Curable composition and semiconductor insulating film-forming agent

Abstract

Provided are: a curable composition comprising the following component (A) and component (B), wherein the total amount of the component (A) and the component (B) is at least 98 mass% with respect to the total amount of the curable composition; and a semiconductor insulating film-forming agent. The (A) component is a silane compound polymer having a repeating unit [repeating unit (1)] represented by formula (a-1) [R1 represents a fluoroalkyl group] and a repeating unit [repeating unit (2)] represented by formula (a-2) [R2 represents an unsubstituted hydrocarbon group or a hydrocarbon group (excluding a fluoroalkyl group) having a substituent, wherein the amount of the repeating unit (1) is at least 40 mol% with respect to the total amount of the repeating unit (1) and the repeating unit (2). (B) is a solvent.

Description

Curable composition and semiconductor insulating film forming agent

[0001] The present invention relates to a curable composition and a semiconductor insulating film-forming agent.

[0002] Conventionally, SiO2 has been deposited as an insulating film for semiconductor devices and the like by a vacuum process such as thermal CVD. ２ However, since vacuum processes are not suitable for forming insulating films that fill deep recesses, the SOG (Spin on Glass) method has been attracting attention in recent years.

[0003] In the SOG method, an insulating film is usually formed by applying an insulating film-forming liquid by spin coating and curing the resulting coating. For example, Patent Document 1 describes a silicon oxide film-forming composition containing a solvent, a silicon oxide-forming compound dissolved and / or dispersed in the solvent, and silicon particles dispersed in the solvent, and a method for forming a silicon oxide film using this composition.

[0004] JP 2015-18952 A

[0005] Patent Document 1 describes that the SOG method can form a relatively thick silicon oxide film in a short time, and that the use of the composition described in Patent Document 1 can form a silicon oxide film that is less susceptible to cracking. According to the examples in Patent Document 1, silicon particles are considered to be an important component for forming a thick film and preventing cracking. However, when using a composition containing silicon particles, the silicon particles must be converted into silicon oxide, which requires heat treatment under harsh conditions (in the example, 900°C for 30 minutes). Therefore, a method for forming an insulating film more efficiently has been sought.

[0006] The present invention has been made under these circumstances, and an object of the present invention is to provide a curable composition that is suitably used as an insulating film forming agent, and a semiconductor insulating film forming agent.

[0007] In order to solve the above problems, the present inventors have conducted extensive research into silicon atom-containing compounds, and as a result have found that by using a polymer of a trifunctional silane compound as a curable component, a cured film can be formed without excessive heating, and that while a cured film of a polymer of a trifunctional silane compound may crack, this problem can be solved by using a polymer of a silane compound having a fluoroalkyl group, which has led to the completion of the present invention.

[0008] Thus, according to the present invention, there are provided the following curable compositions [1] to [8] and a semiconductor insulating film forming agent [9].

[0009] [1] A curable composition containing the following components (A) and (B): Component (A) is a compound represented by the following formula (a-1):

[0010]

[0011] [R １ represents a fluoroalkyl group.] and a repeating unit (repeating unit (1)) represented by the following formula (a-2):

[0012]

[0013] [R ２ represents an unsubstituted hydrocarbon group or a hydrocarbon group having a substituent (excluding a fluoroalkyl group).] and a silane compound polymer having a repeating unit represented by the formula (2), in which the amount of the repeating unit (1) is 40 mol % or more based on the total amount of the repeating unit (1) and the repeating unit (2). (B): Solvent [2] A silane compound polymer having a repeating unit represented by the formula (2), in which the amount of the repeating unit (1) is 40 mol % or more based on the total amount of the repeating unit (1) and the repeating unit (2). １ The composition formula: C ｍ H （２ｍ－ｎ＋１） F ｎ(wherein m represents an integer of 1 to 15, and n represents an integer of 2 or more and (2m+1) or less). [3] The curable composition according to [1] or [2], wherein the total amount of repeating units (1) and repeating units (2) of the component (A) is 70 to 100 mol % based on the total amount of repeating units of the silane compound polymer. [4] The curable composition according to any of [1] to [3], wherein the component (A) has T3 sites represented by the following formula (a-5), and the amount of the T3 sites is 62 mol % or more based on the total amount of T1 sites represented by the following formula (a-3), T2 sites represented by the following formula (a-4), and the T3 sites.

[0014]

[0015] [R ３ is R １ or R ２ represents. １ ~X ３ each independently represents a hydrogen atom or an alkyl group. * represents a bond to another repeating unit and is directly bonded to the silicon atom of that other repeating unit.] [5] The curable composition according to any one of [1] to [4], wherein the mass average molecular weight (Mw) of the component (A) is 500 to 100,000. [6] The curable composition according to any one of [1] to [5], wherein the amount of the component (A) is 10 to 80 mass% based on the total amount of the components (A) and (B). [7] The curable composition according to any one of [1] to [6], wherein the component (B) is a solvent having a boiling point of 150°C or higher. [8] The curable composition according to any one of [1] to [7], wherein the component (B) is a polyether solvent. [9] A semiconductor insulating film-forming agent comprising the curable composition according to any one of [1] to [8].

[0016] According to the present invention, there are provided a curable composition suitable for use as an insulating film forming agent, and a semiconductor insulating film forming agent.

[0017] In this specification, for preferred numerical ranges (e.g., ranges of content, etc.), the lower limit and upper limit values ​​described in stages can be independently combined. For example, the description "preferably 10 to 90, more preferably 30 to 60" can be combined with the "preferable lower limit (10)" and the "more preferable upper limit (60)" to form "10 to 60."

[0018] [Component (A): Silane Compound Polymer] The silane compound polymer of component (A) is a silane compound polymer (hereinafter sometimes referred to as "silane compound polymer (A)") that has a repeating unit represented by the above formula (a-1) [repeating unit (1)] and a repeating unit represented by the above formula (a-2) [repeating unit (2)], in which the amount of repeating unit (1) is 40 mol % or more based on the total amount of repeating unit (1) and repeating unit (2).

[0019] The silane compound polymer (A) has a repeating unit (1) represented by the following formula (a-1).

[0020]

[0021] In formula (a-1), R １ represents a fluoroalkyl group.

[0022] As described below, the silane compound polymer having the repeating unit (1) tends to contain many T sites (T3 sites) that do not contain hydroxy groups or alkoxy groups. Therefore, even when the silane compound polymer having the repeating unit (1) is cured, a large amount of volatile low-molecular-weight compounds are not produced as by-products, and cracks are less likely to occur in the cured product. In this way, by using the silane compound polymer (A) having the repeating unit (1) as a curable component, it is possible to suppress the occurrence of cracks in the cured product.

[0023] R １ As the compound, the composition formula: C ｍ H （２ｍ－ｎ＋１） F ｎ(wherein m represents an integer of 1 to 15, and n represents an integer of 2 or more and (2m+1) or less). In the above composition formula, m is preferably an integer of 1 to 10, and more preferably an integer of 3 to 8.

[0024] Composition formula: C ｍ H （２ｍ－ｎ＋１） F ｎ Examples of the group represented by the formula include CF ３ -, CF ３ CF ２ -, CF ３ (CF ２ ) ２ -, CF ３ (CF ２ ) ３ -, CF ３ (CF ２ ) ４ -, CF ３ (CF ２ ) ５ -, CF ３ (CF ２ ) ６ -, CF ３ (CF ２ ) ７ -, CF ３ (CF ２ ) ８ -, CF ３ (CF ２ ) ９ - and other perfluoroalkyl groups; CF ３ CH ２ CH ２ -, CF ３ CF ２ CH ２ CH ２ -, CF ３ (CF ２ ) ２ CH ２ CH ２ -, CF ３ (CF ２ ) ３ CH ２ CH ２ -, CF ３ (CF ２ ) ４ CH ２ CH ２ -, CF ３ (CF ２ ) ５CH ２ CH ２ -, CF ３ (CF ２ ) ６ CH ２ CH ２ -, CF ３ (CF ２ ) ７ CH ２ CH ２ - and other hydrofluoroalkyl groups.

[0025] Among these, the silane compound polymer (A) having good curability can be easily obtained, and therefore, R １ is CF ３ CH ２ CH ２ -(3,3,3-trifluoropropyl group) is preferred.

[0026] The silane compound polymer (A) has a repeating unit (2) represented by the following formula (a-2).

[0027]

[0028] In formula (a-2), R ２ represents an unsubstituted hydrocarbon group or a hydrocarbon group having a substituent (excluding a fluoroalkyl group).

[0029] The unsubstituted hydrocarbon group preferably has 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, and even more preferably 1 to 6 carbon atoms.

[0030] Examples of the unsubstituted hydrocarbon group include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, and n-decyl; alkenyl groups such as vinyl, allyl, isopropenyl, 1-butenyl, 2-butenyl, and 3-butenyl; alkynyl groups such as ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, and 3-butynyl; cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl; aryl groups such as phenyl, 1-naphthyl, 2-naphthyl, tolyl, and xylyl; and groups combining these, such as benzyl and cyclohexylmethyl.

[0031] The substituted hydrocarbon group may be the unsubstituted hydrocarbon group in which one or more hydrogen atoms have been substituted with a substituent, such as an amino group, an epoxy group, an acryloyloxy group, a methacryloyloxy group, a chlorine atom, or a bromine atom.

[0032] Among these, the silane compound polymer (A) having good curability can be easily obtained, and therefore, R ２ is preferably an alkyl group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, and even more preferably a methyl group.

[0033] The amount of the repeating unit (1) in the silane compound polymer (A) is 40 mol % or more, preferably 40 to 90 mol %, and more preferably 45 to 75 mol %, based on the total amount of the repeating unit (1) and the repeating unit (2). If the amount of the repeating unit (1) is less than 40 mol % based on the total amount of the repeating unit (1) and the repeating unit (2), cracks are likely to occur in the cured product.

[0034] In the silane compound polymer (A), the total amount of the repeating units (1) and (2) is preferably 70 to 100 mol %, more preferably 80 to 100 mol %, and even more preferably 90 to 100 mol %, based on the total amount of repeating units in the silane compound polymer (A). A silane compound polymer (A) in which the total amount of the repeating units (1) and (2) is 70 mol % or more based on the total amount of repeating units in the silane compound polymer (A) tends to have an excellent balance between curability and suppression of crack generation in the cured product.

[0035] When the silane compound polymer (A) has a repeating unit other than the repeating unit (1) and the repeating unit (2) [repeating unit (3)], examples of the repeating unit (3) include repeating units derived from monofunctional silane compounds such as trimethylmethoxysilane, repeating units derived from bifunctional silane compounds such as dimethyldimethoxysilane, repeating units derived from trifunctional silane compounds (excluding the repeating units (1) and (2)), and repeating units derived from tetrafunctional silane compounds such as tetramethoxysilane.

[0036] The repeating unit (1) represented by formula (a-1) and the repeating unit (2) represented by formula (a-2) are represented by the following formula (a-6).

[0037]

[0038] In formula (a-6), R ３ is R １ or R ２ Represents. １／２ indicates that the oxygen atom is shared with the adjacent repeat unit.

[0039] As shown in formula (a-6), the silane compound polymer (A) has a silicon atom to which three oxygen atoms are bonded, which is generally collectively called a T site, and other groups (R ３ Examples of the T site contained in the silane compound polymer (A) include a T1 site represented by the following formula (a-3), a T2 site represented by the following formula (a-4), and a T3 site represented by the following formula (a-5):

[0040]

[0041] [R ３ is R １ or R ２ represents. １ ~X ３ each independently represents a hydrogen atom or an alkyl group. * represents a bond to another repeating unit and is directly bonded to the silicon atom of another repeating unit.

[0042] The silane compound polymer (A) has a T3 site, and the amount of the T3 site is preferably 62 mol % or more, more preferably 62 to 99 mol %, and even more preferably 64 to 91 mol % of the total amount of the T1 site, the T2 site, and the T3 site. The T3 site is a group (-OX １ ~-OX ３ Therefore, the amount of T3 sites is 62 mol % or more of the total amount of T sites, and even if a silane compound polymer (A) containing a large amount of T3 sites is cured, a large amount of volatile low-molecular-weight compounds such as water or alcohol is not produced as by-products. A cured product of such a silane compound polymer (A) is less likely to crack.

[0043] The content ratios of the T1 site, the T2 site, and the T3 site can be determined by a conventional method by measuring the ratio of the T1 site, the T2 site, and the T3 site in the solution state of the silane compound polymer (A). ２９ The silane compound polymer (A) can be determined by measuring Si-NMR. Since the silane compound polymer (A) is soluble in various organic solvents such as ketone solvents such as acetone, aromatic hydrocarbon solvents such as benzene, sulfur-containing solvents such as dimethyl sulfoxide, ether solvents such as tetrahydrofuran, ester solvents such as ethyl acetate, halogen-containing solvents such as chloroform, and mixed solvents consisting of two or more of these, NMR of the silane compound polymer (A) in a solution state can be measured using these solvents.

[0044] The mass average molecular weight (Mw) of the silane compound polymer (A) is preferably 500 to 100,000, more preferably 800 to 50,000, even more preferably 1,000 to 30,000, even more preferably 1,500 to 3,000, and particularly preferably 2,000 to 3,000. The molecular weight distribution (Mw / Mn) of the silane compound polymer (A) is not particularly limited, but is typically 1.0 to 10.0, preferably 1.1 to 6.0. Silane compound polymers (A) having a mass average molecular weight or molecular weight distribution (Mw / Mn) within the above ranges are suitable for use as curable components in curable compositions. The mass average molecular weight (Mw) and number average molecular weight (Mn) can be determined, for example, as standard polystyrene equivalent values ​​by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent.

[0045] The structure of the silane compound polymer (A) may be any of a ladder structure, a double-decker structure, a cage structure, a partially cleaved cage structure, a cyclic structure, and a random structure. The silane compound polymer (A) may be any of a random copolymer, a block copolymer, a graft copolymer, and an alternating copolymer, but from the viewpoint of ease of production, a random copolymer is preferred.

[0046] The content of the silane compound polymer (A) is preferably 10 to 80% by mass, more preferably 20 to 65% by mass, based on the total amount of the silane compound polymer (A) and the component (B).

[0047] The method for producing the silane compound polymer (A) is not particularly limited. For example, the silane compound polymer (A) can be produced by carrying out a step (step PO) of hydrolyzing and polycondensing a trifunctional alkoxysilane compound corresponding to a desired repeating unit in the presence of water and an acid catalyst.

[0048] Step PO is a step of hydrolyzing and polycondensing a trifunctional alkoxysilane compound corresponding to the desired repeating unit in the presence of water and an acid catalyst.

[0049] In the step PO, for example, a compound represented by the following formula (a-7) and a compound represented by the following formula (a-8) are used as the trifunctional alkoxysilane compound.

[0050]

[0051] In formula (a-7) and formula (a-8), R １ , R ２ represents the same meaning as above. OR represents an alkoxy group. OR may be the same or different.

[0052] The number of carbon atoms in the alkoxy group represented by OR is preferably 1 to 6, and more preferably 1 to 3. Examples of the alkoxy group represented by OR include a methoxy group, an ethoxy group, and a propoxy group.

[0053] Specific examples of the trifunctional alkoxysilane compound represented by formula (a-7) include trifluoromethyltrimethoxysilane, trifluoromethyltriethoxysilane, pentafluoroethyltrimethoxysilane, pentafluoroethyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, etc. These trifunctional alkoxysilane compounds can be used alone or in combination of two or more.

[0054] Specific examples of the trifunctional alkoxysilane compound represented by formula (a-8) include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, etc. These trifunctional alkoxysilane compounds can be used alone or in combination of two or more.

[0055] In the method for producing the silane compound polymer (A), the molar ratio of the compound represented by formula (a-7) to the compound represented by formula (a-8) [compound represented by formula (a-7) : compound represented by formula (a-8)] is preferably 40:60 to 90:10, more preferably 45:55 to 75:25, and even more preferably 48:52 to 65:35.

[0056] In step PO, in addition to the trifunctional alkoxysilane compounds, monofunctional alkoxysilane compounds such as trimethylmethoxysilane, bifunctional alkoxysilane compounds such as dimethyldimethoxysilane, trifunctional alkoxysilane compounds other than the compounds represented by formula (a-7) and formula (a-8), and tetrafunctional alkoxysilane compounds such as tetramethoxysilane may be used as monomers.

[0057] In the method for producing the silane compound polymer (A), the total amount of the compound represented by formula (a-7) and the compound represented by formula (a-8) is preferably 70 to 100 mol %, more preferably 80 to 100 mol %, and even more preferably 90 to 100 mol %, based on the total amount of monomers.

[0058] In step PO, it is preferable to add water to the reaction system in an amount sufficient to sufficiently hydrolyze the hydrolyzable groups contained in the monomers (for example, "OR" in formula (a-7) and formula (a-8)). The amount of water added is preferably such that the molar ratio M of water to alkoxy groups, calculated by the following formula (F1), is 1.0 or more, more preferably 1.0 to 5.0, and even more preferably 1.0 to 3.0.

[0059]

[0060] In formula (F1), M Ｈ２Ｏ is the amount of water (mol number) added to the reaction system, and M ＯＲ is the total number of alkoxy groups in the monomer (total number of moles). For example, when 6.0 mol of water is added to 1.0 mol of a trifunctional alkoxysilane compound, the molar ratio M is 6.0 / 3.0 (=2.0).

[0061] When the molar ratio M is 1.0 or more, the hydrolysis reaction of the monomer can be sufficiently progressed, and a silane compound polymer having excellent curability can be easily obtained.

[0062] Examples of the acid catalyst used in step (PO) include inorganic acids such as phosphoric acid, hydrochloric acid, boric acid, sulfuric acid, and nitric acid; and organic acids such as formic acid, citric acid, acetic acid, methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, and p-toluenesulfonic acid. Among these, at least one selected from phosphoric acid, hydrochloric acid, boric acid, sulfuric acid, formic acid, citric acid, acetic acid, and methanesulfonic acid is preferred.

[0063] The amount of the acid catalyst used is usually 0.05 to 10 mol %, preferably 0.1 to 5 mol %, based on the total amount of monomers. By adjusting the amount of the acid catalyst used, the polycondensation reaction can be allowed to proceed appropriately, and a silane compound polymer having the desired molecular weight can be obtained.

[0064] Step PO can be carried out, for example, by placing a trifunctional alkoxysilane compound, water, and an acid catalyst in a reaction vessel and stirring the resulting mixture. In addition to these components, an organic solvent may also be present in the reaction vessel. The presence of an organic solvent in the reaction vessel allows the polymerization reaction to continue even if a solid silane compound polymer is produced during the polymerization reaction.

[0065] The organic solvent used in step PO is not particularly limited as long as it dissolves the trifunctional alkoxysilane compound used as a raw material. However, a high-boiling point solvent (e.g., a solvent with a boiling point of 150°C) is preferred as the organic solvent, as this is less likely to volatilize during step PO and allows step PO to be carried out stably.

[0066] Examples of high-boiling point solvents include polyether solvents such as dipropylene glycol dimethyl ether (boiling point 171°C), diethylene glycol dimethyl ether (boiling point 162°C), and diethylene glycol ethyl methyl ether (boiling point 176°C); ester solvents such as γ-butyrolactone (boiling point 204°C), ethyl lactate (boiling point 154°C), 3-methoxybutyl acetate (boiling point 171°C), and ethylene glycol monoethyl ether acetate (boiling point 156°C); ketone solvents such as cyclohexanone (boiling point 156°C); amide solvents such as N,N-dimethylformamide (boiling point 153°C), N,N-dimethylacetamide (boiling point 165°C), and N-methylpyrrolidone (boiling point 202°C); and sulfoxide solvents such as dimethyl sulfoxide (boiling point 189°C). Among these, polyether solvents are preferred because they are less susceptible to reaction even at high temperatures.

[0067] When an organic solvent is used in step PO, the amount of the organic solvent used is preferably 0.05 to 3 times, more preferably 0.1 to 1.5 times, by volume, the amount of the trifunctional alkoxysilane compound. When the reaction solution obtained in step PO is used as is as the curable composition of the present invention, it is preferable to adjust the amount of the organic solvent used in consideration of the concentration of the silane compound polymer in the curable composition.

[0068] The reaction conditions for step PO are not particularly limited. The reaction temperature for step PO is usually 0 to 180° C., preferably 10 to 170° C. The reaction time for step PO is usually 30 minutes to 50 hours, preferably 1 to 24 hours.

[0069] The process PO may be carried out under constant conditions from start to finish (i.e., it may have one step), or it may have multiple steps with different reaction conditions.

[0070] After the step PO, the reaction solution may be used as an insulating film forming agent as it is, or a step (step PU) of purifying the silane compound polymer produced in the step PO may be carried out. By carrying out the step PU, a highly pure silane compound polymer can be obtained.

[0071] An example of step PU is a purification step using a solvent extraction method. Examples of purification steps using a solvent extraction method include those having the following steps: (Step PU-I) If necessary, volatilizing the solvent from the reaction solution, then adding a water-immiscible organic solvent or water, stirring the mixture, and then allowing it to stand to separate into an organic phase and an aqueous phase; (Step PU-II) A step of separating the organic phase produced in step PU-I and washing the organic phase with water if necessary; and (Step PU-III) A step of concentrating and drying the organic phase separated in step PU-II.

[0072] The amount of solvent and the type of organic solvent added in Step PU-I are not particularly limited as long as they are finally separated into an organic phase and an aqueous phase.

[0073] The silane compound polymer (A) is usually contained in the organic phase. Therefore, in step PU-II, the organic phase produced in step PU-I is separated. Thereafter, the organic phase may be washed with water according to a conventional method.

[0074] Step PU-III can be carried out by a conventional method such as concentration treatment with an evaporator and vacuum drying treatment.

[0075] [Component (B): Solvent] The curable composition of the present invention contains the following component (B): Component (B): Solvent

[0076] The solvent constituting the curable composition of the present invention is not particularly limited as long as it dissolves the silane compound polymer (A). Therefore, when the silane compound polymer (A) is synthesized in the presence of an organic solvent and a uniform reaction solution is obtained, the same solvent as that used in the synthesis can be used as the solvent constituting the semiconductor insulating film-forming agent of the present invention.

[0077] Examples of the solvent constituting the semiconductor insulating film forming agent of the present invention include solvents having a boiling point of 150°C or higher, such as polyether solvents such as dipropylene glycol dimethyl ether (boiling point 171°C), diethylene glycol dimethyl ether (boiling point 162°C), and diethylene glycol ethyl methyl ether (boiling point 176°C); ester solvents such as γ-butyrolactone (boiling point 204°C), ethyl lactate (boiling point 154°C), 3-methoxybutyl acetate (boiling point 171°C), and ethylene glycol monoethyl ether acetate (boiling point 156°C); ketone solvents such as cyclohexanone (boiling point 156°C); amide solvents such as N,N-dimethylformamide (boiling point 153°C), N,N-dimethylacetamide (boiling point 165°C), and N-methylpyrrolidone (boiling point 202°C); and sulfoxide solvents such as dimethyl sulfoxide (boiling point 189°C).

[0078] If a solvent having a boiling point of 150°C or higher is used, evaporation of the solvent during application of the semiconductor insulating film forming agent by spin coating can be avoided, and a film of more uniform thickness can be formed.

[0079] Among these, polyether solvents are preferred. Since polyether solvents easily form azeotropes with water, the use of polyether solvents allows the coating film to be dried efficiently in the drying process. In this specification, polyether solvents refer to compounds having ether groups at the interior and terminal ends of the hydrocarbon chain. Such compounds are stable even at high temperatures and are suitable as solvents for insulating film forming agents.

[0080] The polyether solvent includes a compound represented by the following formula (b-1).

[0081] In formula (b-1), R ａ , R ｃ each independently represents a monovalent hydrocarbon group having 1 to 12 carbon atoms; R ｂ represents a divalent hydrocarbon group having 2 or 3 carbon atoms, and n is an integer of 2 to 4. ｂ may be the same or different.

[0082] The content of the solvent is preferably from 20 to 90% by mass, more preferably from 35 to 80% by mass, based on the total amount of the silane compound polymer (A) and the solvent.

[0083] [Curable Composition] The curable composition of the present invention contains component (A) and component (B). The total amount of component (A) and component (B) is 98% by mass or more, preferably 98.5 to 100% by mass, and more preferably 99 to 100% by mass, based on the total amount of the curable composition.

[0084] A curable composition in which the combined amount of component (A) and component (B) is 98 mass% or more relative to the total amount of the curable composition contains almost no reactive compounds that generate volatile low-molecular-weight compounds during the curing reaction, and therefore cracks are less likely to occur in the cured product.

[0085] When the curable composition of the present invention contains components other than the component (A) and the component (B), examples of the components other than the component (A) and the component (B) include a curing catalyst and a surfactant.

[0086] The curable composition of the present invention can be prepared, for example, by mixing the silane compound polymer (A), a solvent, and other components in a predetermined ratio. When the silane compound polymer (A) is synthesized in a solvent, the reaction mixture may be used as the curable composition of the present invention.

[0087] The viscosity of the curable composition of the present invention at 23° C. is preferably 100,000 mPa·s or less, more preferably 2 to 10,000 mPa·s, and even more preferably 5 to 5,000 mPa·s.

[0088] [Semiconductor insulating film forming agent] The semiconductor insulating film forming agent of the present invention comprises the curable composition of the present invention. When forming a semiconductor insulating film using the semiconductor insulating film forming agent of the present invention, the semiconductor insulating film forming agent is typically applied, the resulting coating is dried, and then the dried coating is cured. Spin coating is preferably used when applying the semiconductor insulating film forming agent. Conditions for drying a coating of the semiconductor insulating film forming agent include, for example, a drying temperature of typically 100 to 200°C, preferably 120 to 180°C, and a drying time of typically 10 to 300 seconds, preferably 40 to 120 seconds. Conditions for curing the dried coating include, for example, a curing temperature of typically 200 to 350°C, preferably 230 to 300°C, and a curing time of typically 30 to 600 seconds, preferably 60 to 300 seconds.

[0089] By using the semiconductor insulating film forming agent of the present invention, it is possible to efficiently form a relatively thick semiconductor insulating film, for example, 0.1 to 5.0 μm, preferably 0.5 to 4.0 μm, and more preferably 1.0 to 3.0 μm.

[0090] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0091] Example 1 A recovery flask was charged with 500 mmol (109.13 g) of 3,3,3-trifluoropropyltrimethoxysilane, 500 mmol (68.11 g) of methyltrimethoxysilane, and 414 g of dipropylene glycol dimethyl ether (an amount sufficient to give a total monomer concentration of 30% by mass). While stirring, an aqueous formic acid solution (6,000 mmol (108.1 g, 2 equivalents relative to the total amount of alkoxy groups contained in the monomers) of 2.5 mmol (0.115 g, 0.25 mol% relative to the total amount of monomers) of formic acid was added dropwise over 30 minutes at 30°C. After completion of the dropwise addition, the contents of the flask were stirred at 50°C for 2 hours, and then at 110°C for 2 hours. 250 g of toluene was added dropwise to the solution to distill off the water and toluene from the system, followed by stirring at 160°C for 2 hours to obtain a solution of a silane compound polymer. Thereafter, the solution was concentrated to obtain a solution of a silane compound polymer (curable composition) with a concentration of 50% by mass.

[0092] [Example 2, Comparative Examples 1 and 2] A solution of a silane compound polymer (curable composition) was obtained in the same manner as in Example 1, except that the monomers were used in the molar ratios shown in Table 1 (however, the total amount of the silane compounds was 1,000 mmol).

[0093] The following measurements were carried out on the silane compound polymers or curable compositions obtained in Examples 1 and 2 and Comparative Examples 1 and 2. The results are shown in Table 1.

[0094] [Measurement of average molecular weight] The mass average molecular weight (Mw) of the silane compound polymer was measured using the following apparatus and conditions: Apparatus name: HLC-8220GPC manufactured by Tosoh Corporation Column: "TSK guard column SuperH-H", "TSK gel SuperHM-H", "TSK gel SuperHM-H", and "TSK gel SuperH2000" connected in sequence Solvent: tetrahydrofuran Standard substance: polystyrene Injection amount: 20 μl Measurement temperature: 40° C. Flow rate: 0.6 ml / min Detector: differential refractometer

[0095] [ ２９ Si-NMR measurement] Device name: AV-500 manufactured by Bruker Biospin ２９Si-NMR resonance frequency: 99.352 MHz Probe: 5 mmφ solution probe Measurement temperature: room temperature (25°C) Sample rotation speed: 20 kHz Measurement method: inverse gate decoupling method ２９ Si flip angle: 90° ２９ Si 90° pulse width: 8.0 μs Repetition time: 5 s Number of integrations: 9200 Observation width: 30 kHz

[0096] < ２９ Si-NMR sample preparation method> In order to shorten the relaxation time, Fe(acac) was used as a relaxation reagent. ３ Silane compound polymer concentration: 15% Fe(acac) ３ Concentration: 0.6% Measurement solvent: acetone Internal standard: TMS

[0097] <Waveform Processing Analysis> For each peak in the spectrum after Fourier transformation, the chemical shift was determined from the peak top position, and each peak was integrated within the following ranges: (Examples 1 and 2, Comparative Example 1) T1 site: -52.5 to -45.0 ppm T2 site: -61.7 to -52.5 ppm T3 site: -74.5 to -61.7 ppm (Comparative Example 2) T1 site: -52.0 to -45.0 ppm T2 site: -60.7 to -52.0 ppm T3 site: -71.5 to -60.7 ppm Based on the obtained values, the proportions of the T1 site, T2 site, and T3 site were calculated.

[0098] [Viscosity Measurement] The viscosity of the curable composition at 23° C. was measured using a vibration viscometer. Device name: VM-10A-L manufactured by Sekonic Corporation

[0099] [Crack Resistance Evaluation Test] A crack resistance evaluation test was performed under the following conditions. A curable composition was spin-coated onto a silicon wafer, and the wafer was heated on a hot plate heated to 150°C for 1 minute to volatilize the solvent and form a 3 μm-thick silane compound polymer film. In this state, the presence or absence of cracks was observed. Next, the wafer was heated on a hot plate heated to 250°C for 1 minute to harden the silane compound polymer film. The obtained cured film was transferred to a 23°C environment and allowed to cool to 23°C, after which the presence or absence of cracks was examined. The same experiment as above was also performed, except that a 6 μm-thick silane compound polymer film was formed instead of the 3 μm-thick silane compound polymer film.

[0100]

[0101] The following can be seen from Table 1. The silane compound polymers contained in the curable compositions obtained in Examples 1 and 2 have a repeating unit having a fluoroalkyl group of 40 mol % or more and contain many T3 sites. Therefore, cracks are less likely to occur in the cured films of the curable compositions obtained in Examples 1 and 2. On the other hand, the silane compound polymers contained in the curable compositions obtained in Comparative Examples 1 and 2 have a repeating unit having a fluoroalkyl group of less than 40 mol % and contain few T3 sites. Therefore, cracks are more likely to occur in the cured films of the curable compositions obtained in Comparative Examples 1 and 2.

Claims

1. A curable composition containing the following components (A) and (B), wherein the total amount of components (A) and (B) is 98 mass% or more based on the total amount of the curable composition: Component (A): Formula (a-1) below [R １ represents a fluoroalkyl group.] and a repeating unit (repeating unit (1)) represented by the following formula (a-2): [R ２ represents an unsubstituted hydrocarbon group or a substituted hydrocarbon group (excluding a fluoroalkyl group).] and a silane compound polymer having a repeating unit represented by the following formula (2): wherein the amount of the repeating unit (1) is 40 mol % or more based on the total amount of the repeating unit (1) and the repeating unit (2). (B): Solvent 2. R of the component (A) １ The composition formula: C ｍ H （２ｍ－ｎ＋１） F ｎ The curable composition according to claim 1, wherein m is an integer of 1 to 15, and n is an integer of 2 or more and (2m+1) or less.

3. The curable composition according to claim 1, wherein the total amount of repeating units (1) and (2) in component (A) is 70 to 100 mol % based on the total amount of repeating units in the silane compound polymer.

4. The curable composition according to claim 1, wherein the component (A) has a T3 site represented by the following formula (a-5), and the amount of the T3 site is 62 mol % or more of the total amount of the T1 site represented by the following formula (a-3), the T2 site represented by the following formula (a-4), and the T3 site. [R ３ is R １ or R ２ represents. １ ~X ３ each independently represents a hydrogen atom or an alkyl group. * represents a bond to another repeating unit and is directly bonded to the silicon atom of another repeating unit.

5. The curable composition according to claim 1, wherein the weight average molecular weight (Mw) of component (A) is 500 to 100,000.

6. The curable composition according to claim 1, wherein the amount of component (A) is 10 to 80% by mass based on the total amount of components (A) and (B).

7. The curable composition according to claim 1, wherein component (B) is a solvent having a boiling point of 150°C or higher.

8. The curable composition according to claim 1, wherein the component (B) is a polyether solvent.

9. A semiconductor insulating film forming agent comprising the curable composition according to claim 1.

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