JP2013151581A - Polysiloxane material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polysiloxane material preventing generation of volatile components to inhibit occurrence of dust during thermal curing, capable of forming a film having excellent uniformity, and useful for an insulating material used for a semiconductor element.SOLUTION: A polysiloxane material has a polycomdensation structural unit derived from a silane compound represented by formula (1): RSiX(wherein Ris hydrogen or 1-10C hydrocarbon; Xis halogen, 1-6C alkoxy or acetoxy, and Rand Xwhen existing plurally are each independent; and n is an integer of 0 to 3). The percentage of the terminal which can react in the polysiloxane material is within a specific range.

Description

  The present invention relates to a polysiloxane material, a polysiloxane material solution containing the polysiloxane material and a method for producing the same, a method for producing a cured film using the polysiloxane material solution, a cured film obtained by the method, and the cured film. It is related with the semiconductor device containing.

  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 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, conventionally, a silicon oxide film is formed on a silicon substrate having a trench by a CVD (chemical vapor deposition) method. However, in recent years, with the miniaturization of semiconductor elements, the opening width of trenches tends to become narrower and the aspect ratio tends to increase. Therefore, in the method of filling silicon oxide by the CVD method, voids (unfilled in the trenches) Part) or seams (seam-like unfilled parts) are likely to occur.

  As a method other than the CVD method, a method of forming a silicon oxide film by embedding a liquid material in a trench by a coating method and baking it in an oxidizing atmosphere is known. As materials used in this method, polysilazane materials (for example, Patent Document 1), polysilane materials (for example, Patent Document 2), silicone materials, and the like are known.

  By the way, since the silicone material is accompanied by dehydration and dealcoholization condensation reaction when the coating film is baked, there is a problem that voids and cracks are easily 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 such voids and cracks, a composition containing silica particles and a polysiloxane compound has been proposed (for example, Patent Document 3). Patent Documents 4 to 7 describe materials obtained by condensation reaction of silica particles and a polysiloxane compound as materials designed for use as an interlayer insulating film.

JP 2001-308090 A JP 2003-31568 A JP 2006-310448 A JP-A-5-263045 Japanese Patent Laid-Open No. 4-10418 JP-A-3-263476 International Publication No. 2010/150861 Pamphlet

  The present inventors have studied an insulating material for a semiconductor element formed of a silicone material. In the process of applying a polysiloxane material on a substrate and thermally curing the volatile component other than the solvent from the coating film. A problem has been found that occurs. Such volatile components may cause dust generation by reaggregating on the surface of the cured film, making the semiconductor surface flattening step subsequent to the insulating film forming step difficult, It becomes a factor of performance variation. Therefore, the generation of such volatile components is a problem to be solved immediately.

  The present invention provides a polysiloxane material useful as an insulating material used in a semiconductor element, capable of suppressing a volatile component to avoid generation of dust during thermosetting and capable of forming a film having excellent uniformity. Is an issue.

  As a result of diligent research to develop a method for achieving the above object, the present inventors have suppressed the generation of volatile components during thermosetting by using a polysiloxane material having the structure shown below. The inventors have found that such a polysiloxane material is useful as an insulating material used for a semiconductor element, and completed the present invention. That is, the present invention is as follows.

[1] The following general formula (1):
R ¹ _n SiX ¹ _4-n (1)
{In the formula, R ¹ is a hydrocarbon group hydrogen atom or a C1-10, X ¹ is a halogen atom, an alkoxy group, or an acetoxy group having 1 to 6 carbon atoms, R ¹ in the case where there are multiple And X ¹ are each independent, and n is an integer of 0-3. }
A polysiloxane material having a polycondensation structural unit derived from a silane compound represented by:
^{From 29} Si-NMR analysis, the following formula (2):
(A) = D * Σ {Dn * (2-n)} / 2 + T * Σ {Tm * (3-m)} / 3 + Q * Σ {Ql * (4-1)} / 4 × 100 (%) 2)
{Where,
D = Σdn / (Σdn + Σtm + Σql)
T = Σtm / (Σdn + Σtm + Σql)
Q = Σql / (Σdn + Σtm + Σql)
Dn = dn / Σdn
Tm = tm / Σtm
Ql = ql / Σql
dn = ²⁹ Integral value of a component having a siloxane bond number corresponding to n among difunctional siloxane components determined from ²⁹ Si-NMR tm = ^{29 A} siloxane bond number corresponding to m among trifunctional siloxane components determined from Si-NMR Integral value of component ql = ²⁹ Integral value of component corresponding to l of siloxane bonds among tetrafunctional siloxane components obtained from Si-NMR (where n is 0, 1 or 2, m is 0, 1, 2 or 3 and l is 0, 1, 2, 3 or 4)
Is}
A polysiloxane material in which the value (A) calculated by the formula satisfies 15% ≦ (A) ≦ 70%.
[2] The polysiloxane material according to the above [1], further comprising silica particles mixed in the polysiloxane material or condensed in the polysiloxane material, or both.
[3] A polysiloxane material solution containing the polysiloxane material according to the above [1] or [2] and a solvent.
[4] A polysiloxane material forming step of obtaining a polysiloxane material by a step including hydrolytic polycondensation of a raw material containing the silane compound represented by the general formula (1), and an alcohol or a ketone in the polysiloxane material At least one solvent selected from the group consisting of esters, ethers and hydrocarbon solvents, having a boiling point of 100 to 200 ° C., and then distilling off components having a boiling point of 100 ° C. or lower by distillation. The manufacturing method of the polysiloxane material solution as described in said [3] including the solution formation process which obtains a polysiloxane material solution by this.
[5] In the polysiloxane material forming step, the polysiloxane material is added by adding silica particles to the system at least at any time before hydrolysis polycondensation, during hydrolysis polycondensation, or after hydrolysis polycondensation. The production of the polysiloxane material solution according to the above [4], which forms a polysiloxane material further comprising silica particles mixed in or condensed in the polysiloxane material, or both of them. Method.
[6] A method for producing a cured film, comprising: a coating step of applying a polysiloxane material solution according to [3] above onto a substrate to obtain a coated substrate; and a baking step of heating the coated substrate obtained in the coating step. .
[7] The method for producing a cured film according to the above [6], wherein the substrate has a trench structure.
[8] A cured film obtained by the production method according to [6] or [7].
[9] A semiconductor device comprising the cured film according to [8].

  The present invention provides a polysiloxane material capable of suppressing the generation of volatile components during thermosetting and forming a film having excellent uniformity. By using the polysiloxane material of the present invention, a cured film useful as an insulating material for a semiconductor device can be produced.

Is a diagram showing the ²⁹ Si-NMR spectrum of Example 3 of the present invention. Is a diagram showing the ²⁹ Si-NMR spectrum of Example 14 of the present invention. Is a diagram showing the ²⁹ Si-NMR spectrum of Comparative Example 1 of the present invention. It is a figure which shows the GC-MS spectrum (prebaking conditions: 140 degreeC for 5 minutes) of Example 3 and Comparative Example 1 of this invention.

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

<Polysiloxane material>
One embodiment of the present invention is the following general formula (1):
R ¹ _n SiX ¹ _4-n (1)
{In the formula, R ¹ is a hydrocarbon group hydrogen atom or a C1-10, X ¹ is a halogen atom, an alkoxy group, or an acetoxy group having 1 to 6 carbon atoms, R ¹ in the case where there are multiple And X ¹ are each independent, and n is an integer of 0-3. }
A polysiloxane material having a polycondensation structural unit derived from a silane compound represented by the following formula (2) from ²⁹ Si-NMR (nuclear magnetic resonance) analysis:
(A) = D * Σ {Dn * (2-n)} / 2 + T * Σ {Tm * (3-m)} / 3 + Q * Σ {Ql * (4-1)} / 4 × 100 (%) 2)
{Where,
D = Σdn / (Σdn + Σtm + Σql)
T = Σtm / (Σdn + Σtm + Σql)
Q = Σql / (Σdn + Σtm + Σql)
Dn = dn / Σdn
Tm = tm / Σtm
Ql = ql / Σql
dn = ²⁹ Integral value of a component having a siloxane bond number corresponding to n among difunctional siloxane components determined from ²⁹ Si-NMR tm = ^{29 A} siloxane bond number corresponding to m among trifunctional siloxane components determined from Si-NMR Integral value of component ql = ²⁹ Integral value of component corresponding to l of siloxane bonds among tetrafunctional siloxane components obtained from Si-NMR (where n is 0, 1 or 2, m is 0, 1, 2 or 3 and l is 0, 1, 2, 3 or 4)
Is}
A polysiloxane material in which the value (A) calculated by the formula (15) satisfies 15% ≦ (A) ≦ 70% is provided. As described above, the present invention makes it possible to suppress a volatile component generated at the time of thermosetting by setting the ratio of the terminal amount capable of reaction in the polysiloxane material within a specific range.

  Preferred embodiments of the present invention provide polysiloxane materials further comprising silica particles that are mixed in or condensed in the polysiloxane material, or both. Unless otherwise specified, in the present disclosure, the “polysiloxane material containing silica particles” refers to a form of being mixed in the polysiloxane material, condensed in the polysiloxane material, or both. A polysiloxane material containing silica particles is meant, and the “polysiloxane material not containing silica particles” means a polysiloxane material containing no silica particles of the above form.

In addition to the effect of suppressing the volatile components generated during thermal curing, the polysiloxane material containing silica particles has a specific range of the amount of terminal amount that can be reacted in the polysiloxane material, The shrinkage rate at the time of thermosetting is reduced, and the effect of suppressing the occurrence of cracks is excellent. Therefore, a polysiloxane material containing silica particles has an advantage that it is more preferable as an insulating material for a semiconductor element due to a combination of these effects. Whether the polysiloxane material contains silica particles can be confirmed by, for example, ²⁹ Si NMR analysis, IR, or X-ray small angle scattering.

The value (A) calculated by the above formula (2) represents the proportion of the terminal amount that can be reacted and contained in the polysiloxane material. It shows that the ratio of the terminal amount which can react in a polysiloxane material is so large that a value (A) is large. ²⁹ Si NMR analysis of a solution or solid of a tetrafunctional siloxane component (Q component) derived from a tetrafunctional silane compound of n = 0 among the silane compounds represented by the general formula (1) contained in the polysiloxane material From the respective peak areas, q0 to q4 component amounts described later corresponding to 0 to 4 siloxane bonds can be obtained. Specifically, all tetrafunctional siloxane components (that is, a component having a siloxane bond number of 0 (q0 component) and a component having a siloxane bond number of 1 (obtained from ²⁹ Si NMR analysis) ( q1 component), a component corresponding to 2 siloxane bonds (q2 component), a component corresponding to 3 siloxane bonds (q3 component), and a component corresponding to 4 siloxane bonds (q4 component) ) To the peak intensity of the component corresponding to the number of siloxane bonds in the polysiloxane material (ie, ql component) is represented by Ql (where each l is 0, 1, 2, 3 or 4).

Similarly, for the trifunctional siloxane component (T component) derived from the trifunctional silane compound of n = 1 in the polysiloxane material, the number of siloxane bonds is 0 to 0 from each peak area of ²⁹ Si NMR analysis of the solution or solid. It is possible to determine the amount Tm of the component corresponding to t0 to t3 corresponding to 3 and the ratio Tm of the peak intensity of the component corresponding to the number of siloxane bonds m (ie, tm component) with respect to all trifunctional siloxane components (where each m is 0 , 1, 2 or 3).

Similarly, the bifunctional siloxane component (D component) derived from the bifunctional silane compound of n = 2 in the polysiloxane material also has a siloxane bond number from each peak area of ²⁹ Si-NMR analysis of a solution or solid. It is possible to determine the ratio Dn of the peak intensity of the component corresponding to the number of siloxane bonds n (ie, the dn component) with respect to the total amount of the bifunctional siloxane components and the d0 to d2 component amounts corresponding to 0 to 2 (where each n is , 0, 1 or 2).

  The value (A) can be obtained from the values of Ql, Tm and Dn according to the equation (2).

  In a general embodiment, the value (A) calculated by the above formula (2) is 15% ≦ (A), preferably 28% ≦ (A), more preferably from the viewpoint of reducing volatile components. 35% ≦ (A). From the viewpoint of obtaining a uniform film, (A) ≦ 70%, preferably (A) ≦ 60%, and more preferably (A) ≦ 40%.

  In particular, in the embodiment of the polysiloxane material containing silica particles, the value (A) calculated by the above formula (2) is 15% ≦ (A), preferably 16%, from the viewpoint of reducing the volatile components. ≦ (A), more preferably 19% ≦ (A), and further preferably 28% ≦ (A). In this embodiment, from the viewpoint of obtaining a uniform film, (A) ≦ 70%, and from the viewpoint of embedding, preferably (A) ≦ 60%, more preferably (A) ≦ 40%. It is.

  The value (A) calculated by the above formula (2) can be controlled by the amount of catalyst, reaction concentration, reaction temperature, reaction time, etc. during the synthesis of the polysiloxane material.

  The weight average molecular weight (Mw) of the polysiloxane material not containing silica particles is preferably 350 or more and 5,000 or less, more preferably 500 or more and 2,000 or less. When the weight average molecular weight (Mw) of the polysiloxane material is 350 or more, the film formability and crack resistance are good, and when it is 5,000 or less, the generation of volatile components is well suppressed.

  On the other hand, the weight average molecular weight (Mw) of the polysiloxane material containing silica particles is preferably 1,000 or more and 8,000 or less, more preferably 1,500 or more and 6,000 or less. If the weight average molecular weight (Mw) of the polysiloxane material is 1,000 or more, the film formability, crack resistance, and trench embedding properties are good, and if the weight average molecular weight is 8,000 or less, trench embedding properties are obtained. And suppression of generation of volatile components is good.

  The weight average molecular weight (Mw) of each of the above polysiloxane materials can be measured using gel permeation chromatography (GPC), and is a value calculated with polymethyl methacrylate (PMMA) which is a standard substance.

(Silane compound)
In the general formula (1), R ¹ is a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. Examples of the hydrocarbon group having 1 to 10 carbon atoms include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylpropyl group, 1,1-dimethylpropyl group, 1,2-dimethylpropyl group, 2,2-dimethylpropyl group, Acyclic or cyclic saturated hydrocarbon group such as cyclopentyl group, n-hexyl group, cyclohexyl group, n-heptyl group, 2-methylhexyl group, n-octyl group, n-nonyl group, n-decyl group, Aromatic hydrocarbon groups such as phenyl group, tolyl group, xylyl group, vinyl group, propenyl group, butenyl group, pentenyl group, hexenyl group, cyclohexenyl group, cyclohexenyl group Acyclic and cyclic unsaturated hydrocarbon groups such as senylethyl group, norbornenylethyl group, heptenyl group, octenyl group, nonenyl group, decenyl group, styryl group, and benzyl group, phenethyl group, 2-methylbenzyl group Arylalkyl groups such as 3-methylbenzyl group and 4-methylbenzyl group.

Among these, R ¹ is a hydrogen atom, a methyl group, or an ethyl group from the viewpoint that a polysiloxane material having a small weight loss and a low shrinkage rate can be provided upon conversion to silicon oxide during firing. It is preferably a methyl group.

In the general formula (1), X ¹ is a halogen atom, an alkoxy group having 1 to 6 carbon atoms, or an acetoxy group. Examples of the halogen atom include chlorine, bromine, iodine and the like. Examples of the alkoxy group having 1 to 6 carbon atoms include methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, t-butoxy group, n-hexyloxy group and cyclohexyloxy group.

Among these, as X ¹ , chlorine, bromine, iodine, methoxy group, ethoxy group, and acetoxy group are preferable from the viewpoint of high reactivity of the condensation reaction, and more preferably methoxy group or ethoxy group.

  In the said General formula (1), n is an integer of 0-3. That is, as the silane compound, a monofunctional silane compound (a compound having n = 3 in the general formula (1)) having a different number of functional groups on the silicon atom, a bifunctional silane compound (n = 2 in the general formula (1)). Compound), a trifunctional silane compound (a compound with n = 1 in the general formula (1)), and a tetrafunctional silane compound (a compound with n = 0 in the general formula (1)), one or two from a series of compounds More than species can be selected. These can be selected according to the physical properties of the target polysiloxane material. Generally, by using a silane compound having a small number of functional groups, a polysiloxane material having a high degree of condensation and excellent toughness can be obtained. In addition, by using a silane compound having a large number of functional groups, a polysiloxane material having good film formability, denseness and high mechanical strength can be obtained.

  From such a viewpoint, as the insulating material used for the semiconductor element, the silane compound is preferably at least trifunctional, and more specifically, a trifunctional silane compound and a tetrafunctional silane compound are used in appropriate combination. Is preferred.

From the viewpoint of crack resistance, the mixing ratio of the trifunctional silane compound and the tetrafunctional silane compound is preferably trifunctional silane compound / 4 functional silane compound = 20/80 to 90/10 (molar ratio). More preferably, trifunctional silane compound / 4 functional silane compound = 30/70 to 85/15 (molar ratio), and still more preferably trifunctional silane compound / 4 functional silane compound = 50/50 to 80/20 ( Molar ratio). The molar ratio can be confirmed by, for example, ¹ H-NMR analysis and ²⁹ Si-NMR analysis.

  Moreover, the ratio which a bifunctional silane compound, a trifunctional silane compound, and a tetrafunctional compound occupy among the silane compounds to be used is preferably 90% or more, more preferably 95% or more in terms of a molar ratio from the viewpoint of reducing volatile components. is there.

(Silica particles)
Certain embodiments of the present invention provide a polysiloxane material comprising silica particles. The silica particle in the present disclosure means a silica particle having an outer dimension of 10 μm or less at maximum. The silica particles typically have a spherical shape, a rod shape, a plate shape, a fiber shape, or a shape in which two or more of these are combined, preferably a spherical shape. The term “spherical” as used herein includes not only true spheres but also cases such as spheroids and oval shapes.

Examples of the silica particles 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). Among these, colloidal silica obtained from alkoxy silicon is preferable from the viewpoint that impurities such as metal ions and halogens are not mixed.

  The average primary particle diameter of the silica particles is preferably 1 nm to 120 nm, more preferably 1 nm to 40 nm, still more preferably 1 nm to 20 nm, and most preferably 1 nm to 15 nm. 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 to 250 nm, more preferably 2 nm to 80 nm, still more preferably 2 nm to 40 nm, and most preferably 2 nm to 30 nm. When the average secondary particle size is 2 nm or more, the crack resistance is good, and when it is 250 nm or less, the embedding property in the trench is good.

  The average primary particle diameter is determined by a specific surface area (BET method) calculated from the pressure and adsorption amount of nitrogen molecules. The average secondary particle diameter is measured with a dynamic light scattering photometer or the like.

  Examples of commercially available colloidal silica include 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.), Quateron PL series (Fuso Chemical) Kogyo Kasei Kogyo Co., Ltd.) and OSCAL series. Examples of the powdery silica particles include Aerosil 130, 300, 380, TT600, OX50 (above, manufactured by Nippon Aerosil Co., Ltd.), Sildex H31, H32, H51, H52, H121. H122 (above, manufactured by Asahi Glass Co., Ltd.), E220A, E220 (above, manufactured by Nippon Silica Industry Co., Ltd.), SYLYSIA470 (produced by Fuji Silysia Co., Ltd.), SG flake (produced by Nippon Sheet Glass Co., Ltd.), and the like.

The silica particles may be obtained in a form dispersed in a dispersion medium. In that case, the content of the silica particles can be calculated using the amount of net silica particles in terms of SiO ₂ , that is, the value obtained by multiplying the weight of the dispersion used by the concentration of silica particles in terms of SiO ₂ .

In the aspect in which the polysiloxane material includes silica particles, the content of the silica particles is preferably 1% by mass or more and 60% by mass or less when the SiO ₂ equivalent of the raw material of the polysiloxane material is 100% by mass, More preferably, they are 10 mass% or more and 50 mass% or less, More preferably, they are 15 mass% or more and 45 mass% or less. When the content is 1% by mass or more, a low shrinkage rate and good crack resistance are obtained, and when the content is 60% by mass or less, the film formability and the embedding property in the trench are good.

(Manufacture of polysiloxane materials)
The polysiloxane material can be produced by a process including hydrolytic polycondensation of the raw material containing the silane compound. The silane compound may be one type or a combination of two or more types. The raw material may be composed only of the silane compound represented by the general formula (1), and may further contain silica particles. The raw material may contain at least one of other silane compounds and condensable components other than the silane compounds and silica particles as an additional component. As said other silane compound, the silane compound etc. which have an acrylic group, an epoxy group, a vinyl group etc. as a reactive functional group, etc. are mentioned, for example. The amount of the additional component used is not limited, but the total amount of the additional component in the raw material is preferably 10% by mass or less, and more preferably 5% by mass or less.

The total concentration of the silane compound and silica particles (when used) in the reaction system (typically in the reaction solution) is preferably 1% by mass or more, more preferably 5% by mass or more, in terms of SiO ₂ concentration. From the viewpoint of controlling the value (A) represented by the above formula (2), that is, from the viewpoint of easily controlling the proportion of the terminal amount capable of reacting in the polysiloxane material, the SiO ₂ equivalent concentration is 70% by mass. The following is preferable.

  Hereinafter, a specific manufacturing procedure of the polysiloxane material will be described. For simplicity, an example in the case of using a raw material composed of the silane compound represented by the general formula (1) will be described below, but also when the system includes at least one of silica particles and additional components. Unless otherwise specified, the same procedure can be used.

The silane compound represented by the general formula (1) can be polycondensed in the presence of water. At this time, from the viewpoint of storage stability, it is preferably 0.1 equivalents or more and 10 equivalents or less with respect to the number of moles of X ¹ contained in the silane compound represented by the general formula (1) under acidic conditions. More preferably, hydrolysis and polycondensation are performed in the presence of 0.4 to 8 equivalents of water.

When the silane compound used for producing the polysiloxane material contains a halogen atom or an acetoxy group as X ¹ in the general formula (1), the reaction system can be prepared by adding water for hydrolysis polycondensation. In order to show acidity, it does not matter whether an acid catalyst is used or not. 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, boric acid and the like. 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 polysiloxane material can be produced in a solvent. The solvent is, for example, 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 hydrocarbons, and amides.

  Examples of the alcohol include monohydric alcohols such as methanol, ethanol, propanol, and butanol, ethylene glycol, diethylene glycol, propylene glycol, glycerin, trimethylolpropane, hexanetriol polyhydric alcohol, and ethylene glycol monomethyl ether and 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 Ether, mono ethers of polyhydric alcohol such as propylene glycol monobutyl ether.

  Examples of the ester include methyl acetate, ethyl acetate, butyl acetate, gamma butyrolactone and the like.

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

  Examples of ethers include monoethers of the above polyhydric alcohols, and, 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, propylene glycol dibutyl ether. , Diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether and the like, polyhydric alcohol ethers obtained by alkyl etherification of some or all of the hydroxyl groups of polyhydric alcohols, and diethyl ether, dipropyl ether, tetrahydrofuran, 1,4-dioxane And anisole.

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

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

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

  Among these solvents, alcohols such as methanol, ethanol, isopropanol and butanol, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, ethers such as ethylene glycol monomethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether and propylene glycol monoethyl ether And amides such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone and N-ethylpyrrolidone are preferable from the viewpoint of easy mixing with water and easy dispersion of silica particles described below.

  These solvents may be used alone or in combination of a plurality of solvents. Further, the reaction may be carried out without using the solvent.

  Although there is no restriction | limiting in particular about the condensation reaction temperature at the time of manufacturing polysiloxane material, Preferably it is -50 degreeC or more and 200 degrees C or less, More preferably, they are 0 degreeC or more and 150 degrees C or less. By performing the reaction in the above temperature range, the molecular weight of the polysiloxane material can be easily controlled, and the synthesis reproducibility is good.

  The condensation reaction in the reaction system not containing silica particles can be carried out under acidic conditions, for example, in an aqueous alcohol solution, at a pH of the reaction system of 1.0 to 4.0, more preferably 2.0 to 3.5.

On the other hand, in the case of producing a polysiloxane material containing silica particles, the silica particles can be added to the system at least at any time before hydrolysis polycondensation, during hydrolysis polycondensation, or after hydrolysis polycondensation. As a method for producing a polysiloxane material containing silica particles, for example, the following method:
(I) A polysiloxane condensate is produced by hydrolytic polycondensation of the silane compound represented by the above general formula (1), and then mixed with silica particles to obtain a mixture of the polysiloxane condensate and silica particles. A method of obtaining a polysiloxane material,
(Ii) After producing a polysiloxane intermediate condensate obtained by hydrolytic polycondensation of the silane compound represented by the general formula (1), the resulting polysiloxane intermediate condensate and silica particles are further subjected to a condensation reaction. And (iii) coexisting silica particles when hydrolyzing and polycondensing the silane compound represented by the general formula (1). A method for producing a polysiloxane material containing a structure in which silica particles are condensed, by adding silica particles to the reaction system in the course of the hydrolysis polycondensation reaction,
Is preferred. (I) and (ii) are methods in which silica particles are added to the system after hydrolytic polycondensation of the silane compound. In (ii), further condensation reaction is performed after hydrolysis polycondensation. (Iii) is a method of incorporating silica particles in the raw material before or during hydrolysis polycondensation of the silane compound.

  In the condensation reaction in the reaction system containing silica particles, the pH of the reaction system is adjusted, for example, preferably in the range of 3.0 to 7.0, more preferably in the range of 3.5 to 6.5. When the pH is 3.0 or more, the storage stability of the finally obtained polysiloxane material is good. Moreover, when pH is 7.0 or less, it not only is excellent in the reproducibility (especially molecular weight reproducibility) of superposition | polymerization, but gelatinization becomes difficult to advance. In the present disclosure, the pH during the reaction is a value measured by a pH electrode of an automatic potentiometric titrator (manufactured by Kyoto Electronics Industry Co., Ltd., AT-610).

  Further, the weight average molecular weight of the polysiloxane intermediate condensate when the above-mentioned method (ii) is used is preferably 100 or more and less than 1300, more preferably 150 or more and 700 or less. The weight average molecular weight is preferably 100 or more from the viewpoint of film formability, and preferably less than 1300 from the viewpoint of suppressing the generation of volatile components. The weight average molecular weight of the polysiloxane intermediate condensate is measured using gel permeation chromatography (GPC) and is a value calculated in terms of standard polyethylene glycol.

  Hereinafter, although the procedure in the case of manufacturing the polysiloxane material containing a silica particle by the method of above-mentioned (ii) is illustrated in detail, this invention is not limited to this.

  The method (ii) described above includes a first step of obtaining a polysiloxane intermediate condensate by hydrolytic polycondensation of the silane compound represented by the general formula (1), and the polysiloxane obtained in the first step. A second step of condensing the intermediate condensate and the silica particles is included.

  The first step can be performed by the same method as described in detail for the hydrolysis polycondensation of the silane compound represented by the general formula (1).

  In the second step, the polysiloxane intermediate condensate is subjected to a condensation reaction of silica particles, and the reaction can be advanced using silica particles dispersed in a dispersion medium. The dispersion medium can be water, an organic solvent, or a mixed solvent thereof. The type of organic solvent used in the condensation reaction varies depending on the dispersion medium in which the silica particles used are dispersed.

  When the silica particle dispersion medium used is aqueous, the aqueous dispersion obtained by adding water and / or an alcohol solvent to the silica particles may be reacted with the polysiloxane intermediate condensate. After the water contained in the liquid is once replaced with alcohol or the like, the alcohol dispersion of silica particles may be reacted with the polysiloxane intermediate condensate. The alcohol that can be used is preferably an alcohol having 1 to 4 carbon atoms from the viewpoint of easy mixing with water, for example, methanol, ethanol, n-propanol, 2-propanol, n-butanol, methoxyethanol, ethoxyethanol. Etc.

  When the dispersion medium of silica particles used is alcohol, ketone, ester, hydrocarbon or the like, water or a solvent such as alcohol, ether, ketone, ester or the like can be used during the condensation reaction. Examples of the alcohol include methanol, ethanol, n-propanol, 2-propanol, n-butanol and the like. 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.

  The condensation reaction between the polysiloxane intermediate condensate and the silica particles is usually carried out in the presence of an acid catalyst. Examples of the acid catalyst include the same acid catalyst as described above for use in hydrolysis polycondensation of a silane compound.

  The reaction temperature in the condensation reaction between the polysiloxane intermediate condensate 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, the weight average molecular weight (Mw) of the condensation reaction product can be easily controlled.

  After obtaining the polysiloxane material by the procedure as described above, a purification treatment may be performed in order to remove impurities such as metal ions. Examples of the method for removing impurities such as metal ions include ion exchange using an ion exchange resin or an ion exchange membrane filter, filtration separation using an ultrafiltration membrane, purification by distillation, and the like.

<Polysiloxane material solution>
Another aspect of the present invention provides a polysiloxane material solution comprising the polysiloxane material according to the present invention described above and a solvent. The polysiloxane material according to one embodiment of the present invention can be combined with a solvent. Examples of the solvent include one or more solvents selected from alcohols, ketones, esters, ethers, and hydrocarbon solvents. The boiling point of these solvents is preferably 100 ° C. or higher and 200 ° C. or lower. The amount of the solvent used 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 polysiloxane material. If the amount of the solvent used is 100 parts by mass or more, the storage stability of the polysiloxane material is good, and if it is 1900 parts by mass or less, the trench embedding property is good.

Examples of the alcohol, ketone, ester, ether, and hydrocarbon solvent include alcohols such as butanol, pentanol, hexanol, octanol, methoxyethanol, ethoxyethanol, propylene glycol monomethoxy ether, propylene glycol monoethoxy ether, and methyl ethyl ketone. , Methyl isobutyl ketone, isoamyl ketone, ethyl hexyl ketone, cyclopentanone, cyclohexanone, γ-butyrolactone and other ketones, butyl acetate, pentyl acetate, hexyl acetate, propyl propionate, butyl propionate, pentyl propionate, hexyl propionate Pionate, propylene glycol monomethyl ether acetate, esters such as ethyl lactate, butyl ethyl ether, butyl propyl Ether, dibutyl ether, anisole, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol dimethyl ether, propylene glycol monomethyl ether, and propylene glycol diethyl ether, toluene, hydrocarbon solvents such as xylene and the like.
These solvents may be used alone or in combination with a plurality of solvents. However, from the viewpoint of good storage stability of the polysiloxane material and good film formability, the boiling point is 100. Preferably, at least one solvent selected from alcohols, ketones, esters, ethers, and hydrocarbon solvents having a temperature of from 200 ° C. to 200 ° C. constitutes 50% by mass or more of the entire solvent contained in the polysiloxane material solution. .

<Method for producing polysiloxane material solution>
Another aspect of the present invention is a method for producing a polysiloxane material solution as described above, comprising:
Polysiloxane material formation for obtaining a polysiloxane material by a process including hydrolytic polycondensation of a raw material containing the silane compound represented by the general formula (1), preferably at a reaction temperature of −50 ° C. to 200 ° C. And at least one solvent selected from the group consisting of alcohols, ketones, esters, ethers and hydrocarbon solvents, and having a boiling point of 100 to 200 ° C., is added to the polysiloxane material, And a solution forming step of obtaining a polysiloxane material solution by distilling off a component having a boiling point of 100 ° C. or less by distillation.

  According to a further aspect of the present invention, in the polysiloxane material forming step, silica particles are added to the system at least at any point before, during or after hydrolysis polycondensation. A method for producing a polysiloxane material solution that forms a polysiloxane material that further includes silica particles that are mixed in or condensed in the polysiloxane material, or both. .

  The polysiloxane material can be produced, for example, by the method described above. Next, after adding a solvent having a boiling point of 100 to 200 ° C. to the obtained polysiloxane material, components having a boiling point of 100 ° C. or less are distilled off by distillation. Thereby, a polysiloxane material solution can be obtained.

  The polysiloxane material according to the present invention is an interlayer insulation for insulating each layer of a laminated structure formed on a substrate in a semiconductor device such as a liquid crystal display element, an integrated circuit element, a semiconductor memory element, and a solid-state imaging element. Film, element isolation film for electrically isolating a plurality of adjacent elements, insulating film for STI that forms a groove-like structure (trench) on a substrate and fills the inside thereof to insulate and isolate elements In addition, it can be suitably used as a PMD (Pre Metal Dielectric) film, a planarizing film, a surface protective film, a sealing film, and the like.

<Method for forming cured film>
Another aspect of the present invention includes a coating step of applying the above-described polysiloxane material solution of the present invention on a substrate to obtain a coated substrate, and a curing step of heating the coated substrate obtained in the coating step. A method for manufacturing a membrane is provided. The polysiloxane material solution produced by the method as described above can be applied onto the substrate by a usual method. Examples of the coating method include spin coating, dip coating, roller blade coating, and spray coating. Among these, the spin coating method is preferable from the viewpoint that the coating thickness during film formation is uniform.

  An example of the substrate is a silicon substrate. The substrate can have a trench structure. For example, when a polysiloxane material solution is applied to a silicon substrate having a trench structure by a spin coating method, it may be applied at a single rotational speed or a combination of multiple rotational speeds. It is preferable that the rotation speed in the first stage is made low and the speed in the second and subsequent stages is made high. By rotating at a low speed in the first stage, the polysiloxane material solution can be spread over the entire surface of the silicon substrate, and the embedding property is improved. Further, the polysiloxane material solution may be applied once or a plurality of times. However, it is preferable that the polysiloxane material solution is applied once from the viewpoint of good film formability and a reduction in manufacturing cost.

In the coating step, there is no particular limitation on the solid content concentration in terms of SiO ₂ (hereinafter also referred to as solid content concentration) in the polysiloxane material solution to be coated on the substrate, according to the film thickness of the target coating film. It can be carried out at any solid concentration.

  Although there is no restriction | limiting in particular about the temperature and time of the said application | coating process, It is preferable that temperature is 0 degreeC or more and 100 degrees C or less, More preferably, they are 20 degreeC or more and 80 degrees C or less, Time is 0.1 minutes or more. It is preferably 30 minutes or less, more preferably 0.2 minutes or more and 10 minutes or less.

  Next, the coated substrate is heated in the firing step. In the application step, after applying the polysiloxane material solution on the substrate, it is preferably pre-cured (prebaked) in the range of 50 ° C. to 200 ° C. in order to remove the residual solvent in the coating film. At this time, the temperature may be raised stepwise or continuously. The atmosphere at the time of preliminary curing (pre-baking) may be an oxidizing atmosphere containing an oxidizing gas such as oxygen or water vapor, or a non-oxidizing atmosphere substantially not containing an oxidizing gas.

  Next, a cured film can be obtained by heating and baking a film obtained by optionally pre-curing (pre-baking). As a heating and baking method, for example, a general heating means such as a hot plate, an oven, or a furnace can be applied. Heating and baking are preferably performed in a non-oxidizing atmosphere. The heating and baking temperature is preferably 200 ° C. or higher and 900 ° C. or lower, more preferably 300 ° C. or higher and 800 ° C. or lower, and further preferably 350 ° C. or higher and 750 ° C. or lower. If the heating and baking temperature is 200 ° C. or higher, the obtained film quality is good, and if it is 900 ° C. or lower, crack resistance is good.

  Examples of the non-oxidizing atmosphere include a vacuum or an inert atmosphere such as nitrogen, helium, argon, or xenon. The concentration of an oxidizing gas such as oxygen or water vapor contained in these inert atmospheres is preferably 1000 ppm or less, more preferably 100 ppm or less, and further preferably 10 ppm or less. There is no restriction | limiting in particular about the pressure of non-oxidizing atmosphere, Any of pressurization, a normal pressure, or pressure reduction may be sufficient.

  In the baking step, it is preferable to perform heat baking in a gas containing hydrogen in a high temperature region of 700 ° C. or higher and 900 ° C. or lower. 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 temperature is lower than 700 ° C., or may be introduced after reaching 700 ° C. Further, after performing the first heating with a gas not containing hydrogen at a temperature of 700 ° C. or more and 900 ° C. or less, the heating and firing are performed in two stages, in which a gas containing hydrogen is introduced and the second heating is performed. Also good. In any method, it is preferable to keep introducing a gas containing hydrogen until the substrate after heating and baking is cooled to a temperature of 400 ° C. or lower, preferably about room temperature.

  As described above, if the baking 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, it is possible to prevent the formation of silanol groups and realize good film properties as an insulating material of a semiconductor element.

  The heat treatment time in the firing step is preferably 1 minute to 24 hours, and more preferably 30 minutes to 12 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 performed simultaneously 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 the light treatment, for example, visible light, ultraviolet light, deep ultraviolet light or the like can be used. As a light source for light treatment, for example, a low-pressure or high-pressure mercury lamp, deuterium lamp, or discharge light of a rare gas such as argon, krypton, or xenon, YAG laser, argon laser, carbon dioxide gas laser, or XeF, XeCl, XeBr Excimer lasers such as KrF, KrCl, ArF or ArCl can be used. The output of these light sources is preferably 10 to 5,000 W.

The light wavelength of these light sources may be absorbed by the polysiloxane material in the film formed on the substrate as much as possible, and is preferably 170 nm or more and 600 nm or less. In light treatment, a light irradiation amount is preferably at 0.1 J / cm ² or more 1,000 J / cm ² or less, more preferably 1 J / cm ² or more 100 J / cm ² or less. Moreover, ozone may be generated simultaneously with the light treatment. By performing the light treatment under the above-described conditions, the oxidation reaction of the polysiloxane material in the film formed on the substrate proceeds, and the film quality after baking can be improved.

  After the baking step, the surface of the cured film may be exposed to a hydrophobizing agent. By exposing the cured film to a hydrophobizing agent, the silanol groups in the cured film react with the hydrophobizing agent, and the surface of the cured film can be hydrophobized.

  Another aspect of the present invention provides a cured film obtained by the production method described above. Yet another embodiment of the present invention provides a semiconductor device including the cured film. Examples of the semiconductor device are a liquid crystal display element, an integrated circuit element, a semiconductor memory element, a solid-state imaging element, and the like. The cured film provided by the present invention is suitable for a semiconductor device, for example, as an interlayer insulating film, an element isolation film, an STI insulating film, a PMD (Pre Metal Dielectric) film, a planarizing film, a surface protective film, a sealing film, and the like. Available to:

  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.

(1) Weight average molecular weight (Mw) measurement
Method 1: Weight average molecular weight (Mw) measurement of polysiloxane intermediate condensate Gel Permeation Chromatography (GPC) SCL-1APvp, Shodex KF-804L column manufactured by Shimadzu was used. In a tetrahydrofuran solvent, the polysiloxane intermediate condensate was measured as a 1% by mass solution, and the weight average molecular weight (Mw) in terms of standard polyethylene glycol was determined by a differential refractometer (RI).

Method 2: Measurement of weight average molecular weight (Mw) of polysiloxane material A gel permeation chromatography (GPC) HLC-8220 manufactured by Tosoh, TSKgelGMH _HR- M column was used. A polysiloxane material was measured in a 1% by mass solution in an acetone solvent, and a weight average molecular weight (Mw) in terms of standard polymethyl methacrylate was determined by a differential refractometer (RI).

(2) ²⁹ Si-NMR measurement of polysiloxane material Sample preparation: 0.6 mass% of chromium acetylacetonate was added to 25 mass% heavy acetone solution of polysiloxane material concentration (in the experiment, solid content concentration). Sample preparation was performed.
Measurement conditions: Nuclear magnetic resonance (NMR) apparatus manufactured by JEOL Ltd .: ECA700 and probe SI10 were used, and the integration was performed with a waiting time of 120 seconds and an integration count of 200 times.
Peak analysis: q0 to q4 components corresponding to 0 to 4 siloxane bonds from each peak area of ²⁹ Si-NMR analysis of a solution or solid of a tetrafunctional siloxane component (Q component) derived from a tetrafunctional silane compound The amount was determined.

^{29 From the} Si-NMR analysis, all the tetrafunctional siloxane components in the polysiloxane material (ie, the component corresponding to 0 siloxane bond (q0 component), the component corresponding to 1 siloxane bond (q1 component), siloxane The peak intensity of the component corresponding to two bonds (q2 component), the component corresponding to three siloxane bonds (q3 component), and the component corresponding to four siloxane bonds (q4 component)) The ratio Q1 (where each l represents 0, 1, 2, 3 or 4) of the peak intensity of the component corresponding to the number of siloxane bonds in the polysiloxane material (ie, the ql component) was determined.

Similarly, the trifunctional siloxane component (T component) derived from the trifunctional silane compound of n = 1 also has a siloxane bond number corresponding to 0 to 3 from each peak area of ²⁹ Si-NMR analysis of solution or solid. The ratio Tm of the peak intensity of the component corresponding to the number of siloxane bonds m (i.e., the tm component) with respect to the total amount of t0 to t3 components and the total trifunctional siloxane component (that is, each m represents 0, 1, 2, or 3) Asked.

Similarly, the bifunctional siloxane component (D component) derived from the bifunctional silane compound of n = 2 also has a siloxane bond number of 0 to 2 from the respective peak areas of ²⁹ Si-NMR analysis of the solution or solid. The ratio Dn (where each n represents 0, 1, or 2) of the peak intensity of the component corresponding to the number of siloxane bonds n to the total bifunctional siloxane component (ie, the dn component) is obtained. It was.

  The value (A) was determined from these values according to the formula (2).

[Film evaluation items]
(3) Preparation of sample for evaluation of volatile components: 1 mL of a polysiloxane material solution is dropped on a 6-inch Si substrate, and this substrate is pre-baked in air at 140 ° C. for 5 minutes or at 50 ° C. for 15 minutes on a hot plate. The solvent was removed.
Measurement conditions: From the obtained coated substrate, a volatile component was collected using a pyronizer LAB pyrolyzer (PY-2010D), and measured with a GC system (6890N) and an MS system (5975) manufactured by Agilent Technologies. did. The measurement conditions of the pyrolyzer are a temperature increase from 150 ° C. to 600 ° C. at a temperature increase rate of 20 ° C./min, and the GC-MS measurement conditions are column: UA-1, oven temperature: 50 ° C. (held for 5 minutes). → 450 ° C. (20 ° C./min), injection temperature: 300 ° C., AUX2 temperature: 360 ° C., flow rate: He (1.0 ml / min). Regarding the obtained measurement results, in the 140 ° C. PB film, the peak signal intensity of holding time of 8 to 15 minutes is less than 60% compared with the signal intensity of Comparative Example 1, and is not marked. In the case of 140 ° C. PB film and 50 ° C. PB film, the peak signal intensity of the retention time of 8 to 15 minutes is reduced to 60% or less as compared with the signal intensity of Comparative Example 1 as ◎. did.

(4) Embedding property After forming a film using a polysiloxane material solution on a Si substrate having a trench having an opening width of 20 nm and a depth of 1 μm (that is, an aspect ratio of 50), the film is formed at 100 ° C. for 2 minutes and subsequently at 140 ° C. for 5 minutes And prebaked in stages on a hot plate. 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 a cross section was observed at 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. When there are no voids or seams at all locations and the trench is filled ◎ When there are voids or seams in 10 or less trenches ○ When there are voids or seams in more than 10 trenches and 100 or less trenches Δ, and a case where there are voids or seams in more than 100 trenches was marked with ×.

(5) Crack resistance The polysiloxane material solution was applied to the Si substrate in various thicknesses to form a film, and then prebaked 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 case where the crack limit film thickness (that is, the maximum film thickness at which no crack is observed) is less than 0.8 μm is x, the case where it is 0.8 μm or more and less than 1.0 μm is Δ, the case where it is 1.0 μm or more and less than 1.2 μm is ○, The case of 1.2 μm or more was marked with “◎”.

[Example 1]
A 500 mL four-necked flask with a reflux tube and a dropping funnel is charged with 22.2 g of methyltrimethoxysilane (MTMS), 8.9 g of tetraethoxysilane (TEOS), and 41 g of ethanol, and heated to reflux at 78 ° C. using an oil bath. did. To this, 19.2 g of water and 0.31 g of a 0.7 mass% nitric acid aqueous solution were added dropwise, and after completion of the dropwise addition, the reaction was carried out at 78 ° C. for 2 hours (first step).

  119 g of ethanol and PL-06L (manufactured by Fuso Chemical Industries, average primary particle diameter 6 nm, water-dispersed silica particles having a concentration of 6.3% by mass) 95.2 g and a 0.7% by mass nitric acid aqueous solution 2.75 g were added dropwise. Later, after heating to 80 ° C., the mixture was refluxed for 4 hours to obtain a polysiloxane material (second step).

  After refluxing, 300 g of propylene glycol methyl ethyl acetate (PGMEA) (boiling point 146 ° C.) was added, and methanol, ethanol, water and nitric acid were distilled off using a rotary evaporator to obtain a polysiloxane material solution (solid content concentration 20% by mass). PGMEA solution) was obtained (third step). The physical property evaluation shown by said (1)-(5) of the produced | generated polysiloxane material solution was performed. The evaluation results are shown in Table 3.

[Examples 2 to 7]
Only the reaction conditions in Example 1 were changed to obtain a polysiloxane material solution. The changed conditions are summarized in Table 1. The evaluation results are summarized in Table 3. Of these examples, for Example 3, the ²⁹ Si-NMR spectrum is shown in FIG. 1, and the results of pyrolysis GC-MS (pre-baking conditions: 140 ° C. for 5 minutes) are shown in FIG. The calculation procedure of the value (A) in the case of Example 3 is shown below.
From the ²⁹ Si-NMR analysis results shown in FIG.
t0 = 0, t1 = 1, t2 = 2.45, t3 = 1.64
q0 = 0, q1 = 0, q2 = 0.12, q3 = 0.83, q4 = 3.35
Got. From these,
T0 = 0, T1 = 0.2, T2 = 0.48, T3 = 0.32.
Q0 = 0, Q1 = 0, Q2 = 0.03, Q3 = 0.19, Q4 = 0.78
T = 0.54, Q = 0.46
Got. When the above values are substituted into the above formula (2), the terminal amount (A) = (0.54 * (0 * 3 + 0.2 * 2 + 0.48 * 1 + 0.32 * 0) /3+0.46* (0 * 4 + 0 * 3 + 0.03 * 2 + 0.19 * 1 + 0.78 * 0) / 4) * 100 (%) = 19%.

[Example 8]
In a 500 mL four-necked flask having a reflux tube and a dropping funnel, 0.4 g of dimethyldimethoxysilane, 21.8 g of methyltrimethoxysilane (MTMS), 8.9 g of tetraethoxysilane (TEOS), and 160 g of ethanol are stirred and stirred. 30 ° C. To this, 19.2 g of water and 3.05 g of a 0.7 mass% nitric acid aqueous solution were added dropwise, and after completion of the addition, the mixture was reacted at 30 ° C. for 1 hour (first step).

  92.6 g of PL-06L (average primary particle diameter 6 nm, water-dispersed silica particles of 6.3% by mass concentration manufactured by Fuso Chemical Industries) was added dropwise thereto, heated to 80 ° C., and then refluxed for 5 hours. A polysiloxane material was obtained (second step).

  After refluxing, 300 g of propylene glycol methyl ethyl acetate (PGMEA) was added, and methanol, ethanol, water and nitric acid were distilled off using a rotary evaporator to obtain a PGMEA solution having a solid content concentration of 20% by mass (third step). ). The physical property evaluation shown by said (1)-(5) of the produced | generated polysiloxane material solution was performed. The evaluation results are shown in Table 3.

[Example 9]
In a 500 mL four-necked flask having a reflux tube and a dropping funnel, 22.2 g of methyltrimethoxysilane (MTMS), 8.9 g of tetraethoxysilane (TEOS), 160 g of ethanol, and PL-06L (average primary particles manufactured by Fuso Chemical Industries) 95.2 g of water-dispersed silica particles having a diameter of 6 nm and a concentration of 6.3% by mass) were added and stirred, heated to 80 ° C. and refluxed. To this, 19.2 g of water and 3.05 g of a 0.7% by mass aqueous nitric acid solution were added dropwise, and after completion of the addition, the mixture was reacted at 78 ° C. for 6 hours to obtain a polysiloxane material (first step).

  Thereafter, 300 g of propylene glycol methyl ethyl acetate (PGMEA) was added, and methanol, ethanol, water and nitric acid were distilled off using a rotary evaporator to obtain a PGMEA solution having a solid content concentration of 20% by mass (second step). . The physical property evaluation shown by said (1)-(5) of the produced | generated polysiloxane material solution was performed. The evaluation results are shown in Table 3.

[Example 10]
In a 500 mL four-necked flask having a reflux tube and a dropping funnel, 22.2 g of methyltrimethoxysilane (MTMS), 8.9 g of tetraethoxysilane (TEOS), 160 g of ethanol, and PL-06L (average primary particles manufactured by Fuso Chemical Industries) 95.2 g of water-dispersed silica particles having a diameter of 6 nm and a concentration of 6.3% by mass) were added and stirred, heated to 78 ° C. and refluxed. 19.2 g of water and 3.05 g of 0.7 mass% nitric acid aqueous solution were added dropwise thereto, and after completion of the addition, the reaction was carried out at 80 ° C. for 0.5 hours to obtain a polysiloxane material (first step).

  Thereafter, 300 g of propylene glycol methyl ethyl acetate (PGMEA) was added, and methanol, ethanol, water and nitric acid were distilled off using a rotary evaporator to obtain a PGMEA solution having a solid content concentration of 20% by mass (second step). . The physical property evaluation shown by said (1)-(5) of the produced | generated polysiloxane material solution was performed. The evaluation results are shown in Table 3.

[Example 11]
In a 500 mL four-necked flask having a reflux tube and a dropping funnel, 13.7 g of methyltrimethoxysilane (MTMS), 23.4 g of tetraethoxysilane (TEOS), and 83 g of ethanol are stirred and heated to 78 ° C. and refluxed. did. 19.2 g of water and 3.05 g of 0.7 mass% nitric acid aqueous solution were added dropwise thereto, and after completion of the dropwise addition, reaction was carried out at 78 ° C. for 2 hours to obtain a polysiloxane material (first step).

  Thereafter, 300 g of propylene glycol methyl ethyl acetate (PGMEA) was added, and methanol, ethanol, water and nitric acid were distilled off using a rotary evaporator to obtain a PGMEA solution having a solid content concentration of 20% by mass (second step). . The physical property evaluation shown by said (1)-(5) of the produced | generated polysiloxane material solution was performed. The evaluation results are shown in Table 3.

[Examples 12 to 15]
Only the reaction conditions in Example 11 were changed to obtain a polysiloxane material solution. The changed conditions are summarized in Table 2. The evaluation results are summarized in Table 3.
The ²⁹ Si-NMR spectrum of Example 14 is shown in FIG.

[Comparative Example 1]
In a 500 mL four-necked flask, 11.6 g of methyltrimethoxysilane (MTMS), 4.4 g of tetraethoxysilane (TEOS), and 20 g of ethanol are added and stirred, and 11.5 g of water and 0.7% by mass nitric acid aqueous solution are stirred here. 1.53 g was added dropwise at room temperature. After completion of the dropwise addition, the mixture was stirred for 30 minutes and allowed to stand for 24 hours to obtain a polysiloxane intermediate condensate (first step).

  Next, 47.6 g of PL-06L (average primary particle size 6 nm, water-dispersed silica particles having a concentration of 6.3% by mass, manufactured by Fuso Chemical Co., Ltd.) 47.6 g and ethanol are added to a four-neck 500 mL flask having a distillation column and a dropping funnel. 80 g was added and stirred for 5 minutes, and the previously synthesized polysiloxane intermediate condensate was added dropwise at room temperature. After completion of dropping, the mixture was stirred for 30 minutes and then refluxed for 4 hours to obtain a polysiloxane material (second step).

After refluxing, 150 g of propylene glycol methyl ethyl acetate (PGMEA) was added, and methanol, ethanol, water and nitric acid were distilled off using a rotary evaporator to obtain a PGMEA solution having a solid content concentration of 20% by mass (third step). ). The physical property evaluation shown by said (1)-(5) of the produced | generated polysiloxane material solution was performed. The evaluation results are shown in Table 3. ^{The 29} Si-NMR spectrum is shown in FIG. 3, and the result of pyrolysis GC-MS (pre-baking conditions: 140 ° C. for 5 minutes) is shown in FIG.

[Comparative Example 2]
In a 1 L separable flask, 11.1 g of methyltrimethoxysilane (MTMS), 4.4 g of tetraethoxysilane (TEOS), and 320 g of ethanol were stirred and cooled to 0 ° C. 9.6 g of water and 0.15 g of a 0.7% by mass nitric acid aqueous solution were added dropwise thereto, and after completion of the dropwise addition, the mixture was reacted at 0 ° C. for 0.25 hour to obtain a polysiloxane material (first step).

  After reflux, 300 g of propylene glycol methyl ethyl acetate (PGMEA) was added, and methanol, ethanol, water and nitric acid were distilled off using a rotary evaporator to obtain a PGMEA solution having a solid content concentration of 20% by mass (second step). ). Table 3 shows the evaluation results of the resulting polysiloxane material solution. However, in this example, since a uniform cured film could not be formed, the measurement of (5) was not performed.

  The cured film obtained from the polysiloxane material of the present invention is a liquid crystal display element, an integrated circuit element, a semiconductor memory element, an interlayer insulating film for a semiconductor device such as a solid-state imaging element, an element isolation film, an STI insulating film, PMD ( It can be suitably used as a Pre Metal Dielectric film, a planarizing film, a surface protective film, a sealing film, and the like.

Claims (9)

The following general formula (1):
R ¹ _n SiX ¹ _4-n (1)
{In the formula, R ¹ is a hydrocarbon group hydrogen atom or a C1-10, X ¹ is a halogen atom, an alkoxy group, or an acetoxy group having 1 to 6 carbon atoms, R ¹ in the case where there are multiple And X ¹ are each independent, and n is an integer of 0-3. }
A polysiloxane material having a polycondensation structural unit derived from a silane compound represented by:
^{From 29} Si-NMR analysis, the following formula (2):
(A) = D * Σ {Dn * (2-n)} / 2 + T * Σ {Tm * (3-m)} / 3 + Q * Σ {Ql * (4-1)} / 4 × 100 (%) 2)
{Where,
D = Σdn / (Σdn + Σtm + Σql)
T = Σtm / (Σdn + Σtm + Σql)
Q = Σql / (Σdn + Σtm + Σql)
Dn = dn / Σdn
Tm = tm / Σtm
Ql = ql / Σql
dn = ²⁹ Integral value of a component having a siloxane bond number corresponding to n among difunctional siloxane components determined from ²⁹ Si-NMR tm = ^{29 A} siloxane bond number corresponding to m among trifunctional siloxane components determined from Si-NMR Integral value of component ql = ²⁹ Integral value of component corresponding to l of siloxane bonds among tetrafunctional siloxane components obtained from Si-NMR (where n is 0, 1 or 2, m is 0, 1, 2 or 3 and l is 0, 1, 2, 3 or 4)
Is}
A polysiloxane material in which the value (A) calculated by the formula satisfies 15% ≦ (A) ≦ 70%.   The polysiloxane material of claim 1, further comprising silica particles that are mixed in the polysiloxane material or condensed in the polysiloxane material, or both.   A polysiloxane material solution comprising the polysiloxane material according to claim 1 or 2 and a solvent. A polysiloxane material forming step of obtaining a polysiloxane material by a step including hydrolytic polycondensation of a raw material containing the silane compound represented by the general formula (1), and an alcohol, a ketone, an ester, By adding a solvent having a boiling point of 100 to 200 ° C., which is selected from the group consisting of an ether and a hydrocarbon solvent, by distilling off components having a boiling point of 100 ° C. or less by distillation, The manufacturing method of the polysiloxane material solution of Claim 3 including the solution formation process which obtains a polysiloxane material solution.   In the polysiloxane material forming step, silica particles are added to the system at least at any point before, during or after hydrolysis polycondensation, and mixed into the polysiloxane material. The method for producing a polysiloxane material solution according to claim 4, wherein a polysiloxane material further comprising silica particles that are or are condensed in the polysiloxane material or are both of them is formed. The manufacturing method of a cured film including the application | coating process which apply | coats the polysiloxane material solution of Claim 3 on a board | substrate, and obtains an application | coating board | substrate, and the baking process which heats the application | coating board | substrate obtained at the said application | coating process.   The method for producing a cured film according to claim 6, wherein the substrate has a trench structure.   A cured film obtained by the production method according to claim 6.   A semiconductor device comprising the cured film according to claim 8.

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