Process for the production of sulfur-containing cyclic siloxanes

Abstract

Sulfur-containing cyclic siloxanes are manufactured under simple procedures and stable conditions by the following method, which includes: reacting a dihalosilane of formula (1) with water to obtain a linear siloxane of formula (2); and reacting the linear siloxane with a sulfurizing agent of formula (3) to obtain a sulfur-containing cyclic siloxane of formula (4), wherein formula (1): [where R] 1 and R 2 Each time it appears, it is independently a hydrogen atom, a hydrocarbon group having 1 to 6 carbon atoms, or a hydrocarbon oxygen group having 1 to 6 carbon atoms; R 1 and R 2 They can be optionally bonded together to form a ring, and X is an independent halogen atom each time it appears; Equation (2): [where R is an halogen atom] 1 and R 2 Each time it appears, it is independently a hydrogen atom, a hydrocarbon group with 1 to 6 carbon atoms, or a hydrocarbon oxygen group with 1 to 6 carbon atoms, and the R atom is bonded to the same silicon atom. 1 and R 2 Optionally bonded to each other to form a ring, X is an independent halogen atom each time it appears, n is an integer from 0 to 2]; Equation (3): Y2S [where Y is an independent hydrogen atom, sodium atom or lithium atom each time it appears]; Equation (4): [where R 1 and R 2 Each time it appears, it is independently a hydrogen atom, a hydrocarbon group with 1 to 6 carbon atoms, or a hydrocarbon oxygen group with 1 to 6 carbon atoms, and the R atom is bonded to the same silicon atom. 1 and R 2 They can be optionally bonded together to form a ring, where n is an integer from 0 to 2.

Description

Technical Field

[0001] This disclosure relates to a method for manufacturing sulfur-containing cyclic siloxanes. Background Technology

[0002] Silane compounds are used in various electrical equipment materials, including semiconductors. In the fabrication of semiconductor devices, these compounds are used as raw materials to form silicon-containing thin films, such as silicon films, silicon oxide films, silicon nitride films, silicon carbonitride films, and silicon oxynitride films, through various vapor deposition processes. For example, Patent Document 1 proposes a method that uses atomic layer deposition (ALD) with bis(diethylamino)silane (BDEAS), an aminosilane compound, as a silicon source to form a uniform silicon oxide film.

[0003] Regarding the synthesis of sulfur-containing cyclic siloxanes, which include sulfur atoms as part of the ring structure, synthetic examples have been reported in the past. For example, methods for reacting a mixture of 5-anisinyl-2,2,3,3-tetramethyl-5-thio-1,4,5,2,3-dithiaphosphazene digermanium pentane and hexamethylcyclotrisiloxane are known (Non-Patent Document 1); methods for reacting hexamethylcyclotrisiloxane and dodecylcyclohexasilane with sulfur (Non-Patent Document 2); and methods for manufacturing hexamethylcyclotrisiloxane and hexamethylcyclotrisilthane by heat treatment (Non-Patent Document 3), etc.

[0004] Existing technical documents Patent documents Patent Document 1: WO2006 / 097525 Non-patent literature 1: Canadian Journal of Chemistry, 1986, vol.64, pp.615-620. Non-patent literature 2: Journal of Organometallic Chemistry, 1988, vol. 346, pp. 287-296 Non-patent literature 3: Journal of Organometallic Chemistry, 1979, vol. 165, p. C1, C3, C4 Summary of the Invention

[0005] The problem that the invention aims to solve However, these previously known methods have drawbacks such as requiring reaction steps at temperatures above 150°C or having a large number of steps. The purpose of this disclosure is to provide a method for producing sulfur-containing cyclic siloxanes under simple procedures and stable conditions.

[0006] Solution for solving the problem One aspect of this disclosure provides manufacturing methods described in the following items.

[0007] [Item 1] A method for manufacturing a sulfur-containing cyclic siloxane includes: a step of reacting a dihalosilane of formula (1) with water to obtain a linear siloxane of formula (2); and a step of reacting the linear siloxane with a sulfiding agent of formula (3) to obtain a sulfur-containing cyclic siloxane of formula (4).

[0008] Equation (1): [In the formula, R] 1 and R 2 Each time it appears, it is independently a hydrogen atom, a hydrocarbon group having 1 to 6 carbon atoms, or a hydrocarbon oxygen group having 1 to 6 carbon atoms; R 1 and R 2 They optionally bond together to form a ring, with X being an independent halogen atom each time it appears. Equation (2): [In the formula, R] 1 and R 2 Each time it appears, it is independently a hydrogen atom, a hydrocarbon group with 1 to 6 carbon atoms, or a hydrocarbon oxygen group with 1 to 6 carbon atoms, and the R atom is bonded to the same silicon atom. 1 and R 2 They can optionally bond together to form a ring, where X is an independent halogen atom in each occurrence, and n is an integer from 0 to 2. Equation (3): Y2S [In the formula, Y is independently a hydrogen atom, a sodium atom, or a lithium atom each time it appears.] Equation (4): [In the formula, R] 1 and R 2 Each time it appears, it is independently a hydrogen atom, a hydrocarbon group with 1 to 6 carbon atoms, or a hydrocarbon oxygen group with 1 to 6 carbon atoms, and the R atom is bonded to the same silicon atom. 1 and R 2 They can be optionally bonded together to form a ring, where n is an integer from 0 to 2. [Item 2] According to the method described in item 1, where R 1 and R 2 Each time it appears, it is independently an alkyl group having 1 to 6 carbon atoms.

[0009] [Item 3] According to the method described in item 1 or 2, where R 1 and R 2 Each time it appears, it is independently either a hydrogen atom or a methyl group.

[0010] [Item 4] The method according to any one of items 1 to 3, wherein n is 0 or 1.

[0011] [Item 5] The method according to any one of items 1 to 4, wherein X is a chlorine atom.

[0012] [Item 6] The method according to any one of items 1 to 5, wherein the sulfur-containing cyclic siloxane is a silicon-containing membrane precursor.

[0013] Invention Effects According to one aspect of the manufacturing method disclosed herein, sulfur-containing cyclic siloxanes can be manufactured under simple procedures and stable conditions. Attached Figure Description

[0014] Figure 1 The term represents 2,2,4,4,6,6,8,8-octamethyl-1,3,5-trioxa-7-thia-2,4,6,8-tetrasilane obtained through embodiments of this disclosure. 1 H-NMR spectrum. Detailed Implementation

[0015] The method for manufacturing sulfur-containing cyclic siloxanes disclosed herein will be described in detail below.

[0016] This disclosure has two processes (hereinafter referred to as process I and process II, respectively).

[0017] <Process I: Hydrolysis Process> Step I is a process in which dihalosilanes are reacted with water to obtain straight-chain siloxanes through hydrolysis.

[0018] If we were to describe the reaction of step I in more detail, it would be the process of reacting a dihalosilane with water to produce a straight-chain siloxane with halogen atoms at both ends as a synthetic intermediate, which can be represented by reaction formula [I].

[0019] Reaction formula [I]: [In the formula, X and R] 1 R 2 And n as described below. [Dihalosilanes] The dihalosilanes in this disclosure can be represented by formula (1).

[0020] Equation (1): [In the formula, R] 1 and R 2Each time it appears, it is independently a hydrogen atom, a hydrocarbon group having 1 to 6 carbon atoms, or a hydrocarbon oxygen group having 1 to 6 carbon atoms; R 1 and R 2 They optionally bond together to form a ring, with X being an independent halogen atom each time it appears. Dihalosilanes can be aliphatic or aromatic.

[0021] One type of dihalosilane can be used, or two or more can be used in combination.

[0022] R 1 and R 2 The hydrocarbon group in it can be an aliphatic group or an aromatic group, preferably an aliphatic group. As R 1 and R 2 Examples of hydrocarbon groups in the form of alkyl groups include: alkyl groups (e.g., methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, or pentyl) with 1 to 6 carbon atoms (e.g., 1, 2, 3, 4, 5, or 6), alkenyl groups (e.g., vinyl or 2-propenyl) with 2 to 6 carbon atoms (e.g., 2, 3, 4, 5, or 6), and alkynyl groups (e.g., ethynyl or propynyl) with 2 to 6 carbon atoms (e.g., 2, 3, 4, 5, or 6).

[0023] R 1 and R 2 The hydroxyl group in it can be an aliphatic group or an aromatic group, preferably an aliphatic group. As R 1 and R 2 Examples of hydrocarbon oxygen groups include: alkoxy groups (e.g., methoxy, ethoxy, or propoxy) with 1 to 6 carbon atoms (e.g., 1, 2, 3, 4, 5, or 6), alkenoxy groups (e.g., ethyleneoxy or 2-propenoxy) with 2 to 6 carbon atoms (e.g., 2, 3, 4, 5, or 6), and alkynoxy groups (e.g., ethynoxy or propynoxy) with 2 to 6 carbon atoms (e.g., 2, 3, 4, 5, or 6).

[0024] R 1 and R 2 The average number of carbon atoms can be 0 to 6, preferably 1 to 3, and more preferably 1 to 2.

[0025] R 1 and R 2 It can be linear, branched, or cyclic, preferably linear or branched, and more preferably linear.

[0026] R bonded to the same silicon atom 1 and R 2 They can bond with each other to form a ring, or they can remain separate. It should be noted that, here, "bonding" refers to R... 1 and R 2 Each has its own bonds (e.g., each R)1 and R 2 (The bonds formed by the removal of hydrogen atoms) bond with each other.

[0027] R 1 and R 2 At least one of them can be other than a hydrogen atom (the hydrocarbon group or the hydrocarbon oxygen group). R 1 and R 2 It can also consist entirely of atoms other than hydrogen atoms. R can be any substance other than hydrogen atoms. 1 and R 2 The quantity relative to R 1 and R 2 The total quantity can be 10% or more, 20% or more, 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, or 90% or more, preferably 50% or more.

[0028] R 1 and R 2 They can be the same or different, but the same is preferred. R 1 and R 2 More preferably, it is an alkyl group having 1 to 6 carbon atoms, and even more preferably, it is a hydrogen atom or a methyl group.

[0029] X is a halogen atom, such as a chlorine atom, a bromine atom, or an iodine atom.

[0030] [Linear siloxanes] The linear siloxanes in this disclosure can be represented by formula (2).

[0031] Equation (2): [In the formula, R] 1 and R 2 Each time it appears, it is independently a hydrogen atom, a hydrocarbon group with 1 to 6 carbon atoms, or a hydrocarbon oxygen group with 1 to 6 carbon atoms, and the R atom is bonded to the same silicon atom. 1 and R 2 They can optionally bond together to form a ring, where X is an independent halogen atom in each occurrence, and n is an integer from 0 to 2. Regarding R 1 R 2 X, referencing the description of dihalosilanes.

[0032] n is an integer from 0 to 2, preferably from 0 to 1, and particularly preferably 1.

[0033] The molecular weight of the linear siloxane is 150 to 1500, preferably 200 to 400.

[0034] The number of carbon atoms in a linear siloxane can be 0 to 60, preferably 0 to 20.

[0035] [Reaction conditions, etc.] Regarding the molar ratio of dihalosilane to water in this reaction, the amount of water relative to 1.0 mole of dihalosilane shown in formula (1) is usually 0.2 to 1.5 moles, preferably 0.5 to 1.0 moles.

[0036] The reaction temperature can range from -10 to 80°C, preferably from 0 to 40°C. From the viewpoint of reactivity and workability, the reaction temperature is preferably above -10°C.

[0037] The reaction time is 0.1 to 100 hours, preferably 1 to 30 hours.

[0038] In this reaction, solvents can be used. Examples of solvents that can be used include: halogenated hydrocarbon solvents such as dichloromethane, dichloroethane, and chloroform; aromatic hydrocarbon solvents such as benzene, toluene, xylene, chlorobenzene, and trichlorobenzene; ether solvents such as diethyl ether, dipropyl ether, diisopropyl ether, 1,2-dimethoxyethane, 1,4-dioxane, tetrahydrofuran (THF), and ethylene glycol dimethyl ether; ketone solvents such as acetone, methyl ethyl ketone, 2-pentanone, 3-pentanone, 2-hexanone, 2-heptanone, 4-heptanone, methyl isobutyl ketone, diisobutyl ketone, acetone-based acetone, and cyclohexanone; ester solvents such as methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, and isobutyl acetate; and mixtures thereof.

[0039] Among them, ether-based solvents such as diethyl ether and tetrahydrofuran (THF) are preferred, and tetrahydrofuran (THF) is more preferred.

[0040] The amount of solvent used can be 1 to 1000 parts by mass relative to 100 parts by mass of the dihalosilane and water, preferably 5 to 500 parts by mass, and more preferably 50 to 400 parts by mass.

[0041] Methods for removing linear siloxanes from a reaction solution include: removing low-molecular-weight components such as solvents and raw materials by vacuum distillation, followed by vacuum distillation.

[0042] In this reaction, a base may be added as needed. Examples of bases include trimethylamine, triethylamine, diisopropylethylamine, pyridine, pyrimidine, pyrazine, and other tertiary amines. The amount of base used relative to 1.0 mole of the dihalosilane is preferably 0.8 to 4.0 moles, more preferably 0.8 to 2.0 moles.

[0043] The base can be added at the end of this reaction.

[0044] <Process II: Circulation Process> Step II is a process in which the linear siloxane obtained in Step I is reacted with a sulfurizing agent to obtain a sulfur-containing cyclic siloxane.

[0045] If we were to further describe the reaction in step II, it would be that the linear siloxane obtained by the reaction represented by the above reaction formula [I] reacts with a sulfurizing agent, thereby forming a cyclic structure within the molecule to obtain a sulfur-containing cyclic siloxane crosslinked by sulfur, which can be represented by reaction formula [II].

[0046] Reaction formula [II]: [In the formula, X, Y, R] 1 R 2 And n as described above or as stated below. [Vulcanizing agent] The vulcanizing agent disclosed herein can be represented by formula (3).

[0047] Equation (3): Y2S [In the formula, Y is independently a hydrogen atom, a sodium atom, or a lithium atom each time it appears.] Y is preferably a hydrogen atom or a lithium atom, more preferably a hydrogen atom.

[0048] [Sulfur-containing cyclic siloxanes] The sulfur-containing cyclic siloxane disclosed herein can be represented by formula (4).

[0049] Equation (4): [In the formula, R] 1 and R 2 Each time it appears, it is independently a hydrogen atom, a hydrocarbon group with 1 to 6 carbon atoms, or a hydrocarbon oxygen group with 1 to 6 carbon atoms, and the R atom is bonded to the same silicon atom. 1 and R 2 They can be arbitrarily bonded together to form a ring, where n is an integer from 0 to 2. R 1 and R 2 The hydrocarbon group in it can be an aliphatic group or an aromatic group, preferably an aliphatic group. As R 1 and R 2 Examples of hydrocarbon groups in the form of alkyl groups include: alkyl groups (e.g., methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, or pentyl) with 1 to 6 carbon atoms (e.g., 1, 2, 3, 4, 5, or 6), alkenyl groups (e.g., vinyl or 2-propenyl) with 2 to 6 carbon atoms (e.g., 2, 3, 4, 5, or 6), and alkynyl groups (e.g., ethynyl or propynyl) with 2 to 6 carbon atoms (e.g., 2, 3, 4, 5, or 6).

[0050] R 1 and R 2 The hydroxyl group in it can be an aliphatic group or an aromatic group, preferably an aliphatic group. As R 1 and R2 Examples of hydrocarbon oxygen groups include: alkoxy groups (e.g., methoxy, ethoxy, or propoxy) with 1 to 6 carbon atoms (e.g., 1, 2, 3, 4, 5, or 6), alkenoxy groups (e.g., ethyleneoxy or 2-propenoxy) with 2 to 6 carbon atoms (e.g., 2, 3, 4, 5, or 6), and alkynoxy groups (e.g., ethynoxy or propynoxy) with 2 to 6 carbon atoms (e.g., 2, 3, 4, 5, or 6).

[0051] R 1 and R 2 The average number of carbon atoms can be 0 to 6, preferably 1 to 3, and more preferably 1 to 2.

[0052] R 1 and R 2 It can be linear, branched, or cyclic, preferably linear or branched, and more preferably linear.

[0053] R bonded to the same silicon atom 1 and R 2 They can bond with each other to form a ring, or they can remain separate. It should be noted that, here, "bonding" refers to R... 1 and R 2 Each has its own bonds (e.g., each R) 1 and R 2 (The bonds formed by the removal of hydrogen atoms) bond together. R 1 and R 2 The structures formed by the bonding of the two groups can be straight-chain or branched alkylene structures, straight-chain or branched oxoalkylene structures, or straight-chain or branched dioxoalkylene structures, and the number of carbon atoms can be 2–12, 2–6, or 4–6.

[0054] R 1 and R 2 At least one of them can be other than a hydrogen atom (the hydrocarbon group or the hydrocarbon oxygen group). R 1 and R 2 It can also consist entirely of atoms other than hydrogen atoms. R can be any substance other than hydrogen atoms. 1 and R 2 The quantity relative to R 1 and R 2 The total quantity can be 10% or more, 20% or more, 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, or 90% or more, preferably 50% or more.

[0055] R 1 and R 2 They can be the same or different, but the same is preferred. R 1 and R 2More preferably, it is an alkyl group having 1 to 6 carbon atoms, and even more preferably, it is a hydrogen atom or a methyl group.

[0056] n is an integer from 0 to 2, preferably from 0 to 1, and particularly preferably 1.

[0057] The sulfur-containing cyclic siloxane has a molecular weight of 150 to 1500, preferably 200 to 600, and more preferably 200 to 400.

[0058] The number of carbon atoms in sulfur-containing cyclic siloxanes can be 0 to 60, preferably 0 to 20.

[0059] [Reaction conditions, etc.] The amount of vulcanizing agent used in this reaction can be 0.8 to 5.0 moles relative to 1.0 mole of linear siloxane, preferably 0.8 to 2.0 moles, and more preferably 1.0 to 1.5 moles. The reaction temperature is preferably 0 to 100°C, and more preferably 10 to 40°C.

[0060] Methods for mixing reaction raw materials include: dissolving a linear siloxane in an organic solvent and then adding a sulfiding agent, and dissolving a sulfiding agent in an organic solvent and then adding a linear siloxane. When Y in the sulfiding agent is a hydrogen atom, the method of adding a sulfiding agent to a linear siloxane is preferred.

[0061] In this reaction, a base may be added as needed. Examples of bases include trimethylamine, triethylamine, diisopropylethylamine, pyridine, pyrimidine, pyrazine, and other tertiary amines. The amount of base used is preferably 0.8 to 4.0 moles relative to 1.0 mole of the linear siloxane, and more preferably 1.5 to 2.5 moles.

[0062] In this reaction, solvents can be used as needed. Solvents can be mixed with the reactants or added after the reaction. Examples of solvents include: aliphatic hydrocarbon solvents such as hexane, cyclohexane, methylcyclohexane, heptane, octane, isooctane, nonane, decane, and undecane; halogenated hydrocarbon solvents such as dichloroethane, dichloromethane, and chloroform; aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, chlorobenzene, and trichlorobenzene; ether solvents such as diethyl ether, dipropyl ether, diisopropyl ether, 1,2-dimethoxyethane, 1,4-dioxane, tetrahydrofuran (THF), and ethylene glycol dimethyl ether; ketone solvents such as acetone, methyl ethyl ketone, 2-pentanone, 3-pentanone, 2-hexanone, 2-heptanone, 4-heptanone, methyl isobutyl ketone, diisobutyl ketone, acetone-based acetone, and cyclohexanone; ester solvents such as methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, and isobutyl acetate, as well as mixtures thereof.

[0063] The solvents used are preferably aromatic hydrocarbon solvents or ether solvents, and more preferably toluene or tetrahydrofuran (THF). One solvent may be used, or two or more solvents may be used in combination.

[0064] The amount of solvent used relative to 100 parts by weight of the linear siloxane can be 10 to 5000 parts by weight, preferably 100 to 5000 parts by weight, and more preferably 500 to 3500 parts by weight.

[0065] In this reaction, if a solid is present in the reaction solution, filtration can be performed after the reaction is complete, if necessary. When filtration is performed, it is ideal to conduct the reaction under a dry, inert gas atmosphere to suppress the decomposition of the sulfur-containing cyclic siloxanes. Specific examples of inert gases include nitrogen and argon. The filtration temperature is not uniquely determined and can range from 10°C to the boiling point of the solvent used, preferably 10–40°C.

[0066] In this reaction, to handle flammable compounds, it is ideal to conduct the reaction in a closed system under an atmosphere of inert gas. Examples of inert gases include nitrogen and argon.

[0067] The reaction time can be 0.1 to 100 hours, preferably 1 to 5 hours.

[0068] Methods for removing sulfur-containing cyclic siloxanes from reaction solutions include: removing low-molecular-weight components such as solvents and raw materials by vacuum distillation, and distilling the sulfur-containing cyclic siloxanes.

[0069] In this reaction, to avoid the hydrolysis of linear siloxanes, it is ideal to carry out the entire reaction under anhydrous conditions. The total water content of all raw materials is in the range of 0 to 5000 ppm by mass, preferably 0 to 500 ppm by mass, relative to the total mass of all raw materials used.

[0070] Ideally, the reaction apparatus should be dried. Examples of drying methods include: heating drying, vacuum drying, and replacement with inert gases such as nitrogen or argon.

[0071] Example The following examples illustrate the present disclosure in detail, but the present disclosure is not limited to these examples.

[0072] <Example 1: Synthesis using hydrogen sulfide> [Process I] After nitrogen purging, dichlorodimethylsilane (252.5 g, 1.956 mol) and THF (250.95 g) were added to a 1000 mL flask equipped with a thermometer, cooling tube, and motor stirrer. Water (21.16 g, 1.176 mol) was then added dropwise over 90 minutes. After the addition was complete, the mixture was stirred for 4 hours while maintaining an internal temperature of 26°C. Then, the flask was cooled to a bath temperature of 1°C, and triethylamine (125.76 g, 1.243 mol) was added dropwise over 45 minutes while maintaining an internal temperature of 1–5°C. After holding for 90 minutes, triethylamine (43.43 g, 0.4292 mol) was added dropwise over 15 minutes, and after holding for 19 minutes, triethylamine (43.20 g, 0.4269 mol) was added dropwise over 15 minutes, and after holding for 30 minutes. Finally, 200 g of THF was added, and the mixture was filtered under reduced pressure in a nitrogen-purged glove box to remove solids. Furthermore, the solid was washed with 300g of THF, and the washing solution was mixed with the filtrate to obtain a solution containing 1,7-dichloro-octamethyltetrasiloxane. Then, the THF was removed by vacuum distillation at a bath temperature of 70°C, an internal temperature of 46–66°C, and a pressure of 62.5–760 Torr, thereby obtaining 1,7-dichloro-octamethyltetrasiloxane.

[0073] After concentration, the solids were removed by vacuum filtration in a nitrogen-purified glove box. GC analysis of the filtered product confirmed a purity of 18.2% by weight, yielding 169.63 g (13.9%) of 1,7-dichloro-octamethyltetrasiloxane. Vacuum distillation was then performed at bath temperatures of 80–120 °C, internal temperatures of 70–104 °C, and vacuum pressures of 1.46–22.8 Torr to obtain 20.8 g (8.07%) of 1,7-dichloro-octamethyltetrasiloxane with an area of ​​over 80% by weight. Repeated operations yielded 1,7-dichloro-octamethyltetrasiloxane for subsequent processes.

[0074] [Process II] After nitrogen replacement, 1,7-dichloro-octamethyltetrasiloxane (79.99 g, 0.223 mol), toluene (452.34 g), and triethylamine (50.75 g, 0.502 mol) were added to another 1000 mL flask equipped with a thermometer, cooling tube, and electric stirrer. Hydrogen sulfide (8.37 g, 0.2453 mol) was blown in over 2 hours while stirring at an internal temperature of 42 °C. After blowing in the hydrogen sulfide, stirring was continued for 1 hour while maintaining an internal temperature of 40–41 °C. Then, pressure filtration was performed in a nitrogen-purified glove box to remove solids. The solids were washed with a solution of toluene (145 g) and triethylamine (7.3 g), and the washing solution was mixed with the filtrate to obtain 616.2 g of a solution containing 2,2,4,4,6,6,8,8-octamethyl-1,3,5-trioxa-7-thia-2,4,6,8-tetrasilhecyl octane. The same operation was performed twice. Through a total of three operations, 1569 g of 2,2,4,4,6,6,8,8-octamethyl-1,3,5-trioxa-7-thia-2,4,6,8-tetrasilhecyl octane was obtained.

[0075] Then, vacuum distillation was performed at a bath temperature of 80°C, an internal temperature of 61–72°C, and a vacuum degree of 211–307 Torr to remove toluene. Next, vacuum distillation was performed at a bath temperature of 100–115°C, an internal temperature of 80–100°C, and a vacuum degree of 1.21–688 Torr to obtain 2,2,4,4,6,6,8,8-octamethyl-1,3,5-trioxa-7-thia-2,4,6,8-tetrasilhecyclooctane with high purity.

[0076] GC analysis following distillation confirmed the yield of 119.4 g (64.1%) of 2,2,4,4,6,6,8,8-octamethyl-1,3,5-trioxa-7-thia-2,4,6,8-tetrasilhecyl octane with a purity of over 98% area. The obtained 2,2,4,4,6,6,8,8-octamethyl-1,3,5-trioxa-7-thia-2,4,6,8-tetrasilhecyl octane was further purified by... 1 The results were identified by H-NMR and GC-MS. 1 The H-NMR attribution is as follows. 1 H-NMR spectrum as follows Figure 1 As shown.

[0077] 1 H-NMR (400MHz, CDCl3): δ0.12 (s, 12H, [ CH3 -Si]), δ0.43 (s, 12H, [ CH3 -SiS]) <Example 2: Synthesis using lithium sulfide> [Process II] After nitrogen replacement, 11.09 g (0.241 mol) of lithium sulfide and 1762 g of tetrahydrofuran were added to a 3000 mL flask equipped with a thermometer, cooling tube, and electric stirrer. While stirring at room temperature (23.5–24 °C), 58.29 g (0.1658 mol) of 1,7-dichloro-octamethyltetrasiloxane was added dropwise over 8 minutes. After the addition was complete, the mixture was stirred for 6 hours while maintaining an internal temperature of 22–23 °C. Then, 0.71 g (0.015 mol) of lithium sulfide was added, and the mixture was stirred for another 90 minutes. Finally, the tetrahydrofuran was removed by vacuum distillation at a bath temperature of 70 °C and an internal temperature of 49–58 °C. Natural filtration was performed in a nitrogen-replaced glove box to remove solids, yielding a solution containing 2,2,4,4,6,6,8,8-octamethyl-1,3,5-trioxa-7-thia-2,4,6,8-tetrasilanecyclooctane as the filtrate.

[0078] Vacuum distillation was performed at a bath temperature of 70–120 °C, an internal temperature of 55–104 °C, and a torque of 4.06–760 Torr to obtain 2,2,4,4,6,6,8,8-octamethyl-1,3,5-trioxa-7-thia-2,4,6,8-tetrasilhecyl octane with high purity. GC analysis of the distillate confirmed a purity of over 99% in 40.8 g (78% yield) of 2,2,4,4,6,6,8,8-octamethyl-1,3,5-trioxa-7-thia-2,4,6,8-tetrasilhecyl octane. The obtained 2,2,4,4,6,6,8,8-octamethyl-1,3,5-trioxa-7-thia-2,4,6,8-tetrasilhecyl octane was... 1 H-NMR and GC-MS identified it as the same compound as in Example 1.

[0079] Industrial availability According to this disclosure, sulfur-containing cyclic siloxanes can be manufactured under simple processes and stable conditions. The method for manufacturing sulfur-containing cyclic siloxanes disclosed herein involves a simple process and a reaction under stable conditions, thus reducing energy consumption and contributing to the reduction of carbon dioxide emissions, making it highly industrially applicable. Furthermore, the sulfur-containing cyclic siloxanes of this disclosure can be used as precursors for silicon-containing thin films, and can be used to manufacture various silicon-containing films such as silicon films, silicon oxide films, silicon nitride films, silicon carbonitride films, and silicon oxynitride films through various vapor deposition processes (atomic layer deposition (ALD), chemical vapor deposition, etc.). These silicon-containing films function in semiconductor devices as insulating films, intermetallic dielectrics, seed layers, spacers, hard masks, trench isolation, anti-diffusion films, etch stop layers, and protective films.

Claims

1. A method for manufacturing a sulfur-containing cyclic siloxane, comprising: The process of reacting the dihalosilane shown in formula (1) with water to obtain the linear siloxane shown in formula (2); as well as The process of reacting the linear siloxane with the sulfiding agent shown in formula (3) to obtain the sulfur-containing cyclic siloxane shown in formula (4) Equation (1): In the formula, R 1 and R 2 Each time it appears, it is independently a hydrogen atom, a hydrocarbon group having 1 to 6 carbon atoms, or a hydrocarbon oxygen group having 1 to 6 carbon atoms; R 1 and R 2 They can be arbitrarily bonded together to form a ring. X is an independent halogen atom each time it appears; Equation (2): In the formula, R 1 and R 2 Each time it appears, it is independently a hydrogen atom, a hydrocarbon group with 1 to 6 carbon atoms, or a hydrocarbon oxygen group with 1 to 6 carbon atoms, and R is bonded to the same silicon atom. 1 and R 2 They can be arbitrarily bonded together to form a ring. X is an independent halogen atom in each occurrence. n is an integer from 0 to 2; Equation (3): Y2S In the formula, Y is independently a hydrogen atom, a sodium atom, or a lithium atom each time it appears; Equation (4): In the formula, R 1 and R 2 Each time it appears, it is independently a hydrogen atom, a hydrocarbon group with 1 to 6 carbon atoms, or a hydrocarbon oxygen group with 1 to 6 carbon atoms, and R is bonded to the same silicon atom. 1 and R 2 They can be arbitrarily bonded together to form a ring. n is an integer between 0 and 2.

2. The method according to claim 1, wherein, R 1 and R 2 Each time it appears, it is independently an alkyl group having 1 to 6 carbon atoms.

3. The method according to claim 1 or 2, wherein, R 1 and R 2 Each time it appears, it is independently either a hydrogen atom or a methyl group.

4. The method according to claim 1 or 2, wherein, n is 0 or 1.

5. The method according to claim 1 or 2, wherein, X is a chlorine atom.

6. The method according to claim 1 or 2, wherein, The sulfur-containing cyclic siloxane is a silicon-containing membrane precursor.

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