is heated in the firing step. In the coating step, it is preferable that after the condensation reaction product solution is applied to the substrate by the above method, pre-curing is performed in the range of 50 ° C. to 200 ° C. in order to remove the residual solvent in the coating film. At that time, the temperature may be raised stepwise or continuously. The pre-curing atmosphere may be an oxidizing atmosphere or a non-oxidizing atmosphere.

  An insulating film can be obtained by heating and baking the film obtained by pre-curing. As the heating and baking method, general heating means such as a hot plate, an oven, and a furnace can be applied. Heating and baking are preferably performed in a non-oxidizing atmosphere. The preferable heating temperature is preferably more than 200 ° C. and 850 ° C. or less, more preferably more than 300 ° C. and 800 ° C. or less, still more preferably more than 350 ° C. and 750 ° C. or less. When the heating temperature is over 200 ° C., the resulting film quality is good, which is preferable, and when it is 850 ° C. or lower, the crack resistance is good, which is preferable.

The non-oxidizing atmosphere is an inert atmosphere such as N ₂ , Ar, or Xe under vacuum. The concentration of an oxidizing gas such as oxygen or water vapor in the inert atmosphere is preferably 1000 ppm or less, more preferably 100 ppm or less, and still more preferably 10 ppm or less. There is no restriction | limiting in particular in the total pressure of non-oxidizing atmosphere, Any of pressurization, a normal pressure, and pressure reduction may be sufficient.

  In the high temperature region of 700 ° C. or higher and 900 ° C. or lower, it is more preferable to perform the baking step in a gas containing hydrogen. The gas containing hydrogen used in the firing process may be introduced from the beginning of the firing process, that is, from the time when the substrate is still at a temperature of 700 ° C. or lower, or may be introduced after reaching 700 ° C. Further, the first heating may be performed once at a temperature of 700 ° C. or more and 900 ° C. or less without using hydrogen, and then the second heating may be performed by introducing a gas containing hydrogen. In any case, it is preferable to keep introducing a gas containing hydrogen until the substrate is cooled to a temperature of 400 ° C. or lower, preferably about room temperature, after firing.

  As described above, if the firing step is performed in a gas containing hydrogen, dangling bonds that are generated are terminated with hydrogen even if the chemical bond between the silicon atom and the organic group is cut at a high temperature exceeding 700 ° C. Therefore, the formation of silanol groups can be prevented.

  The heat treatment time in the firing step is preferably 1 minute to 24 hours, more preferably 30 minutes to 2 hours.

In the firing step, heat firing in an oxidizing atmosphere and light treatment may be used in combination. The temperature when heating and light treatment are simultaneously performed is preferably 20 ° C. or more and 600 ° C. or less, and the treatment time is preferably 0.1 minutes or more and 120 minutes or less. For light treatment, visible light, ultraviolet light, far ultraviolet light, or the like can be used. For the light treatment, low pressure or high pressure mercury lamp; deuterium lamp; discharge light of rare gas such as argon, krypton, xenon; YAG laser, argon laser, carbon dioxide laser, XeF, XeCl, XeBr, KrF, KrCl, An excimer laser such as ArF or ArCl; or the like can be used as a light source. These light sources preferably have an output of 10 to 5,000 W. The light emitted from these light sources may be light having a wavelength of 170 nm to 600 nm, although the condensation reaction product in the film applied to the substrate may absorb even a little. The irradiation amount is preferably 0.1 to 1,000 J / cm ² , more preferably 1 to 100 J / cm ² . Ozone may be generated simultaneously with the light treatment. For example, by performing the light treatment under the above conditions, the oxidation reaction of the condensation reaction product in the film applied to the substrate proceeds, and the film quality after baking can be improved.

  After the baking step, the surface of the insulating film may be exposed to a hydrophobizing agent. By exposing to the hydrophobizing agent, the silanol group in the insulating film formed in the baking step reacts with the hydrophobizing agent, and the surface of the insulating film can be hydrophobized.

  As the hydrophobizing agent, known ones can be used. For example, hexamethyldisilazane, diacetoxydisilazane, dihydroxydimethylsilane, halogenated organic silane and the like can be used. Cyclic siloxanes, organosilicon compounds, and cyclic silazanes can also be used.

  Specific examples of the cyclic siloxane include, for example, (3,3,3-trifluoropropyl) methylcyclotrisiloxane, triphenyltrimethylcyclotrisiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, octamethylcyclo Examples include tetrasiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetraphenylcyclotetrasiloxane, tetraethylcyclotetrasiloxane, and pentamethylcyclopentasiloxane.

  Specific examples of the organosilicon compound include, for example, 1,2-bis (tetramethyldisiloxanyl) ethane, 1,3-bis (trimethylsiloxy) -1,3-dimethyldisiloxane, 1,1,3, 3-tetraisopropyldisiloxane, 1,1,3,3-tetramethyldisiloxane, 1,1,3,3-tetraethyldisiloxane, 1,1,3,3-tetraphenyldisiloxane, 1,1,4 , 4-tetramethyldisylethylene, 1,1,3,3,5,5-hexamethyltrisiloxane, 1,1,3,3,5,5-hexaethyltrisiloxane, 1,1,3,3 , 5,5-hexaisopropyltrisiloxane, 1,1,3,3,5,5,7,7-octamethyltetrasiloxane, 1,1,1,3,5,5-hexamethyltrisiloxane, 1,1 3,3,5,7,7-octamethyltetrasiloxane, 1,3-dimethyltetramethoxydisiloxane, 1,1,3,3-tetramethyl-1,3-diethoxydisiloxane, 1,1,3 , 3,5,5-hexamethyldiethoxytrisiloxane, and siloxane compounds such as tetramethyl-1,3-dimethoxydisiloxane.

  Specific examples of the cyclic silazane include 1,2,3,4,5,6-hexamethylcyclotrisilazane, 1,3,5,7-tetraethyl-2,4,6,8-tetramethylcyclotetra. Examples thereof include cyclic silazane compounds such as silazane and 1,2,3-triethyl-2,4,6-triethylcyclotrisilazane.

These hydrophobizing agents can be used alone or in combination of two or more.
As a method for exposing the surface of the insulating film to the hydrophobizing agent, a method of applying the hydrophobizing agent to the surface of the insulating film in a liquid phase, a method of bringing the hydrophobizing agent into a gas phase and contacting the surface of the insulating film, etc. are applied. can do.

  When applying the hydrophobizing agent to the surface of the insulating film in a liquid phase, the hydrophobizing agent and an organic solvent may be used in combination. In a preferred embodiment, an organic silicon compound is combined with an organic solvent and applied to the surface of the insulating film in a liquid phase.

  When a combination of an organosilicon compound and an organic solvent is used, the concentration of the organosilicon compound is not particularly limited and can be carried out at an arbitrary concentration. There are no particular restrictions on the temperature and time for application in the liquid phase, but preferably 0 ° C. or more and 100 ° C. or less, more preferably 20 ° C. or more and 80 ° C. or less, preferably 0.1 minutes or more and 30 minutes or less, more Preferably it is 0.2 minutes or more and 10 minutes or less.

  When the hydrophobizing agent is brought into contact with the surface of the insulating film in a gas phase, the hydrophobizing agent is preferably diluted with a gas and used. Examples of the gas for dilution include air, nitrogen, argon, hydrogen and the like. Further, instead of diluting with gas, contact under reduced pressure is also possible. The temperature and time when the hydrophobizing agent is brought into contact with the insulating film surface in the gas phase are not particularly limited, but are preferably 0 ° C. or higher and 500 ° C. or lower, more preferably 20 ° C. or higher and 400 ° C. or lower, preferably 0 .1 minutes to 30 minutes, more preferably 0.2 minutes to 10 minutes.

  Before exposing the surface of the insulating film to the hydrophobizing agent, it is preferable to perform a dehydration treatment of the insulating film. Dehydration can be performed by heat-treating the insulating film in dry air or in an inert atmosphere. The temperature of the heat treatment is preferably 250 ° C. or higher and 850 ° C. or lower, more preferably 300 ° C. or higher and 850 ° C. or lower. The heat treatment time is preferably from 0.1 minute to 2 hours, more preferably from 0.2 minute to 1 hour. When the temperature is 250 ° C. or higher, moisture adsorbed on the insulating film can be removed well.

  As described above, the present inventors have optimized the ratio of the silica particles and the polysiloxane compound and the ratio of the components of the polysiloxane compound, thereby increasing the pot life and The inventors have invented a condensation reaction product solution that has good embeddability in the trench, has a low cure shrinkage when fired into silicon oxide, and is excellent in crack resistance and HF resistance. That is, in a particularly preferred embodiment, it is preferable that the condensation component used in the present invention contains a condensation conversion amount of the polysiloxane compound of 50% by mass to 90% by mass and 10% by mass to 50% by mass of silica particles. The above ratio is preferably 10% by mass or more from the viewpoint of low shrinkage rate and good crack resistance, and 50% by mass or less is preferable from the viewpoint of good film formability and trench embedding. . Further, the polysiloxane compound is derived from the component 10 mol% or more and 40 mol% or less derived from the tetrafunctional silane compound represented by the general formula (2) and the trifunctional silane compound represented by the general formula (3). It is particularly preferable that the component consists of 60 mol% or more and 90 mol% or less. It is preferable that the ratio of the component derived from the trifunctional silane compound is 60 mol% or more from the viewpoint of good HF resistance, crack resistance, and embedding property, and that it is 90 mol% or less is the film forming property and the substrate. It is preferable in terms of good adhesion.

The insulating film obtained by using the condensation reaction product solution of the present invention includes an interlayer insulating film for electronic parts such as a liquid crystal display element, an integrated circuit element, a semiconductor memory element, and a solid-state imaging element, an element isolation film, an STI (Shallow). It is suitable for an insulating film for trench isolation (PMD), a PMD (Pre Metal Dielectric) film, a planarizing film, a surface protective film, a sealing film, and the like.
The present invention also has the following aspects.
[1] (I) (i) The following general formula (1):
R ¹ _n SiX ¹ _4-n (1)
{In the formula, n is an integer of 0 to 3, R ¹ is a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and X ¹ is a halogen atom, an alkoxy group having 1 to 6 carbon atoms or An acetoxy group. }
Condensation reaction of a condensation component containing at least 40% by mass to 99% by mass of a polysiloxane compound derived from the silane compound represented by formula (ii) and 1% by mass to 60% by mass of silica particles. And (II) a solvent,
The silane compound represented by the general formula (1) contains at least a tetrafunctional silane compound in which n is 0 in the general formula (1) and a trifunctional silane compound in which n is 1 in the general formula (1). A condensation reaction product solution, which is two or more types of silane compounds.
[2] The condensation component contains a condensation conversion amount of the polysiloxane compound of 50% by mass to 90% by mass and 10% by mass to 50% by mass of the silica particles,
The following general formula (2) in the polysiloxane compound:
SiX ² ₄ (2)
{In the formula, X ² represents a halogen atom, an alkoxy group having 1 to 6 carbon atoms or an acetoxy group. }
The condensation reaction product solution according to the above [1], wherein the proportion of the component derived from the tetrafunctional silane compound represented by the formula is 5 mol% or more and 40 mol% or less.
[3] The following general formula (3) in the polysiloxane compound:
R ² SiX ³ ₃ (3)
{In the formula, R ² represents a hydrocarbon group having 1 to 10 carbon atoms, and X ³ represents a halogen atom, an alkoxy group having 1 to 6 carbon atoms, or an acetoxy group. }
The condensation reaction product solution according to the above [1] or [2], wherein the proportion of the component derived from the trifunctional silane compound represented by the formula is 60 mol% or more and 95 mol% or less.
[4] In ²⁹ Si NMR analysis, the peak intensity (A) of all tetrafunctional siloxane components in the condensation reaction product and the peak intensity (B) of the component corresponding to the number of siloxane bonds in the condensation reaction product are 4 {(B) / (A)} ≧ 0.50
The condensation reaction product solution according to any one of [1] to [3], which satisfies the relationship:
[5] The condensation reaction product solution according to any one of [1] to [4], wherein the condensation reaction product has a weight average molecular weight of 1,000 or more and 20,000 or less.
[6] The condensation reaction product solution according to any one of [1] to [5], which is used for filling a trench formed in a semiconductor element.
[7] A method for producing the condensation reaction product solution according to any one of [1] to [6] above:
The following general formula (2):
SiX ² ₄ (2)
{In the formula, X ² represents a halogen atom, an alkoxy group having 1 to 6 carbon atoms or an acetoxy group. }
5 mol% or more and 40 mol% or less of a tetrafunctional silane compound represented by the following general formula (3):
R ² SiX ³ ₃ (3)
{In the formula, R ² represents a hydrocarbon group having 1 to 10 carbon atoms, and X ³ represents a halogen atom, an alkoxy group having 1 to 6 carbon atoms, or an acetoxy group. }
A first step of obtaining a polysiloxane compound by hydrolytic polycondensation of a trifunctional silane compound represented by the formula: 60 mol% or more and 95 mol% or less in an aqueous alcohol solution under weakly acidic conditions of pH 5 or more and less than 7. When,
A condensation component consisting of 40% by mass to 99% by mass of the polysiloxane compound obtained in the first step and 1% by mass to 60% by mass of silica particles is obtained by using a C 1-4 alcohol. A second step of carrying out a condensation reaction at a temperature of 50 ° C. or higher in an aqueous solution at a pH of 6 to 8, and obtaining a reaction solution;
After adding at least one solvent having a boiling point of 100 ° C. or more and 200 ° C. or less selected from the group consisting of alcohol, ketone, ester, ether and hydrocarbon solvent to the reaction solution obtained in the second step, distillation is performed. And a third step of obtaining a condensation reaction product solution by distilling off a component having a boiling point of 100 ° C. or less.
[8] An application step of applying the condensation reaction product solution according to any one of [1] to [6] onto a substrate to obtain a coated substrate;
And a baking step of heating the coated substrate obtained in the coating step.
[9] The method for forming an insulating film according to [8], wherein the substrate has a trench structure.

  Hereinafter, embodiments of the present invention will be described in more detail with reference to examples and comparative examples. The present invention is not limited to these.

[Evaluation items of polysiloxane compound, condensation reaction product and condensation reaction product solution]
(1) NMR measurement of condensation reaction product (Q4 component amount measurement)
Sample preparation: Samples were prepared by adding 0.9% by weight of chromium acetylacetonate to a 25% by weight heavy acetone solution (concentration of solids in the experiment).
Measurement conditions: Nuclear magnetic resonance (NMR) apparatus manufactured by JEOL Ltd .: ECA700 and probe SI10 were used, and the waiting time was 120 seconds and the number of integrations was 512.
Peak analysis: Using the peak area of each Q component, the peak intensity (A) of all tetrafunctional siloxane components in the condensation reaction product and the component corresponding to 4 siloxane bonds in the condensation reaction product (ie, Q4 component) From the peak intensity (B), the amount of Q4 was calculated according to the following formula: Q4 amount = {(B) / (A)} × 100 (%).

(2) Weight average molecular weight (Mw) measurement of polysiloxane compound The gel permeation chromatography (GPC), HLC-8220, TSKgelGMH _HR- M column made from Tosoh were used. The condensation reaction product was measured as a 1% by mass solution in an acetone solvent, and the weight average molecular weight (Mw) in terms of standard polymethyl methacrylate was determined by a differential refractometer (RI).

(3) Measurement of pH of condensation reaction product solution An equal amount (mass basis) of water was added to a condensation reaction solution having a solid content concentration of 20% by mass and stirred, and this mixed solution was placed on a pH test paper to measure pH.

(4) Measurement of water content of condensation reaction product solution Using a gas chromatograph (GC-14B) manufactured by Shimadzu Corporation, a TCD detector was used to determine the water content of the condensation reaction product solution with a solid content concentration of 20% by mass. It was determined by the internal calibration curve method.

(5) Measurement of the alcohol content of the condensation reaction product solution The alcohol content of the condensation reaction product solution with a solid content concentration of 20% by mass was measured using a gas chromatograph (GC-14B) manufactured by Shimadzu Corporation and using a TCD detector. It was determined by the internal calibration curve method.

(6) Viscosity measurement of a condensation reaction product solution with a solid content concentration of 50% by mass Condensation reaction product solution with a known concentration is concentrated with an evaporator to a solid content concentration of 50% by mass, and the temperature of the condensation reaction product solution after concentration is 25 ° C. or less. Viscosity was measured within 5 minutes. 1.1 ml of a sample having a solid content concentration of 50% by mass is placed in a sample cup of a viscometer (E-type viscometer (RE-85R type, manufactured by Toki Sangyo Co., Ltd., cone rotor: 1 ° 34 ′ × R24)) The rotor was rotated at various rotation speeds. A value was obtained when the viscosity value was stable (when the variation was 2% or less).

(7) Pot Life of Condensation Reaction Product Solution The condensation reaction product solution was allowed to stand at room temperature for 2 weeks and then visually observed for gelation. The case where gelation was observed was B, and the case where gelation was not observed was A.

[Film evaluation items]
(8) Film forming property After a condensation reaction product film was formed on a Si substrate, it was pre-baked stepwise on a hot plate at 100 ° C. for 2 minutes and then at 140 ° C. for 5 minutes. Thereafter, the surface of the film was observed with an optical microscope. The case where striations or comets were observed was B, and the case where it was not observed was A.

(9) Crack resistance After the condensation reaction product films were formed on the Si substrate with various thicknesses, they were pre-baked stepwise on a hot plate at 100 ° C. for 2 minutes and then at 140 ° C. for 5 minutes. Thereafter, firing was performed at 700 ° C. in an N ₂ atmosphere, and the surface of the fired film was observed with an optical microscope. It was determined with an optical microscope whether or not the film had cracks. The crack limit film thickness is less than 0.8 μm as B, 0.8 μm or more and less than 1.0 μm as A, 1.0 μm or more and less than 1.5 μm as AA, and 1.5 μm or more as AAA. .

(10) Shrinkage rate After a condensation reaction product film was formed on a Si substrate, it was pre-baked stepwise on a hot plate at 100 ° C. for 2 minutes and then at 140 ° C. for 5 minutes. The film thickness T1 at this time, and the film thickness T2 after firing fired in an atmosphere of 700 ° C. and an oxygen concentration of 10 ppm or less were then measured according to J. A. The measurement was performed with a spectroscopic ellipsometer M-2000U-Xe manufactured by Woollam. The shrinkage rate was determined from the film thickness before and after firing according to the following formula: shrinkage rate = (1−T2 / T1) × 100 (%). The case where the shrinkage rate is 15% or more is B, the case where it is 12% or more and less than 15% is A, the case where it is 8% or more and less than 12% is AA, and the case where it is less than 8% is AAA.

(11) HF resistance In the same procedure as in (10) above, firing was performed in an atmosphere at 700 ° C. and an oxygen concentration of 10 ppm or less. The fired film was immersed in an aqueous HF solution having a mass ratio of HF: water = 1: 299 for 10 minutes, and the film thickness before and after the HF test was measured with a spectroscopic ellipsometer. If the HF rate at which the film on the Si substrate dissolves is 50 nm / min or more and the refractive index change after HF immersion is 0.01 or more, B, the HF rate is less than 50 nm / min and the refractive index after HF immersion. If the change is 0.01 or more, it is A, and if the HF rate is less than 10 nm / min and the refractive index change after HF immersion is less than 0.01, it is AA.

(12) Adhesiveness The same procedure as (10) above was followed up to firing in an atmosphere at 700 ° C. and an oxygen concentration of 10 ppm or less. The fired film is cut with 6 cutters at 1 mm intervals in each direction of the grid pattern by a cutter to form 25 grid patterns of 1 mm × 1 mm, and a transparent pressure-sensitive adhesive tape is adhered thereto, and the tape is attached. I peeled it off. The subsequent lattice pattern was observed, and AA was assigned when 25 pieces were not peeled off, A was assigned when 1 to 4 pieces were peeled off, and B was assigned when 5 or more pieces were peeled off.

(13) Embedding property After a condensation reaction product is formed on a Si substrate having a trench with an opening width of 20 nm and a depth of 1 μm (ie, an aspect ratio of 50), the hot plate is heated at 100 ° C. for 2 minutes and subsequently at 140 ° C. for 5 minutes. Pre-baked step by step above. Thereafter, firing was performed in an atmosphere of 700 ° C. and an oxygen concentration of 10 ppm or less. After firing, the Si substrate having a trench was cleaved and subjected to FIB processing, and then observed with an acceleration voltage of 1 kV using a scanning electron microscope (SEM) S4800 manufactured by Hitachi. 1000 trench portions were observed in one cleaved substrate. If there is no void or seam at all points and the trench is filled, AAA or 10 or less trenches have voids or seams. AA or more than 10 and 100 or less trenches or seams. A, B when voids or seams exist in more than 100 trenches.

Production Example of Polysiloxane Compound [Production Example 1]
In an eggplant flask, 11.6 g of methyltrimethoxysilane (MTMS), 4.4 g of tetraethoxysilane (TEOS), and 20 g of ethanol were added and stirred, and 11.5 g of water and an appropriate amount for adjusting pH were added thereto. A mixed aqueous solution with nitric acid was added dropwise at room temperature to adjust the pH to 6-7. After completion of dropping, the mixture was stirred for 30 minutes and allowed to stand for 24 hours.

[Production Example 2] to [Production Example 14]
The synthesis was performed in the same manner as in Production Example 1 except that the raw materials listed in Table 1 were used.

Production of condensation reaction product of polysiloxane compound and silica particles An example in which the polysiloxane compound produced in Production Examples 1 to 14 is reacted with silica particles to obtain a condensation reaction product is shown below.
In each Example and each Comparative Example, condensation reaction products having various composition ratios were obtained by changing the ratio of the polysiloxane compound condensation conversion amount and the amount of silica particles charged. In addition, the amount of silica particles in Table 2 is based on the total mass of the condensation conversion amount of the polysiloxane compound and the amount of silica particles.

[Example 1]
In a four-necked 500 mL flask having a distillation tower and a dropping funnel, 47.6 g of PL-06L (water dispersion silica particles having an average primary particle size of 6 nm and a concentration of 6.3% by mass manufactured by Fuso Chemical Industries) and 80 g of ethanol are placed. The mixture was stirred for 5 minutes, and the polysiloxane compound synthesized in Production Example 1 was added dropwise thereto at room temperature. After completion of dropping, the mixture was stirred for 30 minutes and then refluxed for 4 hours. After refluxing, 150 g of propylene glycol methyl ethyl acetate (PGMEA) was added, the oil bath was heated, and methanol, ethanol, water and nitric acid were distilled off from the distillation line to obtain a PGMEA solution of the condensation reaction product. The PGMEA solution of the condensation reaction product was concentrated to obtain a PGMEA solution having a solid concentration of 20% by mass. The physical property evaluation shown by said (1)-(7) of the produced | generated condensation reaction product solution was performed, and the evaluation result was shown in Table 3. ^{The 29} Si NMR spectrum is shown in FIG.

  2 mL of the resulting condensation reaction product solution was dropped on a 6-inch Si substrate, and spin coating was performed in two stages of a rotation speed of 300 rpm for 10 seconds and a rotation speed of 1000 rpm for 30 seconds. The substrate was pre-baked stepwise on a hot plate in air at 100 ° C. for 2 minutes and then at 140 ° C. for 5 minutes to remove the solvent. The obtained Si substrate was heated to 700 ° C. at 5 ° C./min in an atmosphere having an oxygen concentration of 10 ppm or less, baked at 700 ° C. for 30 minutes, and then cooled to room temperature at 2 ° C./min.

  The evaluation shown by said (8)-(12) of the Si substrate after baking was performed, and the evaluation result was shown in Table 4.

  Further, 2 mL of the resulting condensation reaction product solution was dropped on a Si substrate having a trench structure with an opening width of 20 nm and a depth of 1 μm, and spin coating, pre-baking, and baking were performed under the above conditions. The embedding results are shown in Table 4.

[Example 2]
Into a four-necked 500 mL flask having a distillation tower and a dropping funnel, PL-06L (water dispersion silica particles having an average primary particle diameter of 6 nm and a concentration of 6.3% by mass manufactured by Fuso Chemical Industries) and 80 g of ethanol were placed. The mixture was stirred for 5 minutes, and the polysiloxane compound synthesized in Production Example 2 was added dropwise thereto at room temperature. After completion of dropping, the mixture was stirred for 30 minutes and then refluxed for 4 hours. After refluxing, 150 g of propylene glycol methyl ethyl acetate (PGMEA) was added, the oil bath was heated, and methanol, ethanol, water and nitric acid were distilled off from the distillation line to obtain a PGMEA solution of the condensation reaction product. The PGMEA solution of the condensation reaction product was concentrated to obtain a PGMEA solution having a solid concentration of 20% by mass.

  The physical property evaluation shown by said (1)-(7) of the produced | generated condensation reaction product solution was performed, and the evaluation result was shown in Table 3. In addition, film formation, baking, and trench embedding were performed under the same conditions as in Example 1, and the evaluation results are shown in Table 4.

[Example 3]
Into a four-necked 500 mL flask having a distillation tower and a dropping funnel, PL-06L (water dispersion silica particles having an average primary particle diameter of 6 nm and a concentration of 6.3% by mass manufactured by Fuso Chemical Industries) and 80 g of ethanol were placed. The mixture was stirred for 5 minutes, and the polysiloxane compound synthesized in Production Example 3 was added dropwise thereto at room temperature. After completion of dropping, the mixture was stirred for 30 minutes and then refluxed for 4 hours. After refluxing, 150 g of propylene glycol methyl ethyl acetate (PGMEA) was added, the oil bath was heated, and methanol, ethanol, water and nitric acid were distilled off from the distillation line to obtain a PGMEA solution of the condensation reaction product. The PGMEA solution of the condensation reaction product was concentrated to obtain a PGMEA solution having a solid concentration of 20% by mass.

  The physical property evaluation shown by said (1)-(7) of the produced | generated condensation reaction product solution was performed, and the evaluation result was shown in Table 3. In addition, film formation, baking, and trench embedding were performed under the same conditions as in Example 1, and the evaluation results are shown in Table 4.

[Example 4]
Into a four-necked 500 mL flask having a distillation tower and a dropping funnel, 33.3 g of PL-1 (water dispersion silica particles having an average primary particle diameter of 15 nm and a concentration of 12% by mass manufactured by Fuso Chemical Industries) and 80 g of ethanol are placed. The mixture was stirred for minutes, and the polysiloxane compound synthesized in Production Example 4 was added dropwise thereto at room temperature. After completion of dropping, the mixture was stirred for 30 minutes and then refluxed for 4 hours. After refluxing, 150 g of propylene glycol methyl ethyl acetate (PGMEA) was added, the oil bath was heated, and methanol, ethanol, water and nitric acid were distilled off from the distillation line to obtain a PGMEA solution of the condensation reaction product. The PGMEA solution of the condensation reaction product was concentrated to obtain a PGMEA solution having a solid concentration of 20% by mass.

  The physical property evaluation shown by said (1)-(7) of the produced | generated condensation reaction product solution was performed, and the evaluation result was shown in Table 3. In addition, film formation, baking, and trench embedding were performed under the same conditions as in Example 1, and the evaluation results are shown in Table 4.

[Example 5]
Into a four-necked 500 mL flask having a distillation tower and a dropping funnel, 23.8 g of PL-06L (water dispersion silica particles having an average primary particle size of 6 nm and a concentration of 6.3% by mass manufactured by Fuso Chemical Industries) and 80 g of ethanol are placed. The mixture was stirred for 5 minutes, and the polysiloxane compound synthesized in Production Example 5 was added dropwise thereto at room temperature. After completion of dropping, the mixture was stirred for 30 minutes and then refluxed for 4 hours. After refluxing, 150 g of propylene glycol methyl ethyl acetate (PGMEA) was added, the oil bath was heated, and methanol, ethanol, water and nitric acid were distilled off from the distillation line to obtain a PGMEA solution of the condensation reaction product. The PGMEA solution of the condensation reaction product was concentrated to obtain a PGMEA solution having a solid concentration of 20% by mass.

  The physical property evaluation shown by said (1)-(7) of the produced | generated condensation reaction product solution was performed, and the evaluation result was shown in Table 3. In addition, film formation, baking, and trench embedding were performed under the same conditions as in Example 1, and the evaluation results are shown in Table 4.

[Example 6]
Into a four-necked 500 mL flask having a distillation tower and a dropping funnel, 41.7 g of PL-1 (water dispersion silica particles having an average primary particle diameter of 15 nm and a concentration of 12% by mass manufactured by Fuso Chemical Industries) and 80 g of ethanol are placed. The mixture was stirred for minutes, and the polysiloxane compound synthesized in Production Example 6 was added dropwise thereto at room temperature. After completion of dropping, the mixture was stirred for 30 minutes and then refluxed for 4 hours. After refluxing, 150 g of propylene glycol methyl ethyl acetate (PGMEA) was added, the oil bath was heated, and methanol, ethanol, water and nitric acid were distilled off from the distillation line to obtain a PGMEA solution of the condensation reaction product. The PGMEA solution of the condensation reaction product was concentrated to obtain a PGMEA solution having a solid concentration of 20% by mass.

  The physical property evaluation shown by said (1)-(7) of the produced | generated condensation reaction product solution was performed, and the evaluation result was shown in Table 3. In addition, film formation, baking, and trench embedding were performed under the same conditions as in Example 1, and the evaluation results are shown in Table 4.

[Example 7]
Into a four-necked 500 mL flask having a distillation tower and a dropping funnel, 15.9 g of PL-06L (water dispersion silica particles having an average primary particle diameter of 6 nm and a concentration of 6.3% by mass, manufactured by Fuso Chemical Industries) and 80 g of ethanol are placed. The mixture was stirred for 5 minutes, and the polysiloxane compound synthesized in Production Example 7 was added dropwise thereto at room temperature. After completion of dropping, the mixture was stirred for 30 minutes and then refluxed for 4 hours. After refluxing, 150 g of propylene glycol methyl ethyl acetate (PGMEA) was added, the oil bath was heated, and methanol, ethanol, water and nitric acid were distilled off from the distillation line to obtain a PGMEA solution of the condensation reaction product. The PGMEA solution of the condensation reaction product was concentrated to obtain a PGMEA solution having a solid concentration of 20% by mass.

  The physical property evaluation shown by said (1)-(7) of the produced | generated condensation reaction product solution was performed, and the evaluation result was shown in Table 3. In addition, film formation, baking, and trench embedding were performed under the same conditions as in Example 1, and the evaluation results are shown in Table 4.

[Example 8]
In a four-necked 500 mL flask having a distillation tower and a dropping funnel, 47.6 g of PL-06L (water dispersion silica particles having an average primary particle size of 6 nm and a concentration of 6.3% by mass manufactured by Fuso Chemical Industries) and 80 g of ethanol are placed. The mixture was stirred for 5 minutes, and the polysiloxane compound synthesized in Production Example 8 was added dropwise thereto at room temperature. After completion of dropping, the mixture was stirred for 30 minutes and then refluxed for 4 hours. After refluxing, 150 g of propylene glycol methyl ethyl acetate (PGMEA) was added, the oil bath was heated, and methanol, ethanol, water and nitric acid were distilled off from the distillation line to obtain a PGMEA solution of the condensation reaction product. The PGMEA solution of the condensation reaction product was concentrated to obtain a PGMEA solution having a solid concentration of 20% by mass.

  The physical property evaluation shown by said (1)-(7) of the produced | generated condensation reaction product solution was performed, and the evaluation result was shown in Table 3. In addition, film formation, baking, and trench embedding were performed under the same conditions as in Example 1, and the evaluation results are shown in Table 4.

[Example 9]
In a four-necked 500 mL flask having a distillation tower and a dropping funnel, 47.6 g of PL-06L (water dispersion silica particles having an average primary particle size of 6 nm and a concentration of 6.3% by mass manufactured by Fuso Chemical Industries) and 80 g of ethanol are placed. The mixture was stirred for 5 minutes, and the polysiloxane compound synthesized in Production Example 9 was added dropwise thereto at room temperature. After completion of dropping, the mixture was stirred for 30 minutes and then refluxed for 4 hours. After refluxing, 150 g of propylene glycol methyl ethyl acetate (PGMEA) was added, the oil bath was heated, and methanol, ethanol, water and nitric acid were distilled off from the distillation line to obtain a PGMEA solution of the condensation reaction product. The PGMEA solution of the condensation reaction product was concentrated to obtain a PGMEA solution having a solid concentration of 20% by mass.

  The physical property evaluation shown by said (1)-(7) of the produced | generated condensation reaction product solution was performed, and the evaluation result was shown in Table 3. In addition, film formation, baking, and trench embedding were performed under the same conditions as in Example 1, and the evaluation results are shown in Table 4.

[Comparative Example 1]
In a four-necked 500 mL flask having a distillation tower and a dropping funnel, 47.6 g of PL-06L (water dispersion silica particles having an average primary particle size of 6 nm and a concentration of 6.3% by mass manufactured by Fuso Chemical Industries) and 80 g of ethanol are placed. The mixture was stirred for 5 minutes, and the polysiloxane compound synthesized in Production Example 10 was added dropwise thereto at room temperature. After completion of dropping, the mixture was stirred for 30 minutes and then refluxed for 4 hours. After refluxing, 150 g of propylene glycol methyl ethyl acetate (PGMEA) was added, the oil bath was heated, and methanol, ethanol, water and nitric acid were distilled off from the distillation line to obtain a PGMEA solution of the condensation reaction product. The PGMEA solution of the condensation reaction product was concentrated to obtain a PGMEA solution having a solid concentration of 20% by mass.

  The physical property evaluation shown by said (1)-(7) of the produced | generated condensation reaction product solution was performed, and the evaluation result was shown in Table 3. In addition, film formation, baking, and trench embedding were performed under the same conditions as in Example 1, and the evaluation results are shown in Table 4.

[Comparative Example 2]
In a four-necked 500 mL flask having a distillation tower and a dropping funnel, PL-06L (water dispersion silica particles having an average primary particle diameter of 6 nm and a concentration of 6.3% by mass manufactured by Fuso Chemical Industries) and 80 g of ethanol are placed. The mixture was stirred for minutes, and the polysiloxane compound synthesized in Production Example 11 was added dropwise thereto at room temperature. After completion of dropping, the mixture was stirred for 30 minutes and then refluxed for 4 hours. After refluxing, 150 g of propylene glycol methyl ethyl acetate (PGMEA) was added, the oil bath was heated, and methanol, ethanol, water and nitric acid were distilled off from the distillation line to obtain a PGMEA solution of the condensation reaction product. The PGMEA solution of the condensation reaction product was concentrated to obtain a PGMEA solution having a solid concentration of 20% by mass.

  The physical property evaluation shown by said (1)-(7) of the produced | generated condensation reaction product solution was performed, and the evaluation result was shown in Table 3. In addition, film formation, baking, and trench embedding were performed under the same conditions as in Example 1, and the evaluation results are shown in Table 4.

[Comparative Example 3]
50 g of propylene glycol methyl ethyl acetate (PGMEA) is added to the polysiloxane compound synthesized in Production Example 12, the temperature of the oil bath is increased, and methanol, ethanol, water, and nitric acid are distilled off from the distillation line, and a condensation reaction product is obtained. PGMEA solution was obtained. The PGMEA solution of the condensation reaction product was concentrated to obtain a PGMEA solution having a solid concentration of 20% by mass.

The physical property evaluation shown by said (1)-(7) of the produced | generated condensation reaction product solution was performed, and the evaluation result was shown in Table 3. In addition, film formation, baking, and trench embedding were performed under the same conditions as in Example 1, and the evaluation results are shown in Table 4. ^{The 29} Si NMR spectrum is shown in FIG.

[Comparative Example 4]
In a four-necked 500 mL flask having a distillation tower and a dropping funnel, 47.6 g of PL-06L (water dispersion silica particles having an average primary particle size of 6 nm and a concentration of 6.3% by mass manufactured by Fuso Chemical Industries) and 80 g of ethanol are placed. The mixture was stirred for 5 minutes, and the polysiloxane compound synthesized in Production Example 13 was added dropwise thereto at room temperature. After completion of dropping, the mixture was stirred for 30 minutes and then refluxed for 4 hours. After refluxing, 150 g of propylene glycol methyl ethyl acetate (PGMEA) was added, the oil bath was heated, and methanol, ethanol, water and nitric acid were distilled off from the distillation line to obtain a PGMEA solution of the condensation reaction product. The PGMEA solution of the condensation reaction product was concentrated to obtain a PGMEA solution having a solid concentration of 20% by mass.

  The physical property evaluation shown by said (1)-(7) of the produced | generated condensation reaction product solution was performed, and the evaluation result was shown in Table 3. In addition, film formation, baking, and trench embedding were performed under the same conditions as in Example 1, and the evaluation results are shown in Table 4.

[Comparative Example 5]
In a four-necked 500 mL flask having a distillation tower and a dropping funnel, PL-06L (water dispersion silica particles having an average primary particle diameter of 6 nm and a concentration of 6.3% by mass manufactured by Fuso Chemical Industries) and 80 g of ethanol are placed. The mixture was stirred for minutes, and the polysiloxane compound synthesized in Production Example 14 was added dropwise thereto at room temperature. After completion of dropping, the mixture was stirred for 30 minutes and then refluxed for 4 hours. After refluxing, 150 g of propylene glycol methyl ethyl acetate (PGMEA) was added, the oil bath was heated, and methanol, ethanol, water and nitric acid were distilled off from the distillation line to obtain a PGMEA solution of the condensation reaction product. The PGMEA solution of the condensation reaction product was concentrated to obtain a PGMEA solution having a solid concentration of 20% by mass.

  The physical property evaluation shown by said (1)-(7) of the produced | generated condensation reaction product solution was performed, and the evaluation result was shown in Table 3. In addition, film formation, baking, and trench embedding were performed under the same conditions as in Example 1, and the evaluation results are shown in Table 4.

[Comparative Example 6]
A 500 mL eggplant flask was charged with 11.6 g of methyltrimethoxysilane, 4.4 g of tetraethoxysilane, and 20 g of ethanol, and stirred for 5 minutes. 47.6 g of water-dispersed silica particles (mass% concentration) was added. The mixture was stirred for 1 minute, and 10 μl of concentrated nitric acid was added dropwise thereto and stirred for 30 minutes. The concentration was adjusted by concentration and ethanol addition to obtain an ethanol solution having a solid content concentration of 20% by mass of the condensation reaction product.

  The physical property evaluation shown by said (1)-(7) of the produced | generated condensation reaction product solution was performed, and the evaluation result was shown in Table 3. In addition, film formation, baking, and trench embedding were performed under the same conditions as in Example 1, and the evaluation results are shown in Table 4.

[Comparative Example 7]
Methyltrimethoxysilane (11.6 g), tetraethoxysilane (4.4 g) and PGMEA (20 g) were placed in a four-necked 500 mL flask having a distillation column and a dropping funnel, and after stirring for 5 minutes, the temperature of the solution was set to 50 ° C. A mixed aqueous solution of 11.5 g of water and 10 μl of concentrated nitric acid was added dropwise thereto. Subsequently, after stirring at 50 degreeC for 3 hours, 50g of PGMEA was added. Thereafter, the temperature of the oil bath was raised and ethanol, water, and nitric acid were distilled off from the distillation line to obtain a PGMEA solution of a polysiloxane compound. Next, a PGMEA solution of the obtained polysiloxane compound and PGMEA-dispersed silica particles obtained by substituting 15 g of AD-1003 (isopropanol-dispersed silica particles having an average primary particle diameter of 7 nm and a concentration of 20% by mass made by Catalyst Chemical Industries) with PGMEA After mixing and stirring for 5 minutes, a PGMEA solution having a solid content concentration of 20% by mass was obtained.

  The physical property evaluation shown by said (1)-(7) of the produced | generated condensation reaction product solution was performed, and the evaluation result was shown in Table 3. In addition, film formation, baking, and trench embedding were performed under the same conditions as in Example 1, and the evaluation results are shown in Table 4.

  The insulating film obtained by using the condensation reaction product solution of the present invention includes an interlayer insulating film for an electronic component such as a liquid crystal display element, an integrated circuit element, a semiconductor memory element, a solid-state imaging element, an element isolation film, and an STI insulating film. , PMD (Pre Metal Dielectric) film, planarization film, surface protective film, sealing film and the like.

Claims (6)

A method of forming an insulating film for trench embedding formed in a semiconductor element,
(I) (i) The following general formula (1):
R ¹ _n SiX ¹ _4-n (1)
{In the formula, n is an integer of 0 to 3, R ¹ is a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and X ¹ is a halogen atom, an alkoxy group having 1 to 6 carbon atoms or An acetoxy group. }
Condensation reaction of a condensation component containing at least 40% by mass to 99% by mass of a polysiloxane compound derived from the silane compound represented by formula (ii) and 1% by mass to 60% by mass of silica particles. And (II) a solvent,
The silane compound represented by the general formula (1) contains at least a tetrafunctional silane compound in which n is 0 in the general formula (1) and a trifunctional silane compound in which n is 1 in the general formula (1). An application step of applying a condensation reaction product solution, which is two or more types of silane compounds, onto a substrate to obtain a coated substrate;
A baking step of heating the coated substrate obtained in the coating step;
A method for forming an insulating film for filling a trench, comprising: The condensation component contains a condensation conversion amount of the polysiloxane compound of 50% by mass to 90% by mass and the silica particles of 10% by mass to 50% by mass,
The following general formula (2) in the polysiloxane compound:
SiX ² ₄ (2)
{In the formula, X ² represents a halogen atom, an alkoxy group having 1 to 6 carbon atoms or an acetoxy group. }
The method for forming an insulating film for filling a trench according to claim 1, wherein the proportion of the component derived from the tetrafunctional silane compound represented by the formula is 5 mol% or more and 40 mol% or less. The following general formula (3) in the polysiloxane compound:
R ² SiX ³ ₃ (3)
{In the formula, R ² represents a hydrocarbon group having 1 to 10 carbon atoms, and X ³ represents a halogen atom, an alkoxy group having 1 to 6 carbon atoms, or an acetoxy group. }
The method for forming an insulating film for filling a trench according to claim 1 or 2, wherein the proportion of the component derived from the trifunctional silane compound represented by the formula is 60 mol% or more and 95 mol% or less. ^{In 29} Si NMR analysis, the peak intensity (A) of all tetrafunctional siloxane components in the condensation reaction product and the peak intensity (B) of the component corresponding to 4 siloxane bonds in the condensation reaction product are represented by {(B ) / (A)} ≧ 0.50
The method for forming an insulating film for trench embedding according to any one of claims 1 to 3, satisfying the relationship:   5. The method for forming an insulating film for filling a trench according to claim 1, wherein the condensation reaction product has a weight average molecular weight of 1,000 or more and 20,000 or less. A condensation reaction product solution for forming an insulating film for filling a trench formed in a semiconductor element,
(I) (i) The following general formula (1):
R ¹ _n SiX ¹ _4-n (1)
{In the formula, n is an integer of 0 to 3, R ¹ is a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and X ¹ is a halogen atom, an alkoxy group having 1 to 6 carbon atoms or An acetoxy group. }
Condensation reaction of a condensation component containing at least 40% by mass to 99% by mass of a polysiloxane compound derived from the silane compound represented by formula (ii) and 1% by mass to 60% by mass of silica particles. And (II) a solvent,
The silane compound represented by the general formula (1) contains at least a tetrafunctional silane compound in which n is 0 in the general formula (1) and a trifunctional silane compound in which n is 1 in the general formula (1). A condensation reaction product solution for forming an insulating film for trench embedding, which is two or more kinds of silane compounds.

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