Seal composition and seal

Abstract

The present disclosure relates to a sealing material composition, a sealing material, a gate valve sealing material for a semiconductor manufacturing device, and a semiconductor manufacturing device, the sealing material composition being a plasma-resistant sealing material composition for a semiconductor manufacturing device and containing a silicone polymer and a vulcanizing agent, the silicone polymer contains a polysiloxane compound having an unsubstituted or substituted aromatic monovalent hydrocarbon group in a side chain. According to the present disclosure, it is possible to provide a sealing material composition which can be used in a low-temperature environment, has plasma resistance, and can manufacture a sealing material for a semiconductor manufacturing device using a relatively inexpensive material.

Description

Technical Field

[0001] This invention relates to sealing compositions, and more particularly to various types of sealing components including sealing components, gate valve seals for semiconductor manufacturing apparatuses including the sealing components, and semiconductor manufacturing apparatuses. Background Technology

[0002] Japanese Patent Application Publication No. 2001-002923 (Patent Document 1) and Japanese Patent Application Publication No. 2018-016795 (Patent Document 2) respectively disclose fluorosilicone rubber compositions and perfluoroelastomer compositions for sealing components.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2001-002923

[0006] Patent Document 2: Japanese Patent Application Publication No. 2018-016795 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] To achieve miniaturization and high integration of circuits in the semiconductor field, low-temperature etching processes have been proven effective. Typically, silicone rubber and fluorosilicone rubber are used as seals in low-temperature environments. However, the usable temperature of silicone rubber used for seals is generally around -45°C, and even fluorosilicone rubber, which has relatively good low-temperature properties, can only reach -65°C, indicating insufficient low-temperature performance. Therefore, seals capable of operating in even lower temperatures (e.g., -70 to -100°C) are needed.

[0009] On the other hand, in seals used in plasma environments, perfluoroelastomers, which are resistant to plasma, are mostly used. However, perfluoroelastomers are very expensive and have relatively poor low-temperature properties, making them difficult to use in low-temperature environments.

[0010] The object of this invention is to provide a sealing composition that can be used in low-temperature environments, has plasma resistance, and can be manufactured using relatively inexpensive materials for sealing semiconductor manufacturing devices. Another object of this invention is to provide a sealing composition comprising an organosilicon polymer capable of manufacturing sealing components for semiconductor manufacturing devices, having a relatively low glass transition temperature and suppressed weight loss during plasma resistance testing.

[0011] Solution for solving the problem

[0012] The present invention provides the following sealing composition, sealing element, gate valve seal for semiconductor manufacturing apparatus, and semiconductor manufacturing apparatus.

[0013] [1] A sealing composition having plasma resistance for use in semiconductor manufacturing apparatus, comprising a silicone polymer and a vulcanizing agent, said silicone polymer comprising a polysiloxane compound having unsubstituted or substituted aromatic monovalent hydrocarbon groups on its side chains.

[0014] [2] The sealing composition according to [1], wherein the polysiloxane compound comprises a structural unit represented by the following formula (1).

[0015]

[0016] [In the formula, R] 1 Independently represents an unsubstituted or substituted aromatic monovalent hydrocarbon group, R 2 Independently represents an unsubstituted or substituted aromatic monovalent hydrocarbon group, an unsubstituted or substituted unsaturated or saturated hydrocarbon group without an aromatic hydrocarbon group, an alkoxy hydroxyl group, or a hydrogen atom, where n represents an integer from 1 to 7000.

[0017] [3] According to the sealing composition of [2], the ratio of the structural units represented by the formula (1) in the polysiloxane compound is 1 to 70 mol%.

[0018] [4] The sealing composition according to any one of [1] to [3], wherein the polysiloxane compound has a (R) group at the end of the main chain. 3 )3Si-R 4 - represents a group, [where R is a group]. 3 Independently representing unsubstituted or substituted aromatic monovalent hydrocarbon groups, unsubstituted or substituted unsaturated or saturated hydrocarbon groups without aromatic hydrocarbon groups, alkoxy or hydroxyl groups, R 4 Independently representing alkylene groups with 1 to 5 oxygen and carbon atoms.

[0019] [5] The sealing composition according to any one of [1] to [4], wherein the polysiloxane compound comprises a structural unit represented by the following formula (2).

[0020]

[0021] [In the formula, R] 5 and R 6 Independently represents an unsubstituted or substituted unsaturated or saturated hydrocarbon group, alkoxy group, or hydroxyl group that does not contain an aromatic hydrocarbon group; o represents an integer from 100 to 10000.

[0022] [6] A sealing composition according to any one of [1] to [5], wherein the polysiloxane compound has a vinyl group at the end of at least one of the side chain and the main chain.

[0023] [7] The sealing composition according to any one of [1] to [6] further comprises at least one of a filler in the amount of 1 to 160 parts by weight relative to 100 parts by weight of the silicone polymer and a pigment in the amount of 0.05 to 3 parts by weight.

[0024] [8] The sealing composition according to any one of [1] to [7], wherein the vulcanizing agent comprises a peroxide compound.

[0025] [9] The sealing composition according to any one of [1] to [8], wherein the content of the vulcanizing agent is 0.2 to 8 parts by weight relative to 100 parts by weight of the organosilicon polymer.

[0026]

[10] The sealing composition according to any one of [1] to [9], wherein the sealing composition further comprises a perfluoropolyether compound.

[0027]

[11] The sealing composition according to any one of [1] to

[10] , wherein the metal ion content is less than 1000 ppm.

[0028]

[12] A seal comprising a crosslinked material of a seal composition as described in any one of [1] to

[11] .

[0029]

[13] A gate valve seal for a semiconductor manufacturing apparatus, comprising the seal as described in

[12] .

[0030]

[14] A semiconductor manufacturing apparatus comprising a seal as described in

[12] .

[0031] Invention Effects

[0032] According to the present invention, a sealing composition is provided that can be used in low-temperature environments, exhibits excellent plasma resistance, and can be manufactured using relatively inexpensive materials for sealing semiconductor manufacturing devices. According to the present invention, a sealing composition comprising an organosilicon polymer is provided that can be used to manufacture sealing components for semiconductor manufacturing devices, having a relatively low glass transition temperature and suppressed weight loss during plasma resistance testing. Detailed Implementation

[0033] The following describes embodiments of the present invention, but the present invention is not limited to the following embodiments.

[0034] <Sealing Composition>

[0035] One aspect of the present invention provides a sealing composition for use in semiconductor manufacturing apparatus that exhibits plasma resistance. The sealing composition comprises a silicone polymer and a vulcanizing agent. The silicone polymer comprises a polysiloxane compound (hereinafter also referred to as a first polysiloxane compound) having unsubstituted or substituted aromatic monovalent hydrocarbon groups on its side chains. The inventors have discovered that, despite being a relatively inexpensive material, the first polysiloxane compound can provide a sealing composition with low-temperature properties and plasma resistance. In this specification, "plasma resistance" means a weight reduction rate (%) of 1.0% or less in the plasma resistance test described later. By using the sealing composition of the present invention, it is possible to produce seals with plasma resistance equal to or better than those comprising perfluoroelastomers. Furthermore, by using the sealing composition of the present invention, it is possible to produce seals with a weight reduction rate equal to or even less than that comprising perfluoroelastomers in the plasma resistance test described later.

[0036] The first polysiloxane compound may have one or more unsubstituted or substituted aromatic monovalent hydrocarbon groups on the Si atoms constituting the main chain. In this specification, a polysiloxane compound refers to a compound having a backbone (main chain) formed by multiple siloxane bonds (-Si-O-Si-).

[0037] Examples of unsubstituted aromatic monovalent hydrocarbon groups include aryl groups such as phenyl and tolyl; and aralkyl groups such as benzyl and phenethyl. Substituted aromatic monovalent hydrocarbon groups can be those in which some or all of the hydrogen atoms of the groups exemplified above as unsubstituted aromatic monovalent hydrocarbon groups are replaced by halogen atoms such as fluorine or chlorine; examples include chlorophenyl. From the viewpoint of low-temperature properties and plasma resistance, phenyl is preferred. The first polysiloxane compound preferably has a diphenylsilyl group in which two phenyl groups are bonded to one Si atom constituting the main chain.

[0038] The first polysiloxane compound may contain a structural unit represented by the following formula (1) (hereinafter also referred to as the first structural unit).

[0039]

[0040] [In the formula, R] 1 Independently represents an unsubstituted or substituted aromatic monovalent hydrocarbon group, R 2 Independently represents an unsubstituted or substituted aromatic monovalent hydrocarbon group, an unsubstituted or substituted unsaturated or saturated hydrocarbon group without an aromatic hydrocarbon group, an alkoxy group, a hydroxyl group, or a hydrogen atom, where n represents an integer from 1 to 7000.

[0041] As R 1 and R 2Examples of unsubstituted or substituted aromatic monovalent hydrocarbon groups in R are illustrated above. 2 The unsubstituted saturated hydrocarbon groups that do not contain aromatic hydrocarbon groups include, for example: methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, cyclohexyl, octyl, decyl, dodecyl, and other alkyl groups. As R 2 Unsubstituted unsaturated hydrocarbon groups that do not contain aromatic hydrocarbon groups can be listed as vinyl, allyl, propenyl, isopropenyl, butenyl, isobutylenyl, etc. As R 1 From the viewpoint of low-temperature properties and plasma resistance, phenyl is preferred. As R 2 The substituted unsaturated hydrocarbon group or saturated hydrocarbon group that does not contain an aromatic hydrocarbon group can be a group in which some or all of the hydrogen atoms of the groups exemplified above as unsubstituted unsaturated hydrocarbon groups or saturated hydrocarbon groups without an aromatic hydrocarbon group are replaced by halogen atoms such as fluorine or chlorine. Examples include chloromethyl and 3,3,3-trifluoropropyl. As R 2 The alkoxy group in R can be exemplified by, for example, methoxy, ethoxy, propoxy, butoxy, etc. 1 From the viewpoint of low-temperature properties and plasma resistance, phenyl is preferred. As R 2 From the viewpoint of low-temperature properties and plasma resistance, phenyl is preferred.

[0042] The proportion of the first structural unit in the first polysiloxane compound can be, for example, 1 to 70 mol%, preferably 2 to 65 mol% from the viewpoint of low-temperature properties and plasma resistance, and more preferably 3 to 60 mol%.

[0043] The first polysiloxane compound can have a (R) terminal at the main chain. 3 )3Si-R 4 - The group represented (hereinafter also called the terminal group) [where R] 3 Independently representing unsubstituted or substituted aromatic monovalent hydrocarbon groups, unsubstituted or substituted unsaturated or saturated hydrocarbon groups without aromatic hydrocarbon groups, alkoxy or hydroxyl groups, R 4 [Independently representing alkylene groups with 1 to 5 carbon atoms]. As R 3 Examples of unsubstituted or substituted aromatic monovalent hydrocarbon groups, unsubstituted or substituted unsaturated or saturated hydrocarbon groups without aromatic hydrocarbon groups, and alkoxy groups are applicable to the above illustrations. As R 4 Alkyl groups having 1 to 5 carbon atoms, such as methylene, ethylene, and propylene. As R 3 Preferably, it is methyl, methoxy, or hydroxyl. As R... 4 Preferably, it contains oxygen atoms and ethylene.

[0044] The first polysiloxane compound may contain a structural unit (second structural unit) represented by the following formula (2).

[0045]

[0046] [In the formula, R] 5 and R 6 Independently representing unsubstituted or substituted unsaturated or saturated hydrocarbon groups, alkoxy groups, or hydroxyl groups that do not contain aromatic hydrocarbon groups; o represents an integer from 100 to 10000. The ratio of the second structural unit in the first polysiloxane compound can be, for example, 30 to 99 mol%.

[0047] As R 5 and R 6 Examples of unsubstituted or substituted unsaturated or substituted hydrocarbon groups and alkoxy groups that do not contain aromatic hydrocarbon groups are applicable to the above illustrations. In the second structural unit, R 5 and R 6 At least one of them is preferably an unsubstituted unsaturated hydrocarbon group that does not contain an aromatic hydrocarbon group, more preferably a vinyl group. In R 5 and R 6 When one of the components is an unsubstituted unsaturated hydrocarbon group that does not contain an aromatic hydrocarbon group, the other component is preferably an unsubstituted saturated hydrocarbon group that does not contain an aromatic hydrocarbon group, and more preferably a methyl group.

[0048] The first polysiloxane compound preferably has a vinyl group at least at the end of either the side chain or the main chain. When the first polysiloxane compound has a vinyl group at least at the end of either the side chain or the main chain, the first polysiloxane compound may have one or more vinyl groups. When the first polysiloxane compound has a vinyl group at least at the end of either the side chain or the main chain, the percentage of the vinyl structural units in the first polysiloxane compound may be, for example, 0.001 to 10 mol%, with the lower limit of the percentage being, for example, 0.005 mol%, 0.01 mol%, 0.05 mol%, or 0.1 mol%, and the upper limit of the percentage being, for example, 8 mol%, 6 mol%, or 4 mol%.

[0049] The first polysiloxane compound is preferably a compound represented by the following formula (3).

[0050]

[0051] In equation (3), R 1 R 2 R 3 R 4 R 5 R 6 The above definitions apply to o and n.

[0052] The first polysiloxane compound is more preferably a compound represented by the following formula (4).

[0053]

[0054] In equation (4), R 3 The above definitions apply to p and q. p and q represent integers independently, and the sum of p and q can be from 100 to 10000. For example, the sum of p and q can be from 1000 to 10000, or 2000 to 10000, or 3000 to 10000, or 5000 to 10000. The sum of p, q, and n can be from 1000 to 10000, or 2000 to 10000, or 3000 to 10000, or 5000 to 10000.

[0055] The first polysiloxane compound can be a copolymer containing a first structural unit. The first polysiloxane compound can be obtained by copolymerizing the copolymerizable component containing the first structural unit with other copolymerizable components (e.g., copolymerizable components containing a second structural unit). The compound shown in formula (4) can be obtained, for example, by copolymerizing a dimethylsiloxane copolymerizable component, a diphenylsiloxane copolymerizable component, and a methylvinylsiloxane copolymerizable component.

[0056] The first polysiloxane compound can be used as a silica-filled silicone rubber compound, as described below. Examples of commercially available products include "KE-186-U", "KE-183-U", and "KE-136Y-U" manufactured by Shin-Etsu Chemical Industry Co., Ltd., and "SE-955-U" manufactured by Dow Toray Co., Ltd.

[0057] The silicone polymer may contain one or more first polysiloxane compounds. Furthermore, the silicone polymer may contain other polysiloxane compounds besides the first polysiloxane compound (hereinafter also referred to as second polysiloxane compounds). Examples of second polysiloxane compounds include dimethylsilicone, vinyl methylsilicone, and fluorovinyl methylsilicone. Preferably, the silicone polymer contains only the first polysiloxane compound. Furthermore, it may also be used as a blend with other rubbers, provided it does not impair the purpose of the invention.

[0058] Peroxide compounds can be used as vulcanizing agents, for example. There are no particular limitations on the peroxide compounds as long as they can be used with organosilicon polymers; examples include benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, di-tert-butyl peroxide, tert-butyl peroxide (cumyl peroxide), dicumyl peroxide, 1,1-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyn-3, 1,3-di(tert-butylperoxyisopropyl)benzene, 2,5-dimethyl-2,5-di(benzoyl peroxide)hexane, tert-butyl perbenzoate, tert-butyl isopropyl peroxide carbonate, and n-butyl-4,4-di(tert-butylperoxy)valerate. The vulcanizing agent can contain one or more peroxide compounds.

[0059] The content of the vulcanizing agent in the sealing composition can be, for example, 0.2 to 8 parts by weight, preferably 0.5 to 4 parts by weight, relative to 100 parts by weight of the organosilicon polymer.

[0060] The sealing composition may also contain a perfluoropolyether compound. The perfluoropolyether compound can be a low molecular weight compound such as an oligomer or a high molecular weight compound such as a polymer. From the viewpoint of low-temperature properties and plasma resistance, it is preferable to include a perfluoropolyether polymer. For example, the perfluoropolyether polymer may have groups at the ends of its main chain that can undergo crosslinking reactions with the silicone polymer. Commercially available perfluoropolyether polymers can be used. Examples of commercially available perfluoropolyether polymers include SIFEL (registered trademark) (manufactured by Shin-Etsu Chemical Co., Ltd.). The content of the perfluoropolyether polymer in the sealing composition relative to 100 parts by weight of the silicone polymer can be, for example, 0.5 to 50 parts by weight, preferably 1 to 25 parts by weight.

[0061] In addition to the components mentioned above, the sealing composition may also contain other components, such as pigments, fillers, anti-aging agents, antioxidants, vulcanization accelerators, processing aids (stearic acid, etc.), stabilizers, tackifiers, silane coupling agents, plasticizers, flame retardants, mold release agents, waxes, lubricants, and other additives. Other examples of additives are viscosity reducers (anti-sticking agents) such as fluorinated oils (e.g., perfluoroethers). Additives may be used individually or in combination of two or more.

[0062] Examples of pigments include, for example, at least one selected from the group consisting of inorganic pigments and organic pigments. Examples of inorganic pigments include, for example, white pigments (e.g., silica, zinc white, lead white, zinc barium white, titanium dioxide, precipitated barium sulfate, and barite powder), red pigments (e.g., red lead oxide, iron oxide red), yellow pigments (e.g., chrome yellow, zinc yellow), blue pigments (e.g., ultramarine blue, Prussian blue, yttrium indium manganese blue), and black pigments (e.g., carbon black). Examples of organic pigments include, for example, azo pigments (azo lake pigments, insoluble azo pigments, condensed azo pigments, etc.); anthraquinone pigments, thioindole pigments, perinone pigments, perylene pigments, quinacridone pigments, isoindoline pigments, isoindoline pigments, dioxazine pigments, quinoline pigments, diketopyrrolopyrrole pigments, and other polycyclic pigments, phthalocyanine pigments, etc. As organic pigments, organic pigments classified as pigments in the color index can be used. Preferably, the pigments used are metal-free organic pigments. Even when the sealing element is used in harsh plasma or ozone environments, such as in semiconductor applications, and the annular seal is etched, there is no concern about the dispersion of substances originating from metal elements. When the sealing composition contains pigments, the pigment content in the sealing composition can be, for example, 0.05 to 3 parts by weight relative to 100 parts by weight of the silicone polymer.

[0063] Examples of fillers include: silica, quartz powder, clay, talc, diatomaceous earth, barium sulfate, mica, graphite, aluminum hydroxide, aluminum silicate, calcium silicate, hydrotalcite, calcium oxide, titanium dioxide, zinc oxide, iron oxide, aluminum oxide, magnesium carbonate, calcium carbonate, zinc carbonate, carbon black, granular or powdered resins (fluororesins, etc.), metal powders, glass powders, ceramic powders, etc. When the sealing composition contains a filler, it is advantageous from the viewpoint of improving the mechanical strength of the seal. Preferably, the filler is selected from at least one of the group consisting of silica, carbon black, and fluororesins.

[0064] Examples of silica include fumed silica, precipitated silica, and fused silica. When the sealing composition contains silica, the silica content relative to 100 parts by weight of the silicone polymer can be, for example, 6 to 120 parts by weight. When the sealing composition contains silica, a silicone rubber compound incorporating silica into the silicone polymer can be used. Alternatively, compounds such as Shin-Etsu Chemical Co., Ltd.'s "KE-186-U" and Dow Toray Co., Ltd.'s "SE-955-U" can be used directly as silicone rubber compounds. Furthermore, it can be used as a blend with other rubbers, provided it does not impair the purpose of this invention.

[0065] Examples of carbon black include MT carbon. From the viewpoint of preventing filler dispersion during use in semiconductor manufacturing equipment, it is preferable that the sealing composition does not contain metallic fillers. When the sealing composition contains carbon black, the carbon black content in the sealing composition may be, for example, 1 to 30 parts by weight relative to 100 parts by weight of the silicone polymer.

[0066] When the sealing composition contains a fluoropolymer filler, it tends to improve plasma resistance. The fluoropolymer can be included in the sealing composition, for example, in the form of fluoropolymer particles. When the sealing composition contains a fluoropolymer filler, the content of the fluoropolymer filler in the sealing composition can be, for example, 1 to 30 parts by weight, preferably 5 to 25 parts by weight, and more preferably 10 to 20 parts by weight, relative to 100 parts by weight of the silicone polymer.

[0067] Fluoropolymers used as fillers are resins containing fluorine atoms within their molecules. Examples include polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-ethylene copolymer (ETFE), polychlorotrifluoroethylene (PCTFE), chlorotrifluoroethylene-ethylene copolymer (ECTFE), polyvinylidene fluoride (PVDF), polyvinylidene fluoride (PVF), vinylidene fluoride-hexafluoropropylene copolymer (VDF-HFP copolymer), and vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene copolymer (VDF-HFP-TFE copolymer). Fluoropolymers can be used alone or in combination with two or more types.

[0068] Among the aforementioned materials, from the viewpoint of preventing damage to properties such as permanent compression set caused by resin melting at high temperatures, fluoropolymers with relatively high melting points, such as PFA and PTFE, are preferred.

[0069] Fluoropolymers used as fillers can also contain functional groups. These functional groups can be introduced, for example, by copolymerizing monomers containing such functional groups. If the aforementioned crosslinking monomer is copolymerized as a monomer containing functional groups, crosslinking between the fluoropolymer and the perfluoroelastomer is also promoted by the aforementioned crosslinking agent, thus further improving the mechanical strength of the crosslinked sealant composition. Examples of fluoropolymers containing functional groups include the nitrile-containing polytetrafluoroethylene disclosed in Japanese Patent Application Publication No. 2013-177631. Furthermore, fluoropolymers can also be modified fluoropolymers such as "TFM-modified PTFE" (manufactured by Daikin Industries, Ltd.).

[0070] When the sealing composition contains a silicone polymer and a fluoropolymer filler, the compounding method of the silicone polymer and the fluoropolymer can be, for example, 1) compounding the silicone polymer and the fluoropolymer using a mixing roller; or 2) compounding the silicone polymer and the fluoropolymer using a mixer, a twin-screw extruder, or other similar apparatus.

[0071] When the sealing composition contains a filler, the content of the filler in the sealing composition (total content when two or more are contained) may be, for example, 1 to 160 parts by mass relative to 100 parts by mass of the silicone polymer, preferably 1 to 100 parts by mass, and more preferably 1 to 80 parts by mass.

[0072] The metal ion content of the sealing composition can be, for example, less than 1000 ppm, less than 300 ppm, less than 100 ppm, or less than 50 ppm. Sealing compositions with metal ion content within the above ranges are preferably used as seals in semiconductor manufacturing apparatuses undergoing plasma processing.

[0073] The sealing composition can be prepared by uniformly mixing an organosilicon polymer, a vulcanizing agent, and pigments, silica, etc., as needed. Existing known equipment such as mixing rollers, pressure kneaders, and internal mixers (Banbury mixers) can be used as the mixing machine. The various components can be mixed and kneaded in one step, or the components other than those participating in the crosslinking reaction (such as crosslinking accelerators, crosslinking delayers, and crosslinking agents) can be pre-mixed uniformly, and then the components participating in the crosslinking reaction are mixed, i.e., the mixing is carried out in multiple stages.

[0074] The seal of the present invention comprises a crosslinked product of the above-described sealing composition. The seal can be manufactured by crosslinking (vulcanizing) the seal with a rubber composition and then molding it. The methods used for crosslinking and molding can be existing and known methods such as injection molding, compression molding, and transfer molding.

[0075] The heating temperature during molding (primary crosslinking temperature) can be, for example, above 100°C and below 220°C, and the heating time (primary crosslinking time) can be, for example, above 0.5 minutes and below 120 minutes. Secondary crosslinking can also be performed after vulcanization molding. The secondary crosslinking temperature can be, for example, above 120°C and below 280°C, and the secondary crosslinking time can be, for example, above 0.5 hours and below 24 hours.

[0076] The usable temperature range of the seal can be, for example, -70 to 150°C, preferably -100 to 200°C, and more preferably -130 to 230°C. In this specification, the usable temperature of the seal can be evaluated by measuring the glass transition temperature as described in the section on embodiments described later.

[0077] The hardness (Shore A hardness) of the seal can be, for example, around 25 to 90. A hardness within this range is preferred from the perspectives of ease of installation into semiconductor manufacturing equipment and airtightness.

[0078] The weight reduction rate (%) of the seal during the plasma resistance test can be, for example, 1.0% or less. The plasma resistance test can be performed according to the method described in the section on embodiments described later. The weight reduction rate (%) of the seal during the plasma resistance test is preferably 0.8% or less, more preferably 0.6% or less. Regarding the weight reduction rate of the seal of the present invention, in the plasma resistance test, it can be equal to or lower than that of a seal containing a perfluoroelastomer.

[0079] Another aspect of the present invention is a seal comprising a crosslinked material of the above-described sealing composition. The seal of the present invention can be used in semiconductor manufacturing apparatuses, and is particularly preferred as a seal for fixed or moving parts of a vacuum chamber in a semiconductor manufacturing apparatus that performs plasma processing, due to its plasma resistance. Furthermore, since the seal of the present invention exhibits plasma resistance equal to or better than that of seals containing perfluoroelastomers, it is also preferred for use in semiconductor manufacturing apparatuses employing seals containing perfluoroelastomers. Examples of seal applications include various types such as O-rings, gaskets, and washers.

[0080] Another aspect of the present invention is a semiconductor manufacturing apparatus including the aforementioned sealing element. In addition to semiconductor manufacturing apparatus, the semiconductor manufacturing apparatus of the present invention also includes, for example, liquid crystal panel manufacturing apparatus, plasma panel manufacturing apparatus, plasma display panel manufacturing apparatus, plasma-addressable liquid crystal panel manufacturing apparatus, organic EL panel manufacturing apparatus, field emission display panel manufacturing apparatus, solar cell substrate manufacturing apparatus, semiconductor transport apparatus, etc.

[0081] The present invention will be further described in detail below through examples. Unless otherwise specified, "%" and "parts" in the examples refer to mass percentage and mass parts, respectively.

[0082] <Examples 1-10 and Comparative Examples 1-5>

[0083] The sealing composition is prepared according to the following steps, and then the seal is manufactured. First, the specified amounts of each compounding agent are mixed using an open mill roll according to the formulation shown in Table 1 (the units of the compounding amounts in Table 1 are parts by mass). Next, the obtained sealing composition is pressed at 120°C for 20 minutes, and then subjected to secondary crosslinking using heat at 200°C for 4 hours to obtain the seal.

[0084] [Table 1]

[0085]

[0086] Details of the complexing components in Table 1 are as follows.

[0087] PVMQ1: Phenylvinylmethylsilyl, "KE-186-U", Shin-Etsu Chemical Industry Co., Ltd.

[0088] PVMQ2: Phenylvinylmethylsilyl, “KE-183-U”, Shin-Etsu Chemical Industry Co., Ltd.

[0089] PVMQ3: Phenylvinylmethylsilyl, "KE-136Y-U", Shin-Etsu Chemical Industry Co., Ltd.

[0090] PVMQ4: Phenylacetylmethylsilyl, “SE-955-U”, Dow Toray Co., Ltd.

[0091] Crosslinking agent 1: p-methylbenzoyl peroxide, "C-23N", Shin-Etsu Chemical Industry Co., Ltd.

[0092] Crosslinking agent 2: Bis(4-methylbenzoyl) peroxide, “RC14”, Dow Toray Co., Ltd.

[0093] Crosslinking agent 3: 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, “C-8A”, Shin-Etsu Chemical Industry Co., Ltd.

[0094] Filler 1: PTFE, “Lubron L5”, Daikin Industries, Ltd.

[0095] Additive 1: Perfluoropolyether compound, “Saiper8070A”, Shin-Etsu Chemical Co., Ltd.

[0096] Additive 2: Perfluoropolyether compound, “Saiper8070B”, Shin-Etsu Chemical Co., Ltd.

[0097] Pigment 1: “Violet#V4879”, RESINO COLOR INDUSTRY Co., Ltd.

[0098] [Table 2]

[0099]

[0100] Details of the compounding components in Table 2 are as follows.

[0101] FVMQ: Fluorosilicone compound, “FE-271-U”, Shin-Etsu Chemical Industry Co., Ltd.

[0102] VMQ1: Silicone rubber compound, “KE-971-U”, Shin-Etsu Chemical Co., Ltd.

[0103] VMQ2: Silicone rubber compound, “KE-951-U”, Shin-Etsu Chemical Industry Co., Ltd.

[0104] FFKM: Perfluorinated elastomer, “PFE191T”, 3M.

[0105] FKM: Fluororubber, “DAI-EL G783”, Daikin Industries, Ltd.

[0106] Crosslinking agent 4: 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, “C-8A”, Shin-Etsu Chemical Industry Co., Ltd.

[0107] Crosslinking agent 5: Benzoyl peroxide, "C1A", Shin-Etsu Chemical Co., Ltd.

[0108] Crosslinking agent 6: 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, Tokyo Chemical Industry Co., Ltd.

[0109] Acid acceptor 1: Magnesium oxide, "Kyowamag MA150", Kyowa Chemical Industry Co., Ltd.

[0110] Acid acceptor 2: Calcium hydroxide, “CALDIC#2000”, Omi Chemical Industry Co., Ltd.

[0111] Filler 2: MT carbon, “Thermax N990”, Cancarb.

[0112] Pigment 2: "Ferro Blue V-3285", Ferro Japan.

[0113] Pigment 3: “KE-COLOR-BR”, Shin-Etsu Chemical Industry Co., Ltd.

[0114] (Evaluation of seals)

[0115] The obtained cross-linked molded articles (sealants) were evaluated as follows. The results are shown in Table 1.

[0116] [1] Determination of glass transition temperature

[0117] Using a DVA-225 (manufactured by IT Measurement & Control Co.), the molded parts were measured under the following conditions: measurement temperature: -150~150℃, heating rate: 2℃ / min, frequency: 1Hz, measurement mode: tensile, and air environment. The glass transition temperature was taken as the peak value of tanδ. The glass transition temperature is an indicator of the low-temperature operating range of a seal. The lower the glass transition temperature, the more advantageous it is for use in low-temperature environments.

[0118] [2] Plasma resistance test

[0119] The plasma resistance (weight loss rate) of the obtained molded articles was measured. Specifically, the measurement was performed as follows.

[0120] Using a flat plasma treatment device with an electrode diameter of φ240mm, the obtained molded body was irradiated with plasma for 1 hour under the following conditions: RF: 250W, O2 gas to CF4 gas flow ratio (O2:CF4): 180:20, gas flow rate: 200sccm, and vacuum degree: 133Pa.

[0121] Then, the weight of the molded body before and after the test is measured, and the weight reduction rate (%) is calculated using the following formula to evaluate the plasma resistance. The smaller the weight reduction rate, the more favorable the plasma resistance.

[0122] Weight reduction rate (%) = [(Weight of molded body before test - Weight of molded body after test) / Weight of molded body before test] × 100

[0123] [3] Determination of metal ion content

[0124] The obtained molded body was washed with dilute acid and then ashed with nitric acid. Concentrated acid was added and the mixture was heated to concentrate it. Dilute acid (recovery solution) was then added for further heating and recovery. The solution was transferred to a fluoropolymer container and qualitative analysis was performed using ICP-MS. It should be noted that internal standard elements were pre-added to the recovery solution. The determination was performed using an Agilent 750 OCS (manufactured by Agilent Technologies).

[0125] [4] Determination of normal physical properties

[0126] Hardness (Shore A type) was measured according to JIS K 6253:2012 using a Shore A hardness tester. Tensile testing was performed according to JIS K 6251, with a No. 3 dumbbell specimen. Tensile strength (MPa), elongation (%), and 100% modulus (MPa) were determined using a Schubert tensile testing machine.

[0127] As shown in Table 1, in Examples 1-10, the glass transition temperature was significantly lower than that of Comparative Example 1 using FFKM, and the weight reduction rate in the plasma resistance evaluation was also lower than that of Comparative Examples 2-5 using phenyl-free silicone polymers. Therefore, according to the present invention, it is possible to provide a sealing composition that can be used in low-temperature environments and has plasma resistance at a low cost.

Claims

1. A sealing composition, wherein, The sealing composition is a plasma-resistant sealing composition for semiconductor manufacturing equipment, and comprises an organosilicon polymer and a vulcanizing agent. The organosilicon polymer comprises polysiloxane compounds having unsubstituted or substituted aromatic monovalent hydrocarbon groups on their side chains.

2. The sealing composition according to claim 1, wherein, The polysiloxane compound comprises a structural unit represented by the following formula (1): In the formula, R 1 Independently represents unsubstituted or substituted aromatic monovalent hydrocarbon groups. R 2 Independently representing an unsubstituted or substituted aromatic monovalent hydrocarbon group, an unsubstituted or substituted unsaturated or saturated hydrocarbon group without an aromatic hydrocarbon group, an alkoxy group, a hydroxyl group, or a hydrogen atom. n represents an integer from 1 to 7000.

3. The sealing composition according to claim 2, wherein, The ratio of the structural units represented by formula (1) in the polysiloxane compound is 1 to 70 mol%.

4. The sealing composition according to claim 2, wherein, The polysiloxane compound has a terminal component (R) at the end of the main chain. 3 )3Si-R 4 - indicates a group, In the formula, R 3 Independently representing unsubstituted or substituted aromatic monovalent hydrocarbon groups, unsubstituted or substituted unsaturated or saturated hydrocarbon groups without aromatic hydrocarbon groups, alkoxy or hydroxyl groups, R 4 Alkylene groups, which independently represent 1 to 5 oxygen and carbon atoms.

5. The sealing composition according to claim 4, wherein, The polysiloxane compound comprises a structural unit represented by the following formula (2): In the formula, R 5 and R 6 Independently representing unsubstituted or substituted unsaturated or saturated hydrocarbon groups, alkoxy groups, or hydroxyl groups that do not contain aromatic hydrocarbon groups. o represents an integer from 100 to 10000.

6. The sealing composition according to claim 5, wherein, The polysiloxane compound has a vinyl group at the end of at least one of its side chain and main chain.

7. The sealing composition according to claim 1, wherein, The sealing composition further comprises at least one of: a filler in the amount of 1 to 160 parts by weight relative to 100 parts by weight of the silicone polymer, and a pigment in the amount of 0.05 to 3 parts by weight.

8. The sealing composition according to claim 1, wherein, The vulcanizing agent contains a peroxide-based compound.

9. The sealing composition according to claim 1, wherein, The content of the vulcanizing agent is 0.2 to 8 parts by mass relative to 100 parts by mass of the organosilicon polymer.

10. The sealing composition according to claim 1, wherein, The sealing composition also contains a perfluoropolyether compound.

11. The sealing composition according to claim 1, wherein, The metal ion content is below 1000 ppm.

12. A seal comprising a crosslinked compound of the seal composition as claimed in claim 1.

13. A gate valve seal for a semiconductor manufacturing apparatus, comprising the seal as claimed in claim 12.

14. A semiconductor manufacturing apparatus comprising the seal as claimed in claim 12.

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