Polysiloxane composition

Abstract

Provided is a polysiloxane composition that can form a low dielectric constant film having high mechanical strength. The present invention relates to a method for producing a polysiloxane, an ionic liquid, an acid, and an ionic liquid. ) solvent, and the blending ratio of (II) ionic liquid to (III) acid ((II) / ( III)) has an equivalent ratio of 0.001 to 0.09.

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] Polysiloxanes are known for their high-temperature resistance. When forming a cured film from a composition containing polysiloxane, the coating is heated to a high temperature, which rapidly promotes the condensation reaction of the silanol groups in the polysiloxane and the reaction of polymers with unsaturated bonds, resulting in curing. If unreacted reactive groups remain, they may react with chemicals used in the device manufacturing process. Considering the effects on other materials in the substrate and the equipment conditions, there is a need to develop a composition containing polysiloxane that can be cured at a lower temperature.

[0003] It has been proposed to combine an epoxy resin with an anionic polymerizable curing agent and an ionic liquid in order to cure the epoxy resin at low temperatures (Patent Document 1), but the comparative example not containing the anionic polymerizable curing agent did not cure.

[0004] It is desirable to reduce parasitic capacitance and increase the signal propagation speed by using low-dielectric-constant insulating materials. One method for reducing the dielectric constant in a film is to incorporate very small, uniformly dispersed pores into the film. For example, it has been proposed to form a coating film using a solution containing polysiloxane, followed by heat treatment to decompose and volatilize the organic components, thereby forming numerous pores after the volatilized components (Patent Document 2). Films formed in this way may have low mechanical strength. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-14781 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-292638 Summary of the Invention [Problem to be solved by the invention]

[0006] The inventors have found that there are still one or more problems that require improvement, such as the following: High temperature heating is required for curing; storage stability needs to be improved; the dielectric constant of the cured film needs to be lowered; the mechanical strength of the cured film is low; and electrical properties need to be improved. [Means for solving the problem]

[0007] The polysiloxane composition according to the present invention comprises: (I) polysiloxane, (II) ionic liquids, (III) an acid, and (IV) Solvent comprising The compounding ratio of the (II) ionic liquid to the (III) acid ((II) / (III)) is 0.001 to 0.09 in terms of equivalent ratio.

[0008] The method for producing a cured film according to the present invention comprises applying the above-described composition to a substrate to form a film, and subjecting the film to heating, light irradiation, or a combination thereof.

[0009] The cured film according to the present invention has been or can be produced by the above-described method.

[0010] The electronic device according to the present invention comprises the above-described cured film.

[0011] The method for producing an electronic device according to the present invention comprises the method for producing the cured film described above. [Effects of the Invention]

[0012] The polysiloxane composition according to the present invention can be expected to have one or more of the following effects. It can be cured at a temperature lower than the temperature range used for general thermosetting compositions; it has sufficient storage stability; it can form a cured film with a suppressed dielectric constant; it can form a cured film with sufficient mechanical strength; and it can form a cured film with sufficient electrical properties. DETAILED DESCRIPTION OF THE INVENTION

[0013] [Definition] In this specification, unless otherwise specified, the definitions and examples set forth in this paragraph shall be followed. The singular includes the plural, and "one" and "the" mean "at least one." An element of a concept can be expressed by a plurality of species, and when an amount thereof (e.g., mass % or mole %) is stated, the amount refers to the sum of the plurality of species. "And / or" includes all combinations of elements as well as any single element. When a numerical range is indicated using "~" or "-", it includes both endpoints and the units are the same. For example, 5 to 25 mol % means 5 mol % or more and 25 mol % or less. "C x-y "," "C x ~C y " and "C x " refers to the number of carbons in a molecule or substituent. For example, C 1-6 Alkyl refers to alkyl chains having from 1 to 6 carbons (methyl, ethyl, propyl, butyl, pentyl, hexyl, etc.). When a polymer has multiple types of repeating units, these repeating units are copolymerized. This copolymerization may be alternating copolymerization, random copolymerization, block copolymerization, graft copolymerization, or a mixture of these. When polymers or resins are represented by structural formulas, the n or m in parentheses indicates the repeating number. The temperature unit is Celsius. For example, 20 degrees means 20 degrees Celsius. The additive refers to the compound itself that has that function (for example, in the case of a base generator, it refers to the compound itself that generates a base). The compound may be dissolved or dispersed in a solvent and added to the composition. In one embodiment of the present invention, such a solvent is preferably contained in the composition of the present invention as solvent (IV) or another component.

[0014] Hereinafter, embodiments of the present invention will be described in detail.

[0015] Polysiloxane composition The polysiloxane composition according to the present invention (hereinafter sometimes simply referred to as the composition) comprises (I) a polysiloxane, (II) an ionic liquid, (III) an acid, and (IV) a solvent. The compounding ratio of the (II) ionic liquid to the (III) acid ((II) / (III)) is 0.001 to 0.09 in terms of equivalent ratio. Each component contained in the composition according to the present invention will be described in detail below.

[0016] (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.

[0017] Preferably, the polysiloxane used in the present invention comprises a repeating unit represented by the following formula (Ia) and a repeating unit represented by the following formula (Ib).

[0018] Formula (Ia) is: [ka] where: R 1 is hydrogen, monovalent to trivalent, C 1-30 or a linear, branched, or cyclic, saturated or unsaturated aliphatic hydrocarbon group of 6-30 is an aromatic hydrocarbon group of the formula 1-6 linear, branched or cyclic alkyl, or C 6-10 and more preferably hydrogen, methyl, ethyl, or phenyl, and even more preferably methyl. The aliphatic hydrocarbon group and the aromatic hydrocarbon group are each unsubstituted or substituted with fluorine, hydroxy or C 1-8 is substituted with alkoxy, In the aliphatic hydrocarbon group and the aromatic hydrocarbon group, no methylene is replaced, or one or more methylenes are replaced by oxy, imido or carbonyl, provided that R 1 is not hydroxy or alkoxy, R 1 If is divalent or trivalent, R 1 connects Si atoms contained in multiple repeating units together.

[0019] In formula (Ia), R 1 is a monovalent group, R 1Examples of R include, in addition to hydrogen, (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 is preferred because it is easy to obtain raw materials, provides sufficient film hardness after curing, and has sufficient chemical resistance. 1 is preferably methyl. In addition, R is preferably methyl because it increases the solubility of polysiloxane in solvents and makes the cured film less susceptible to cracking. 1 It is also preferred that is phenyl.

[0020] R 1 When R is a divalent or trivalent group, 1 is 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.

[0021] The number of repeating units represented by formula (Ia) is preferably 1% or more, more preferably 20% or more, based on the total number of repeating units contained in the polysiloxane molecule. If the compounding ratio of the repeating units represented by formula (Ia) is high, the electrical properties of the cured film may be reduced, the adhesion of the cured film to the contact film may be reduced, and the hardness of the cured film may be reduced, making the film surface more susceptible to scratches. Therefore, the number of repeating units represented by formula (Ia) is preferably 95% or less, more preferably 90% or less, based on the total number of repeating units of the polysiloxane.

[0022] Formula (Ib) is: [ka] The number of repeating units represented by formula (Ib) is preferably 8% or more, more preferably 10 to 99%, and even more preferably 10 to 80%, based on the total number of repeating units contained in the polysiloxane molecule. If the compounding ratio of the repeating units represented by formula (Ib) is high, compatibility with solvents and additives decreases and film stress increases, making cracks more likely to occur, while if the compounding ratio is low, the hardness of the cured film decreases.

[0023] The polysiloxane used in the present invention may contain repeating units other than those described above, but the number of repeating units other than those described above is preferably 20% or less, and more preferably 10% or less, based on the total number of repeating units contained in the polysiloxane molecule. A preferred embodiment of the present invention is one in which no repeating units other than those described above are contained.

[0024] The polysiloxane used in the present invention may further contain a repeating unit represented by the following formula (Ic): [ka] where 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, C6~30 represents an aromatic hydrocarbon group of the formula 1-6 linear, branched or cyclic alkyl, or C 6-10 is preferably hydrogen, methyl, ethyl, or phenyl, and even more preferably R 2 is methyl. The aliphatic hydrocarbon group and the aromatic hydrocarbon group are each unsubstituted or substituted with fluorine, hydroxy or C 1-8 is substituted with alkoxy, In the aliphatic hydrocarbon group and the aromatic hydrocarbon group, no methylene is replaced, or one or more methylenes are replaced by oxy, imido or carbonyl, provided that R 2 is not hydroxy or alkoxy, R 2 If is divalent or trivalent, R 2 connects Si atoms contained in multiple repeating units together. By including the repeating unit of formula (Ic), the polysiloxane can have a partially linear structure. However, since this reduces heat resistance, it is preferable that the linear structure portion is small. Specifically, the number of repeating units of formula (Ic) is 20% or less, more preferably 10% or less, based on the total number of repeating units of the polysiloxane.

[0025] The polysiloxane used in the present invention preferably has a silanol group at the terminal. Here, silanol refers to a group in which an OH group is directly bonded to the Si skeleton of the polysiloxane, and is a group in which a hydroxy group is directly bonded to a silicon atom in a polysiloxane containing the above-mentioned repeating units, etc. That is, -O in the above formula 0.5 -O 0.5Silanol is formed by bonding H. The silanol content in polysiloxane varies depending on the synthesis conditions of polysiloxane, such as the monomer blend ratio and the type of reaction catalyst. This silanol content can be evaluated by quantitative infrared absorption spectroscopy. The absorption band assigned to silanol (SiOH) is 900±100 cm in the infrared absorption spectrum. -1 The intensity of this absorption band increases when the silanol content is high.

[0026] When polysiloxane is measured and analyzed by the FT-IR method (for example, a composition containing polysiloxane and a solvent is used to form a film on a Si wafer, and the film is heated at 150°C for 2 minutes, and baseline correction is performed on the FT-IR spectrum of the film), the peak wavelength is 1100±100cm -1 The area intensity S1 of the absorption band assigned to Si-O, which has a peak in the range of 900±100cm -1 The ratio S2 / S1 to the integrated intensity S2 of the absorption band assigned to SiOH having a peak in this range is preferably 0.020 to 0.20, and more preferably 0.020 to 0.15. The intensity of the absorption band is determined taking into consideration noise in the infrared absorption spectrum. A typical infrared absorption spectrum of polysiloxane has a band intensity of 900±100 cm -1 and an absorption band attributable to Si-OH, with a peak in the range of 1100±100cm. -1 The absorption bands attributable to Si-O, which have peaks in the range of 1000 to 10000, are confirmed. The area intensities of these absorption bands can be measured as areas taking into account a baseline that takes noise and other factors into account. Note that the tail of the absorption band attributable to Si-OH and the tail of the absorption band attributable to Si-O may overlap, and in such cases, the wavenumber corresponding to the minimum point between the two absorption bands in the spectrum is used as the boundary. The same applies when the tail of another absorption band overlaps with the tail of an absorption band attributable to Si-OH or Si-O.

[0027] The mass average molecular weight of the polysiloxane used in the present invention is preferably 500 to 10,000, and from the viewpoints of solubility in organic solvents, coatability onto substrates, and solubility in alkaline developers, it is more preferably 500 to 6,000, and even more preferably 1,000 to 5,000. 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.

[0028] The polysiloxane may be used alone or in combination of two or more kinds. The content of the polysiloxane is preferably 2.0 to 40.0 mass %, more preferably 3.0 to 30.0 mass %, based on the total mass of the polysiloxane composition.

[0029] Such polysiloxanes are, for example, of the formula (ia): R 1’ [Si(OR a )3] p (ia) (where, p is an integer from 1 to 3; R 1’ is hydrogen, monovalent to trivalent, C 1-30 or a linear, branched or cyclic, saturated or unsaturated aliphatic hydrocarbon group having a valence of 1 to 3, 6-30 is an aromatic hydrocarbon group of the formula The aliphatic hydrocarbon group and the aromatic hydrocarbon group are each unsubstituted or substituted with fluorine, hydroxy or C 1-8 is substituted with alkoxy, In the aliphatic hydrocarbon group and the aromatic hydrocarbon group, no methylene is replaced, or one or more methylenes are replaced by oxy, imido or carbonyl, provided that R 1’ is not hydroxy or alkoxy, R a is C 1-10 and preferably methyl, ethyl, n-propyl, isopropyl, and n-butyl. 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.

[0030] 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.

[0031] Specific examples of the silicon compound represented by general formula (ib) include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-iso-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, tetra-tert-butoxysilane, and tetrakis(2-ethylbutoxy)silane, and among these, tetramethoxysilane, tetraethoxysilane, and tetra-iso-propoxysilane are preferred.

[0032] Here, two or more types of silicon compounds can be used in combination.

[0033] (II) Ionic Liquid The composition according to the present invention comprises an ionic liquid. An ionic liquid is a salt that exists as a liquid over a wide temperature range and is a liquid consisting only of ions. Generally, a salt having a melting point of 100°C or less is defined as an ionic liquid. The ionic liquid used in the present invention has a melting point of 100°C or less, preferably 80°C or less, more preferably 60°C or less, and even more preferably 30°C or less. The ionic liquid used in the present invention is preferably a basic ionic liquid, and is preferably a combination of a strong base and a weak acid.

[0034] The cation of the ionic liquid is preferably at least one cation selected from the group consisting of imidazolium-based ions, pyrrolidinium-based ions, piperidinium-based ions, pyridinium-based ions, and ammonium-based ions, and more preferably an imidazolium-based ion.

[0035] The imidazolium-based ion is preferably represented by the following formula (A): [ka] where: R 11 , R 12 , R 13 , R 14 and R 15are each independently hydrogen, straight-chain or branched C 1-18 Alkyl, cyclic C 5-12 Alkyl, or C 6-14 It is aryl.

[0036] Specific examples of imidazolium ions include 1-methylimidazolium, 1-methyl-2-ethylimidazolium, 1-methyl-3-octylimidazolium, 1,2-dimethylimidazolium, 1,3-dimethylimidazolium, 2,3-dimethylimidazolium, 3,4-dimethylimidazolium, 1,2,3-trimethylimidazolium, 1,3,4-trimethylimidazolium, 1,3,4,5-tetramethylimidazolium, 1-ethylimidazolium, 1-ethyl-2-methylimidazolium, 1-ethyl-3-methylimidazolium, 1 -Ethyl-2,3-dimethylimidazolium, 2-ethyl-3,4-dimethylimidazolium, 1-propylimidazolium, 1-propyl-2-methylimidazolium, 1-propyl-3-methylimidazolium, 1-propyl-2,3-dimethylimidazolium, 1,3-dipropylimidazolium, 1-butylimidazolium, 1-butyl-2-methylimidazolium, 1-butyl-3-methylimidazolium, 1-butyl-4-methylimidazolium, 1-butyl-2,3-dimethylimidazolium, 1-butyl-3,4-dimethylimidazolium 1-butyl-3,4,5-trimethylimidazolium, 1-butyl-2-ethylimidazolium, 1-butyl-3-ethylimidazolium, 1-butyl-2-ethyl-5-methylimidazolium, 1,3-dibutylimidazolium, 1,3-dibutyl-2-methylimidazolium, 1-pentylimidazolium, 1-pentyl-2-methylimidazolium, 1-pentyl-3-methylimidazolium, 1-pentyl-2,3-dimethylimidazolium, 1-hexylimidazolium, 1-hexyl-2-methylimidazolium, 1-hexyl-3-methylimidazolium Examples of the imidazolium include 1-ethyl-3-methylimidazolium, 1-hexyl-2,3-dimethylimidazolium, 1-octyl-2-methylimidazolium, 1-octyl-3-methylimidazolium, 1-decyl-3-methylimidazolium, 1-dodecyl-3-methylimidazolium, 1-tetradecyl-3-methylimidazolium, 1-hexadecyl-3-methylimidazolium and 1-benzyl-3-methylimidazolium, and preferred are 1-ethyl-3-methylimidazolium, 1-ethyl-2,3-dimethylimidazolium, 1,3-dimethylimidazolium, 1,2,3-trimethylimidazolium, 1-propyl-3-methylimidazolium, 1-propyl-2,3-dimethylimidazolium, 1-butyl-3-methylimidazolium, 1-butyl-2,3-dimethylimidazolium, and 1-octyl-3-methylimidazolium.

[0037] The pyrrolidinium-based ion is preferably represented by the following formula (B): [ka] where: R 21 , R 22 , R 23 , R 24 , R 25 and R 26 are each independently hydrogen, straight-chain or branched C 1-18 Alkyl, cyclic C 5-12 Alkyl, or C 6-14 It is aryl.

[0038] Specific examples of pyrrolidinium ions include 1-methyl-1-ethylpyrrolidinium, 1-methyl-1-propylpyrrolidinium, 1-methyl-1-butylpyrrolidinium, 1-methyl-1-pentylpyrrolidinium, 1-methyl-1-hexylpyrrolidinium, and 1-methyl-1-octylpyrrolidinium, with 1-methyl-1-propylpyrrolidinium being preferred.

[0039] The piperidinium-based ion is preferably represented by the following formula (C): [ka] where: R 31 , R 32 , R 33 , R 34 , R 35 , R 36 and R 37 are each independently hydrogen, straight-chain or branched C 1-18 Alkyl, cyclic C 5-12 Alkyl, or C6-14 It is aryl.

[0040] Specific examples of piperidinium ions include 1-methyl-1-ethylpiperidinium, 1-methyl-1-propylpiperidinium, 1-methyl-1-butylpiperidinium, 1-methyl-1-pentylpiperidinium, 1-methyl-1-hexylpiperidinium, and 1-methyl-1-octylpiperidinium, with 1-methyl-1-butylpiperidinium being preferred.

[0041] The pyridinium-based ion is preferably represented by the following formula (D): [ka] where: R 41 , R 42 , R 43 , R 44 , R 45 and R 46 are each independently hydrogen, straight-chain or branched C 1-18 Alkyl, cyclic C 5-12 Alkyl, or C 6-14 It is aryl.

[0042] Specific examples of pyridinium ions include 1-methylpyridinium, 1-ethylpyridinium, 1-propylpyridinium, 1-butylpyridinium, 1-pentylpyridinium, 1-hexylpyridinium, 1-octylpyridinium, 1-methyl-3-ethylpyridinium, 1-methyl-4-ethylpyridinium, 1-methyl-3-butylpyridinium, 1-methyl-4-butylpyridinium, 1-ethyl-3-methylpyridinium, 1-ethyl-4-methylpyridinium, 1-propyl-3-methylpyridinium, 1-propyl-4-methylpyridinium, 1-butyl-3-methylpyridinium, 1-butyl-4-methylpyridinium, 1-hexyl-4-methylpyridinium, and 1-octyl-4-methylpyridinium, with 1-butylpyridinium and 1-ethyl-4-methylpyridinium being preferred.

[0043] The ammonium-based ion is preferably represented by the following formula (E): [ka] where: R 51 , R 52 , R 53 and R 54 are each independently a linear or branched C 1-18 Alkyl, linear or branched C 1-18 Hydroxyalkyl, cyclic C 5-12 Alkyl, or C 6-14 It is aryl.

[0044] Specific examples of ammonium ions include trimethylethylammonium, trimethylbutylammonium, triethylmethylammonium, tripropylmethylammonium, tributylmethylammonium, trihexylmethylammonium, trioctylmethylammonium, tetrabutylammonium, 2-hydroxyethyltrimethylammonium, and tris(2-hydroxyethyl)methylammonium, and preferred are tetrabutylammonium, tributylmethylammonium, and 2-hydroxyethyltrimethylammonium.

[0045] The anion of the ionic liquid is preferably at least one anion selected from the group consisting of formate ion, acetate ion, propionate ion, lactate ion, oleate ion, salicylate ion, dicyanamide ion, cyanamide ion, thiocyanate ion, methyl sulfate ion, ethyl sulfate ion, hydrogen sulfate ion, methanesulfonate ion, trifluoromethanesulfonate ion, p-toluenesulfonate ion, bis(trifluoromethylsulfonyl)imide ion, bis(fluorosulfonyl)imide ion, methyl carbonate ion, hydrogen carbonate ion, diethyl phosphate ion, dibutyl phosphate ion, hexafluorophosphate ion, tetrafluoroborate ion, chloride ion, and bromide ion, and more preferably acetate ion, dicyanamide ion, cyanamide ion, chloride ion, and bromide ion.

[0046] In a preferred embodiment, specific examples of the ionic liquid include trimethylbutylammonium bis(trifluoromethylsulfonyl)imide, tributylmethylammonium dicyanamide, tributylmethylammonium bis(trifluoromethylsulfonyl)imide, tris(2-hydroxyethyl)methylammonium methylsulfate, 2-hydroxyethyltrimethylammonium acetate, 2-hydroxyethyltrimethylammonium lactate, 2-hydroxyethyltrimethylammonium salicylate, tetrabutylammonium chloride, 1,3-dimethylimidazolium methylsulfate, 1,2,3-trimethylimidazolium methylsulfate, 1-ethyl-3-methylimidazolium acetate, 1-ethyl-3-methylimidazolium dicyanamide, and 1-ethyl-3-methylimidazolium methylsulfate. Imidazolium methyl sulfate, 1-ethyl-3-methylimidazolium thiocyanate, 1-ethyl-2,3-dimethylimidazolium bis(trifluoromethylsulfonyl)imide, 1-propyl-3-methylimidazolium acetate, 1-propyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-propyl-2,3-dimethylimidazolium bis(trifluoromethylsulfonyl)imide, 1-butyl-3-methylimidazolium acetate, 1-butyl-3-methylimidazolium dicyanamide, 1-butyl-3-methylimidazolium thiocyanate, 1-butyl-3-methylimidazolium bromide, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-2,Examples include 3-dimethylimidazolium bis(trifluoromethylsulfonyl)imide, 1-octyl-3-methylimidazolium acetate, 1-octyl-3-methylimidazolium bromide, 1-octyl-3-methylimidazolium tetrafluoroborate, 1-methyl-1-butylpyrrolidinium dicyanamide, 1-methyl-1-octylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-methyl-1-butylpiperidinium bis(trifluoromethylsulfonyl)imide, 1-ethyl-3-methylpyridinium ethyl sulfate, 1-butyl-4-methylpyridinium bis(trifluoromethylsulfonyl)imide, and 1-butylpyridinium tetrafluoroborate. In a more preferred embodiment, the ionic liquid has an imidazolium ion as the cation and an acetate as the anion, and specific examples include 1-ethyl-3-methylimidazolium acetate, 1-propyl-3-methylimidazolium acetate, 1-butyl-3-methylimidazolium acetate, and 1-octyl-3-methylimidazolium acetate.

[0047] Ionic liquids have a catalytic effect that accelerates the curing of polysiloxane, and it is believed that curing can be completed even at relatively low temperatures. The blending ratio of (II) ionic liquid to (I) polysiloxane ((II) ionic liquid / (I) polysiloxane), in mass ratio, is preferably 0.000030 to 0.10, more preferably 0.000050 to 0.10, more preferably 0.00010 to 0.10, and even more preferably 0.0010 to 0.05. This is because within such a range, the effect of low-temperature curing is more pronounced, and the density of the cured film tends to increase. Furthermore, compared to commonly used curing accelerators (e.g., thermal base generators), ionic liquids can be present more uniformly in the composition, which is thought to be effective in suppressing voids.

[0048] The ionic liquid may be used alone or in combination of two or more kinds. The content of the ionic liquid is preferably 0.00020 to 4.0 mass%, more preferably 0.00020 to 3.2 mass%, more preferably 0.0010 to 1.0 mass%, and more preferably 0.010 to 0.50 mass%, based on the total mass of the composition according to the present invention.

[0049] (III) Acid The composition according to the present invention comprises an acid. The acid may be an inorganic acid or an organic acid, but is preferably an organic acid, more preferably a carboxylic acid.

[0050] Carboxylic acids include acetic acid, formic acid, propionic acid, butyric acid, valeric acid, acrylic acid, benzoic acid, oxalic acid, maleic acid, fumaric acid, phthalic acid, succinic acid, glutaconic acid, aspartic acid, glutamic acid, malic acid, citraconic acid, acetylenedicarboxylic acid, itaconic acid, mesaconic acid, 3-aminohexanedioic acid, malonic acid, diphenic acid, pyromellitic acid, tricarballylic acid, aconitic acid, hemimellitic acid, trimesic acid, trimellitic acid, mellophanic acid, prenitic acid, ethylenetetracarboxylic acid, 1,2,3,4-butanetetracarboxylic acid, and 1,2,4,5-cyclohexanetetracarboxylic acid. , 3,3',4,4'-biphenyltetracarboxylic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, and mellitic acid, and preferably oxalic acid, maleic acid, fumaric acid, phthalic acid, succinic acid, malic acid, citraconic acid, acetylenedicarboxylic acid, malonic acid, benzoic acid, pyromellitic acid, trimellitic acid, or 1,4,5,8-naphthalenetetracarboxylic acid, and more preferably maleic acid, phthalic acid, citraconic acid, benzoic acid, pyromellitic acid, trimellitic acid, or 1,4,5,8-naphthalenetetracarboxylic acid.

[0051] The acid preferably has high sublimability so that it sublimates when heated for curing. Specifically, the sublimation temperature is preferably 90 to 350° C., more preferably 90 to 250° C. This is because the acid sublimes when the film is cured, reducing the amount of the remaining cured film.

[0052] Without being bound by theory, as described above, ionic liquids function as catalysts that accelerate the curing of polysiloxanes at low temperatures. Compositions containing ionic liquids, polysiloxanes, and solvents may continue to cure even during long-term storage at room temperature, resulting in gelation and other problems. In contrast, it is believed that combining an acid suppresses the catalytic action of the ionic liquid and provides good storage stability. It is believed that the acid sublimes during heating for curing, thereby enabling the catalytic action of the ionic liquid to be expressed, allowing the composition to cure at low temperatures. Furthermore, the acid functions as a pore-generating material. It sublimes when heated for curing, generating micropores in the cured film. To lower the dielectric constant, the acid preferably contains an acid having an aromatic ring. Specifically, it is more preferable that component (III) contains phthalic acid, benzoic acid, pyromellitic acid, trimellitic acid, or 1,4,5,8-naphthalenetetracarboxylic acid.

[0053] The compounding ratio of the ionic liquid (II) to the acid (III) ((II) / (III)) is preferably 0.001 to 0.09, more preferably 0.001 to 0.07, in terms of equivalent ratio.

[0054] The acid may be used alone or in combination of two or more. The content of the acid is preferably 0.10 to 10.0 mass %, more preferably 0.20 to 9.0 mass %, based on the total mass of the composition according to the present invention. When the content of the acid is within this range, the effect of lowering the dielectric constant is enhanced and cracks can be effectively suppressed.

[0055] (IV) Solvent The solvent is not particularly limited as long as it can uniformly dissolve or disperse the components (I) to (III) 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; propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether (PGME) and propylene glycol monoethyl ether; propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monoethyl ether acetate, ...methyl ether acetate (PGMEA), propylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monoethyl ether acetate (PGMEA), propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether acetate (PGMEA Examples of suitable solvents include propylene glycol alkyl ether acetates such as propylene glycol monomethyl 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, glycerin, 3-methoxybutanol, and 1,3-butanediol, esters such as ethyl lactate, butyl acetate, 3-methoxybutyl acetate, ethyl 3-ethoxypropionate, and methyl 3-methoxypropionate, and cyclic esters such as γ-butyrolactone. Preferred solvents are selected from the group consisting of PGMEA, PGME, 3-methoxybutanol, 1,3-butanediol, propylene glycol monomethyl ether acetate, ethyl lactate, butyl acetate, and 3-methoxybutyl acetate. The solvents may be used alone or in combination of two or more.

[0056] 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 fine grooves and the film thickness required outside the grooves. The solvent content is preferably 50 to 98 mass%, more preferably 60 to 98 mass%, based on the total mass of the composition according to the present invention.

[0057] The composition according to the present invention essentially comprises (I) to (IV), but can be combined with additional compounds as needed. The materials that can be combined are described below. The total amount of components other than (I) to (IV) in the entire composition is preferably 10% or less, more preferably 5% or less, and even more preferably 1% or less, based on the total mass of the composition. It is also one aspect of the present invention that the composition according to the present invention does not contain any components other than (I) to (IV).

[0058] The composition according to the present invention may contain other additives as needed, such as surfactants, adhesion promoters, antifoaming agents, and thermal curing accelerators. 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.

[0059] Method for producing cured film The method for producing a cured film according to the present invention comprises applying the composition according to the present invention to a substrate to form a film, and then heating the film, irradiating it with light, or a combination thereof. In the present invention, "on the substrate" includes cases where the composition is applied directly to the substrate, and cases where the composition is applied to the substrate via one or more intermediate layers. The method for forming a cured film is described below in order of steps.

[0060] (1) Applicable process The shape of the substrate is not particularly limited and can be selected as desired depending on the purpose. However, the composition according to the present invention has the characteristic of easily penetrating narrow grooves and forming a uniform cured film even inside the grooves, and therefore can 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.

[0061] 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.

[0062] The application 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, inkjet 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 necessary. When the substrate is a film, gravure coating can also be used. If desired, a drying step can be separately provided after film formation. Furthermore, if necessary, the application step can be repeated once or twice or more times to form a film with a desired thickness.

[0063] (2) Pre-baking process After forming a film by applying the composition, the film may be dried and pre-baked (pre-heat treatment) to reduce the amount of solvent remaining in the film.

[0064] (3) Curing process The film is heated, irradiated with light, or a combination thereof to form a cured film. In the present invention, the cured film means one having an S2 / S1 ratio of less than 0.003. Heating can be performed using a hot plate or oven. The heating temperature in this curing step is not particularly limited as long as it is a temperature at which a cured film is formed, and can be set arbitrarily. However, if silanols remain, the cured film may have insufficient chemical resistance or a high dielectric constant. From these perspectives, a relatively high heating temperature is generally selected, but when the composition of the present invention is used, curing can be achieved at a relatively low temperature. Specifically, heating at 500°C or less is preferred, and 450°C or less is more preferred. On the other hand, to promote the curing reaction, the heating temperature is preferably 120°C or higher, more preferably 140°C or higher, and even more preferably 170°C or higher. Furthermore, the heating time is not particularly limited, and when a hot plate is used, it is preferably 1 to 60 minutes, more preferably 1 to 30 minutes. The light irradiation preferably has a peak wavelength of 150 to 600 nm, more preferably 200 to 580 nm. Broadband UV light can also be used. One or more lamps can be used as the light source for irradiation light. Heating and light irradiation can also be combined. The curing step is preferably carried out in an air atmosphere.

[0065] The cured film according to the present invention has been or can be produced by the above-described method. The formed cured film is a low-dielectric-constant siliceous film having dispersed pores. The relative dielectric constant of the cured film is preferably 2.2 to 2.9, and more preferably 2.4 to 2.9. The relative dielectric constant can be measured, for example, using a mercury probe device manufactured by Semilab. The thickness of the cured film to be formed is selected depending on the application, but is preferably 0.10 to 3.0 μm, and more preferably 0.10 to 2.5 μm. The cured film of the present invention can further achieve sufficient transparency, chemical resistance, environmental resistance, heat resistance, etc. Therefore, it can be suitably used in a wide range of applications, such as an interlayer insulating film for low-temperature polysilicon, a buffer coating film for IC chips, or a transparent protective film.

[0066] The electronic device according to the present invention comprises the above-described cured film. The method for producing an electronic device according to the present invention comprises the method for producing a cured film according to the present invention described above.

[0067] 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.

[0068] Gel permeation chromatography (GPC) is performed using an alliance™ e2695 high-speed GPC system (Nihon Waters, Inc.) and a Super Multipore HZ-N GPC column (Tosoh Corporation). Measurements are 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 (hereinafter sometimes referred to as Mw) is calculated as the molecular weight relative to the standard sample.

[0069] Synthesis Example 1: Polysiloxane A 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 PGME and cooled to 0.2°C. Next, 96.6g of a 37% by weight solution of tetra-n-butylammonium hydroxide in methanol was added dropwise through a dropping funnel and stirred for 2 hours. After that, 500ml of n-propyl acetate was added, and the mixture was cooled again to 0.2°C. 1.1 equivalents of 3% by weight aqueous hydrochloric acid (relative to TBAH) was added and stirred for 1 hour to neutralize. 1,000ml of n-propyl acetate and 250ml 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 250cc of water and then concentrated under reduced pressure to remove water and solvent. PGMEA was added to obtain a polysiloxane A solution. The resulting polysiloxane A has an Mw of 2,630 and an S2 / S1 ratio of 0.041. Note that S2 / S1 here is measured using a polysiloxane A solution in the same manner as the S2 / S1 measurement method described below, except that heating is not performed.

[0070] Synthesis Example 2: Polysiloxane B A 2L flask equipped with a stirrer, thermometer, and condenser was charged with 32.5g of 40% by weight tetra-n-butylammonium hydroxide (TBAH) aqueous solution and 308ml of 2-methoxypropanol (PGME). A mixed solution of 19.6g of methyltrimethoxysilane and 9.4g 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, 500ml of n-propyl acetate (n-PA) was added, followed by 1.1 equivalents of 3% by weight maleic acid aqueous solution relative to the TBAH, and the mixture was neutralized and stirred for 1 hour. 500ml of n-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 obtain polysiloxane B solution. The resulting polysiloxane B has a Mw of 2,180 and an S2 / S1 ratio of 0.10.

[0071] How to measure S2 / S1 A composition containing polysiloxane and a solvent is dropped onto a 4-inch Si wafer, spin-coated at 1000 rpm, and then heated on a hot plate at 150°C for 2 minutes to obtain a film. The FT-IR spectrum of the film is measured at room temperature using an FTIR-6100 (JASCO). Taking noise into consideration, baseline correction is performed, and the FT-IR spectrum is measured at 900±100 cm. -1 The absorption band (S2) attributed to Si-OH has a peak in the range of 1100 ± 100 cm -1 The integrated intensity of the absorption band (S1) assigned to Si-O, which has a peak in the range of 1 / 2, is measured, and the value of S2 / S1 is calculated. Note that the tail of the absorption band assigned to Si-OH may overlap with the tail of the absorption band assigned to Si-O. In such cases, the wave number corresponding to the minimum point between the two absorption bands in the spectrum is used as the boundary. The same applies when the tail of another absorption band overlaps with the tail of the absorption band assigned to Si-OH or Si-O.

[0072] Preparation of Polysiloxane Composition Polysiloxane compositions of Examples 101 to 105, 201 to 206, and 301 and Comparative Examples 101 and 201 were prepared with the compositions and contents shown in the following Tables 1 to 3. In the tables, the numerical values ​​for the compositions represent mass %. [Table 1] [Table 2] [Table 3] In the table, Ionic liquid A: 1-ethyl-3-methylimidazolium acetate (EMIMAc), Ionic liquid B: 2-hydroxyethyltrimethylammonium acetate, Naph4: 1,4,5,8-naphthalenetetracarboxylic acid is.

[0073] Production of cured films In all cases except for Example 301, the polysiloxane composition was applied to a 4-inch Si wafer using a spin coater (1HDX2 manufactured by Mikasa Co., Ltd.) and prebaked at 130°C for 120 seconds. Thereafter, the composition was heated at 400°C for 30 minutes for curing to obtain a cured film. In Example 301, a cured film is obtained in the same manner as above, except that after the heating for curing, the film is irradiated with light from a high-pressure mercury lamp for 30 minutes. The thickness of each of the obtained cured films was 0.3 μm.

[0074] Dielectric constant and withstand voltage evaluation The dielectric constant and withstand voltage of the resulting cured film are measured using a mercury probe device (MCV-530) manufactured by Semilab.

[0075] Hardness and modulus evaluation The hardness and elastic modulus of the resulting cured film are measured using an indentation hardness tester ENT-2100 (Elionix).

Claims

1. (I) polysiloxane, (II) ionic liquids, (III) an acid, and (IV) Solvent comprising A polysiloxane composition in which the blending ratio of the ionic liquid (II) to the acid (III) ((II) / (III)) is 0.001 to 0.09 in terms of equivalent ratio.

2. (I) The polysiloxane contains a repeating unit represented by the following formula (Ia): 【Chemistry 1】 (where, R １ is hydrogen, monovalent to trivalent, C １－３０ or a linear, branched or cyclic, saturated or unsaturated aliphatic hydrocarbon group of the formula ６－３０ is an aromatic hydrocarbon group of the formula The aliphatic hydrocarbon group and the aromatic hydrocarbon group are each unsubstituted or substituted with fluorine, hydroxy or C １－８ is substituted with alkoxy, In the aliphatic hydrocarbon group and the aromatic hydrocarbon group, no methylene is replaced, or one or more methylenes are replaced by oxy, imido or carbonyl, provided that R １ is not hydroxy or alkoxy, R １ is divalent or trivalent, R １ connects Si atoms contained in multiple repeating units together), and A repeating unit represented by the following formula (Ib): 【Chemistry 2】 A polysiloxane having silanol groups at the terminal or side chain, comprising: A film was formed on a Si wafer using a composition containing the polysiloxane and a solvent, and heated at 150° C. for 2 minutes. The FT-IR spectrum of the film thus obtained was subjected to baseline correction, and the peak wavelength was 1100±100 cm －１ and the area intensity S1 of the absorption band attributable to Si—O having a peak in the range of 900±100 cm －１ 2. The composition according to claim 1, wherein the integrated intensity S2 of an absorption band assigned to SiOH having a peak in the range of 0.020 to 0.20 is measured, and the calculated ratio S2 / S1 is 0.020 to 0.

20.

3. R １ But hydrogen, C １－６ or a linear, branched or cyclic alkyl of C ６－１０ The composition of claim 2 wherein the aryl is:

4. (II) The composition according to any one of claims 1 to 3, wherein the cation of the ionic liquid is at least one cation selected from the group consisting of imidazolium-based ions, pyrrolidinium-based ions, piperidinium-based ions, pyridinium-based ions, and ammonium-based ions.

5. (II) The composition according to any one of claims 1 to 4, wherein the anion of the ionic liquid is at least one anion selected from the group consisting of formate ion, acetate ion, propionate ion, lactate ion, oleate ion, salicylate ion, dicyanamide ion, cyanamide ion, thiocyanate ion, methyl sulfate ion, ethyl sulfate ion, hydrogen sulfate ion, methanesulfonate ion, trifluoromethanesulfonate ion, p-toluenesulfonate ion, bis(trifluoromethylsulfonyl)imide ion, bis(fluorosulfonyl)imide ion, methyl carbonate ion, hydrogen carbonate ion, diethyl phosphate ion, dibutyl phosphate ion, hexafluorophosphate ion, tetrafluoroborate ion, chloride ion, and bromide ion.

6. 6. The composition according to claim 1, wherein the weight average molecular weight of the polysiloxane (I) is 500 to 10,000 as measured by gel permeation chromatography.

7. The composition according to any one of claims 1 to 6, wherein the blending ratio ((II) / (I)) of the ionic liquid (II) to the polysiloxane (I) is 0.000030 to 0.10 in mass ratio. thing.

8. The composition according to any one of claims 1 to 7, wherein the acid is an organic acid.

9. The composition according to any one of claims 1 to 8, wherein the ratio of the number of repeating units represented by formula (Ib) is 8% or more, based on the total number of repeating units contained in the polysiloxane (I).

10. (IV) The composition according to any one of claims 1 to 9, wherein the solvent is at least one selected from the group consisting of propylene glycol monomethyl ether, propylene glycol monoethyl ether, 3-methoxybutanol, 1,3-butanediol, propylene glycol monomethyl ether acetate, ethyl lactate, butyl acetate, and 3-methoxybutyl acetate.

11. The composition according to any one of claims 1 to 10, wherein the content of (IV) the solvent is 50 to 98 mass % based on the total mass of the composition.

12. A method for producing a cured film, comprising applying the composition according to any one of claims 1 to 11 to a substrate to form a film, and heating the film, irradiating the film with light, or a combination thereof.

13. The method for producing a cured film according to claim 12, wherein the heating is carried out at a temperature of 120°C or higher.

14. The method for producing a cured film according to claim 12 or 13, wherein the light irradiation has a peak wavelength of 150 to 600 nm.

15. A cured film produced by the method according to any one of claims 12 to 14.

16. The cured film according to claim 15, having a dielectric constant of 2.2 to 2.

9.

17. An electronic device comprising the cured film according to claim 15 or 16.

18. A method for producing a cured film of an electronic device, comprising the steps of: Manufacturing method.

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