Siloxane compound, composition comprising siloxane compound, method for producing cured film, cured film, and electronic device

Abstract

[Problem] To provide a siloxane compound. The production method according to the present invention produces applications for semiconductor devices and display devices, and thus may be used with nano-technology processes. For example, the method can produce liquid crystal, quantum dots, or OLED displays formed on substrates, which can be controlled with semiconductors. Preferred performance of the production method according to the invention may be supported by at least one of the properties of high-performance materials and advanced materials. [Means of Solution] A siloxane compound having a siloxane bonding degree of 0.25 to 0.885, preferably 0.40 to 0.875, more preferably 0.50 to 0.86, still more preferably 0.60 to 0.85 and even more preferably 0.70 to 0.82.

Description

ForeignFiling Text P25-249- 1 -[DESCRIPTION][Title of Invention]SILOXANE COMPOUND, COMPOSITION COMPRISING SILOXANE COMPOUND, METHOD FOR PRODUCING CURED FILM, CURED FILM,5 AND ELECTRONIC DEVICE[Technical Field]

[0001] The present disclosure relates to a siloxane compound, a composition comprising a siloxane compound, a method for producing a cured film, a cured film, and an electronic device.[Background Art]

[0002] Siloxane compounds are useful as SOD (Spin on Dielectric) materials, and are used, for example, for insulating materials of electronic devices such as semiconductor devices.15

[0003] PTL 1 describes a specific gate insulator film-forming composition comprising a polysiloxane, barium titanate, and a solvent.

[0004] PTL 2 discloses a silica coating film-forming composition comprising a hydrolytic condensation product of a hydrolyzable silicon compound comprising two silicon atoms linked via a specific divalent20 organic group and a specific hydrolyzable silicon compound, a solvent and an onium salt at specific blending ratios.[Citation List][Patent Literature]

[0005] [PTL 1] Japanese Patent Application Publication No. 2022-537638 [PTL 2] Japanese Patent Application Publication No. 2007-291167 [Summary of Invention] [Technical Problem]

[0006] The inventors believed that siloxane compounds still have one or more problems that needed to be improved. Examples of the problems30 comprise the followings: reduction of the dielectric constant of a cured film; increase in the hardness of a cured film; improvement of the electrical properties of a cured film;ForeignFiling Text P25-249- 2 - increase in the stability of a siloxane compound; improvement of embedding properties of a composition comprising a siloxane compound and a cured film thereof to a substrate; reduction of the time required for curing; suppression of shrinkage associated with film curing; suppression of5 peeling associated with film curing; suppression of cracking of a cured film; improvement of the manufacturing yield of a cured film; more uniform application of a composition; increase in the insulating properties of a cured film; increase in the dielectric breakdown field of a cured film; suppression of the flat band voltage of a cured film; increase in the chemical resistance of a cured film; reduction of the wet etching rate of a cured film; increase in the heat resistance of a cured film; increase in the acid resistance of a cured film; suppression of voids in a cured film; and increase in adhesion to a wiring material or a silica film.

[0007] With the foregoing in the view, the present invention is to provide a15 siloxane compound, a composition comprising a siloxane compound, a method for producing a cured film, a cured film, and an electronic device. [Solution to Problem]

[0008] A siloxane compound according to one embodiment has a siloxane bonding degree of 0.25 to 0.885, preferably 0.40 to 0.875, more preferably20 0.50 to 0.86, still more preferably 0.60 to 0.85 and even more preferably 0.70 to 0.82.

[0009] A siloxane compound of one embodiment comprises a unit C represented by formula (3), and has a silanol content of 0.12 to 0.40, preferably 0.14 to 0.30 and more preferably 0.14 to 0.25:30 wherein:R21and R22are each independently H, F, -OH, -COOH, -SO2H, C6-20ForeignFiling Text P25-249- 3 - aryl, or C1-20 alkyl; preferably, H, F, -OH, phenyl, naphthyl, phenanthryl, anthracenyl, linear C1-20 alkyl, branched C3-20 alkyl, or cyclic C3-20 alkyl; more preferably, H, F, -OH, linear C1-15 alkyl or branched C3-15 alkyl; still more preferably, H, F, -OH, linear C1-10 alkyl, or branched C3-10 alkyl; and5 even more preferably, H, F, -OH, methyl, ethyl, n-propyl, isopropyl, n-butyl, or tert-butyl;L21is C1-20 alkylene or -CR23=CR24-; preferably linear C1-20 alkylene, branched C3-20 alkylene, cyclic C3-20 alkylene, or -CR23=CR24-; more preferably, linear C1-10 alkylene, branched C3-10 alkylene, or -CR23=CR24-; still more preferably, linear C1-5 alkylene, branched C3-5 alkylene, or - CR23=CR24-; even more preferably, -CH2-, -CH2CH2-, -CH(CH3)-, - CH2CH2CH2-, -CH(CH3)CH2-, or -CR23=CR24-; one or more non-adjacent -CH2- groups of R21, R22and L21may be replaced with -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, C6-20 arylene, -15 CR23=CR24-, or -C=C-, provided that the one or more non-adjacent -CH2- groups are unsubstituted when L21is -CH2-;R23and R24are each independently H or C1-10 alkyl; preferably, H, linear C1-10 alkyl, branched C3-10 alkyl, or cyclic C3-10 alkyl; and more preferably, H, linear C1-5 alkyl, or branched C3-5 alkyl;20 one or more H atoms of R21, R22and L21may each independently be replaced with -OH, -COOH, -SO2H or C6-20 aryl; and n21 is 0, 1 or 2, n24 is 3-n21 , n22 is 0, 1 or 2, and n23 is 2-n22.

[0010] A composition according to one embodiment comprises the abovedescribed siloxane compound and a solvent: the solvent is preferably one or more solvents selected from the group consisting of: an aromatic compound, more preferably benzene, toluene, xylene, ethylbenzene, diethylbenzene, trimethylbenzene, or triethylbenzene; a saturated hydrocarbon compound, more preferably cyclohexane, decahydronaphthalene, n-pentane, i-pentane, n-hexane, i-30 hexane, n-heptane, i-heptane, n-octane, i-octane, n-nonane, i-nonane, n- decane, ethylcyclohexane, methylcyclohexane, or p-menthane; an unsaturated hydrocarbon compound, more preferably cyclohexene orForeignFiling Text P25-249- 4 - dipentene; an ether compound, more preferably dipropyl ether, dibutyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, or anisole; an ester compound, more preferably n-butyl acetate, i-butyl acetate, n-amyl acetate, ethyl lactate, or i-amyl acetate; and5 a ketone compound, more preferably methyl isobutyl ketone.

[0011] A method for producing a cured film according to one embodiment comprises the following steps (a) and (b-1 ):(a) applying the above-described composition above a substrate to form a coating film; preferably, spin-coating the above-described composition above the substrate for 5 to 100 seconds at 500 to 2,500 RPM, more preferably for 10 to 70 seconds at 600 to 2,000 RPM, and still more preferably for 10 to 50 seconds at 700 to 1 ,900 RPM; and(b-1 ) heating the coating film; preferably heating at 30 to 500°C, more preferably 40 to 450°C, and still more preferably 50 to 420°C for preferably15 30 seconds to 600 minutes, more preferably 1 to 400 minutes, still more preferably 1.5 to 200 minutes, and even more preferably 2 to 150 minutes.

[0012] A cured film according to one embodiment is a cured film obtained by the above-described method, that has a thickness of 0.1 to 3,000 nm, preferably 1 to 1 ,500 nm, more preferably 2 to 1 ,200 nm, and still more20 preferably 3 to 1 ,000 nm.

[0013] An electronic device according to one embodiment comprises the above-described cured film.

[0014] A method for producing an electronic device according to one embodiment comprises the above-described method.

[0015] Use of a siloxane compound according to one embodiment is use of the above-described siloxane compound for forming a cured film on a substrate.

[0016] Use of a composition according to one embodiment is use of the above-described composition for forming a cured film on a substrate.30[Technical Effects of the Invention]ForeignFiling Text P25-249- 5 -

[0017] According to the present disclosure, one or more of the following effects can be expected: reduction of the dielectric constant of the cured film; increase in the hardness of the cured film; improvement of the electrical properties of the5 cured film; increase in the stability of the siloxane compound; improvement of embedding properties of the composition comprising the siloxane compound and the cured film thereof to a substrate; reduction of the time required for curing; suppression of shrinkage associated with film curing; suppression of peeling associated with film curing; suppression of cracking of the cured film; improvement of the manufacturing yield of the cured film; sufficiently uniform application of the composition; increase in the insulating properties of the cured film; increase in the dielectric breakdown field of the cured film; suppression of the flat band voltage of the cured film; increase in the chemical resistance of the cured film; reduction of the wet etching rate15 of the cured film; increase in the heat resistance of the cured film; increase in the acid resistance of the cured film; suppression of voids in the cured film; and increase in adhesion to a wiring material and a silica film.

[0018] The foregoing description should not be considered to disclose all embodiments of the present invention and all advantages relating to the20 present invention.[Description of Embodiments]

[0019] Embodiments of the present invention is described below. The present invention is not limited to these embodiments, and may be variously modified within the spirit and scope of the present invention.

[0020] DefinitionsIn the present disclosure, unless specifically limited otherwise, the definitions and examples described in this paragraph shall apply to the terms and symbols.The singular form comprises the plural form, and the term “one” or “the”30 means “at least one”. An element of a concept can be expressed by multiple types, and when the amount (for example, mass% or mol%) thereof is stated, the amount means the sum of the multiple types.ForeignFiling Text P25-249- 6 -The term “and / or” comprises all combinations of elements, and also comprises the use of each of the elements alone.When a numerical range is shown with the use of “to” or these comprise both end points, and the units are common. For example, 5 to 255 mol% means 5 mol% or more and 25 mol% or less.The notation “Cx-y”, “Cx-Cy”, and “Cx” indicates the number of carbon atoms in a molecule or substituent. For example, “C1-6 alkyl” refers to an alkyl chain having 1 or more and 6 or less carbon atoms (such as methyl, ethyl, propyl, butyl, pentyl, or hexyl).Cyclic alkyl means alkyl having a ring structure, and cyclic alkylene means alkylene having a ring structure.An aromatic compound means a compound having an aromatic ring and comprises polycyclic aromatic compounds.The unit of temperature is Celsius. For example, the term 20 degrees15 means 20 degrees Celsius.The additive means the compound per se having the indicated function. For example, a base-generator refers to a compound per se that generates a base. There may also be embodiments in which the compound is dissolved or dispersed in a solvent and is added to a composition.20 The phrase “application above a substrate” means that the composition of the present invention (hereinafter, sometimes simply referred to as composition) may be applied directly on the substrate or applied with one or more other layers interposed. Examples of other layers include SOC (Spin On Carbon) and adhesion enhancing films. Preferably, the composition is applied directly on a substrate.The term “solid matter” suitably means all components in the composition other than a solvent.The term “solid content” suitably refers to the value obtained by dividing the total mass of all components in the composition other than the solvent30 by the mass of the entire composition.

[0021] <Siloxane compound>(First embodiment)ForeignFiling Text P25-249- 7 -In the first embodiment, the siloxane compound has a siloxane bonding degree of 0.25 to 0.885. The siloxane bonding degree is preferably 0.40 to 0.875, more preferably 0.50 to 0.86, still more preferably 0.60 to 0.85, and even more preferably 0.70 to 0.82.5

[0022] It is believed that when the siloxane compound having a siloxane bonding degree of 0.885 or less is used, the embedding properties of a composition comprising the siloxane compound and a cured film thereof into a substrate are improved. It is also believed that when the siloxane bonding degree is 0.25 or more, the degree of formation of a network based on -Si-O-Si- (hereinafter referred to as siloxane network) in the siloxane compound is sufficiently high. Because of this, it is believed that the cured film has a sufficiently high film hardness.

[0023] The siloxane bonding degree is the value determined according to the following manner. The siloxane compound is subjected to29Si nuclear15 magnetic resonance analysis (29Si NMR), and from the integral intensity ratios of resonant frequency peaks, the abundance ratios of Q1 , Q2, Q3, Q4, T1 , T2, T3, D1 , D2, and M1 which are units in the siloxane compound are calculated respectively. The siloxane bonding degree of the siloxane compound is determined according to the following formula, wherein R(Q1 ),20 R(Q2), R(Q3), R(Q4), R(T1 ), R(T2), R(T3), R(D1 ), R(D2), and R(M1 ) are the abundance ratios of the units, respectively.Siloxane bonding degree =[R(Q1 )+2R(Q2)+3R(Q3)+4R(Q4)+R(T1 )+2R(T2)+3R(T3)+R(D1 )+2R(D2)+R (M1 )] / [4{R(Q 1 )+R(Q2)+R(Q3)+R(Q4)}+3{R(T1 )+R(T2)+R(T3)}+2{R(D1 )+R( D2)}+R(M1 )]

[0024] The respective units are as follows.Q1 : a unit in which Si is attached to one oxygen atom attached to another Si (hereinafter referred to as Osi) and three oxygen atoms respectively attached to monovalent groups (hereinafter referred to as OR).30 Q2: a unit in which Si is attached to two Osi atoms and two OR atoms.Q3: a unit in which Si is attached to three Osi atoms and one OR atom.Q4: a unit in which Si is attached to four Osi atoms.ForeignFiling Text P25-249- 8 -T1 : a unit in which Si is attached to one Osi atom, two OR atoms and one atom other than Osi and OR (hereinafter referred to as additional atom). T2: a unit in which Si is attached to two Osi atoms, one OR atom, and one additional atom.5 T3: a unit in which Si is attached to three Osi atoms and one additional atom.D1 : a unit in which Si is attached to one Osi atom, one OR atom, and two additional atoms.D2: a unit in which Si is attached to two Osi atoms and two additional atoms.M1 : a unit in which Si is attached to one Osi atom and three additional atoms.

[0025] The shift value ranges in which peaks of29Si nuclear magnetic resonance analysis assigned to the units are observed are as follows in15 measurements using tetramethylsilane as a standard.Q1 : -89 to -80 ppm Q2: -93 to -90 ppm Q3: -100 to -95 ppm Q4: -108 to -106 ppm20 T 1 : -52 to -48 ppm T2: -57 to -55 ppm T3: -64 to -60 ppm D1 : -14 to -11 ppm D2: -22 to -19 ppm M1 : 6 to 10 ppm

[0026] In one suitable embodiment of the present disclosure, the siloxane compound comprises at least one unit selected from the group consisting of a unit A1 represented by formula (a1), a unit A2 represented by formula (a2), a unit A3 represented by formula (a3) and a unit A4 represented by30 formula (a4). Preferably, the siloxane compound comprises the unit A4 and at least one unit selected from the group consisting of the unit A1 , the unit A2, and the unit A3:ForeignFiling Text P25-249[C2]R1, R2, R3, R4, R5, and R6are each independently H, C6-20 aryl, or C1-2015 alkyl; preferably, H, C6-20 aryl, linear C1-20 alkyl, branched C3-20 alkyl, or cyclic C3-20 alkyl; more preferably, H, phenyl, naphthyl, phenanthryl, anthracenyl, linear C1-15 alkyl, or branched C3-15 alkyl; still more preferably, H, linear C1-10 alkyl or branched C3-10 alkyl; and even more preferably, H, methyl, ethyl, n-propyl, isopropyl, n-butyl, or tert-butyl.20 One or more non-adjacent -CH2- groups of R1, R2, R3, R4, R5, and R6may each independently be replaced with -O-, -S-, -CO-, -CO-O-, -O-CO-, - O-CO-O-, C6-20 arylene, -CR7=CR8-, or -C=C-. An embodiment in which all - CH2- groups of R1, R2, R3, R4, R5, and R6are unsubstituted is preferable.R7and R8are each independently H or C1-10 alkyl; preferably, H, linear C1-10 alkyl, branched C3-10 alkyl or cyclic C3-10 alkyl; and more preferably, H, linear C1-5 alkyl or branched C3-5 alkyl.One or more H atoms of R1, R2, R3, R4, R5and R6may each independently be replaced with -OH, -COOH, -SO2H, or C6-20 aryl. An embodiment in which all H atoms of R1, R2, R3, R4, R5and R6are30 unsubstituted is preferable.ForeignFiling Text P25-249- 10 -

[0027] It is believed that when the siloxane compound comprises the unit A4, the embedding properties of a composition comprising the siloxane compound and a cured film thereof into a substrate are further improved.

[0028] The siloxane compound may comprise a terminal group other than5 the unit A4 (hereinafter referred to as additional terminal group). Provided that n4 is the number of the unit A4 and neis the number of all terminal groups in the siloxane compound, n4 / neis preferably 80% or more, more preferably 90% or more, and still more preferably 95% or more.An embodiment in which n4 / neis 100%, i.e. , the siloxane compound is free of the additional terminal group is also a preferred embodiment of the present invention.

[0029] The meaning of O0.5 in the structural formulae in the present application is described in detail. The structure of the siloxane compound has a basic skeleton of the network in which Si and O are continuously15 bonded. The following is an example of the network., ting unit in the dashed line is represented by the following formula with using the expression O0.5 for descriptive purposes:ForeignFiling Text P25-249- 11 -As the siloxane compound has a basic skeleton of the network formed with continuous binding of Si and 0, it is not appropriate to represent the structure comprising Si-0 as repeating units. For this reason, the expression O0.5 is used for descriptive purposes to represent repeating5 units of the siloxane compound.

[0030] Specific examples of the unit A2 are as follows.[C5]30ForeignFiling_Text P25-249- 12 -

[0031] Specific examples of the unit A3 are as follows.[C6]o.5 2 5( 3)2, - o.5 3( 2 5)2, - o.5 ( 2 5)3, -Oo.5SiOC3H7(OCH3)2, -Oo.5Si[OCH(CH3)CH3](OCH3)2, -ForeignFiling Text P25-249- 13 -O0.5SiOC2H5(OC3H7)(OCH3), -Oo.5Si[OCH(CH3)CH3](OCH3)(OC2H5), - Oo.5Si[OCH(CH3)CH3](OC2H5)2, -Oo.5Si(OC3H7)3, -O0.5SiOC3H7(OC2H5)2, and -Oo.5Si[OCH(CH3)CH3]3.

[0033] The siloxane compound may comprise only one type of each of the5 units A2 to A4, or may comprise two or more types thereof.

[0034] In the present embodiment, the siloxane compound preferably further comprises a unit B represented by formula (2), provided that the unit B is not a part of any of the unit A1 , the unit A2, the unit A3 and the unit A4:R11is H, F, -OH, -COOH, -SO2H, Ce-20 aryl, or C1-20 alkyl; preferably, H, F, -OH, -COOH, -SO2H, Ce-20 aryl, linear C1-20 alkyl, branched C3-20 alkyl, or15 cyclic C3-20 alkyl; more preferably, H, F, -OH, phenyl, naphthyl, phenanthryl, anthracenyl, linear C1-15 alkyl, or branched C3-15 alkyl; still more preferably, H, F, -OH, linear C1-10 alkyl or branched C3-10 alkyl; and even more preferably, H, F, -OH, methyl, ethyl, n-propyl, isopropyl, n-butyl, or tertbutyl.20One or more non-adjacent -CH2- groups of R11may be replaced with -S-, -CO-, C6-20 arylene, -CR12=CR13-, or -C=C-. An embodiment in which all - CH2- groups of R11are unsubstituted is preferable.R12and R13are each independently H or C1-10 alkyl; preferably, H, linear C1-10 alkyl, branched C3-10 alkyl or cyclic C3-10 alkyl; and more preferably, H, linear C1-5 alkyl or branched C3-5 alkyl.One or more H atoms of R11may be replaced with -COOH, -SO2H, or Ce- 20 aryl. An embodiment in which all H atoms of R11are unsubstituted is more preferable. n11 is 1 or 2, preferably 2.30 n12 is 3-n11.ForeignFiling Text P25-249- 14 -

[0035] The siloxane compound may comprise only one type of unit B or may comprise two or more types thereof. When two R11groups are comprised in one unit, the two R11groups may be of one type or two types. It is preferable that all R11groups be the same in one unit.5

[0036] How the unit represented by formula (i) is interpreted in formula (2) is described in detail.R11is methyl, n11 is 1 and n12 is 2.15

[0037] In the present embodiment, the siloxane compound preferably further comprises a unit C represented by formula (3), provided that the unit B is not a part of the unit C:[C9]R21and R22are each independently H, F, -OH, -COOH, -SO2H, C6-20 aryl, or C1-20 alkyl; preferably, H, F, -OH, phenyl, naphthyl, phenanthryl, anthracenyl, linear C1-20 alkyl, branched C3-20 alkyl, or cyclic C3-20 alkyl; more preferably, H, F, -OH, linear C1-15 alkyl or branched C3-15 alkyl; still more preferably, H, F, -OH, linear C1-10 alkyl or branched C3-10 alkyl; and even more preferably, H, F, -OH, methyl, ethyl, n-propyl, isopropyl, n-butyl,30 or tert-butyl.L21is C1-20 alkylene or -CR23=CR24-; preferably linear C1-20 alkylene, branched C3-20 alkylene, cyclic C3-20 alkylene, or -CR23=CR24-; moreForeignFiling Text P25-249- 15 - preferably, linear C1-10 alkylene, branched C3-10 alkylene, or -CR23=CR24-; still more preferably, linear C1-5 alkylene, branched C3-5 alkylene, or - CR23=CR24-; and even more preferably, -CH2-, -CH2CH2-, -CH(CH3)-, - CH2CH2CH2-, CH(CH3)CH2-, or -CR23=CR24-.5 One or more non-adjacent -CH2- groups of R21, R22, and L21may be replaced with -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, C6-20 arylene, - CR23=CR24-, or -C=C-; provided that when L21is -CH2-, the one or more non-adjacent -CH2- groups are unsubstituted. An embodiment in which all - CH2- groups of R21, R22, and L21are unsubstituted is preferable.R23and R24are each independently H or C1-10 alkyl; preferably, H, linear C1-10 alkyl, branched C3-10 alkyl or cyclic C3-10 alkyl; and more preferably, H, linear C1-5 alkyl or branched C3-5 alkyl.One or more H atoms of R21, R22and L21may each independently be replaced with -OH, -COOH, -SO2H or C6-20 aryl. An embodiment in which all15 H atoms of R21, R22, and L21are unsubstituted is more preferable. n21 is 0, 1 or 2, preferably 0. n24 is 3-n21 . n22 is 0, 1 or 2, preferably 0. n23 is 2-n22.20

[0038] It is believed that because the siloxane compound comprises the unit C, a cured film has a higher film hardness.

[0039] The siloxane compound may comprise only one type of unit C or may comprise two or more types thereof. When more than one R21group is comprised in one unit, the more than one R21group may be of one type or two or more types. It is preferable that all R21groups be the same in one unit. The same applies to R22.

[0040] How the unit represented by formula (ii) is interpreted in formula (3) is described in detail.[C10]30ForeignFiling Text P25-249- 16 -n21 is 1 , n24 is 2, n22 is 0, n23 is 2,R21is methyl and L21is methylene.

[0041] Provided that NA is the total number of the units A1 to A4, NB is the number of the unit B, and NC is the number of the unit C, NB / (NA+NB+NC) is preferably 40 to 80%, more preferably 50 to 75%, and still more preferably 55 to 75%. NA / (NA+NB+NC) is preferably 15 to 35%, more preferably 15 to 30%, and still more preferably 20 to 30%.15

[0042] The siloxane compound may comprise a unit (hereinafter referred to as additional unit) other than the unit A1 , the unit A2, the unit A3, the unit B, and unit C. Provided that nsis the total number of the unit A1 , the unit A2, the unit A3, the unit B, and the unit C, and naii is the total number of the units in the siloxane compound, ns / naii is preferably 80% or more, more20 preferably 90% or more, and still more preferably 95% or more.An embodiment in which ns / naii is 100%, i.e. , the siloxane compound is free of the additional unit is also a preferred embodiment of the present invention.It should be noted that the units as in this context do not comprise terminal groups.

[0043] The siloxane compound preferably has a silanol group. The silanol group as used herein is a group (-SiOH) in which hydroxy group is directly attached to a silicon atom. The siloxane compound has a silanol content of preferable 0.12 to 0.40, more preferably 0.14 to 0.30 and still more30 preferably 0.14 to 0.25.It is believed that when the silanol content is 0.12 or more, theForeignFiling Text P25-249- 17 - embedding properties of a composition comprising the siloxane compound and a cured film into a substrate are further improved. It is also believed that when the silanol content is 0.40 or less, the degree of formation of the siloxane network in the siloxane compound is higher. Because of this, it is5 believed that the cured film has a higher film hardness.

[0044] The silanol content is calculated by formula (4).(4): Silanol content = R(SUM)-R(AI), whereinR(SUM) = 1 - siloxane bonding degree; and R(AI) = alkoxysilyl content.

[0045] The alkoxysilyl content is the value determined by the following method.The siloxane compound is subjected to29Si nuclear magnetic resonance analysis (29Si NMR) and13C nuclear magnetic resonance analysis (13C15 NMR), and the values and the abundance ratios indicated below are determined from the integral intensity ratios of the resonant frequency peaks: R(T) =[R(T1 )+R(T2)+R(T3)] / [4{R(Q1 )+R(Q2)+R(Q3)+R(Q4)}+3{R(T1 )+R(T2)+R(T20 3)}+2{R(D1 )+R(D2)}+R(M1 )];R(AI / T) = abundance ratio of the alkoxysilyl group represented by formula(5) to all T units as determined by13C nuclear magnetic resonance analysis;R(D) =[R(D1 )+R(D2)] / [4{R(Q1 )+R(Q2)+R(Q3)+R(Q4)}+3{R(T1 )+R(T2)+R(T3)}+2{ R(D1 )+R(D2)}+R(M1 )]; andR(AI / D) = abundance ratio of the alkoxysilyl group represented by formula (5) to all D units as determined by13C nuclear magnetic resonance analysis.30 With the determined abundance ratios, the alkoxysilyl content is calculated from the following formula (6-1 ) or (6-2).(6-1 ): alkoxysilyl content = R(T)xR(AI / T)ForeignFiling Text P25-249- 18 -(6-2): alkoxysilyl content = R(D)xR(AI / D)When the siloxane compound has multiple types of alkoxysilyl groups represented by formula (5), the abundance ratio is determined for each type, and the sum thereof is regarded as R(AI / T) or R(AI / D).bly, linear C1-20 alkyl, branched C3-20 alkyl, or cyclic C3-20 alkyl; more preferably, linear C1-15 alkyl or branched C3-15 alkyl; still more preferably, linear C1-10 alkyl or branched C3-10 alkyl; and even more preferably, methyl, ethyl, n-propyl, isopropyl, n-butyl, or tert-butyl.

[0046] The alkoxysilyl content may be calculated by using either formula15 (6-1 ) or (6-2). However, formula (6-2) is used when the siloxane compound does not contain T unit, and formula (6-1 ) is used when the siloxane compound does not contain D unit.

[0047] In13C nuclear magnetic resonance analysis using tetramethylsilane as a standard, peaks assigned to all T and D units can be observed within20 the shift value range of -9 to -2 ppm. Within this shift value range, generally, peaks at higher shift values are the peaks assigned to all T units, and peaks at lower shift values are the peaks assigned to all D units.In13C nuclear magnetic resonance analysis using tetramethylsilane as a standard, peaks assigned to alkoxysilyl groups can be observed within the shift value range of 30 to 100 ppm. Generally, a peak appears at a higher shift value when the number of carbon atoms in the alkoxysilyl group is high.Examples of the shift value ranges in which alkoxysilyl groups can be observed include 48 to 60 ppm for methoxysilyl group and 57 to 60 ppm for30 ethoxysilyl group.

[0048] The siloxane compound preferably comprises an alkoxysilyl group represented by formula (5).ForeignFiling Text P25-249- 19 -

[0049] In the present disclosure, the alkoxysilyl content means the content of the alkoxysilyl group represented by formula (5) of the siloxane compound, and is the value calculated by formula (6-1 ) or (6-2) as described above. The siloxane compound has the alkoxysilyl content of5 preferably 0.001 to 0.065, more preferably 0.005 to 0.05, and still more preferably 0.010 to 0.04.It is believed that when the alkoxysilyl content is 0.001 or more, the stability of the siloxane compound in the state of solution is improved. It is believed that when the alkoxysilyl content is 0.065 or less, the embedding properties of a composition comprising the siloxane compound and a cured film into a substrate can be further improved.

[0050] The siloxane compound has a mass average molecular weight (Mw) of preferably 500 to 3,000, more preferably 750 to 2,200, still more preferably 850 to 2,000, and even more preferably 1 ,000 to 1 ,800.15 It is believed that when Mw is 500 or more, formation of a uniform coating film is facilitated. It is believed that when Mw is 3,000 or less, the embedding properties of a composition comprising the siloxane compound and a cured film thereof into a substrate are improved.

[0051] In the present disclosure, Mw is measured by gel permeation20 chromatography (GPC) using polystyrene as a standard. The measurement is performed using monodisperse polystyrene as a standard sample and tetrahydrofuran as a developing solvent under measurement conditions of a flow rate of 0.5 mL / min and a column temperature of 40°C. Mw is calculated as the molecular weight relative to the standard sample.

[0052] The siloxane compound is suitably applied to electronic devices because the siloxane compound can form a cured film having excellent hardness and electrical properties. The siloxane compound can be used, for example, for formation of a cured film on a substrate. Examples of the substrate include a silicon substrate, a glass substrate, and a resin film, and30 the substrate is preferably a silicon substrate.

[0053] (Second embodiment)In the second embodiment, the siloxane compound comprises a unit CForeignFiling Text P25-249- 20 - represented by formula (3) and has a silanol content of 0.12 to 0.40, preferably 0.14 to 0.30, and more preferably 0.14 to 0.25.The definitions, examples and descriptions of R21, R22, L21, n21 , n22, n23, and n24 are as described in the (First embodiment).

[0054] The siloxane compound may comprise only one type of unit C or may comprise two or more types thereof. When more than one R21group is comprised in one unit, the more than one R21group may be of one type or two or more types. It is preferable that all R21groups be the same in one unit. The same applies to R22.15

[0055] It is believed that when the siloxane compound used comprises the unit C and has the silanol content of 0.40 or less, a cured film has a sufficiently high film hardness. It is believed that when the silanol content is 0.40 or less, the degree of formation of the network (hereinafter referred to as siloxane network) based on -Si-O-Si- is sufficiently high, which20 contributes to improved film hardness.It is also believed that when the silanol content is 0.12 or more, the embedding property of a composition comprising the siloxane compound and a cured film thereof into the substrate is improved.

[0056] The siloxane compound preferably has an alkoxysilyl group. The alkoxysilyl content is preferably 0.001 to 0.065, more preferably 0.005 to 0.05, and still more preferably 0.010 to 0.04.It is believed that when the alkoxysilyl content is 0.001 or more, the stability of the siloxane compound in the state of solution is improved. It is believed that when the alkoxysilyl content is 0.065 or less, the embedding30 properties of a composition comprising the siloxane compound and a cured film into a substrate can be further improved.ForeignFiling Text P25-249- 21 -

[0057] In the second embodiment, the definitions and descriptions of the silanol group, the alkoxysilyl group, the silanol content, and the alkoxysilyl content are as described in the (First embodiment).

[0058] In the second embodiment, the siloxane compound preferably5 comprises at least one unit among the unit A1 , the unit A2, the unit A3, and the unit A4. More preferably, the siloxane compound comprises the unit A4 and comprises at least one unit among the unit A1 , the unit A2, and the unit A3.The definitions, examples, and descriptions of the unit A1 , the unit A2, the unit A3, and the unit A4 are as described in the (First embodiment).

[0059] It is believed that when the siloxane compound comprises the unit A4, the embedding properties of a composition comprising the siloxane compound and a cured film thereof into a substrate are further improved.

[0060] The siloxane compound may comprise a terminal group15 (hereinafter referred to as additional terminal group) other than the unit A4. Provided that n4 is the number of the unit A4 and neis the number of all terminal groups in the siloxane compound, n4 / neis preferably 80% or more, more preferably 90% or more, and still more preferably 95% or more.An embodiment in which n4 / neis 100%, i.e. , the siloxane compound is20 free of the additional terminal group is also a preferred embodiment of the present invention.

[0061] Specific examples of the units A2, A3 and A4 are as described in the (First embodiment).

[0062] The siloxane compound may comprise only one type of each of the units A2 to A4, or may comprise two or more types thereof.

[0063] In the second embodiment, the siloxane compound preferably comprises a unit B represented by formula (2), provided that the unit B is not a part of any of the unit C, the unit A1 , the unit A2, the unit A3, and the unit A4.30 [C13]ForeignFiling Text P25-249- 22 -The definitions, examples, and descriptions of R11, n11 , and n12 are as5 described in the (First embodiment).

[0064] The siloxane compound may comprise only one type of unit B or may comprise two or more types thereof. When two R11groups are comprised in one unit, the two R11groups may be of one type or two types. It is preferable that all R11groups be the same in one unit.

[0065] The siloxane compound has a siloxane bonding degree of preferably 0.25 to 0.885, more preferably 0.40 to 0.875, still more preferably 0.50 to 0.86, still more preferably 0.60 to 0.85 and even more preferably 0.70 to 0.82.It is believed that when the siloxane bonding degree is 0.25 or more, the15 degree of formation of the siloxane network in the siloxane compound is sufficiently high. Because of this, it is believed that the cured film has a sufficiently high film hardness. It is believed that when the siloxane bonding degree is 0.885 or less, the embedding properties of a composition comprising the siloxane compound and a cured film thereof into a substrate20 are improved.In the second embodiment, the definitions and descriptions of the siloxane bonding degree are as described in the (First embodiment).

[0066] The siloxane compound has a mass average molecular weight (Mw) of preferably 500 to 3,000, more preferably 750 to 2,200, still more preferably 850 to 2,000, and even more preferably 1 ,000 to 1 ,800.It is believed that when Mw is 500 or more, formation of a uniform coating film is facilitated. It is believed that when Mw is 3,000 or less, the embedding properties of a composition comprising the siloxane compound and a cured film thereof into a substrate are improved.30

[0067] In the second embodiment, the definitions and descriptions of Mw are as described in the (First embodiment).ForeignFiling Text P25-249- 23 -

[0068] Provided that NA is the total number of units A1 to A4, NB is the number of the unit B, and NC is the number of the unit C, NC / (NA+NB+NC) is preferably 40 to 80%, more preferably 50 to 75%, and still more preferably 55 to 75%. NA / (NA+NB+NC) is preferably 15 to 35%, more5 preferably 15 to 30%, and still more preferably 20 to 30%.

[0069] In the second embodiment, examples and descriptions of applications of the siloxane compound are as described in the (First embodiment).

[0070] <Composition>A composition according to one embodiment comprises the siloxane compound according to the present invention and a solvent.

[0071] The solvent preferably is one or more solvents selected from the group consisting of: an aromatic compound, more preferably benzene, toluene, xylene, ethylbenzene, diethylbenzene, trimethylbenzene, or15 triethylbenzene; a saturated hydrocarbon compound, more preferably cyclohexane, decahydronaphthalene, n-pentane, i-pentane, n-hexane, i- hexane, n-heptane, i-heptane, n-octane, i-octane, n-nonane, i-nonane, n- decane, ethylcyclohexane, methylcyclohexane, or p-menthane; an unsaturated hydrocarbon compound, more preferably cyclohexene or20 dipentene; an ether compound, more preferably dipropyl ether, dibutyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, or anisole; an ester compound, more preferably n-butyl acetate, i-butyl acetate, n-amyl acetate, ethyl lactate, or i-amyl acetate; and a ketone compound, more preferably methyl isobutyl ketone.

[0072] As one preferred embodiment of the present invention, the solvent is one or more solvents selected from dibutyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate and ethyl lactate; preferably is one or more solvents selected from propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate; and30 more preferably is propylene glycol monomethyl ether.

[0073] The boiling point of the solvent is preferably 60 to 200°C, more preferably 70 to 180°C, still more preferably 80 to 160°C and even moreForeignFiling Text P25-249- 24 - preferably 80 to 145°C. The boiling point of the solvent in the present invention is the boiling point at 1 atm.

[0074] It is believed that when the solvent has a boiling point of 60°C or higher, the composition can be applied above the substrate more uniformly.5 It is believed that when the solvent has a boiling point of 200°C or lower, a coating film of the composition can be more efficiently cured.

[0075] The content of the siloxane compound is preferably 5 to 40 mass% and more preferably 10 to 30 mass%, based on the total mass of the composition. The content of the solvent is preferably 60 to 95 mass% and more preferably 70 to 90 mass%, based on the total mass of the composition.It is believed that when the content of the siloxane compound is 5 mass% or more and / or the content of the solvent is 95 mass% or less, based on the total mass of the composition, a coating film of the15 composition can be more efficiently cured. It is believed that when the content of the siloxane compound is 40 mass% or less and / or the content of the solvent is 60 mass% or more, based on the total mass of the composition, the composition can be applied above the substrate more uniformly.20

[0076] The solid content of the composition is preferably 3 to 50 mass%, more preferably 5 to 30 mass%, and still more preferably 10 to 20 mass%.

[0077] It is believed that when the solid content of the composition is 3 mass% or more, a coating film of the composition can be more efficiently cured. It is believed that when the solid content of the composition is 50 mass% or less, the composition can be applied above the substrate more uniformly.

[0078] The composition may comprise a siloxane compound (hereinafter referred to as additional siloxane compound) different from the above siloxane compound. Provided that MA is the mass of the siloxane30 compound in the composition and MB is the mass of the additional siloxane compound in the composition, MB / MA is preferably 0 to 0.2, more preferably from 0 to 0.1 , and still more preferably 0 to 0.05.ForeignFiling Text P25-249- 25 -An embodiment in which the composition is free of the additional siloxane compound (MB / MA=0) is also a preferred embodiment of the present invention.

[0079] The composition may further comprise an additive. Examples of the5 additive include a silanol condensation catalyst, a fluorine-containing compound, an adhesion promoter, a corrosion-resistant additive, a crosslinking agent, a dispersant, a filler, a functional dye (such as those providing functional effects including conductivity, thermal conductivity and magnetic properties), nanoparticles, optical dyes (such as those providing optical effects including color tone, refractive index and pearlescent effects), particles that reduce thermal expansion, a polymerization initiator, a polymerization inhibitor, a primer, a rheology modifier (such as a thickener), and a binding enhancer. The additive is different from the siloxane compound, the additional siloxane compound, and the solvent.15 The content of the additive (the total content when using more than one additive) is preferably 0 to 10 parts by mass, more preferably 0 to 5 parts by mass, still more preferably 0 to 1 part by mass and even more preferably 0 to 0.5 parts by mass, based on 100 parts by mass of the siloxane compound. An embodiment in which the composition is free of additives is20 also a preferred embodiment.

[0080] Examples of the silanol condensation catalyst include a photoacid generator, a photobase generator, a thermal acid generator, and a thermal base generator. In the present disclosure, the photoacid generator or photobase generator refers to a compound that undergoes bond cleavage by exposure to light to generate an acid or base. Examples of the light include visible light, ultraviolet rays, infrared, X-rays, electron beams, a- rays, and y-rays. In the present disclosure, the thermal acid generator or thermal base generator refers to a compound that undergoes a bond cleavage by heat to generate an acid or base. It is believed that the30 generated acid or base contributes to the polymerization reaction of the siloxane compound.ForeignFiling Text P25-249- 26 -

[0081] Examples of the photoacid generator include diazomethane compounds, triazine compounds, sulfonate esters, iodonium salts such as diphenyliodonium salts, sulfonium salts such as triphenylsulfonium salts, ammonium salts, phosphonium salts, and sulfonimide compounds.5

[0082] Examples of the photobase generator include polysubstituted amide compounds having amide groups, lactams, imide compounds; and ionic photobase generators comprising, as anion, amide anion, methide anion, borate anion, phosphate anion, sulfonate anion, or carboxylate anion.

[0083] Examples of the thermal acid generator include aliphatic sulfonic acids and salts thereof; aliphatic carboxylic acids such as citric acid, acetic acid, and maleic acid and salts thereof; aromatic carboxylic acids such as benzoic acid, phthalic acid and salts thereof; aromatic sulfonic acids and salts thereof; aromatic diazonium salts; and phosphonic acid and salts15 thereof.

[0084] Examples of the thermal base generator include compounds that generate bases such as imidazole and tertiary amines.

[0085] Examples of the fluorine-containing compound include fluorine- containing surfactants having fluorinated hydrocarbon groups and20 hydrophilic groups such as FLUORAD (3M) and Surfion (AGC Seimi Chemical).

[0086] The composition may comprise an additional surfactant other than the fluorine-containing surfactant. Examples of the additional surfactant include nonionic surfactants, anionic surfactants, and amphoteric surfactants. Specific examples of the additional surfactant include MEGAFACE (DIC).

[0087] The nanoparticles may be selected from particles of nitrides, titanates, diamonds, oxides, sulfides, sulfites, sulfates, silicates, and carbides. The nanoparticles may optionally be surface-modified using a30 capping agent. The particle size of the nanoparticles may be, for example, 1 to 100 nm, 1 to 50 nm, or 1 to 25 nm. The particle size can be measured by any standard method known to those skilled in the art.ForeignFiling Text P25-249- 27 -

[0088] Examples of the polymerization initiator include polymerization initiators that generate acids, bases, or radicals with radiation, and polymerization initiators that generate acids, bases, or radicals with heat. Examples of the radiation include visible light, ultraviolet rays, infrared, X-5 rays, electron beams, a-rays, and y-rays.

[0089] Examples of the photo-radical generator include azo-based generators, peroxide-based generators, acyl phosphine oxide-based generators, alkylphenone-based generators, oxime ester-based generators, and titanocene-based generators. Among others, alkylphenone-based generators, acyl phosphine oxide-based generators, and oxime ester-based generators are preferred, and 2,2-dimethoxy-1 ,2-diphenylethan-1 -one, 1- hydroxy-cyclohexylphenyl ketone, 2-hydroxy-2-methyl-1 -phenylpropan-1 - one, 1 -[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1 -propan-1 -one, 2- hydroxy-1 -{4-[4-(2-hydroxy-2-methylpropionyl)-benzyl]phenyl}-2-15 methylpropan-1 -one, 2-methyl-1 -(4-methylthiophenyl)-2-morpholinopropan- 1 -one, 2-benzyl-2-dimethylamino-1 -(4-morpholinophenyl)1 -butanone, 2- (dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)-phenyl]-1- butanone, 2,4,6-trimethylbenzoyl diphenylphosphine oxide, bis(2,4,6- trimethylbenzoyl)-phenyl-phosphine oxide, 1 ,2-octanedione, 1-[4-20 (phenylthio)phenyl]-, 2-(O-benzoyloxime), ethanone, 1-[9-ethyl-6-(2- methylbenzoyl)-9H-carbazol-3-yl]-, l-(O-acetyloxime) and the like can be used.

[0090] Examples of the polymerization inhibitor include ultraviolet absorbers and nitron, nitrogen oxide radicals, hydroquinone, catechol, phenothiazine, phenoxazine, hindered amine, and derivatives thereof. Specifically, methyl hydroquinone, catechol, 4-t-butylcatechol, 3- methoxycatechol, phenothiazine, chlorpromazine, phenoxazine, TINUVIN 144, 292, and 5100 (BASF) as hindered amines, and TINUVIN 326, 328, 384-2, 400, and 477 (BASF) as ultraviolet absorbers can be used.30

[0091] The binding enhancer has the effect of preventing a coating film from being peeled off from a substrate due to stress applied when the composition according to one embodiment is applied above the substrate toForeignFiling Text P25-249- 28 - form the coating film and cured by heating. As the binding enhancer, imidazole compounds, silane coupling agents and the like are preferred. Examples of the imidazole compound include 2-hydroxybenzimidazole, 2- hydroxyethylbenzimidazole, benzimidazole, 2-hydroxyimidazole, imidazole,5 2-mercaptoimidazole and 2-aminoimidazole.

[0092] Examples of the silane coupling agent include epoxysilane coupling agents, aminosilane coupling agents and mercaptosilane coupling agents.Specifically, 3-glycidoxypropyltrimethoxysilane, 3- glycidoxypropyltriethoxysilane, N-2-(aminoethyl)-3- aminopropyltrimethoxysilane, N-(2-aminoethyl)-3- aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-amino- propyltriethoxysilane, 3-ureidopropyltriethoxysilane, 3- chloropropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3- isocyanatopropyltriethoxysilane, and the like can be used.15

[0093] As the silane coupling agent, a silane compound having an acid group can also be used. Examples of the acid group include carboxy groups, acid anhydride groups and phenolic hydroxy groups.

[0094] The composition can form a cured film having excellent hardness and electrical properties, and thus is useful as a composition for producing20 an electronic device, particularly a composition for producing a semiconductor device. The composition can be used, for example, for formation of a cured film on a substrate. Examples of the substrate include a silicon substrate, a glass substrate, and a resin film, and the substrate is preferably a silicon substrate.

[0095] Considering that the composition is used for producing electronic devices and as a more preferred embodiment, for producing semiconductor devices, it is preferred that the composition have a low content of alkali metal and alkaline earth metal. The total concentration of the alkali metal and alkaline earth metal of the composition is preferably 1 ppm or less,30 more preferably 100 ppb or less and still more preferably 10 ppb or less.

[0096] <Method for producing cured film>A method for producing a cured film according to one embodimentForeignFiling Text P25-249- 29 - comprises the following steps (a) and (b-1 ):(a) applying the composition above a substrate to form a coating film; and(b-1 ) heating the coating film.5

[0097] The coating film may be formed in step (a) according to any method conventionally known as the method for applying a composition. Specific examples thereof include dip coating, roller coating, bar coating, brush coating, spray coating, doctor blade coating, flow coating, spin coating and slit coating, and spin coating is preferred.

[0098] When a coating film is formed by spin coating, the composition is spin coated above a substrate preferably at 500 to 2,500 RPM, more preferably 600 to 2,000 RPM, and still more preferably 700 to 1 ,900 RPM.

[0099] When a coating film is formed by spin coating, the composition is spin coated above a substrate by maintaining the rotation for preferably 5 to15 100 seconds, more preferably 10 to 70 seconds, and still more preferably 10 to 50 seconds.

[0100] Examples of the substrate include a silicon substrate, a glass substrate, and a resin film, and the substrate is preferably a silicon substrate.20

[0101] In step (b-1 ), the coating film is heated at preferably 30 to 500°C, more preferably 40 to 450°C, and still more preferably 50 to 420°C for preferably 30 seconds to 600 minutes, preferably 1 to 400 minutes, more preferably 1 .5 to 200 minutes, and still more preferably 2 to 150 minutes. The coating film can be dried and cured by heating. The heating can be performed, for example, using at least one device selected from a hot plate and a clean oven.

[0102] The heating may be performed in multiple stages. For example, after the coating film is dried, curing can proceed at a higher temperature.When the heating is performed in a first stage (b-1 -1 ) and a second30 stage (b-1 -2), heating of the first stage (b-1 -1 ) is carried out at preferably 30 to 300°C, more preferably 40 to 250°C, and still more preferably 50 to 200°C for preferably 30 seconds to 30 minutes, more preferably 1 to 10ForeignFiling Text P25-249- 30 - minutes, still more preferably 1 .5 to 5 minutes, and even more preferably 2 to 3 minutes. The heating of the second stage (b-1-2) is performed at preferably 250 to 500°C, more preferably 300 to 450°C, and still more preferably 350 to 420°C for preferably 1 to 600 minutes, more preferably 55 to 400 minutes, still more preferably 10 to 200 minutes, and even more preferably 30 to 150 minutes.

[0103] The step (a) and the heating of the first step (b-1 -1 ) in this order may be repeated twice or more to achieve a desired thickness of the coating film formed.

[0104] The heating of step (b-1 ) can be performed in an atmosphere comprising oxygen, an atmosphere comprising air, or an atmosphere comprising an inert gas such as nitrogen. When heating is performed in multiple stages, each stage may be performed in different atmosphere.It is preferred that a part of the heating of step (b-1 ) be performed in an15 atmosphere in which the nitrogen partial pressure is 0.5 to 1 time the total pressure. For example, the heating of the first stage (b-1 -1 ) of step (b-1 ) may be performed in an atmosphere comprising air, and the heating of the second stage (b-1 -2) may be performed in an atmosphere in which the nitrogen partial pressure is 0.5 to 1 time the total pressure.20

[0105] The method for producing the cured film can further comprise step (b-2) simultaneously with and / or after the step (b-1 ):(b-2) irradiating the coating film with ultraviolet rays.

[0106] The ultraviolet rays have a wavelength of preferably 13.5 to 248 nm, more preferably 50 to 240 nm, still more preferably 100 to 230 nm and even more preferably 150 to 225 nm.

[0107] The intensity of the ultraviolet rays is preferably 0.10 to 3 J / cm2, more preferably 0.15 to 2 J / cm2, still more preferably 0.20 to 1.5 J / cm2and even more preferably 0.30 to 1 .0 J / cm2.

[0108] Examples of a light source used for ultraviolet irradiation include a30 high-pressure mercury lamp, a low-pressure mercury lamp, a metal halide lamp, a xenon lamp, a laser diode, and a LED.ForeignFiling Text P25-249- 31 -

[0109] <Cured film>A cured film according to one embodiment is a cured product of the composition. The cured film can be obtained, for example, by the abovedescribed production method.5

[0110] The thickness of the cured film is preferably 0.1 to 3,000 nm, more preferably 1 to 1 ,500 nm, still more preferably 2 to 1 ,200 nm, and even more preferably 3 to 1 ,000 nm. In the present disclosure, the thickness of the cured film is the value measured by Ellipsometer M-2000 (J. A. Woollam).

[0111] The cured film has excellent hardness and electrical characteristics, and thus is useful as an insulating film for electronic devices. The cured film can be used, for example, as a surface protective film, a buffer coat film, and an interlayer dielectric film of semiconductor devices.

[0112] Electronic device>15 An electronic device according to one embodiment comprises the cured film. Examples of the electronic device include a semiconductor device and an electronic component such as a capacitor and a printed circuit board.

[0113] <Method for producing electronic device>A method of producing an electronic device according to one20 embodiment comprises the method for producing the cured film described above.

[0114] <Use of siloxane compound>Use according to one embodiment is use of the siloxane compound according to the present invention for forming a cured film on a substrate.

[0115] <Use of composition>Use according to one embodiment is use of the composition according to the present invention for forming a cured film on a substrate.[Examples]

[0116] The present invention is described in detail by the following30 examples. It is to be noted that the aspects of the present invention are not limited to only these examples.ForeignFiling Text P25-249- 32 -

[0117] In the following examples, Mw is measured by GPC with polystyrene as a standard. GPC is performed using Waters ACQUITY APC System (Nihon Waters K.K.), Shodex GPC HK-401 column and Shodex GPC HK-404L column (Shoko Science Co., Ltd.). The measurement is5 performed using monodisperse polystyrene as a standard sample and tetrahydrofuran as a developing solvent under measurement conditions of a flow rate of 0.5 mL / min and a column temperature of 40°C. Mw is calculated as the molecular weight relative to the standard sample.

[0118] Unless stated otherwise, all of the steps in the Examples are performed at room temperature.

[0119] <Synthesis of siloxane compounds><Example 1 >To a 500-mL four-neck flask equipped with a magnetic stirrer bar, a nitrogen inlet, a thermocouple and a dropping funnel, 21.8 g of15 methyltriethoxysilane, 7.2 g of bis(triethoxysilyl)methane, 12.8 g of tetraethoxysilane, and 42.5 g of propylene glycol monomethyl ether are charged. To a dropping funnel, 20.2 g of 3.6 mass% hydrochloric acid is placed. The hydrochloric acid is added dropwise to the flask. The mixture is stirred at 40°C for 1 hour. 200 g of normal propyl acetate and 100 g of20 water are added to the solution. The flask is allowed to stand to separate the solution into two layers. The resulting organic layer is washed once with 100 g of water. The organic layer is concentrated under reduced pressure to remove the water and solvent from the organic layer. Propylene glycol monomethyl ether is added so that the solid content of the concentrate is 15 mass%, thereby preparing a composition comprising a siloxane compound. The resulting siloxane compound has Mw of 1 ,230.

[0120] <Example 2>To a four-neck flask described in Example 1 , 21 .8 g of methyltriethoxysilane, 7.5 g of 1 ,2-bis(triethoxysilyl)ethane, 12.8 g of30 tetraethoxysilane, and 42.9 g of propylene glycol monomethyl ether are charged. To a dropping funnel, 20.2 g of 3.6 mass% hydrochloric acid is placed. The hydrochloric acid is added dropwise to the flask. The mixtureForeignFiling Text P25-249- 33 - is stirred at 40°C for 1 hour. 200 g of normal propyl acetate and 100 g of water are added to the solution. The flask is allowed to stand to separate the solution into two layers. The resulting organic layer is washed once with 100 g of water. The organic layer is concentrated under reduced pressure5 to remove water and solvent from the organic layer. Propylene glycol monomethyl ether is added so that the solid content of the concentrate is 15 mass%, thereby preparing a composition comprising a siloxane compound. The resulting siloxane compound has Mw of 1 ,444.

[0121] <Example 3>To the four-neck flask described in Example 1 , 18.2 g of methyltriethoxysilane, 7.2 g of bis(triethoxysilyl)methane, 17.0 g of tetraethoxysilane, and 22.4 g of propylene glycol monomethyl ether are charged. To a dropping funnel, 20.0 g of 0.2 mass% hydrochloric acid is placed. The hydrochloric acid is added dropwise to the flask. The mixture is15 stirred at 40°C for 3 hours. 100 g of normal propyl acetate and 50 g of water are added to the solution. The flask is allowed to stand to separate the solution into two layers to obtain an organic layer. The organic layer is concentrated under reduced pressure to remove the water and solvent from the organic layer. Propylene glycol monomethyl ether is added so that the20 solid content of the concentrate is 15 mass%, thereby preparing a composition comprising a siloxane compound. The resulting siloxane compound has Mw of 1 ,425.

[0122] <Example 4>To a four-neck flask described in Example 1 , 18.2 g of methyltriethoxysilane, 14.3 g of bis(triethoxysilyl)methane, 12.8 g of tetraethoxysilane, and 46.1 g of propylene glycol monomethyl ether are charged. To a dropping funnel, 21 .9 g of 3.6 mass% hydrochloric acid is placed. The hydrochloric acid is added dropwise to the flask. The mixture is stirred at 40°C for 1 hour. 200 g of normal propyl acetate and 100 g of30 water are added to the solution. The flask is allowed to stand to separate the solution into two layers. The resulting organic layer is washed once with 100 g of water. The organic layer is concentrated under reduced pressureForeignFiling Text P25-249- 34 - to remove the water and solvent from the organic layer. Propylene glycol monomethyl ether is added so that the solid content of the concentrate is 15 mass%, thereby preparing a composition comprising a siloxane compound. The resulting siloxane compound has Mw of 1 ,433.5

[0123] <Example 5>To a four-neck flask described in Example 1 , 18.2 g of methyltriethoxysilane, 35.9 g of bis(triethoxysilyl)methane, and 55.9 g of propylene glycol monomethyl ether are charged. To a dropping funnel, 25.2 g of 3.6 mass% hydrochloric acid is placed. The hydrochloric acid is added dropwise to the flask. The mixture is stirred at 40°C for 1 hour. 200 g of normal propyl acetate and 100 g of water are added to the solution. The flask is allowed to stand to separate the solution into two layers. The resulting organic layer is washed once with 100 g of water. The organic layer is concentrated under reduced pressure to remove the water and15 solvent from the organic layer. Propylene glycol monomethyl ether is added so that the solid content of the concentrate is 15 mass%, thereby preparing a composition comprising a siloxane compound. The resulting siloxane compound has Mw of 1 ,661 .

[0124] <Example 6>20 To a four-neck flask described in Example 1 , 32.5 g of an aqueous solution of 40 mass% tetra-normal-butylammonium hydroxide and 283.4 g of propylene glycol monomethyl ether are charged. To a dropping funnel, a mixed solution of 19.6 g of methyltrimethoxysilane and 9.2 g of tetramethoxysilane is placed. The mixed solution is added dropwise to the flask and the resulting mixture is stirred at 40°C for 2 hours. To the flask sequentially, 444 g of normal propyl acetate and 213 g of an aqueous solution of 3 mass% maleic acid are added. The resulting mixture is stirred at 40°C for 1 hour. To the solution, 250 g of water is added. The flask is allowed to stand to separate the solution into two layers. The resulting30 organic layer is washed three times with 250 g of water and concentrated under reduced pressure to remove the water and solvent. Propylene glycol monomethyl ether is added so that the solid content of the concentrate isForeignFiling Text P25-249- 35 -15 mass%, thereby preparing a composition comprising a siloxane compound. The resulting siloxane compound has Mw of 2,068.

[0125] cComparative Example 1 >To a four-neck flask described in Example 1 , 21 .8 g of5 methyltriethoxysilane, 7.2 g of bis(triethoxysilyl)methane, 12.8 g of tetraethoxysilane, and 209.6 g of propylene glycol monomethyl ether are charged. A mixed solution of 140.3 g of a solution of 37 mass% tetra- normal-butylammonium hydroxide in methanol and 25.9 g of water is placed into a dropping funnel. The mixed solution is added dropwise to the flask. The mixture is stirred at 40°C for 1 hour. 400 g of normal propyl acetate and 572 g of 1 .4 mass% hydrochloric acid are added. The mixture is stirred at 40°C for 15 minutes. The flask is allowed to stand to separate the solution into two layers, The resulting organic layer is washed three times with 200 g of water. The organic layer is concentrated under reduced15 pressure to remove the water and solvent from the organic layer. Propylene glycol monomethyl ether is added so that the solid content of the concentrate is 15 mass%, thereby preparing a composition comprising a siloxane compound. The resulting siloxane compound has Mw of 2,281.

[0126] <Calculation of siloxane bonding degree>20 The siloxane compounds of Examples 1 to 6 and Comparative Example 1 are respectively subjected to29Si nuclear magnetic resonance analysis (29Si NMR) using JNM ECZ500R (JEOL). From the integral intensity ratios of resonant frequency peaks, the abundance ratios of the units of the respective siloxane compounds, namely Q1 , Q2, Q3, Q4, T1 , T2, T3, D1 , D2, and M1 are calculated. In Examples 1 to 6 and Comparative Example 1 , the abundance ratios of D1 , D2, and M1 are 0.

[0127] In the Examples, the ranges of shift values in which peaks of29Si nuclear magnetic resonance analysis assigned to the units are observed are as follows:30 Q1 : -89 to -80 ppm Q2: -93 to -90 ppm Q3: -100 to -95 ppmForeignFiling Text P25-249- 36 -Q4: -108 to -106 ppmT 1 : -52 to -48 ppmT2: -57 to -55 ppmT3: -64 to -60 ppm5

[0128] The degrees of siloxane bond of the siloxane compounds are determined from the abundance ratios of the units, R(Q1 ), R(Q2), R(Q3), R(Q4), R(T1 ), R(T2), and R(T3), and the following formula. The results are shown in Table 1 below.Siloxane bonding degree =[R(Q1 )+2R(Q2)+3R(Q3)+4R(Q4)+R(T1 )+2R(T2)+3R(T3)] / [4{R(Q1 )+R(Q2)+ R(Q3)+R(Q4)}+3{R(T1 )+R(T2)+R(T3)}]

[0129] <Calculation of silanol content and alkoxysilyl content>The siloxane compounds of Examples 1 to 6 and Comparative Example 1 are subjected to29Si nuclear magnetic resonance analysis (29Si NMR)15 and13C nuclear magnetic resonance analysis (13C NMR) using JNM ECZ500R (JEOL). From the integral intensity ratios of resonant frequency peaks in29Si NMR, R(T) of the respective siloxane compounds represented by the following formula are determined.R(T)=[R(T1 )+R(T2)+R(T3)] / [4{R(Q1 )+R(Q2)+R(Q3)+R(Q4)}+3{R(T1 )+R(T220 )+R(T3)]The abundance ratios R(AI / T) of the alkoxysilyl groups to all T units for the respective siloxane compounds are determined from the integral intensity ratios of the resonant frequency peaks in13C NMR and the abundance ratios of the silicon atoms to the carbon atoms in all T units of the respective siloxane compounds. In Examples 1 to 5 and Comparative Example 1 , the alkoxysilyl group is ethoxysilyl group and assigned to the peak at 58 ppm in13C NMR. In Example 6, the alkoxysilyl group is methoxysilyl group and assigned to the peak at 50 ppm in13C NMR.The abundance ratio of silicon atoms to carbon atoms in all T units is the30 same as the abundance ratio of silicon atoms to carbon atoms that are not detached by the polysiloxane network formation of a raw material monomer. For example, in the case of methyltriethoxysilane, theForeignFiling Text P25-249- 37 - abundance ratio of silicon atoms to carbon atoms is 1 :1 .The degree of the siloxane bond determined in <Calculation of siloxane bonding degree> is denoted as B.

[0130] The silanol content and the alkoxysilyl content of each siloxane5 compound are determined by the following formulae. The results are shown in Table 1 below.Alkoxylsilyl content = R(T)xR(AI / T)Silanol content = 1-B-R(AI)

[0131] <Formation of cured film>The compositions of Examples 1 to 6 and Comparative Example 1 are respectively applied to a 4-inch silicon wafer by spin coating to form coating films. Spin coating is performed by maintaining 1 ,000 RPM for 20 seconds. The wafer on which the coating film has been formed is pre-baked on a hot plate at 130°C for 2 minutes. The wafer is heated at 400°C for 2 hours in a15 clean oven under an atmosphere comprising nitrogen to form a cured film of 400 nm. The nitrogen partial pressure in the atmosphere comprising nitrogen is 1013.25 hPa. The film thickness is measured with M-2000.

[0132] Evaluation of dielectric breakdown field>As described in <Formation of cured fi Im > , cured films are formed from20 the siloxane compounds of Examples 1 to 6 and Comparative Example 1. The C-V and l-V electrical properties of the respective cured films are measured using MCV-530 (Semilab). The dielectric breakdown field (Ebd) is determined according to the following steps.

[0133] The 4-inch N-type silicon wafer on which each cured film has been formed is placed on a stage (electrode) of the apparatus, and a mercury probe (electrode) is brought into contact with the cured film on the surface. The leak current of the cured film is measured while increasing the voltage applied by 5 V from 0 V to 500 V. A leak current density is obtained by dividing the leak current by the contact area between the mercury and the30 cured film. An applied electric field is obtained by dividing the applied voltage by the thickness of the cured film. Ebd is obtained as a measured value of the maximum applied electric field in which the leak current densityForeignFiling Text P25-249 does not exceed 1 pA / cm2. The cured film having Ebd of above 4 MV / cm is graded as A, and the cured film having Ebd of 4 MV / cm or less is graded as B. The results are shown in Table 1 below.

[0134] Evaluation of embedding properties>5 Cured films of the siloxane compounds of Examples 1 to 6 and Comparative Example 1 are formed as described in <Formation of cured film > except that 4-cm square structural substrate pieces each having a groove of 20 nm width and 500 nm depth are used instead of the 4-inch silicon wafers. The structural substrates are cleaved perpendicular to the grooves. The groove cross-sections are observed with an electron microscope Regulus-8230 (Hitachi High-Tech) to observe the presence or absence of voids. The cured film in which no void is observed is graded asA, and the cured film in which one or more voids are observed is graded asB. The results are shown in Table 1 below.

[0135] [Table 1]30

Claims

1. ForeignFiling Text P25-249[CLAIMS]

1. A siloxane compound having a siloxane bonding degree of 0.25 to 0.885, preferably 0.40 to 0.875, more preferably 0.50 to 0.86, still more preferably5 0.60 to 0.85 and even more preferably 0.70 to 0.82.

2. The siloxane compound according to claim 1 , comprising at least one unit among a unit A1 represented by formula (a1 ), a unit A2 represented by formula (a2), a unit A3 represented by formula (a3), and a unit A4 represented bywherein:R1, R2, R3, R4, R5, and R6are each independently H, C6-20 aryl, or C1-20 alkyl; preferably, H, C6-20 aryl, linear C1-20 alkyl, branched C3-20 alkyl, or cyclic C3-20 alkyl; more preferably, H, phenyl, naphthyl, phenanthryl, anthracenyl, linear Ci- 15 alkyl, or branched C3-15 alkyl; still more preferably, H, linear C1-10 alkyl or branched C3-10 alkyl; and even more preferably, H, methyl, ethyl, n-propyl,30 isopropyl, n-butyl, or tert-butyl;ForeignFiling Text P25-249- 40 - one or more non-adjacent -CH2- groups of R1, R2, R3, R4, R5, and R6may each independently be replaced with -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO- O-, C6-20 arylene, -CR7=CR8- or -C=C-;R7and R8are each independently H or C1-10 alkyl; preferably, H, linear C1-105 alkyl, branched C3-10 alkyl or cyclic C3-10 alkyl; and more preferably, H, linear C1-5 alkyl or branched C3-5 alkyl; and one or more H atoms of R1, R2, R3, R4, R5and R6may each independently be replaced with -OH, -COOH, -SO2H, or C6-20 aryl.

3. The siloxane compound according to claim 2, further comprising a unit B represented by formula (2):anthracenyl, linear C1-15 alkyl, or branched C3-15 alkyl; still more preferably, H, F, -OH, linear C1-10 alkyl or branched C3-10 alkyl; and even more preferably, H, F, -OH, methyl, ethyl, n-propyl, isopropyl, n-butyl, or tert-butyl; one or more non-adjacent -CH2- groups of R11may be replaced with -S-, - CO-, C6-2o arylene, -CR12=CR13-, or -C^C-;R12and R13are each independently H or C1-10 alkyl; preferably, H, linear C1-10 alkyl, branched C3-10 alkyl or cyclic C3-10 alkyl; and more preferably, H, linear C1-5 alkyl or branched C3-5 alkyl; one or more H atoms of R11may be replaced with -COOH, -SO2H, or C6-2030 aryl; and n11 is 1 or 2, and n12 is 3-n11 ,ForeignFiling Text P25-249- 41 - provided that the unit B is not a part of any of the unit A1 , the unit A2, the unitA3, and the unit A4.

4. The siloxane compound according to claim 3, further comprising a unit C5 represented by formula (3):[C3]wherein:R21and R22are each independently H, F, -OH, -COOH, -SO2H, C6-20 aryl, or C1-20 alkyl; preferably, H, F, -OH, phenyl, naphthyl, phenanthryl, anthracenyl,15 linear C1-20 alkyl, branched C3-20 alkyl, or cyclic C3-20 alkyl; more preferably, H, F, -OH, linear C1-15 alkyl or branched C3-15 alkyl; still more preferably, H, F, - OH, linear C1-10 alkyl or branched C3-10 alkyl; and even more preferably, H, F, - OH, methyl, ethyl, n-propyl, isopropyl, n-butyl, or tert-butyl;L21is C1-20 alkylene or -CR23=CR24-; preferably linear C1-20 alkylene, branched20 C3-20 alkylene, cyclic C3-20 alkylene, or -CR23=CR24-; more preferably, linear Ci- 10 alkylene, branched C3-10 alkylene, or -CR23=CR24-; still more preferably, linear C1-5 alkylene, branched C3-5 alkylene, or -CR23=CR24-; even more preferably, -CH2-, -CH2CH2-, -CH(CH3)-, -CH2CH2CH2-, -CH(CH3)CH2-, or - CR23=CR24-; one or more non-adjacent -CH2- groups of R21, R22and L21may be replaced with -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, C6-2o arylene, -CR23=CR24-, or -C=C-, provided that the one or more non-adjacent -CH2- groups are unsubstituted when L21is -CH2-;R23and R24are each independently H or C1-10 alkyl; preferably, H, linear C1-1030 alkyl, branched C3-10 alkyl or cyclic C3-10 alkyl; and more preferably, H, linear C1-5 alkyl or branched C3-5 alkyl;ForeignFiling Text P25-249- 42 - one or more H atoms of R21, R22and L21may each independently be replaced with -OH, -COOH, -SO2H, or C6-20 aryl; and n21 is 0, 1 or 2, n24 is 3-n21 , n22 is 0, 1 or 2, and n23 is 2-n22; provided that the unit B is not a part of the unit C.5

5. The siloxane compound according to any one of claims 1 to 4, having a silanol content of 0.12 to 0.40, preferably 0.14 to 0.30, and more preferably 0.14 to 0.25.

6. The siloxane compound according to any one of the claims 1 to 5, having an alkoxysilyl content of 0.001 to 0.065, preferably 0.005 to 0.05, and more preferably 0.010 to 0.04, the alkoxysilyl content being a content of an alkoxysilyl group represented by formula (5):wherein:R41is C 1-20 alkyl; preferably, linear C1-20 alkyl, branched C3-20 alkyl, or cyclic C3-20 alkyl; more preferably, linear C1-15 alkyl or branched C3-15 alkyl; still more preferably, linear C1-10 alkyl or branched C3-10 alkyl; and even more preferably, methyl, ethyl, n-propyl, isopropyl, n-butyl, or tert-butyl.

7. A siloxane compound comprising a unit C represented by formula (3), and having a silanol content of 0.12 to 0.40, preferably 0.14 to 0.30, and more preferably 0.14 to 0.25:[C5]ForeignFiling Text P25-249- 43 -5 wherein:R21and R22are each independently H, F, -OH, -COOH, -SO2H, C6-20 aryl, or C1-20 alkyl; preferably, H, F, -OH, phenyl, naphthyl, phenanthryl, anthracenyl, linear C1-20 alkyl, branched C3-20 alkyl, or cyclic C3-20 alkyl; more preferably, H, F, -OH, linear C1-15 alkyl or branched C3-15 alkyl; still more preferably, H, F, - OH, linear C1-10 alkyl or branched C3-10 alkyl; and even more preferably, H, F, - OH, methyl, ethyl, n-propyl, isopropyl, n-butyl, or tert-butyl;L21is C1-20 alkylene or -CR23=CR24-; preferably linear C1-20 alkylene, branched C3-20 alkylene, cyclic C3-20 alkylene, or -CR23=CR24-; more preferably, linear Ci-15 10 alkylene, branched C3-10 alkylene, or -CR23=CR24-; still more preferably, linear C1-5 alkylene, branched C3-5 alkylene, or -CR23=CR24-; even more preferably, -CH2-, -CH2CH2-, -CH(CH3)-, -CH2CH2CH2-, -CH(CH3)CH2-, or - CR23=CR24-; one or more non-adjacent -CH2- groups of R21, R22and L21may be replaced20 with -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, C6-2o arylene, -CR23=CR24-, or -C=C-, provided that the one or more non-adjacent -CH2- groups are unsubstituted when L21is -CH2-;R23and R24are each independently H or C1-10 alkyl; preferably, H, linear C1-10 alkyl, branched C3-10 alkyl or cyclic C3-10 alkyl; and more preferably, H, linear C1-5 alkyl or branched C3-5 alkyl; one or more H atoms of R21, R22and L21may each independently be replaced with -OH, -COOH, -SO2H, or C6-20 aryl; and n21 is 0, 1 or 2, n24 is 3-n21 , n22 is 0, 1 or 2, and n23 is 2-n22.

8. 30 The siloxane compound according to claim 7, having an alkoxysilyl content of 0.001 to 0.065, preferably 0.005 to 0.05, and more preferably 0.010 to 0.04, theForeignFiling Text P25-249 alkoxysilyl content being a content of an alkoxysilyl group represented by formula (5):[C6]5 rl—H- Si— OR41 ( 5 )1wherein:R41is C 1-20 alkyl; preferably, linear C1-20 alkyl, branched C3-20 alkyl, or cyclic C3-20 alkyl; more preferably, linear C1-15 alkyl or branched C3-15 alkyl; still more preferably, linear C1-10 alkyl or branched C3-10 alkyl; and even more preferably, methyl, ethyl, n-propyl, isopropyl, n-butyl, or tert-butyl.

9. The siloxane compound according to claim 7 or 8, comprising at least one unit among a unit A1 represented by formula (a1 ), a unit A2 represented by formula (a2), a unit A3 represented by formula (a3), and a unit A4 represented by formula (a4):[C7]30 wherein:ForeignFiling Text P25-249- 45 -R1, R2, R3, R4, R5, and R6are each independently H, C6-20 aryl, or C1-20 alkyl; preferably, H, C6-20 aryl, linear C1-20 alkyl, branched C3-20 alkyl, or cyclic C3-20 alkyl; more preferably, H, phenyl, naphthyl, phenanthryl, anthracenyl, linear Ci- 15 alkyl, or branched C3-15 alkyl; still more preferably, H, linear C1-10 alkyl or5 branched C3-10 alkyl; and even more preferably, H, methyl, ethyl, n-propyl, isopropyl, n-butyl, or tert-butyl; one or more non-adjacent -CH2- groups of R1, R2, R3, R4, R5, and R6may each independently be replaced with -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO- O-, C6-20 arylene, -CR7=CR8- or -C=C-;R7and R8are each independently H or C1-10 alkyl; preferably, H, linear C1-10 alkyl, branched C3-10 alkyl or cyclic C3-10 alkyl; and more preferably, H, linear C1-5 alkyl or branched C3-5 alkyl; and one or more H atoms of R1, R2, R3, R4, R5and R6may each independently be replaced with -OH, -COOH, -SO2H, or C6-20 aryl.15

10. The siloxane compound according to any one of claims 7 to 9, further comprising a unit B represented by formula (2):lic C3-20 alkyl; more preferably, H, F, -OH, phenyl, naphthyl, phenanthryl, anthracenyl, linear C1-15 alkyl, or branched C3-15 alkyl; still more preferably, H, F, -OH, linear C1-10 alkyl or branched C3-10 alkyl; and even more preferably, H, F, -OH, methyl, ethyl, n-propyl, isopropyl, n-butyl, or tert-butyl;30 one or more non-adjacent -CH2- groups of R11may be replaced with -S-, - CO-, C6-20 arylene, -CR12=CR13-, or -C^C-;ForeignFiling Text P25-249- 46 -R12and R13are each independently H or C1-10 alkyl; preferably, H, linear C1-10 alkyl, branched C3-10 alkyl or cyclic C3-10 alkyl; and more preferably, H, linear C1-5 alkyl or branched C3-5 alkyl; one or more H atoms of R11may be replaced with -COOH, -SO2H, or C6-205 aryl; and n11 is 1 or 2, and n12 is 3-n11 , provided that the unit B is not a part of any of the unit C, the unit A1 , the unit A2, the unit A3, and the unit A4.

11. The siloxane compound according to any one of claims 7 to 10, having a siloxane bonding degree of 0.25 to 0.885, preferably 0.40 to 0.875, more preferably 0.50 to 0.86, still more preferably 0.60 to 0.85, and even more preferably 0.70 to 0.82.

12. 15 The siloxane compound according to any one of claims 1 to 11 , having a mass average molecular weight of 500 to 3,000, preferably 750 to 2,200, more preferably 850 to 2,000, and still more preferably 1 ,000 to 1 ,800.

13. The siloxane compound according to claim 3 or 10, wherein, provided that NA20 is the total number of the units A1 to A4, NB is the number of the unit B, and NC is the number of the unit C, NB / (NA+NB+NC) is 40 to 80%, preferably 50 to 75%, and more preferably 55 to 75%.

14. The siloxane compound according to any one of claim 3, 10 and 13, wherein, provided that NA is the total number of the units A1 to A4, NB is the number of the unit B, and NC is the number of the unit C, NA / (NA+NB+NC) is 15 to 35%, preferably 15 to 30%, and more preferably 20 to 30%.

15. A composition comprising the siloxane compound according to any one of30 claims 1 to 14 and a solvent; wherein the solvent is preferably one or more solvents selected from the group consisting of: an aromatic compound, more preferably benzene, toluene, xylene, ethylbenzene, diethylbenzene,ForeignFiling Text P25-249- 47 - trimethylbenzene, or triethylbenzene; a saturated hydrocarbon compound, more preferably cyclohexane, decahydronaphthalene, n-pentane, i-pentane, n- hexane, i-hexane, n-heptane, i-heptane, n-octane, i-octane, n-nonane, i- nonane, n-decane, ethylcyclohexane, methylcyclohexane, or p-menthane; an5 unsaturated hydrocarbon compound, more preferably cyclohexene or dipentene; an ether compound, more preferably dipropyl ether, dibutyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, or anisole; an ester compound, more preferably n-butyl acetate, i-butyl acetate, n-amyl acetate, ethyl lactate, or i-amyl acetate; and a ketone compound, more preferably methyl isobutyl ketone.

16. A method for producing a cured film, comprising the following steps (a) and (b- 1 ):(a) applying the composition according to claim 15 above a substrate to form a15 coating film, preferably spin-coating the composition above the substrate for 5 to 100 seconds at 500 to 2,500 RPM, more preferably for 10 to 70 seconds at 600 to 2,000 RPM, and still more preferably for 10 to 50 seconds at 700 to 1 ,900 RPM; and20 (b-1 ) heating the coating film, preferably heating at 30 to 500°C, more preferably 40 to 450°C and still more preferably 50 to 420°C for preferably 30 seconds to 600 minutes, more preferably 1 to 400 minutes, still more preferably 1 .5 to 200 minutes and even more preferably 2 to 150 minutes.

17. The method for producing the cured film according to claim 16, further comprising step (b-2) simultaneously with and / or after the step (b-1 ):(b-2) irradiating the coating film with ultraviolet rays, wherein the ultraviolet rays have a wavelength of preferably 13.5 to 248 nm,30 more preferably 50 to 240 nm, still more preferably 100 to 230 nm and even more preferably 150 to 225 nm.

18. ForeignFiling Text P25-249- 48 -The method for producing the cured film according to claim 17, wherein an intensity of the ultraviolet rays is 0.10 to 3 J / cm2, preferably 0.15 to 2 J / cm2, more preferably 0.20 to 1 .5 J / cm2, and still more preferably 0.30 to 1 .0 J / cm2.

19. 5 The method for producing the cured film according to any one of claims 16 to 18, wherein a part of the heating in the step (b-1 ) is performed in an atmosphere in which a nitrogen partial pressure is 0.5 to 1 time the total pressure.

20. A cured film obtained by the method according to any one of claims 16 to 19, having a thickness of 0.1 to 3,000 nm, preferably 1 to 1 ,500 nm, more preferably 2 to 1 ,200 nm, and still more preferably 3 to 1 ,000 nm.

21. An electronic device comprising the cured film according to claim 20.15

22. A method for producing an electronic device, the method comprising the method for according to any one of claims 16 to 19.

23. Use of the siloxane compound according to any one of claims 1 to 14 for20 forming a cured film on a substrate.

24. Use of the composition according to claim 15 for forming a cured film on a substrate.30

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