Polysiloxane composition

Abstract

Provided is a polysiloxane composition that can suppress the generation of voids during the formation of a siliceous film. [Solution] The polysiloxane composition comprises a polysiloxane, a dicarboxylic acid having a first acid dissociation constant pKa1 of 4.0 or less and represented by the following formula (II): HOOC-L-COOH (II) (wherein L is a single bond, a hydroxy-substituted alkylene or amino-substituted alkylene having 1 to 6 carbon atoms, a substituted or unsubstituted alkenylene having 2 to 4 carbon atoms, a substituted or unsubstituted alkynylene having 2 to 4 carbon atoms, or a substituted or unsubstituted arylene having 6 to 10 carbon atoms), and a solvent.

Description

[Technical Field]

[0001] The present invention relates to a polysiloxane composition. The present invention also relates to a method for producing a film using the composition, a film using the composition, and an electronic device including the film. [Background technology]

[0002] In the manufacture of electronic devices, particularly semiconductor devices, interlayer insulating films are sometimes formed between transistor elements and bit lines, between bit lines and capacitors, between capacitors and metal wiring, between multiple metal wirings, and the like. Furthermore, insulating materials are sometimes embedded in isolation trenches provided on the surface of a substrate. Furthermore, after semiconductor elements are formed on the surface of a substrate, a covering layer is sometimes formed using an encapsulating material to form a package. Such interlayer insulating films and covering layers are often made of siliceous materials.

[0003] Meanwhile, in the field of electronic devices, device rules are gradually becoming finer, and there is a demand for smaller insulating structures that separate the elements incorporated into the devices. However, as insulating structures become finer, defects are occurring more frequently in siliceous films that form trenches, etc., and this is becoming a serious problem, leading to a decrease in the manufacturing efficiency of electronic devices.

[0004] On the other hand, methods for forming siliceous films include chemical vapor deposition (CVD), sol-gel methods, and methods of applying and baking a composition containing a silicon-containing polymer. Of these, methods for forming siliceous films using a composition are often used because they are relatively simple. To form such siliceous films, a composition containing a silicon-containing polymer such as polysilazane, polysiloxane, polysiloxazane, or polysilane is applied to the surface of a substrate or the like, and then baked to oxidize the silicon contained in the polymer, resulting in a siliceous film.

[0005] Polysiloxanes, especially silsesquioxanes, are known as highly heat-resistant and highly transparent materials. Silsesquioxanes are composed of trifunctional siloxane structural units RSi(O 1.5 ), and its chemical structure is intermediate between inorganic silica (SiO2) and organic silicone (R2SiO). Although it is soluble in organic solvents, the cured product is a unique compound that exhibits the high heat resistance characteristic of inorganic silica. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-93111 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-277502 [Patent Document 3] U.S. Patent No. 8,642,437 Summary of the Invention [Problem to be solved by the invention]

[0007] In particular, it has been found that when a siliceous film is produced using a polysiloxane having a structure in which the siloxane structural unit contains few organic groups, voids tend to occur in the film. The present invention was made in light of the above-mentioned circumstances, and has as its object to provide a polysiloxane composition that can suppress the generation of voids during the formation of a siliceous film, and also to provide a method for producing a siliceous film and an electronic device using the same. [Means for solving the problem]

[0008] The polysiloxane composition according to the present invention comprises: Polysiloxane, The first acid dissociation constant pKa1 is 4.0 or less, and has the following formula (II): HOOC-L-COOH (II) (Wherein, L is single bond, hydroxy-substituted alkylene or amino-substituted alkylene having 1 to 6 carbon atoms; substituted or unsubstituted alkenylene having 2 to 4 carbon atoms; a substituted or unsubstituted alkynylene having 2 to 4 carbon atoms, or Substituted or unsubstituted arylenes with 6 to 10 carbon atoms is) and a dicarboxylic acid represented by the formula: Solvent and The compound comprises:

[0009] Furthermore, a method for producing a siliceous film according to the present invention comprises applying the above composition to a substrate to form a coating film, and heating the coating film.

[0010] Moreover, the electronic device according to the present invention comprises the above-mentioned siliceous film. [Effects of the Invention]

[0011] The polysiloxane composition of the present invention has excellent embedding properties even when applied to substrates with high aspect ratios. Furthermore, it can suppress the generation of voids during the production of a siliceous film. The resulting siliceous film also has excellent flatness and electrical insulation properties, making it suitable for use in optical devices such as interlayer insulating films for semiconductor elements, passivation films, substrate planarization films, antireflection films, optical filters, high-brightness light-emitting diodes, touch panels, solar cells, and optical waveguides. DETAILED DESCRIPTION OF THE INVENTION

[0012] <Polysiloxane composition> The polysiloxane composition according to the present invention (hereinafter sometimes simply referred to as the composition) comprises a polysiloxane, a dicarboxylic acid having a specific structure, and a solvent. Each component contained in the composition according to the present invention will be described in detail below.

[0013] (I) Polysiloxane The polysiloxane used in the present invention is not particularly limited in structure and can be selected from any structure depending on the purpose. The skeletal structure of polysiloxane can be classified into a silicone skeleton (2 oxygen atoms bonded to silicon atom), a silsesquioxane skeleton (3 oxygen atoms bonded to silicon atom), and a silica skeleton (4 oxygen atoms bonded to silicon atom) depending on the number of oxygen atoms bonded to silicon atom. In the present invention, any of these may be used. The polysiloxane molecule may contain a combination of multiple of these skeleton structures.

[0014] Preferably, the polysiloxane used in the present invention has the following formula (Ia): [ka] (In the formula, R 1 is hydrogen, monovalent to trivalent, C 1~30 a linear, branched or cyclic, saturated or unsaturated, aliphatic hydrocarbon group, or a monovalent to trivalent, C 6~30 represents an aromatic hydrocarbon group represented by the formula: In the aliphatic hydrocarbon group and the aromatic hydrocarbon group, one or more methylenes are unsubstituted or substituted with oxy, imido or carbonyl, one or more hydrogens are unsubstituted or substituted with fluorine, hydroxy or alkoxy, and one or more carbons are unsubstituted or substituted with silicon; R 1 If is divalent or trivalent, R 1 connects Si atoms contained in multiple repeating units) Repeating units represented by and / or Formula (Ib) below: [ka] The compound comprises a repeating unit represented by the following formula:

[0015] In general formula (Ia), R 1 is a monovalent group, R 1Examples of R include (i) alkyls such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, and decyl; (ii) aryls such as phenyl, tolyl, and benzyl; (iii) fluoroalkyls such as trifluoromethyl, 2,2,2-trifluoroethyl, and 3,3,3-trifluoropropyl; (iv) fluoroaryls; (v) cycloalkyls such as cyclohexyl; (vi) nitrogen-containing groups having an amino or imide structure, such as isocyanate and amino; and (vii) oxygen-containing groups having an epoxy structure, such as glycidyl, or an acryloyl or methacryloyl structure. Preferred are methyl, ethyl, propyl, butyl, pentyl, hexyl, phenyl, tolyl, glycidyl, and isocyanate. Preferred fluoroalkyls are perfluoroalkyls, particularly trifluoromethyl and pentafluoroethyl. R 1 Compounds in which the R is methyl are preferred because the raw materials are readily available, the film hardness after curing is high, and the film has high chemical resistance. Phenyl is also preferred because it increases the solubility of the polysiloxane in solvents and makes the cured film less susceptible to cracking. 1 It is preferable that the compound has a hydroxyl, glycidyl, isocyanate, or amino group, since this improves the adhesion to the substrate.

[0016] Also, R 1 When R is a divalent or trivalent group, 1is preferably, for example, (i) a group obtained by removing two or three hydrogen atoms from an alkane such as methane, ethane, propane, butane, pentane, hexane, heptane, octane, or decane; (ii) a group obtained by removing two or three hydrogen atoms from a cycloalkane such as cycloheptane, cyclohexane, or cyclooctane; (iii) a group obtained by removing two or three hydrogen atoms from an aromatic compound composed solely of hydrocarbons such as benzene or naphthalene; or (iv) a group obtained by removing two or three hydrogen atoms from a nitrogen- and / or oxygen-containing cycloaliphatic hydrocarbon compound containing an amino group, an imino group, and / or a carbonyl group such as piperidine, pyrrolidine, or isocyanurate. (iv) is more preferred because it improves pattern sagging and adhesion to the substrate.

[0017] Preferably, R 1 is hydrogen or C 1~10 a linear, branched or cyclic aliphatic hydrocarbon group, or C 6~10 is an aromatic hydrocarbon group. More preferably, R 1 is selected from the group consisting of hydrogen, methyl, ethyl, and phenyl, and more preferably, R 1 is methyl.

[0018] The polysiloxane used in the present invention has the following formula (Ic): [ka] (In the formula, R 2 are each independently hydrogen, monovalent to trivalent, C 1~30 a linear, branched or cyclic, saturated or unsaturated, aliphatic hydrocarbon group, or a monovalent to trivalent, C 6~30 represents an aromatic hydrocarbon group represented by the formula: In the aliphatic hydrocarbon group and the aromatic hydrocarbon group, one or more methylenes are unsubstituted or substituted with oxy, imido or carbonyl, one or more hydrogens are unsubstituted or substituted with fluorine, hydroxy or alkoxy, and one or more carbons are unsubstituted or substituted with silicon; R 2 If is divalent or trivalent, R 2 connects Si atoms contained in multiple repeating units) It may further contain a repeating unit represented by the following formula:

[0019] Preferably, R 2 is hydrogen or C 1~10 a linear, branched or cyclic aliphatic hydrocarbon group, or C 6~10 is an aromatic hydrocarbon group. More preferably, R 2 are each independently selected from the group consisting of a hydrogen atom, methyl, ethyl, and phenyl. More preferably, R 2 is methyl.

[0020] The polysiloxane used in the present invention preferably has silanol groups at its terminals. The silanol content can be determined by measuring the silanol content at 1100±100 cm in the infrared absorption spectrum attributed to Si—O. -1 The area intensity S1 of the absorption band in the range of 900±100 cm -1 The ratio of the area intensity S2 of the absorption band in the range is defined as S2 / S1. In the present invention, S2 / S1 is preferably 0.05 to 0.25.

[0021] Since the polysiloxane used in the present invention is required to have high hardness and heat resistance, the ratio of the number of repeating units represented by formula (Ib) to the total number of repeating units represented by formulas (Ia) and (Ib) contained in the molecule is preferably 1 to 100%, more preferably 20 to 100%. Furthermore, the ratio of repeating units other than repeating units (Ia) and (Ib) to all repeating units in the molecule is preferably 90% or less, more preferably 80% or less.

[0022] The mass average molecular weight of the polysiloxane used in the present invention is usually 500 to 5,000, and from the viewpoints of solubility in organic solvents, coatability onto substrates, and solubility in alkaline developers, it is preferably 500 to 4,000, and more preferably 1,000 to 3,000. Here, the mass average molecular weight is the mass average molecular weight in terms of polystyrene, and can be measured by gel permeation chromatography using polystyrene as the standard.

[0023] Such polysiloxanes are, for example, of the formula (ia): R 1’ [Si(OR a )3] p (ia) (In the formula, p is an integer from 1 to 3; R 1’ is hydrogen, monovalent to trivalent, C 1~30 a linear, branched or cyclic, saturated or unsaturated, aliphatic hydrocarbon group, or a monovalent to trivalent, C 6~30 represents an aromatic hydrocarbon group represented by the formula: In the aliphatic hydrocarbon group and the aromatic hydrocarbon group, one or more methylenes are unsubstituted or substituted with oxy, imido or carbonyl, one or more hydrogens are unsubstituted or substituted with fluorine, hydroxy or alkoxy, and one or more carbons are unsubstituted or substituted with silicon; R a is C 1~10 (representing alkyl) and / or silicon compounds represented by Formula (ib): Si(OR b )4(ib) (In the formula, R b is C 1~10 and preferably methyl, ethyl, n-propyl, isopropyl, and n-butyl. The silicon compound represented by The compound can be obtained by hydrolysis and condensation in the presence of an acidic or basic catalyst, if necessary.

[0024] In the general formula (ia), preferred R 1’ is the preferred R 1 is the same as: In general formula (ia), R a Examples of R include methyl, ethyl, n-propyl, isopropyl, and n-butyl. a There are multiple R a may be the same or different.

[0025] Specific examples of the silicon compound represented by the general formula (ia) include, for example, methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, methyltri-n-butoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, ethyltri-n-butoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-butyltrimethoxysilane, n-butyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, decyltrimethoxysilane, Examples include phenyltrimethoxysilane, phenyltriethoxysilane, trifluoromethyltrimethoxysilane, trifluoromethyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, tris-(3-trimethoxysilylpropyl)isocyanurate, tris-(3-triethoxysilylpropyl)isocyanurate, and tris-(3-trimethoxysilylethyl)isocyanurate. Of these, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, and phenyltrimethoxysilane are preferred.

[0026] Specific examples of the silicon compound represented by the general formula (ib) include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-iso-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, and tetra-tert-butoxysilane. Examples thereof include tetrakis(2-ethylbutoxy)silane, and tetrakis(2-ethylbutoxy)silane, and among these, tetramethoxysilane, tetraethoxysilane, and tetra-iso-propoxysilane are preferred.

[0027] Here, two or more types of silicon compounds can be used in combination.

[0028] (II) Dicarboxylic Acid The dicarboxylic acid used in the present invention is The first acid dissociation constant pKa1 is 4.0 or less, and has the following formula (II): HOOC-L-COOH (II) (Wherein, L is single bond, hydroxy-substituted alkylene or amino-substituted alkylene having 1 to 6 carbon atoms; substituted or unsubstituted alkenylene having 2 to 4 carbon atoms; a substituted or unsubstituted alkynylene having 2 to 4 carbon atoms, or Substituted or unsubstituted arylenes with 6 to 10 carbon atoms is) It is expressed as: In the present invention, alkenylene refers to a divalent group having one or more double bonds, and similarly, alkynylene refers to a divalent group having one or more triple bonds.

[0029] Preferably, L is single bond, hydroxy-substituted alkylene having 2 to 4 carbon atoms, an unsubstituted alkenylene having 2 to 4 carbon atoms and one C=C bond; or Unsubstituted arylene having 6 to 10 carbon atoms and More preferably, L is a single bond, vinylene, or hydroxyethylene.

[0030] The first acid dissociation constant is the value listed in CRC Handbook of Chemistry and Physics 97th Edition, pp 5-88, and the values ​​for representative dicarboxylic acids are as follows: Maleic acid 1.92, Fumaric acid 3.02, oxalic acid 1.25, o-phthalic acid 2.94, Malic acid 3.40, succinic acid 4.21, Malonic acid 2.85, Aspartic acid 1.99, glutamic acid 2.13, 3-Aminohexanedioic acid 2.14

[0031] Specific examples of dicarboxylic acids used in the present invention include oxalic acid, maleic acid, fumaric acid, malic acid, o-phthalic acid, aspartic acid, glutamic acid, and 3-aminohexanedioic acid, and preferably oxalic acid, maleic acid, fumaric acid, malic acid, or o-phthalic acid, and more preferably maleic acid and oxalic acid. The dicarboxylic acids may be used alone or in combination of two or more.

[0032] In the composition according to the present invention, the molar ratio of the dicarboxylic acid used in the present invention to the number of moles of the polysiloxane used in the present invention is 0.1 to 6.0, more preferably 0.15 to 2.0, and even more preferably 0.2 to 1.0.

[0033] (III) Solvent The solvent is not particularly limited as long as it can uniformly dissolve or disperse the polysiloxane and dicarboxylic acid, and the additives added as needed. Examples of solvents that can be used in the present invention include ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, and ethylene glycol monobutyl ether, diethylene glycol dialkyl ethers such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, and diethylene glycol dibutyl ether, ethylene glycol alkyl ether acetates such as methyl cellosolve acetate and ethyl cellosolve acetate, and propylene glycol monoalcohols such as propylene glycol monomethyl ether and propylene glycol monoethyl ether. Examples of suitable solvents include alkyl ethers, propylene glycol alkyl ether acetates such as propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monoethyl ether acetate, and propylene glycol monopropyl ether acetate, aromatic hydrocarbons such as benzene, toluene, and xylene, ketones such as methyl ethyl ketone, acetone, methyl amyl ketone, methyl isobutyl ketone, and cyclohexanone, alcohols such as ethanol, propanol, butanol, hexanol, cyclohexanol, ethylene glycol, and glycerin, esters such as ethyl lactate, ethyl 3-ethoxypropionate, and methyl 3-methoxypropionate, and cyclic esters such as γ-butyrolactone. These solvents may be used alone or in combination of two or more, and the amount used will vary depending on the coating method and the required film thickness after coating.

[0034] The solvent content of the composition according to the present invention can be appropriately selected according to the mass average molecular weight, distribution, and structure of the polysiloxane used, so as to improve workability depending on the coating method employed, and taking into consideration the permeability of the solution into the fine grooves and the film thickness required outside the grooves. The composition according to the present invention generally contains 50 to 99.9 mass %, preferably 60 to 99 mass %, of the solvent, based on the total mass of the composition.

[0035] The composition of the present invention essentially comprises the above-described components (I) to (III), but can be combined with additional compounds as needed. The materials that can be combined are described below. The content of components other than components (I) to (III) in the entire composition is preferably 10% or less, more preferably 5% or less, based on the total mass.

[0036] The composition according to the present invention may contain other additives as needed, such as surfactants, adhesion promoters, antifoaming agents, and thermal curing accelerators.

[0037] The surfactant is added for the purpose of improving coating properties, developability, etc. Examples of surfactants that can be used in the present invention include nonionic surfactants, anionic surfactants, and amphoteric surfactants.

[0038] Examples of the nonionic surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene oleyl ether, and polyoxyethylene cetyl ether; polyoxyethylene fatty acid diesters, polyoxyethylene fatty acid monoesters, polyoxyethylene polyoxypropylene block polymers; acetylene alcohol derivatives such as acetylene alcohol and polyethoxylate of acetylene alcohol; acetylene glycol derivatives such as acetylene glycol and polyethoxylate of acetylene glycol; fluorine-containing surfactants such as Fluorad (trade name, manufactured by Sumitomo 3M Limited), Megafac (trade name, manufactured by DIC Corporation), and Sulfuron (trade name, manufactured by Asahi Glass Co., Ltd.); and organic siloxane surfactants such as KP341 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.). Examples of the acetylene glycol include 3-methyl-1-butyn-3-ol, 3-methyl-1-pentyn-3-ol, 3,6-dimethyl-4-octyne-3,6-diol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,5-dimethyl-1-hexyn-3-ol, 2,5-dimethyl-3-hexyne-2,5-diol, and 2,5-dimethyl-2,5-hexanediol.

[0039] Examples of anionic surfactants include ammonium salts or organic amine salts of alkyldiphenyletherdisulfonic acids, ammonium salts or organic amine salts of alkyldiphenylethersulfonic acids, ammonium salts or organic amine salts of alkylbenzenesulfonic acids, ammonium salts or organic amine salts of polyoxyethylene alkylethersulfonic acids, and ammonium salts or organic amine salts of alkylsulfuric acids.

[0040] Further, examples of amphoteric surfactants include 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolium betaine and lauric acid amidopropyl hydroxysulfone betaine.

[0041] These surfactants can be used alone or in combination of two or more kinds, and the amount to be added is usually 50 to 10,000 ppm, preferably 100 to 8,000 ppm, based on the composition of the present invention.

[0042] The adhesion promoter has the effect of preventing peeling of the pattern due to stress applied after baking when a cured film is formed using the composition according to the present invention. As the adhesion promoter, imidazoles and silane coupling agents are preferred, and among imidazoles, 2-hydroxybenzimidazole, 2-hydroxyethylbenzimidazole, benzimidazole, 2-hydroxyimidazole, imidazole, 2-mercaptoimidazole, and 2-aminoimidazole are preferred, and 2-hydroxybenzimidazole, benzimidazole, 2-hydroxyimidazole, and imidazole are particularly preferred.

[0043] As a defoaming agent, alcohol (C1- 18 ), higher fatty acids such as oleic acid and stearic acid, higher fatty acid esters such as glycerin monolaurate, polyethers such as polyethylene glycol (PEG) (Mn 200 to 10,000) and polypropylene glycol (PPG) (Mn 200 to 10,000), silicone compounds such as dimethylsilicone oil, alkyl-modified silicone oil, and fluorosilicone oil, and the above-mentioned organosiloxane surfactants. These can be used alone or in combination, and the amount added is preferably 0.1 to 3 parts by mass per 100 parts by mass of the total mass of the polysiloxane.

[0044] Examples of the thermal curing accelerator include a thermal base generator, a thermal acid generator, etc. By including a thermal curing accelerator in the composition according to the present invention, the curing speed of the coating film when heated can be increased. In the present invention, the thermal acid generator or thermal base generator refers to a compound that generates an acid or a base by bond cleavage caused by heat. It is preferable that these do not generate an acid or a base, or generate only a small amount of an acid or a base, when subjected to heat during pre-baking after application of the composition. Examples of thermal acid generators include salts and esters that generate organic acids, such as various aliphatic sulfonic acids and their salts, various aliphatic carboxylic acids and their salts, such as citric acid, acetic acid, and maleic acid, various aromatic carboxylic acids and their salts, such as benzoic acid and phthalic acid, aromatic sulfonic acids and their ammonium salts, various amine salts, aromatic diazonium salts, and phosphonic acids and their salts. Among the thermal acid generators, salts of organic acids and organic bases are particularly preferred, and salts of sulfonic acids and organic bases are even more preferred. Preferred sulfonic acids include p-toluenesulfonic acid, benzenesulfonic acid, p-dodecylbenzenesulfonic acid, 1,4-naphthalenedisulfonic acid, and methanesulfonic acid. These acid generators can be used alone or in combination. Examples of thermal base generators include compounds that generate bases such as imidazole, tertiary amines, and quaternary ammonium, as well as mixtures thereof. Examples of bases that can be released include imidazole derivatives such as N-(2-nitrobenzyloxycarbonyl)imidazole, N-(3-nitrobenzyloxycarbonyl)imidazole, N-(4-nitrobenzyloxycarbonyl)imidazole, N-(5-methyl-2-nitrobenzyloxycarbonyl)imidazole, and N-(4-chloro-2-nitrobenzyloxycarbonyl)imidazole, and 1,8-diazabicyclo[5.4.0]undecene-7. Like acid generators, these base generators can be used alone or in combination. The amount of the heat curing accelerator added is preferably 0.01 to 1 part by mass per 100 parts by mass of the total mass of the polysiloxane.

[0045] Furthermore, the composition of the present invention can also be used as a photosensitive composition by further incorporating a photobase generator, a photoacid generator, or the like.

[0046] <Method of manufacturing siliceous film> The method for producing a siliceous film according to the present invention comprises applying the composition according to the present invention to a substrate to form a coating film, and heating the coating film. The method for forming a siliceous film will be described below in order of steps.

[0047] (1) Coating process The shape of the substrate is not particularly limited and can be selected as desired depending on the purpose. However, the composition of the present invention is characterized by its ability to easily penetrate narrow grooves and form a uniform siliceous film even inside the grooves, and can therefore be applied to substrates having grooves or holes with a high aspect ratio. Specifically, it can be applied to substrates having at least one groove whose deepest width is 0.2 μm or less and whose aspect ratio is 2 or more. The shape of the groove is not particularly limited, and the cross section may be any shape, such as a rectangular, forward tapered, reverse tapered, or curved shape. Furthermore, both ends of the groove may be open or closed.

[0048] Representative examples of substrates having at least one trench with a high aspect ratio include substrates for electronic devices equipped with transistor elements, bit lines, capacitors, etc. The fabrication of such electronic devices may include processes such as forming an insulating film between a transistor element and a bit line, between a transistor element and a capacitor, between a bit line and a capacitor, or between a capacitor and a metal wiring, called PMD, forming an insulating film between multiple metal wirings, called IMD, or filling an isolation trench, followed by a through-hole plating process for forming holes that penetrate vertically through the filling material of the fine trench.

[0049] The coating can be carried out by any method. Specifically, it can be arbitrarily selected from dip coating, roll coating, bar coating, brush coating, spray coating, doctor coating, flow coating, spin coating, slit coating, etc. Furthermore, as the substrate to which the composition is applied, a suitable substrate such as a silicon substrate, glass substrate, or resin film can be used. These substrates may have various semiconductor elements formed thereon as needed. When the substrate is a film, gravure coating can also be used. If desired, a separate drying step can be provided after the coating. Furthermore, if necessary, the coating step can be repeated once or twice or more times to form a coating film with the desired thickness.

[0050] (2) Pre-baking process After forming a coating film by applying the composition, the coating film is preferably prebaked (preheated) to dry it and reduce the amount of solvent remaining in the coating film. The prebaking step can be carried out generally at a temperature of 70 to 250°C, preferably 100 to 200°C, for 10 to 300 seconds, preferably 30 to 180 seconds, using a hot plate, or for 1 to 30 minutes using a clean oven.

[0051] (3) Curing process The coating is heated to form a siliceous film. In the present invention, the siliceous film means a film in which the ratio of the number of oxygen atoms to the number of silicon atoms in the polymer is 1.2 or more. The heating device used in the curing step can be the same as that used in the pre-baking step. The heating temperature in this heating step is not particularly limited and can be set arbitrarily as long as it is a temperature at which a siliceous film is formed. However, if silanol groups remain, the chemical resistance of the siliceous film may be insufficient or the dielectric constant of the siliceous film may increase. From these perspectives, a relatively high heating temperature is generally selected. Specifically, heating at 360°C or less is preferred, 300°C or less is more preferred, and 250°C or less is particularly preferred. On the other hand, to promote the curing reaction, the heating temperature is preferably 70°C or higher, more preferably 100°C or higher, and particularly preferably 110°C or higher. The heating time is not particularly limited and is generally 10 minutes to 24 hours, preferably 30 minutes to 3 hours. Note that this heating time is the time after the film temperature reaches the desired heating temperature. It usually takes several minutes to several hours for the film to reach the desired temperature from the temperature before heating. The curing step is preferably performed in a nitrogen atmosphere.

[0052] During this curing process, voids may occur. In particular, void generation tends to increase as the organic group content of the polysiloxane decreases. However, when the composition of the present invention is used, void generation is suppressed even when the organic group content of the polysiloxane is low.

[0053] <Siliceous film and electronic device comprising same> The siliceous film according to the present invention can be produced by applying the composition according to the present invention to a substrate and curing it. Siliceous films formed using the compositions of the present invention can achieve excellent transparency, chemical resistance, environmental resistance, electrical insulation, heat resistance, etc. Therefore, they can be suitably used in a wide range of applications, such as interlayer insulating films for low-temperature polysilicon, buffer coating films for IC chips, and transparent protective films.

[0054] The present invention will be explained in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples and comparative examples.

[0055] Gel permeation chromatography (GPC) was performed using an alliance™ e2695 high-performance GPC system (trade name, manufactured by Nihon Waters K.K.) and a Super Multipore HZ-N GPC column (trade name, manufactured by Tosoh Corporation). Measurements were performed using monodisperse polystyrene as a standard sample and tetrahydrofuran as a developing solvent under measurement conditions of a flow rate of 0.6 mL / min and a column temperature of 40°C, and the mass-average molecular weight was calculated as the molecular weight relative to the standard sample.

[0056] <Synthesis Example 1 (Synthesis of Polysiloxane A)> A 2L flask equipped with a stirrer, thermometer, and condenser was charged with 32.5 g of 40% by weight tetra-n-butylammonium hydroxide (TBAH) aqueous solution and 308 ml of 2-methoxypropanol (PGME). A mixed solution of 19.6 g of methyltrimethoxysilane and 9.2 g of tetramethoxysilane was then prepared in a dropping funnel. The mixed solution was added dropwise to the flask and stirred at room temperature for 2 hours. After that, 500 ml of n-propyl acetate (n-PA) was added, followed by 1.1 equivalents of 3% maleic acid aqueous solution relative to the TBAH, and the mixture was neutralized and stirred for 1 hour. 500 ml of n-propyl acetate (n-PA) and 250 ml of water were added to the neutralized solution, and the reaction mixture was separated into two layers. The resulting organic layer was washed three times with 250 cc of water and then concentrated under reduced pressure to remove water and solvent. PGME was added to adjust the solids concentration of the concentrate to 7% by weight. The molecular weight (polystyrene equivalent) of the obtained polysiloxane A was measured by GPC, and the weight average molecular weight (hereinafter sometimes abbreviated as "Mw") was found to be 2,068.

[0057] <Synthesis Example 2 (Synthesis of Polysiloxane B)> A 2L flask equipped with a stirrer, thermometer, and condenser was charged with 14.0g of methyltrimethoxysilane, 15.4g of tetramethoxysilane, and 308ml of 2-methoxypropanol (PGME) and cooled to 0.2°C. Next, 96.6g of a 37% by mass tetra-n-butylammonium hydroxide (TBAH) methanol solution was added dropwise from the dropping funnel into the flask and stirred for 2 hours. After that, 500ml of normal propyl acetate (n-PA) was added, and the mixture was cooled again to 0.2°C. 1.1 equivalents of 3% aqueous hydrochloric acid relative to the TBAH was added, followed by neutralization and stirring for 1 hour. 1000ml of normal propyl acetate (n-PA) and 250ml of water were added to the neutralized solution, and the reaction solution was separated into two layers. The resulting organic layer was washed three times with 250cc of water and then concentrated under reduced pressure to remove water and solvent. PGME was added and adjusted so that the solids concentration of the concentrate was 7% by mass. The resulting polysiloxane B had a Mw of 1,157.

[0058] <Synthesis Example 3 (Synthesis of Polysiloxane C)> A 2L flask equipped with a stirrer, thermometer, and condenser was charged with 49.9g of 40% by weight tetra-n-butylammonium hydroxide (TBAH) aqueous solution, 3.7g of water, and 37ml of 2-methoxypropanol (PGME). Next, a mixed solution of 13.4g of methyltriethoxysilane, 15.6g of tetraethoxysilane, and 47ml of 2-methoxypropanol (PGME) was prepared in a dropping funnel. The mixed solution was added dropwise to the flask and stirred at 40°C for 2 hours. After cooling to room temperature, 110ml of methyl tert-butyl ether (MTBE) was added, and then 1.1 equivalents of 3% aqueous hydrochloric acid (based on the TBAH) was added and neutralized with stirring for 15 minutes. 1000 ml of methyl tert-butyl ether (MTBE) and 250 ml of water were added to the neutralized solution, and the reaction solution was separated into two layers. The resulting organic layer was washed three times with 250 cc of water and then concentrated under reduced pressure to remove water and solvent, and PGME was added to adjust the solids concentration of the concentrate to 7% by mass. The resulting polysiloxane C had a Mw of 2,495.

[0059] <Synthesis Example 4 (Synthesis of Polysiloxane D)> A 2-L flask equipped with a stirrer, thermometer, and condenser was charged with 84.3 g of tetraethoxysilane and 566 ml of isopropanol (IPA). Next, 8.0 g of hydrochloric acid and 30 g of water were added to a dropping funnel. The resulting mixture was added dropwise to the flask and stirred at 25°C for 3 hours. After this, 200 ml of 2-methoxypropanol (PGME) was added and the mixture was concentrated under reduced pressure to remove the acid catalyst, water, and solvent. PGME was then added to adjust the solids concentration of the concentrate to 45% by mass. The resulting polysiloxane D had a Mw of 1,066.

[0060] <Synthesis Example 5 (Synthesis of Polysiloxane E)> A 2L flask equipped with a stirrer, thermometer, and condenser was charged with 29.1g of methyltrimethoxysilane, 0.6g of phenyltrimethoxysilane, 0.4g of tetramethoxysilane, and 308ml of 2-methoxypropanol (PGME) and cooled to 0.2°C. Next, 96.6g of a 37% by mass tetra-n-butylammonium hydroxide (TBAH) methanol solution was added dropwise from the dropping funnel into the flask and stirred for 2 hours. After that, 500ml of normal propyl acetate (n-PA) was added, and the mixture was cooled again to 0.2°C. 1.1 equivalents of 3% aqueous hydrochloric acid solution relative to the TBAH was added, followed by neutralization and stirring for 1 hour. 1000ml of normal propyl acetate (n-PA) and 250ml of water were added to the neutralized solution, and the reaction solution was separated into two layers. The resulting organic layer was washed three times with 250cc of water and then concentrated under reduced pressure to remove water and solvent. PGME was added to adjust the solids concentration of the concentrate to 7% by mass. The resulting polysiloxane E had a Mw of 1,286.

[0061] <Examples 1 to 18 and Comparative Examples 1 to 4 (Preparation of Polysiloxane Compositions)> Polysiloxane compositions of Examples 1 to 18 and Comparative Examples 1 to 4 were prepared containing the polysiloxane and maleic acid shown in Table 1 below, with the remainder being PGMEA, in the ratios shown in Table 1. In the table, % means % by mass (the same applies to Table 2). [Table 1] The calculation was based on the molecular weight of maleic acid being 116.1.

[0062] This polysiloxane composition was applied by spin coating onto a Si wafer having a trench (width: approximately 20 nm, height: 500 nm), and after application, the wafer was pre-baked on a hot plate at 200°C for 2 minutes. It was then cured by heating at 200°C for 2 hours in a clean oven under a nitrogen atmosphere. The cross-sectional shape was then observed using a scanning electron microscope (SEM, S-4700, manufactured by Hitachi High-Technologies Corporation) to confirm the presence or absence of voids. The evaluation criteria were as follows: A: The trench was filled and no voids were observed. B: The trench was filled and voids were observed.

[0063] <Examples 19 to 23 and Comparative Examples 5 to 14 (Preparation of Polysiloxane Compositions Using Dicarboxylic Acids Other than Maleic Acid)> Polysiloxane compositions of Examples 19 to 23 and Comparative Examples 5 to 14 were prepared containing the polysiloxane and dicarboxylic acid shown in Table 2 below in the ratios shown in Table 2, with the remainder being PGME. The presence or absence of voids was confirmed in the same manner as above, and the results obtained are shown in Table 2. [Table 2] The molecular weight was calculated as follows: Maleic acid 116.1, fumaric acid 116.1, Oxalic acid 90.0, Malic acid 134.1, o-phthalic acid 166.1, succinic acid 118.1, and Malonic acid 104.1.

Claims

1. (I) a polysiloxane; (II) First acid dissociation constant pKa １ is 4.0 or less, and has the following formula (II): HOOC-L-COOH (II) (Wherein L is single bond, a hydroxy-substituted alkylene or amino-substituted alkylene having 1 to 6 carbon atoms; substituted or unsubstituted alkenylene having 2 to 4 carbon atoms; a substituted or unsubstituted alkynylene having 2 to 4 carbon atoms, or Substituted or unsubstituted arylene having 6 to 10 carbon atoms is) and a dicarboxylic acid represented by the formula: (III) an organic solvent; A polysiloxane composition comprising: the weight average molecular weight of the polysiloxane is 500 to 5,000; the molar ratio of the dicarboxylic acid to the polysiloxane is 0.15 to 2.0; The polysiloxane has the following formula (Ia): 【Chemistry 1】 (In the formula, R １ is methyl) and / or Formula (Ib) below: 【Chemistry 2】 It consists of repeating units represented by the ratio of the number of repeating units represented by formula (Ib) to the total number of repeating units represented by formula (Ia) and formula (Ib) contained in the polysiloxane is 1 to 100%, The content of components other than (I) to (III) in the entire composition is 5% or less based on the total mass, provided that (I) polysiloxane contains the following siloxy unit (I.1): 【Transformation 3】 (In the formula, a=1 or 2; b=0, 1, or 2; a+b=1, 2, or 3; Y may be the same or different and have the formula (I.3): -E-(NHH-G) ｈ -(NH ２ ) ｉ (I.3) (In the formula, h=0 or 1; i=0 or 1, h+i=1 or 2; E is an aliphatic, alicyclic, or aromatic divalent hydrocarbon group having 1 to 30 carbon atoms; G, if present, is an aliphatic hydrocarbon group having 1 to 10 carbon atoms, monovalent when i=0, and divalent when i=1; Z １ are the same or different and are monovalent hydrocarbon groups having 1 to 30 carbon atoms, optionally containing one or more unsaturations and / or one or more fluorine atoms or hydroxyl groups, and are monovalent hydrocarbon groups optionally containing one or more fluorine atoms. Polysiloxane compositions, excluding polysiloxanes comprising:

2. The L is single bond, hydroxy-substituted alkylene having 2 to 4 carbon atoms; an unsubstituted alkenylene having 2 to 4 carbon atoms and one C═C bond; or Unsubstituted arylene having 6 to 10 carbon atoms 2. The composition of claim 1, wherein:

3. 3. The composition according to claim 1, wherein the dicarboxylic acid is selected from the group consisting of oxalic acid, maleic acid, fumaric acid, malic acid, and o-phthalic acid.

4. A method for producing a siliceous film, comprising applying the composition according to any one of claims 1 to 3 to a substrate to form a coating film, and heating the coating film.

5. A method for producing an electronic device, comprising the method for producing a siliceous film according to claim 4.

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