Method for purifying alkoxy silicon compounds

Abstract

The object of the present invention is to provide a method for refining an alkoxy silicon compound containing metal impurities by treating the refined alkoxy silicon compound with a chelate resin having a functional group containing a sulfur atom and a nitrogen atom, thereby the adsorption capacity of the refined alkoxy silicon compound to the chelate resin is small, and the alkoxy silicon compound can reduce the metal impurities. The solution is to treat the alkoxy silicon compound with a chelate resin having a functional group shown in any one of the following formulas (1-1) to (1-3). (In formulas (1-1) to (1-3), * represents the binding end with the resin as a carrier)

Description

Technical Field

[0001] The present invention relates to an industrially useful method for purifying an alkoxysilicon compound in which metal impurities that cause defects in a photolithography process in semiconductor device manufacturing are reduced. Background Art

[0002] The coating film-forming composition for lithography used in the lithography process in the manufacture of semiconductor devices is required to reduce metal impurities that cause minute defects (eg, about 1 to 100 nm, referred to as defects) on a wafer.

[0003] As a method for removing such metal impurities, a method of removing them by treatment with a silica gel column is known (Non-Patent Document 1), but the removal rate is poor and is not suitable for industrial scale.

[0004] As a method for removing metal impurities, a method using an ion exchange resin is known, but there are problems such as hydrolysis of alkoxysilane or high adsorption of the compound to be purified on the ion exchange resin, which deteriorates the purification efficiency economically.

[0005] Furthermore, purification by distillation can also be used as a method for efficiently removing metal impurities, but has problems such as being unable to be applied when the compound to be purified is solid or has a high boiling point, or when the compound to be purified has low thermal stability.

[0006] Prior art literature

[0007] Non-patent literature

[0008] Non-patent document 1: Experimental Chemistry Lectures, Vol. 2, p114 Summary of the invention

[0009] Problems to be solved by the invention

[0010] The present invention is proposed to solve such a problem, and its purpose is to provide a method for refining an alkoxy compound and an alkoxy compound by treating a purified alkoxy silicon compound containing metal impurities with a chelate resin having a functional group containing specific atoms, thereby the purified alkoxy silicon compound has a small amount of adsorption to the chelate resin and can reduce metal impurities.

[0011] Methods for solving problems

[0012] The inventors have repeatedly conducted in-depth research to achieve the above-mentioned purpose, and as a result, have discovered that a method for suppressing the adsorption of the refined alkoxy silicon compound to the chelate resin and efficiently reducing the metal impurities by treating the refined alkoxy silicon compound containing metal impurities with a chelate resin having functional groups containing sulfur atoms and nitrogen atoms has been completed.

[0013] That is, the present invention provides the following method for purifying an alkoxysilicon compound and an alkoxysilicon compound.

[0014] 1. A method for refining an alkoxy silicon compound, characterized in that the alkoxy silicon compound to be refined containing metal impurities is treated with a chelate resin having a functional group containing a sulfur atom and a nitrogen atom.

[0015] 2. The method for purifying an alkoxysilicon compound according to item 1 above, wherein the functional group is represented by any one of the following formulae (1-1) to (1-3).

[0016]

[0017] (In formulas (1-1) to (1-3), * represents the end connected to the resin as a carrier)

[0018] 3. according to the process for purification of above-mentioned 1 or above-mentioned 2 described alkoxy silicon compounds, it is characterized in that, with the mixture that comprises above-mentioned resin or the mixture of above-mentioned resin and other resins, the refined alkoxy silicon compound that comprises metallic impurities is handled.

[0019] 4. according to the method for purification of above-mentioned 1 or above-mentioned 2 described alkoxy silicon compounds, it is characterized in that, use is selected from above-mentioned resin, comprises the mixture of above-mentioned resin, other resin and above-mentioned resin and other resin's mixture more than two kinds of materials, one by one successively the refined alkoxy silicon compound that comprises metallic impurities is handled.

[0020] 5. The method for purifying an alkoxysilicon compound according to any one of 1 to 4 above, wherein the alkoxysilicon compound has a molecular weight of 5,000 or less.

[0021] 6. The method for purifying an alkoxysilicon compound according to any one of 1 to 5 above, wherein the alkoxysilicon compound is a compound obtained by reacting a compound having a hydroxyl group, an amino group or an aryl group with an alkoxysilicon compound in the presence of a transition metal catalyst.

[0022] 7. The method for purifying an alkoxysilicon compound according to 6 above, wherein the alkoxysilicon compound is a compound obtained by reacting a compound having an allyl group with an alkoxysilicon compound having a Si—H bond in the presence of a transition metal catalyst.

[0023] 8. The method for purifying an alkoxysilicon compound according to item 7 above, wherein the alkoxysilicon compound having a Si—H bond is a trialkoxysilane compound.

[0024] 9. The method for purifying an alkoxysilicon compound according to any one of 1 to 8 above, wherein the alkoxysilicon compound is a compound obtained by reacting an isocyanuric acid derivative having an allyl group with an alkoxysilicon compound having a Si—H bond.

[0025] 10. An alkoxy silicon compound, which is obtained by treating a purified alkoxy silicon compound containing metal impurities with a chelate resin having functional groups containing sulfur atoms and nitrogen atoms, and wherein the amount of residual metal impurities is less than 1 ppm based on 100% by weight.

[0026] 11. According to the alkoxy silicon compound described in 10 above, the residual metal is any one of Pt, Ir, Re, Ni, Mo, Fe, Ti, Ca and Sr.

[0027] Effects of the Invention

[0028] According to the method for purifying an alkoxysilicon compound of the present invention, metal impurities can be reduced economically and efficiently regardless of the properties of the alkoxysilicon compound to be purified.

[0029] Furthermore, regardless of the properties of the purified alkoxysilicon compound, an alkoxysilicon compound with reduced metal impurities can be obtained economically and efficiently. DETAILED DESCRIPTION

[0030] <Chelate resin>

[0031] Chelating resin is a material formed by combining the surface of the resin of carrier such as chelating functional group and polystyrene or cross-linked porous polystyrene. Under the situation of porous carrier, the chelating functional group can be combined with the inside of pore. By combining the surface of chelating functional group and carrier, it can contact with metal impurities efficiently in solution.

[0032] As the carrier in the chelate resin, silicon dioxide or the material containing silicon dioxide component can also be used.Silicon dioxide or the material containing silicon dioxide component can be any one of synthetic products and natural products, but is preferably a carrier without impurities dissolving, and can use synthetic quartz (SiO2) that for example the silicon dioxide molding obtained by hydrolyzing high-purity alkoxysilane is sintered and manufactured.The material containing silicon dioxide component can use forsterite (2MgO·SiO2), zircon (ZrO2·SiO2), mullite (3Al2O3·2SiO2), steatite (MgO·SiO2), cordierite (2MgO·2Al2O3·5SiO2) etc.

[0033] When modifying silica or a material containing silica components with a chelating functional group, a silane coupling agent having a functional group that can react with the end of the chelating functional group can react with the silica component on the surface of the material particles containing silica components to modify the surface and introduce the chelating functional group. As the functional group that can react with the end of the chelating functional group, for example, vinyl, allyl, hydroxyl, halogen, epoxy, thiol, etc. can be cited. The silane coupling agent can have 1 to 3 hydrolyzable groups, but can have 3 hydrolyzable groups from the consideration of the adhesion to the carrier. The chelating resin obtained by attaching the chelating functional group to the silica particles can be filled in a column and used directly.

[0034] When polystyrene is modified with a chelating functional group, chloromethyl groups can be introduced on the surface of polystyrene particles by using a chloromethylating agent (e.g., chloromethyl methyl ether), and the chloromethyl groups further react with the chelating functional group, thereby introducing the chelating functional group into the polystyrene. The polystyrene is in the form of particles and can be directly filled into a column for use.

[0035] When using polystyrene as the carrier in the resin, in order to avoid impurity dissolution, polystyrene can use highly cross-linked cross-linked porous polystyrene. As cross-linking agent, divinyl compounds can be used, for example divinylbenzene, divinylmethane etc. can be used. In addition, as adsorbent, preferably use the polystyrene with large specific surface area, can use porous polystyrene. About the porousization of polystyrene, by adding a small amount of non-solvent to carry out polymerization when styrene polymerization, porous polystyrene can be obtained.

[0036] The carrier can be used in the form of particles. In the case of polystyrene or cross-linked porous polystyrene, the particles can be used in a particle size of, for example, 1 μm to 10 mm, 1 μm to 1 mm, or 10 μm to 1 mm. In the case of silicon dioxide or a substance containing silicon dioxide, the particles can be used in a particle size of 1 μm to 1 mm, 1 μm to 500 μm, or 10 μm to 100 μm.

[0037] The chelate resin used in the present invention is characterized by having a functional group containing a sulfur atom and a nitrogen atom. Specific examples of the chelating functional group having a sulfur atom and a nitrogen atom include groups represented by the following formulas (1-1) to (1-3).

[0038]

[0039] (In formulas (1-1) to (1-3), * represents the end connected to the resin as a carrier)

[0040] There are no particular limitations as long as the material has these functional groups, and commercially available materials can be used.

[0041] The chelate resin used in the present invention generally shows the following metal adsorption capacity. The chelate resin with the functional group of formula (1-1) is effective for capturing the metal that can capture is Ag, Pt, Cu, Fe, Os, Pd, Rh, Sc, Sn, etc., metal, metal ions, their metal hydroxide colloids, metal oxide colloids. The platinum and palladium ions in the organic solvent can be captured especially effectively. About the functional group amount, every 1g of chelate resin can contain about 0.1 mmol to 5 mmol. Formula (1-1) can be obtained from Muromachi Chemicar Society as chelate resin, trade name Muromac XMS-5812. Formula (1-1) can be obtained from Pyrolight Society as chelate resin, trade name S914.

[0042] The chelating resin with the functional group of formula (1-2) and formula (1-3) can capture a large amount of metals under various conditions, and is effective for the metal, metal ion, their metal hydroxide colloid, and metal oxide colloid of Ca, Cd, Cr, Cs, Cu, Fe, Ir, La, Mg, Os, Pd, Pt, Rh, Ru, Sc, Sn, Zn etc. that can capture the metal that can capture. Particularly, it is best to capture Sn, Pt, its ion, its metal hydroxide colloid, and metal oxide colloid. About the functional group amount, every 1g chelating resin can contain about 0.1 mmol~5 mmol. Formula (1-2) can be obtained as chelating resin, trade name S920 from Piurolight society. Formula (1-3) can be obtained as chelating resin, trade name MuromacXMS-5418 from Muromachi Chemical society.

[0043] The removal of metal impurities using a chelating resin is carried out by treating a solution obtained by redissolving an oily or solid refined alkoxy silicon compound in an organic solvent, or a solution containing refined alkoxy silicon obtained by synthesizing the refined alkoxy silicon compound and post-treating it with a chelating resin through a contact catalytic method or a fixed layer method.

[0044] So-called contact catalysis is a method in which a refined solution is mixed with a resin and stirred for a certain period of time and then the resin is removed by filtering. In addition, the so-called fixed bed method is a method in which metallic impurities are removed from a refined solution by passing the refined solution through fixed beds such as a column or a packed tower filled with a resin.

[0045] The number of treatments is usually once but may be multiple times ranging from 2 to 100. The treatment time (residence time) by the contact catalytic method varies depending on the type of the alkoxysilicon compound to be purified, the type of the chelate resin, the type of the solvent used, and the amount of the solvent used.

[0046] Though the usage amount of the chelating resin used in the present invention is relevant with the kind of the refined alkoxy silicon compound, the kind of the employed organic solvent, it is about 0.01~1000 mass % with respect to the amount of the refined alkoxy silicon compound, is preferably 0.1~500 mass %, and is more preferably 1 mass %~100 mass %.

[0047] Resin used in the present invention can be used alone or in combination with two or more mixtures. In addition, except resin used in the present invention, the mixture mixed with other resins can also be used.

[0048] Further, as the processing that carries out with the resin, also can not be only once, but repeatedly handle.In this case, can use be selected from 2 or more materials in the mixture of the resin used in the present invention, the mixture that comprises the resin used in the present invention, other resins and the resin used in the present invention and other resins, one by one successively or simultaneously the refined alkoxy silicon compound that comprises metallic impurities is handled.

[0049] <Purified alkoxysilicon compound>

[0050] The purified alkoxysilicon compound used in the present invention can be a commercial product or a compound synthesized by a known method. Any of them can effectively remove and reduce the contained metal impurities. As specific examples of commercially available purified alkoxysilicon compounds, the following compounds (2-1) to (2-28) manufactured by Shin-Etsu Chemical Co., Ltd. can be cited.

[0051]

[0052] In addition, the purified alkoxysilicon compound can be synthesized by a known method (such as WO2011 / 102470, WO2019 / 003767, Japanese Patent Application Laid-Open No. 2003-26809, etc.), and can be obtained by reacting trialkoxysilicon with a compound having a hydroxyl group, an amino group or an allyl group in the presence of a transition metal catalyst.

[0053] Specific examples include compounds of the following formulae (3-1) to (3-19).

[0054]

[0055]

[0056] <Organic solvents>

[0057] In the present invention, the solvent used when treating the purified alkoxysilicon compound with the chelate resin may include, for example, the organic solvents described below, but is not limited thereto.

[0058] Examples of the organic solvent include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, propylene glycol propyl ether acetate, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, cycloheptanone, cyclopentyl methyl ether, 4-methyl-2-pentanol, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, ethyl ethoxylate, 2-hydroxyisobutyrate acetate, and ethyl acetate. The solvents include ethyl ester, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, 2-heptanone, methoxycyclopentane, anisole, γ-butyrolactone, N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, n-heptane, hexane, isopropyl ether, diisobutyl ether, diisoamyl ether, tert-butyl methyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, and 2,5-dimethyltetrahydrofuran. These solvents may be used alone or in combination of two or more.

[0059] Preferred among these solvents are propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl lactate, butyl lactate, cyclohexanone, n-heptane, hexane, toluene, isopropyl ether, diisobutyl ether, diisoamyl ether, tert-butyl methyl ether, cyclopentyl methyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, and 2,5-dimethyltetrahydrofuran, etc. Propylene glycol monomethyl ether, cyclopentyl methyl ether, propylene glycol monomethyl ether acetate, toluene, and isopropyl ether are particularly preferred.

[0060] The amount of the organic solvent used is not particularly limited as long as it is an amount that can sufficiently dissolve the purified alkoxysilicon compound, but is about 2 to 1000 parts by mass, preferably 4 to 100 parts by mass, based on the purified alkoxysilicon compound.

[0061] Example

[0062] <GC analysis conditions>

[0063] The adsorption amounts shown in the examples described below are the results of measurements obtained by GC, and the measurement conditions and the like are as follows.

[0064] Device: GC-2010Plus, manufactured by Shimadzu Corporation

[0065] Column: DB-1 dimethylpolysiloxane, 0.25 μm, 0.25 mm × 30 m (Agilent Technology Co., Ltd.)

[0066] Inlet temperature: 250℃

[0067] Split ratio: 100

[0068] Column temperature: 100°C (hold for 15 minutes), heating (15°C / min), 250°C (hold for 5 minutes), heating (15°C / min), 300°C (hold for 5 minutes)

[0069] Line speed: 32.0cm / sec

[0070] Detector temperature: 300℃ (FID)

[0071] Analysis time: 38.33 minutes

[0072] Injection volume: 1.0 μL

[0073] Dilution solvent: propylene glycol monomethyl ether (PGME), cyclopentyl methyl ether (CPME) or acetonitrile

[0074] <Synthesis of purified alkoxysilicon compound (A)>

[0075] [Synthesis example 1]

[0076] In a 500 mL four-necked flask, 30.09 g of monoallyl isocyanurate (manufactured by Shikoku Chemical Industry Co., Ltd.), 150.73 g of toluene, and 1.71 g of Karstedt catalyst [xylene solution of platinum (0)-1,3-divinyl-1,1,3,3-tetramethyldisiloxane coordination compound (~2 mass % as platinum)] (manufactured by SIGMA-ALDRICH) were added, and stirred at 25°C. Then, 37.78 g of triethoxysilane (manufactured by Tokyo Chemical Industry Co., Ltd.) was added dropwise to the mixture in the flask so that the temperature of the mixture became 30°C or less, and the temperature was raised to 100°C after the addition, and the reaction was carried out for 25 hours. After the reaction, toluene and triethoxysilane contained in excess were removed from the obtained reaction solution by an evaporator, 303.70 g of dichloromethane was added to the obtained crude product, and the mixture was separated three times with 155.14 g of ion-exchanged water to take out the organic layer. Dichloromethane was removed from the obtained organic layer by an evaporator, and 330.86 g of tetrahydrofuran was added to the obtained crude product to dissolve the crude product, and the mixture was stirred at 25° C. for 10 minutes, and then filtered to separate into a filtrate and a filtrate. Then, tetrahydrofuran was removed from the obtained filtrate by an evaporator, and 276.18 g of toluene was added to the obtained crude product, and the mixture was stirred at 25° C. for 10 minutes, and then filtered to separate into a filtrate and a filtrate. Then, toluene was removed from the obtained filtrate by an evaporator, and the target substance, a purified alkoxysilicon compound (A) (ICA-TEOS) (yield 43.2%), was obtained as a light yellow solid.

[0077]

[0078] The purified alkoxysilicon compound (A) obtained was measured 1 The results are shown below. The solvent used in the measurement was deuterated dimethyl sulfoxide, the measurement temperature was room temperature, and the reference sample was tetramethylsilane (TMS).

[0079] 1 H-NMR (500MHz): 0.50~0.60ppm (m, 2H), 1.10~1.15ppm (t, 9H), 1.50~1.60ppm (m, 2H), 3. 55~3.65ppm (t, 2H), 3.48~3.52ppm (m, 4H), 3.70~3.80ppm (m, 6H), 11.3~11.4ppm (s, 2H)

[0080] In addition, the amount of residual Pt in a 1 wt % propylene glycol monomethyl ether (PGME) solution of the obtained purified alkoxysilicon compound (A) was measured by inductively coupled plasma mass spectrometry (ICP-MS 7500 manufactured by Agilent Technologies). The result was 8.2 ppm when the purified alkoxysilicon compound (A) was converted to 100 wt %.

[0081] <Purification of the purified alkoxysilicon compound (A) using a chelate resin>

[0082] The chelate resins used in the examples and comparative examples are as follows.

[0083]

[0084] * indicates a bonding end with a resin serving as a carrier, and the resin serving as the carrier is polystyrene, cross-linked porous polystyrene, or the like.

[0085]

[0086] * indicates a bonding end with a resin serving as a carrier, and the resin serving as the carrier is polystyrene, cross-linked porous polystyrene, or the like.

[0087] [Example 1]

[0088] The alkoxy silicon compound (A) obtained in Synthesis Example 1 was diluted with PGME to prepare a 1% by weight solution. 10 g of the solution was added with 1 g of chelating resin S914 (trade name) made by Piluronite with thiourea groups, and after stirring at room temperature for 4 hours, filtered to obtain a purified alkoxy silicon compound solution. For the resulting solution, GC was used to measure the adsorption capacity, and inductively coupled plasma mass spectrometry (ICP-MS 7500 made by Agilent Technology) was used to measure the remaining Pt amount. The results of the measurement of the adsorption capacity and the remaining Pt amount are shown in Table 1. The remaining Pt amount shows the value when the alkoxy silicon compound is converted to 100% by weight.

[0089] [Example 2]

[0090] Table 1 shows the results of the same treatment using a chelate resin S920 manufactured by Piurolite having a thiourea group instead of the chelate resin manufactured by Piurolite in Example 1.

[0091] [Example 3]

[0092] Table 1 shows the results of the same treatment using a chelate resin Muromac XMS-5418 (trade name) manufactured by Muromachi Chemical Co., Ltd. having a thiourea group instead of the chelate resin manufactured by Pyrolight Co., Ltd. in Example 1.

[0093] [Example 4]

[0094] The purified alkoxysilicon compound (A) obtained in Synthesis Example 1 was diluted with cyclopentyl methyl ether (CPME) instead of PGME as the dilution solvent in Example 3 to prepare a 1 wt % solution, and the same treatment was carried out. The obtained results are shown in Table 1.

[0095] [Comparative Example 1]

[0096] The same treatment was performed using a chelate resin CRB03 (trade name) made by Mitsubishi Chemical Co., Ltd. having an N-methyl-glucosamine group instead of the chelate resin made by Piurolight Co., Ltd. in Example 1. The adsorption amount was measured for the resulting solution, and it was confirmed that 44% of ICA-TEOS was adsorbed on CRB03.

[0097] [Comparative Example 2]

[0098] The same treatment was performed using chelate resin CR20 (trade name) made by Mitsubishi Chemical Co., Ltd. having polyamine groups instead of the chelate resin made by Pluronic Co., Ltd. in Example 1. The adsorption amount was measured for the resulting solution, and it was confirmed that ICA-TEOS was adsorbed by 15% on CR20.

[0099] [Comparative Example 3]

[0100] The same treatment was carried out using the chelate resin IRC748 (trade name) produced by Olgano Co., Ltd. having an iminodiacetic acid group instead of the chelate resin produced by Pyrolight Co., Ltd. in Example 1. The obtained solution was turbid and could not be treated subsequently.

[0101] [Comparative Example 4]

[0102] The same treatment was carried out using the chelate resin IRC747UPS (trade name) produced by Olgano Co., Ltd. having an aminophosphoric acid group instead of the chelate resin produced by Pyrolight Co., Ltd. in Example 1. The obtained solution was turbid and could not be treated subsequently.

[0103] Table 1

[0104]

[0105] As shown in Table 1, under the situation of the resin of embodiment 1~4, can suppress the adsorption capacity of alkoxy silicon compound to the resin and simultaneously remove platinum, on the contrary, under the situation of the resin of comparative example 1~2, it is known that the adsorption capacity of alkoxy silicon compound to the resin is large, impractical. In addition under the situation of the resin of comparative example 3~4, solution is turbid, can not continue the processing of metal removal afterwards.

Claims

1. A method for refining an alkoxy silicon compound, characterized in that: The purified alkoxysilicon compound containing metal impurities is treated with a chelating resin having a functional group containing a sulfur atom and a nitrogen atom. The functional group is represented by any one of the following formulae (1-1) to (1-3), In formulae (1-1) to (1-3), * represents the end connected to the resin as a carrier, The alkoxysilicon compound is a compound represented by the following formula (3-1) to (3-19), The metal impurity is Pt, During the treatment, one or two solvents selected from propylene glycol monomethyl ether and cyclopentyl methyl ether are used.

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