US010676365B2

(12 ) United States Patent (10 ) Patent No.: US 10,676,365 B2 Abe et al. (45 ) Date of Patent : Jun . 9 , 2020

(54 ) HYDROGENATED SILANE COMPOSITION (56 ) References Cited ( 71) Applicant: NIPPON SHOKUBAI CO ., LTD ., U.S. PATENT DOCUMENTS Osaka ( JP ) 4,554,180 A 11/1985 Hirooka 2012/0003819 Al 1/2012 Francis et al . (72 ) Inventors: Takashi Abe , Osaka ( JP ) ; Tatsuhiko 2012/0024223 A1 2/2012 Torres , Jr. et al . Akiyama, Osaka ( JP ) 2014/0219893 A1 * 8/2014 Imoto CO1B 33/04 423/210 ( 73 ) Assignee : NIPPON SHOKUBAI CO ., LTD . , 2016/0311692 A1 10/2016 Kitamura et al . Osaka (JP ) FOREIGN PATENT DOCUMENTS ( * ) Notice : Subject to any disclaimer, the term of this JP 60-26664 2/1985 patent is extended or adjusted under 35 JP 2013-187261 9/2013 U.S.C. 154 ( b ) by 0 days. JP 2013-537705 10/2013 JP 2015-134755 7/2015 (21 ) Appl. No.: 16 /110,345 * cited by examiner (22 ) Filed : Aug. 23 , 2018 Primary Examiner Amber R Orlando (65 ) Prior Publication Data Assistant Examiner Syed T Iqbal US 2019/0135641 A1 May 9 , 2019 (74 ) Attorney, Agent, or Firm Wenderoth , Lind & Ponack , L.L.P. Foreign Application Priority Data ( 30 ) (57 ) ABSTRACT Aug. 31, 2017 (JP ) 2017-167649 At least one embodiment of the present disclosure provides a hydrogenated silane composition containing cyclohexasi (51 ) Int . Cl. lane of a cyclic hydrogenated silane having high storage COIB 33/04 ( 2006.01 ) stability . (52 ) U.S. Ci. The at least one embodiment of the present disclosure relates CPC COIB 33/04 ( 2013.01 ) ; CO1P 2006/80 to a hydrogenated silane composition , wherein a content ( 2013.01 ) ratio of normal hexasilane and silylcyclopentasilane to (58 ) Field of Classification Search cyclohexasilane is 0.0020 or less on a mass basis . CPC CO1B 33/04 ; CO1P 2006/80 See application file for complete search history. 8 Claims, No Drawings US 10,676,365 B2 1 2 HYDROGENATED SILANE COMPOSITION For example , in the case where a composition containing cyclohexasilane contains normal hexasilane of a linear BACKGROUND OF THE INVENTION hydrogenated silane and silylcyclopentasilane of a cyclic hydrogenated silane having a branched structure in a large Field of the Invention 5 amount even if the number of the silicon atoms is the same between these , this may have an influence on vaporization of This application claims the benefit of priority based on cyclohexasilane due to different vaporization pressure , so Japanese Patent Application No. 2017-167649 , filed on Aug. that there is the need to control a ratio of normal hexasilane 31, 2017. The entire content of the specification of Japanese and silylcyclopentasilane . Patent Application No. 2017-167649, filed on Aug. 31 , 10 In addition , when the hydrogenated silane composition 2017 , is incorporated into this application by reference . containing cyclohexasilane contains normal hexasilane of At least one embodiment of the present disclosure relates the linear hydrogenated silane and silylcyclopentasilane of to a hydrogenated silane composition . Specifically , at least the cyclic hydrogenated silane having a branched structure one embodiment of the present disclosure relates to the in a large amount, the stability of cyclohexasilane tends to hydrogenated silane composition containing normal hexasi- 15 decrease . For example , in silylcyclopentasilane of the cyclic lane of a linear hydrogenated silane and silylcyclopentasi hydrogenated silane having a branched structure , a bond lane of a cyclic hydrogenated silane having a branched between a silyl group at a side chain and cyclopentasilane structure . backbone is easily broken , so that a degradation of cyclo hexasilane tends to be caused . Description of Related Art 20 On the other hand , as described in Patent Document 3 , when the polysilane is produced with photopolymerization , A silicon thin film has been used for applications such as there is the need to control easily decomposable silylcyclo solar cells and semiconductors , and this silicon thin film has pentasilane in order to initiate and promote the photopoly been previously prepared by a vapor deposition film - form merization . ing method ( CVD method ) using monosilane as a raw 25 Therefore , there is the need to control a ratio of normal material . In addition , other reported methods for preparing hexasilane of the linear hydrogenated silane and silylcyclo silicon thin films include a CVD method using as a raw pentasilane of the cyclic hydrogenated silane having a material a cyclic silane compound represented by a general branched structure contained in the hydrogenated silane formula (SiH2 ) n ( n = 4 , 5 , or 6 ) ( Patent Document 1 ), a CVD composition containing cyclohexasilane in the viewpoints of method using as a raw material cyclohexasilane (Patent 30 the stability and the polymerization reactivity . Document 2) , a method for producing a polysilane by The object of at least one embodiment of the present forming a layer composed of a solution containing as a disclosure is to provide a hydrogenated silane composition solute cyclopentasilane and cyclohexasilane on a substrate , containing cyclohexasilane of a cyclic hydrogenated silane and carrying out photopolymerization (Patent Document 3 ) , having high storage stability . and the like . 35 As a method for preparing a cyclic hydrogenated silane , Solutions to the Problems Patent Document 4 discloses a method for preparing a cyclic hydrogenated silane in which a cyclization reaction of a The hydrogenated silane composition of at least one halosilane is carried out under the presence of a given embodiment of the present disclosure is characterized in that coordination compound to obtain a neutral complex of a 40 a content ratio of normal hexasilane and silylcyclopentasi cyclic halogenated silane, and the neutral complex of a lane to cyclohexasilane is 0.0020 or less on a mass basis . cyclic halogenated silane is reduced to prepare the cyclic hydrogenated silane. Effects of the Invention PRIOR ART DOCUMENTS 45 According to the present disclosure , the storage stability of cyclohexasilane of the cyclic hydrogenated silane can be Patent Documents improved . Patent Document 1 : Japanese unexamined patent application MODE FOR CARRYING OUT THE INVENTION publication No. 1985-26664 50 Patent Document 2 : Japanese unexamined patent application The hydrogenated silane composition of the present dis publication No. 2013-537705 closure is characterized in that a content ratio of normal Patent Document 3 : Japanese unexamined patent application hexasilane and silylcyclopentasilane to cyclohexasilane is publication No. 2013-187261 0.0020 or less on a mass basis . Patent Document 4 : Japanese unexamined patent application 55 The content ratio of normal hexasilane and silylcyclopen publication No. 2015-134755 tasilane to cyclohexasilane is 0.0020 or less , preferably 0.0018 or less , more preferably 0.0016 or less, and even SUMMARY OF THE INVENTION preferably 0.0014 or less on a mass basis . The content ratio may be 0 or more, 0.00001 or more or 0.00005 or more . Problems to be Solved by the Invention 60 When the above content ratio is satisfied , as mentioned below , the storage stability of cyclohexasilane is improved Thus, the cyclic hydrogenated silane, particularly cyclo because a content of the linear hydrogenated silane and the hexasilane frequently has been used as film - forming mate cyclic hydrogenated silane having a branched structure are rials of semiconductors in many years , and cyclohexasilane reduced as possible as. In addition , the stability on the film of the cyclic hydrogenated silane having the storage stability 65 formation with the liquid phase is also improved . has been required in the viewpoint of obtaining the uniform The content ratio of normal hexasilane and silylcyclopen film as films suitably used in the semiconductors . tasilane to cyclohexasilane can be determined based on gas US 10,676,365 B2 3 4 chromatograms obtained in the following gas chromatogra phy conditions and the following formula ( 1 ) . [Chemical Formula 2 ] ( 2 ) ( total area of gas chromatograms of normal hexasi SiH3 lane and silylcyclopentasilane) (area of gas 5 chromatograms of cyclohexasilane ) ( 1 ) SiH Gas Chromatography Conditions H2Si SiH2 Device : GC2014 manufactured by Shimadzu Corporation Detection : FID Column : Agilent J & W GC column DB - 5 ms Phenyl 10 2HSi — H2Si Arylene polymer, 0.25 umx0.25 mmx30 m Temperature of vaporization chamber : 250 ° C. A content of silylcyclopentasilane is preferably 0.0001 % Temperature of detector: 280 ° C. to 0.5 % by mass , more preferably 0.005 % to 0.4 % by mass , Temperature elevating conditions : 1 ) at 50 ° C. for 5 minutes, and even preferably 0.01 % to 0.3 % by mass per 100 % by 2 ) elevation of temperature up to 250 ° C. at a temperature 15 mass of the hydrogenated silane composition . elevating rate of 20 ° C./minute , 3 ) elevation of temperature A total content of normal hexasilane and silylcyclopen up to 280 ° C. at a temperature elevating rate of 10 ° C./min tasilane is preferably 0.0002 % to 0.6 % by mass, more ute , and 4 ) at 280 ° C. for 10 minutes preferably 0.01 % to 0.5 % by mass, and even preferably 0.02 The area of the gas chromatograms means a total area of 20 to 0.4 % by mass per 100 % by mass of the hydrogenated the cyclic hydrogenated silane or the linear hydrogenated silane composition . silane obtained in gas chromatography conditions. A ratio of In at least one embodiment of the present disclosure , in each of the cyclic hydrogenated silanes and each of the the case where the hydrogenated silane composition (pref linear hydrogenated silanes may be determined from the erably cyclohexasilane) is prepared through a given heat area of the gas chromatograms. 25 treatment, the content of the linear hydrogenated silane The purity of the cyclic hydrogenated silane or the linear ( normal hexasilane ) and the cyclic hydrogenated silane hydrogenated silane may be determined using a calibration having a branched structure ( silylcyclopentasilane) is curve method (mesitylene as a standard material) in place of increased , so that the storage stability of cyclohexasilane a percentage method using an area of gas chromatograms. cannot be improved sufficiently in some cases. The hydrogenated silane composition of the present dis- 30 In at least one embodiment of the present disclosure , closure may be those obtained by preparing cyclohexasilane using an appropriate method , the hydrogenated silane com of the cyclic hydrogenated silane , those obtained by solid position can be obtained by decreasing a content of the linear liquid separation of cyclohexasilane, and those obtained by hydr nated silane (normal hexasilane ) and the cyclic distilling cyclohexasilane . In addition , in the case where the hydrogenated silane having a branched structure ( silylcy cyclic hydrogenated silane or the linear hydrogenated silane 35 clopentasilane ) from the hydrogenated silane composition other than cyclohexasilane is prepared , those satisfying the containing cyclohexasilane obtained in various methods. A above content ratio are included in the hydrogenated silane method for preparing the hydrogenated silane composition composition of the present disclosure . Therefore , the hydro containing cyclohexasilane before decreasing the content of genated silane composition of at least one embodiment of the linear hydrogenated silane and the cyclic hydrogenated the present disclosure may contain a cyclic hydrogenated 40 silane having a branched structure is not limited particularly , silane other than cyclohexasilane and silylcyclopentasilane and various known methods can be used . Among these , a and a linear hydrogenated silane other than normal hexasi method for reducing a cyclic halosilane obtained from the lane as long as the content ratio is satisfied . cyclization of a halosilane is suitable . A content of cyclohexasilane is preferably 97 % by mass Examples of the halosilane (the halogenated silane ) or more , more preferably 97.5 % by mass or more , even 45 include dihalogenated silanes such as dichlorosilane , dibro preferably 98.0 % by mass or more per 100 % by mass of the mosilane, diiodosilane , difluorosilane; trihalogenated hydrogenated silane composition , and a content of cyclo silanes such as trichlorosilane , tribromosilane, triiodosilane hexasilane is desirably and extremely near 100 % by mass , and trifluorosilane ; and tetrahalogenated silanes such as and may be 99.9 % by mass or less or 99.7 % by mass or less tetrachlorosilane, tetrabromosilane , tetraiodosilane and tet per 100 % by mass of the hydrogenated silane composition . 50 rafluorosilane . Among these, trihalogenated silanes are pref Normal hexasilane is , for example , a compound repre erable , and trichlorosilane is particularly preferable . sented by the following formula ( 1 ) . A method for cyclizing the halosilane is not limited particularly , and the following method ( A ) or (B ) is pre ferred . [Chemical Formula 1 ] 55 ( A ) a method for obtaining a salt of a cyclic halosilane by contacting a halosilane ( a halogenated monosilane) with a SiH2 SiH2 phosphonium salt and / or an ammonium salt [hereinafter , SiH3 SiH3 referred to as method A in some cases ] SiH2 SiH2 ( B ) a method for obtaining a neutral complex of a cyclic 60 halosilane by contacting a halosilane with at least one A content of normal hexasilane is preferably 0.5 % by compound selected from the group consisting of the follow mass or less , more preferably 0.4 % by mass or less , even ing (I ) and ( II ) ( hereinafter , referred to as method B in some preferably 0.3 % by mass or less , and preferably 0.0001 % by cases ] mass or more or 0.001 % by mass or more per 100 % by mass ( I ) a compound represented as XR , [hereinafter , referred of the hydrogenated silane composition . 65 to as compound I in some cases ] (when X is Por P = 0 , n = 3 Silylcyclopentasilane is , for example , a compound repre and each R represents a substituted or unsubstituted alkyl sented by the following formula ( 2 ) . group or aryl group and each R is the same or different; when US 10,676,365 B2 5 6 X is S , S = 0 or O , n = 2 and each R represents a substituted because the salt of the cyclic halosilane is precipitated in a or unsubstituted alkyl group or aryl group and each R is the reaction solution in the preparation of salt of the cyclic same or different; when X is CN , n = 1 and each R represents halosilane . a substituted or unsubstituted alkyl group or aryl group , and In the above formulas ( 11 ) and (12 ), the monovalent anion the number of amino groups in XR , is 0 or 1 ) 5 represented by A - includes halide ions ( C1- , Br- , I- , and the ( II ) at least one heterocyclic compound selected from the like ), borate ions (BF4 and the like ), and phosphorous group consisting of substituted or unsubstituted N-, O-, S - or anions (PF . and the like ) . Among them , halide ions are P -containing heterocyclic compounds that have an unshared preferable , Cl- , Br- and I are more preferable , and Cl- and electron pair in the ring [hereinafter , referred to as com Brºare particularly preferable , from the viewpoint of easy pound II in some cases ] (the number of tertiary amino 10 availability . groups as the substituent of the heterocyclic compound is 0 One or both of the phosphonium salt and the ammonium or 1 ) . First, the above met A is explained . salt may be used . The phosphonium salt may be used The phosphonium salt is preferably a quaternary phos individually or in two or more phosphonium salts . The phonium salt, and preferably includes a salt represented by 15 ammoniumammonium saltssaltmay . In addition be used ,individually the phosphonium or in twosalt orandmore the the following general formula (11 ) . In the following formula ammonium salt may be generated from a corresponding ( 11 ), each of Rl to R4 may different, and all of Ri to R4 is tertiary phosphine and tertiary amine in a reacting system . preferably the same group . The amount of the phosphonium salt and /or the ammo 20 nium salt to be used or the total amount thereof in the case Chemical Formula 3 ] where two or more kinds are used is preferably not less than 0.01 mol, more preferably not less than 0.05 mol, further ( 11) preferably not less than 0.08 mol, and preferably not more than 1.0 mol, more preferably not more than 0.7 mol, and R2 —P+ -R4A 25 further preferably not more than 0.5 mol, based on 1 mol of the halosilane. When the amount of the phosphonium salt R3 and /or the ammonium salt is within the above range , the yield of the salt of the cyclic halosilane tends to improve . In addition , the ammonium salt is preferably a quaternary The above method A is preferably carried out under the ammonium salt, and preferably includes a salt represented 30 presence of a chelate ligand such as a polyether compound , by the following general formula (12 ) . In the following a polythioether compound and a polydentate phosphine formula ( 12 ), each of RS to R8 may different, and all of RS compound . When the cyclization coupling reaction of the to R8 is preferably the same group . method A is carried out under the presence of the chelate ligand , and the salt of the cyclic halosilane can be efficiently 35 produced . In addition , the number of a hydrogen atom or a [ Chemical Formula 4 ] composition ratio in the obtained cyclic halosilane can be adjusted by appropriately selecting a kind of the chelate ( 12 ) ligand to be used . Examples of the polyether compound include, for RÓ - N - R8A 40 example, dialkoxyalkanes such as 1,1- dimethoxyethane , 1,2 -dimethoxyethane , 1,2 - diethoxyethane, 1,2 -dipropoxy R7 ethane , 1,2 -diisopropoxyethane , 1,2 -dibutoxyethane , 1,3 -di methoxypropane, 1,3 -diethoxypropane , 1,3 -dipropoxypro In the above formulas ( 11) and ( 12 ) , Rito R7 and R to R8 pane, 1,3 -diisopropoxypropane , 1,3 -dibutoxypropane , 1,4 each independently represent a hydrogen atom , an alkyl 45 dimethoxybutane , 1,4 - diethoxybutane , 1,4 group or an aryl group ; and A represents a monovalent dipropoxybutane , 1,4 -diisopropoxybutane , and 1,4 anion . dibutoxybutane ; diaryloxyalkanes such as 1,2 The examples of alkyl groups of Rl to R4 and R to R $ diphenoxyethane, 1,3 - diphenoxypropane, and 1,4 preferably include linear alkyl groups such as a methyl diphenoxybutane . Among these, 1,2 -dimethoxyethane is group, an ethyl group , a propyl group , a butyl group , a pentyl 50 particularly preferable . group , a hexyl group , a heptyl group , an octyl group , a nonyl Examples of the polythioether compound include those in group , a decyl group , an undecyl group , a dodecyl group , a which oxygen atom of the polyether compounds exemplified tridecyl group , a tetradecyl group , a pentadecyl group , a above is substituted with sulfur atom . hexadecyl group ; cyclic alkyl groups such as a cyclopropyl Examples of the polydentate phosphine compound group , a cyclobutyl group , a cyclopentyl group , a cyclohexyl 55 include, for example , bis ( dialkylphosphino) alkanes such group , and a cycloheptyl group . The alkyl groups have 1,2 -bis (dimethylphosphino ) ethane, 1,2 -bis (diethylphos carbon atoms of preferably 1 to 16 , and more preferably 1 phino ) ethane , 1,2- bis ( dipropylphosphino ) ethane, 1,2 - bis to 8 . (dibutylphosphino ) ethane, 1,3 -bis (dimethylphosphino ) The examples of the aryl groups of R ' to R7 and RS to R8 propane, 1,3 -bis (diethylphosphino ) propane , 1,3 -bis (dipro preferably include aryl groups having a carbon number of 6 60 pylphosphino ) propane, 1,3 -bis ( dibutylphosphino ) propane, to 18 such as a phenyl group and a naphthyl group . The aryl 1,4 - bis (dimethylphosphino ) butane, 1,4 -bis (diethylphos groups of RI1 to R4 and R? to R $ are more preferably an aryl phino ) butane , 1,4 - bis ( dipropylphosphino ) butane, and 1,4 group having a carbon number of 6 to 12 . bis ( dibutylphosphino ) butane ; bis ( diarylphosphino ) Each of Ri to R + and R to R8 is preferably an alkyl group alkanes such as 1,2 - bis ( diphenylphosphino ) ethane, 1,3 - bis or an aryl group , and more preferably an aryl group . When 65 ( diphenylphosphino ) propane, 1,4 - bis ( diphenylphosphino ) R1 to R4 and Rs to R8 are aryl groups, as set forth below , a butane . Among them , 1,2 -bis (diphenylphosphino ) ethane is salt of a cyclic halosilane is easily obtained at high purity particularly preferable . US 10,676,365 B2 7 8 The used amount of the chelate ligand may be appropri halosilane with the Lewis acid , and is , for example , prefer ately adjusted , and is preferably 0.01 mol or more, more ably 0.5 mol ormore , more preferably 1.5 mol or more , and preferably 0.05 mol or more , even more preferably 0.1 mol preferably 20 mol or less, more preferably 10 mol or less, or more, and preferably 50 mol or less, more preferably 40 relative to 1 mol of the salt of the cyclic halosilane . mol or less , even more preferably 30 mol or less, per 1 mol 5 The reaction of the salt of the cyclic halosilane with the of the halosilane . Lewis acid is preferably carried out in a solvent or a As the salt of the cyclic halosilane obtained in themethod dispersion medium that is simply referred to as a solvent. A , a compound represented by the following formula ( 13 ) is Examples of the solvent ( reaction solvent) used in the preferably used . reaction include hydrocarbon solvents such as hexane, tolu 10 ene; ether solvents such as diethyl ether , tetrahydrofuran , cyclopentyl methyl ether , diisopropyl ether and methyl [Chemical Formula 5 ] tertiary -butyl ether, and others. These organic solvents may be used individually or two or more of them may be used in ( 13 ) combination . In order to remove water and dissolved oxygen ? , 15 contained in the reaction solvent , it is preferable that the x , Si -1 - si (SiX_He ) •L ? m K ” , reaction solvent is subjected to purification such as distilla tion and dehydration prior to the reaction . SiSi) n Reaction temperature upon carrying out the reaction of the salt of the cyclic halosilane with the Lewis acid may be In the above formula ( 13 ), x ' and X ? each independently 20 appropriately adjusted depending on the reactivity, and is represent a halogen atom ; L represents an anionic ligand ; p preferably –80 ° C. or higher , more preferably –50 ° C. or is an integer of -2 to 0 as a valence of the ligand L ; K higher , even preferably -30 ° C. or higher, and preferably represents a counter cation ; q is an integer of 0 to 2 as a 200 ° C.or lower, more preferably 150 ° C. or lower , and even valence of the counter cation K ; n is an integer of 0 to 5 ; a , preferably 100 ° C. or lower. b and c are integers of 0 to 2n + 6 , wherein a + b + c = 2n + 6 but 25 Next, the above method B is explained . a and c are not simultaneously 0 ; d is an integer of 0 to 3 , In XR , of the above compound I, X is coordinated to the wherein a and d are not simultaneously 0 ; e is an integer of cyclic halosilane to form a neutral complex of the cyclic 0 to 3 , wherein d + e = 3 ; m is a number of 1 to 2 ; s is an integer halosilane . When X is P or P = 0 , X is trivalent, and n of 1 or more ; and t is an integer of 1 or more . representing the number of R is 3. Each R represents a The salt of the cyclic halosilane may be contacted and 30 substituted or unsubstituted alkyl group or aryl group and reacted with a Lewis acid to obtain a free cyclic halosilane . each R is the same or different. R is more preferably a The free cyclic halosilane means noncomplex cyclic halosi substituted or unsubstituted aryl group . Examples of R as the lanes such as Si C110 , SigCl12 , or SigCl, H in which a part alkyl group include linear, branched or cyclic alkyl groups , of halogen atoms is substituted with hydrogen . Concretely , and preferably alkyl groups having 1 to 16 carbon atoms, the corresponding free cyclic halosilane can be obtained by 35 such as linear alkyl groups such as a methyl group , an ethyl contacting a salt of a cyclic halosilane with a Lewis acid , group, a propyl group , a butyl group , a pentyl group , a hexyl making the Lewis acid electrophilically act on an anionic group , a heptyl group , an octyl group , a nonyl group , a decyl ligand contained in the salt of the cyclic halosilane, and group , an undecyl group , a dodecyl group , a tridecyl group , extracting the anionic ligand from the salt of the cyclic a tetradecyl group , a pentadecyl group , a hexadecyl group ; halosilane to separate a counter cation . 40 cyclic alkyl groups such as a cyclopropyl group , a cyclobu The kind of the Lewis acid is not particularly restricted , tyl group , a cyclopentyl group , a cyclohexyl group , and a and it is preferable to use a metal halide. Examples of the cycloheptyl group . Preferable examples of R as the aryl metal halide include metal chlorides , metal bromides, metal group include aryl groups having about 6 to 18 carbon iodides and others , and from the viewpoint of reactivity and atoms, such as a phenyl group and a naphthyl group . ease of control of the reaction , a metal chloride is preferably 45 In XR , of the compound I, when X is N and the number used . Examples of the metal element constituting the metal of an amino group is 1 in XR , X is coordinated to the cyclic halide include group 13 elements such as boron , aluminum , halosilane to form the neutral complex of the cyclic halosi gallium , indium and thallium ; group 11 elements such as lane. When X is N , X is trivalent, and n representing the copper, silver and gold ; group 4 elements such as titanium number of R is 3. Each R represents a substituted or and zirconium ; iron , zinc, calcium and others. Specific 50 unsubstituted alkyl group or aryl group and each R is the examples of the Lewis acid include boron halides such as same or different. R is more preferably a substituted or boron trifluoride , boron trichloride and boron tribromide ; unsubstituted alkyl group . Examples of R as the alkyl group aluminum halides such as aluminum chloride and aluminum include linear , branched or cyclic alkyl groups , and prefer bromide ; gallium halides such as gallium chloride and ably alkyl groups having 1 to 16 carbon atoms, more gallium bromide; indium halides such as indium chloride 55 preferably alkyl groups having 1 to 4 carbon atoms, such as and indium bromide ; thallium halides such as thallium a methyl group , an ethyl group , a propyl group and a butyl chloride and thallium bromide ; copper halides such as group , and even preferably alkyl groups having 1 to 3 carbon copper chloride and copper bromide ; silver halides such as atoms. Preferable examples of R as the aryl group include silver chloride and silver bromide ; gold halides such as gold aryl groups having about 6 to 18 carbon atoms, such as a chloride and gold bromide; titanium halides such as titanium 60 phenyl group and a naphthyl group . chloride and titanium bromide ; zirconium halides such as When X is P , P = 0 , or N in XRm , the substituent that may zirconium chloride and zirconium bromide ; iron halides be possessed by the alkyl group is , for example , an alkoxy such as iron chloride and iron bromide ; zinc halides such as group , an amino group , a cyano group , a carbonyl group and zinc chloride and zinc bromide ; calcium halides such as a sulfonyl group , and the substituent that may be possessed calcium chloride and calcium bromide ; and others . 65 by the aryl group is , for example , an alkoxy group , an amino The used amount of the Lewis acid may be appropriately group , a cyano group , a carbonyl group and a sulfonyl adjusted depending on the reactivity of the salt of the cyclic group . Examples of the amino group include a dimethyl US 10,676,365 B2 9 10 amino group and a diethylamino group , and the number of includes one that is coordinated to a cyclic halosilane , and the amino groups is notmore than 1 in XR3. This is intended amines that are comparatively low in volume and are to eliminate a tertiary polyamine. In the meantime, three Rs symmetry, such as diethylmethylamine and triethylamine , may be the same or different. are considered to be comparatively efficiently coordinated . When X is S , S = 0 , or O , X is divalent, and n represent- 5 However , only with a tertiary amine represented by XR , of ing the number of R is 2. R is the same as R in the case where the above compound I , the yield of the neutral complex of X is P , P = 0 , and R is preferably a substituted or unsubsti a cyclic halosilane tends to decrease, and therefore , a com tuted alkyl group or aryl group . R is more preferably a pound I other than the tertiary amines is preferably used in substituted or unsubstituted aryl group. In addition , when X combination . is CN , X is monovalent, and n representing the number of R 10 The tertiary amine is used in an amount of preferably 0.5 is 1. R is the same as R in the case where X is P , P = 0 , and to 4 mol relative to 1 mol of a halosilane , and particularly R is preferably a substituted or unsubstituted alkyl group or preferably the same mol as 1 mol of a halosilane . aryl group . R is more preferably a substituted or unsubsti Without limiting particularly , in at least one embodiment tutedSpecific aryl groupexamples. of the compound I include a compound 15 of the present disclosure , it is preferable that a tertiary in which X is P , or P = 0 , such as triphenylphosphine ( PPhz) , polyamine having two or more carbon atoms and having triphenylphosphine oxide (Ph3P = O ), tris ( 4 -methoxyphe three or more amino groups is not used . The use of the nyl) phosphine ( P (MeOPh ) 3 ) ; a compound in which X is tertiary polyamine is not preferred in the viewpoint of the S – O such as dimethyl sulfoxide ; and a compound in which safety because a salt of a cyclic halosilane containing a X is CN such as p -tolunitrile (referred to as p- methylben- 20 silicon atom in the counter cation is produced and silane gas zonitrile ) is generated in the storage and the reduction reaction . The heterocyclic compound of the above (II ) or the The cyclization reaction of the halosilane in the above compound II is required to have an unshared electron pair in methods A and B can be conducted in an organic solvent as the ring , and the unshared electron pair coordinates to a necessary . As the organic solvent, a solvent that does not cyclic halosilane to form a neutral complex of the cyclic 25 prevent the cyclization reaction is preferred , and preferable halosilane. Examples of such a heterocyclic compound examples thereof include hydrocarbon -based solvents ( e.g. include at least one substituted or unsubstituted N-, O-, S - or P - containing heterocyclic compound that has an unshared hexane , heptane, benzene, and toluene) , halogenated hydro electron pair in the ring . The substituents that may be carbon -based solvents ( e.g. chloroform , dichloromethane possessed by the heterocyclic compound are the same as the 30 and 1,2 -dichloroethane ) , ether- based solvents ( e.g. diethyl substituents that may be possessed by R as an aryl group . ether , tetrahydrofuran , cyclopentylmethyl ether, diisopropyl Examples of the heterocyclic compound include pyridines, ether, and methyl tertiary -butyl ether ) and aprotic polar imidazoles, pyrazoles, oxa oles, thiazoles , imidazolines, solvents such as acetonitrile . Among these , the chlorinated pyrazines, thiophenes and furans, and specific examples hydrocarbon - based solvents such as chloroform , dichlo thereof include N , N -dimethyl - 4 - aminopyridine , tetrahydro- 35 romethane and 1,2 - dichloroethane are preferred . These thiophene , and tetrahydrofuran . organic solvents may be used individually or in combination Among the compound I and the compound II , a com of two or more thereof. pound that is a liquid at a reaction temperature can also play The amount of the organic solvent to be used is not a role of a solvent . particularly limited , and it is generally preferred to be An amount of the compound I and the compound II may 40 adjusted so that the concentration of the halosilane is pref be determined appropriately . The compound I and the com erably 0.5 to 10 mol/ L , more preferably 0.8 to 8 mol/ L , and pound II is used in an amount of preferably 0.1 to 50 mol, further preferably 1 to 5 mol/ L . and more preferably 0.5 to 3 mol, per 6 mol of a halosilane. The reaction temperature in the cyclization reaction can The neutral complex of a cyclic halosilane obtained in the be appropriately set according to the reactivity and is , for above method B contains silicon atoms of 3 to 8 , preferably 45 example , about 0 to 120 ° C., and preferably about 15 to 70 ° 5 or 6 , particularly preferably 6 of the halosilane as a raw C. Further, the cyclization reaction is recommended to be material and a ring of which each of silicon atoms is bonded conducted in an atmosphere of inert gas such as nitrogen . to each other , and the neutral complex of a cyclic silane is After the cyclization reaction, a reaction solution contain represented by the general formula [ Y ]i [Si ,, Z2m - 2H2] . In the ing the cyclic halosilane is preferably washed with a non above general formula , Y is the above compound I or the 50 halogen solvent. In other words, after the cyclization reac above compound II , each Z represents a halogen atom of any tion , a solution or dispersion containing the cyclic halosilane of Cl, Br, I and F and each Z is the same or different, 1 is (the salt of the cyclic halosilane, the free cyclic halosilane , 1 or 2 , m is 3 to 8 , preferably 5 or 6 , particularly preferably the neutral complex of a cyclic halosilane ) is produced . In 6 , and a is 0 to 2m - 1 , preferably O to m . addition , the solution or the dispersion containing the cyclic The cyclization reaction of the halosilane in the methods 55 halosilane is concentrated or filtered to prepare a solid of the A and B is preferably conducted by adding a tertiary amine . cyclic halosilane , and the solid may be washed with the Thereby, produced hydrochloric acid can be neutralized by halogen solvents such as chloroform , dichloromethane , 1,2 adding the tertiary amine. dichloromethane, and the non -halogen solvents including Specific examples of the tertiary amine used in the aprotic polar solvents such as acetonitrile and hydrocarbon cyclization reaction preferably include triethylamine, tripro- 60 solvents such as hexane, heptane, benzene, tolune to purify pylamine, tributylamine, trioctylamine , triisobutylamine , the solid of the cyclic halosilane. By washing the cyclic triisopentylamine , diethylmethylamine , diisopropylethyl halosilane with the non -halogen solvents , a content of impu amine (DIPEA ) , dimethylbutylamine , dimethyl- 2 - ethylhex rities such as halogen elements contained in the hydroge ylamine , diisopropyl- 2 - ethylhexylamine , methyldioctylam nated silane composition tends to remarkably decrease. On ine, and the like . 65 the other hand , a content of normal hexasilane of impurities Here, the tertiary amine may be used individually or in and a ring -opened product and the like tends to increase combination of two or more thereof. The tertiary amine also because a solid residue is increased at the reduction and the US 10,676,365 B2 11 12 inner temperature is increased at the distillation in the case A molar ratio of cyclic halosilane to reducing agent is where the cyclic halosilane is not purified sufficiently with preferably 1: 3 to 5 , and more preferably 1: 3 . When the molar washing step . ratio is over the above range , an amount of produced normal Before washing with the non -halogen solvent, the cyclic hexasilane of ring -opened products becomes large in some halosilane is preferably washed with the halogen solvent. An 5 cases due to the excess progress of the reducing reaction . amine hydrochloride can be removed by washing with the Further, a content of the linear hydrogenated silane of the halogen solvent and the halogen solvent can be removed by hydrogenated silane composition tends to decrease by reduc washing with the non -halogen solvent. When the content of ing an amount of the reducing agent used in the reducing the halogen solvent contained in the solid or solution of the reaction and the hydrogenated silane composition contain cyclic halosilane is decreased because the halogen solvent is 10 ing the cyclic hydrogenated silane having the branched silyl reacted with various reducing agents , the yield of the hydro group in an appropriate content tends to be easily obtained . genated silane tends to improve at the subsequent reduction Further, a Lewis acid catalyst may be used as a reduction reaction . auxiliary in combination with the above reducing agents in Washing with the halogen solvent and washing with the the reduction step. The Lewis acid catalyst may be metal non- halogen solvent may be carried out one time or two or 15 halide compounds including metal chlorides such as alumi more times , respectively . num chloride, titanium chloride , zinc chloride, tin chloride The cyclic halosilane can be obtained by the purification and iron chloride; metal bromides such as aluminum bro as a solid having high purity . In addition , the cyclic halosi mide , titanium bromide, zinc bromide , tin bromide and iron lane can be obtained as a composition containing the cyclic bromide ; metal iodides such as aluminum iodide , titanium halosilane and impurities if necessary . The composition 20 iodide, zinc iodide, tin iodide and iron iodide; and metal containing the cyclic halosilane contains the cyclic halosi fluorides such as aluminum fluoride , titanium fluoride , zinc lane in a content of preferably 80 % by mass ormore , more fluoride, tin fluoride and iron fluoride. These Lewis acid preferably 90 % by mass or more, and even preferably 95 % catalysts may be used individually or in combination of two by mass or more . The upper limit of the content of the cyclic or more thereof. halosilane is , for example , 99.99 % by mass . Examples of the 25 The reduction reaction can be carried out under the impurities include a solvent, a residue of the compound I or presence of an organic solvent as necessary. Examples of the the compound II , a degradation product of the cyclic halosi organic solvent include hydrocarbon -based solvents such as lane, a halosilane polymer , and the like . A content of the hexane and toluene; and ether -based solvents such as diethyl impurities in the composition containing the cyclic halosi ether, tetrahydrofuran , cyclopentyl methyl ether, diisopropyl lane is preferably 20 % by mass or less, more preferably 10 % 30 ether, and methyl tertiary butyl ether . These organic solvents by mass or less , and even preferably 5 % by mass or less , and may be used individually or in combination of two or more the lower limit of the content of the impurities is , for thereof. The organic solvent solution obtained in the pro example , 0.01 % by mass. duction of the cyclic halosilane may be directly used as an The hydrogenated silane composition containing the organic solvent solution in the reduction step , or an organic cyclic hydrogenated silane can be prepared by reducing the 35 solvent may be distilled off from an organic solvent solution cyclic halosilanes (the salt of the cyclic halosilane, the free containing the cyclic halosilane and a newly added organic cyclic halosilane, the neutral complex of the cyclic halosi solventmay be used in the reduction step . Here, the organic lane ) . The reduction step is preferably carried out under the solvent to be used in the reduction reaction is preferably presence of the reducing agent. subjected to purification such as distillation or dehydration The reducing agent that can be used in the reduction step 40 before the reaction in order to remove water and dissolved is not particularly limited , and one or more reducing agents oxygen contained therein . selected from the group consisting of aluminum -based An amount of the organic solvent to be used in the reducing agents and boron - based reducing agents are pref reduction reaction is adjusted such that the concentration of erably used . Examples of the aluminum - based reducing a cyclic halosilane is preferably 0.01 to 1 mol/ L , more agent include metal hydrides such as lithium aluminum 45 preferably to 0.02 to 0.7 mol/ L , and further preferably to hydride (LiAlH4 ; LAH ), diisobutyl aluminum hydride 0.03 to 0.5 mol/ L . When the reaction is carried out in the ( DIBAL ) and bis ( 2 -methoxyethoxy ) aluminum sodium above range , a content of the impurities such as halogen hydride (“ Red - Al” ( registered trademark of Sigma- Aldrich elements contained in the hydrogenated silane composition Corporation ). Examples of the boron -based reducing agent tends to remarkably decrease . include metal hydrides such as sodium borohydride and 50 The reduction can be carried out by bringing the cyclic lithium triethylborohydride, and diborane . It is preferable halosilane into contact with the reducing agent. When the that a metal hydride is used as the reducing agent. The cyclic halosilane is brought into contact with the reducing reducing agents may be used individually or in combination agent, the contact is preferably carried out under the pres of two or more thereof . ence of a solvent. In order to contact the cyclic halosilane An amount of the reducing agent in the reduction step 55 with the reducing agent under the presence of the solvent, may be set appropriately , and an equivalent of a hydride of for example , (a ) the reducing agent is directly added to a the reducing agent to one of silicon -halogen bond of the solution or a dispersion of the cyclic halosilane , (b ) a cyclic halosilane is preferably at least 0.9 equivalent or solution or a dispersion obtained by dissolving or dispersing more . The amount of the reducing agent is adjusted to be the reducing agent in the solvent is added to a solution or a more preferably 1.0 to 50 equivalents, even preferably 1.0 to 60 dispersion of the cyclic halosilane, ( c ) the cyclic halosilane 30 equivalents , particularly preferably 1.0 to 15 equivalents , and the reducing agent are simultaneously or sequentially and most preferably 1.0 to 2 equivalents . When the amount added to the solvent, and the like may be adopted . Among of the reducing agent is too much large, the productivity them , the embodiment (b ) is particularly preferable . tends to decrease due to much times required for the Also , when the cyclic halosilane is brought into contact post -treatment . On the other hand , when the amount of the 65 with the reducing agent , it is preferred that at least one of the reducing agent is too much small, the yield tends to decrease solution or the dispersion of the cyclic halosilane and the due to halogens without reducing . solution or the dispersion of the reducing agent is added US 10,676,365 B2 13 14 dropwise to the reaction system in which the reduction is carried out. One or both of the cyclic halosilane and the [Chemical Formula 6 ] reducing agent are added dropwise as described above , whereby exothermic generated in the reduction reaction can be controlled by the dropwise addition rate or the like , thus 5 + + 6 an effect of leading to improved productivity can be obtained 2 Ph3P 6 HSICI : such that it is possible to downsize a condenser or the like . yr The preferred embodiment when one or both of the cyclic halosilane and the reducing agent are added dropwise 10 includes the following three embodiments . That is , A ) an [PPh3 ] 2 [Si.Cl12 ] + 6 N + embodiment in which a solution or dispersion of the cyclic halosilane is charged in the reactor, and a solution or ? Clº dispersion of the reducing agent is added dropwise thereto , B ) an embodiment in which a solution or dispersion of the For example , when trichlorosilane is used as a starting reducing agent is charged in the reactor, and a solution or 15 material and triphenylphosphine (PPhz ) is used as the com dispersion of the cyclic halosilane is added dropwise thereto , pound I, a complex containing 6 -membered ring dode and C ) an embodiment in which a solution or dispersion of cachlorocyclohexasilane (neutral complex including triph the cyclic halosilane and a solution or dispersion of the enylphosphine coordinated to dodecachlorocyclohexasilane reducing agent are simultaneously or sequentially added 20 (scheme [ PPh3 ].2 [ThisSi , C1,2 neutral ]) ) is complex generally of aproduced cyclic halosilane as in the does above not dropwise to the reactor. Among them , the embodiment A ) is contain any silicon atom other than the silicon atoms that preferable . form the ring structure , and therefore, in the reduction , When one or both of the cyclic halosilane and the reduc alkylation or arylation , silane gas and organic monosilane ing agent are added dropwise by the embodiments A ) to C ) , are not generated , or silane gas and organic monosilane are the concentration in the solution or dispersion containing the 25 decreased in a small amount even if silane gas and organic cyclic halosilane is preferably not less than 0.01 mol/ L , monosilane are generated . more preferably not less than 0.02 mol/ L , further preferably The yield and yield constant of the neutral complex of a not less than 0.04 mol/ L , and particularly preferably not less cyclic halosilane produced in the cyclization reaction can be than 0.05 mol/ L . When the concentration of the cyclic calculated by a methylation reaction represented by the halosilane is too low , the amount of the solvent thatneeds to 30 tivelyfollowing. scheme, in which the complex reacts quantita be removed by distillation when isolating the objective product is increased , and thus the productivity tends to be lowered . On the other hand , the concentration in the solution or dispersion containing the cyclic halosilane is preferably [ Chemical Formula 7 ] 35 Me2 Mez notmore than 1 mol/ L , more preferably not more than 0.8 MeMgBr/ THF Si -Si, mol/ L , and further preferably not more than 0.5 mol/ L . [PPh3 ] 2 [ Si6C112 ] MezSi SiMe + The lower limit of the temperature during dropwise Si Si addition ( specifically , the temperature of a solution or a Mez Mez dispersion during dropwise addition ) is preferably -198 ° C., 40 (Si6Me12 ) more preferably –160 ° C., further preferably -100 ° C. The 2 PPhz + 12 MgBrCl upper limit of the temperature during dropwise addition is preferably + 150 ° C., more preferably + 100 ° C., further As a method for reducing a neutral complex of a cyclic preferably + 80 ° C., and particularly preferably + 40 ° C. The 45 halosilane ( e.g. [PPh3 ] 2 [ Si ,C1121 ) to obtain a cyclic hydro temperature of a reaction container ( reaction temperature ) genated silane ( e.g. cyclohexasilane ), for example , when may be appropriately set according to the types of a cyclic LiAlH4 is used as a reducing agent, the scheme is repre halosilane and a reducing agent, and generally , the lower sented as follows. limit is preferably set to -198 ° C., more preferably –160 ° C., further preferably -100 ° C. The upper limit of the tempera 50 ture of a reaction container (reaction solution ) is preferably [Chemical Formula 8 ] [PPh3 ]2 [S16C112 ] 3 LiAlH4 + 150 ° C., more preferably + 100 ° C., further preferably + 80 ° H H C., and particularly preferably + 40 ° C. When the reaction H Si H temperature is low , the decomposition or polymerization of 55 H Si Si - H an intermediate product or an object product can be sup + 2 Ph3P + 3 LiAlCl4 H - Si Si H pressed , resulting in improvement of yield . The reaction Si H time may be properly determined depending on the extent of ? / H reaction progress , and is usually not less than 10 minutes and not more than 72 hours , preferably not less than 1 hour and 60 Cyclohexasilane (CHS ) not more than 48 hours, and more preferably not less than 2 hours and not more than 24 hours . Hereinafter , many methods for reducing a content of the As one example , a scheme example using in the above linear hydrogenated silane and the cyclic hydrogenated method B trichlorosilane as the halosilane , triphenylphos- 65 silane having a branched structure of the hydrogenated phine (PPhz ) as the compound I , N , N - diisopropylethylamine silane composition are provided together the above method , (DIPEA ) as the tertiary amine is shown below . and it is recommended that appropriate methods are com US 10,676,365 B2 15 16 bined based on the degree of decreasing the content of the under reduced pressure . A method for distilling under linear hydrogenated silane and the cyclic hydrogenated reduced pressure is not limited particularly , and the distil silane having a branched structure . That is , in the case where lation under the reduced pressure may be carried out in the content of the linear hydrogenated silane and the cyclic known distillation column and may be carried out under hydrogenated silane having a branched structure cannot be 5 light shielding condition . When the inner temperature of the decreased to an intended content in one method , multiple distillation bottom is lowered by setting a heating tempera methods may be combined to decrease the content of the ture into a low temperature at the distillation , a contentof the linear hydrogenated silane and the cyclic hydrogenated linear hydrogenated silane of the hydrogenated silane com silane having a branched structure to a desired content. position tends to decrease , and the hydrogenated silane It is preferred that the reduction reaction is usually carried 10 composition containing the cyclic hydrogenated silane hav out under an atmosphere of an inert gas such as nitrogen gas ing the branched silyl group in an appropriate content tends or argon gas . to be easily obtained . The distillation is preferably carried The hydrogenated silane composition containing cyclo out by dividing the whole fraction into multiple fractions hexasilane produced in the reduction reaction can be isolated and an appropriate fraction may be selected from obtained by, for example , subjecting the reaction liquid obtained after 15 fractions, taking into the consideration of the content of the the reduction to solid - liquid separation to separate a solid linear hydrogenated silane and the cyclic hydrogenated ( impurities such as a salt of a by -product ) , distilling off the silane having a branched structure . In the case where many solvent under reduced pressure , to distill the hydrogenated fractions corresponding to first fraction at the distillation are silane composition . removed , a content of the linear hydrogenated silane of the As a method of solid - liquid separation , filtration is pref- 20 hydrogenated silane composition tends to decrease , and the erably employed for its simpleness, and the method is not hydrogenated silane composition containing the cyclic limited thereto , and common solid - liquid separations such as hydrogenated silane having the branched silyl group in an centrifugation and decantation can be appropriately appropriate content tends to be easily obtained . employed . One method for decreasing a content of normal hexasilane Asmentioned above , a content of the linear hydrogenated 25 of the linear hydrogenated silane and silylcyclopentasilane silane and the cyclic hydrogenated silane having a branched of the cyclic hydrogenated silane having a branched struc structure of the hydrogenated silane composition tends to ture of the hydrogenated silane composition includes a decrease , by washing the cyclic halosilane used in the method for carrying out a distillation (particularly distilla reduction reaction with the non -halogen solvent or by car tion under reduced pressure ) two or more times . For rying out solid - liquid separation of the hydrogenated silane 30 example , a solution containing the hydrogenated silane composition containing the cyclic hydrogenated silane composition is distilled under the reduced pressure , an obtained in the reduction reaction at least two times . appropriate fraction containing the cyclic hydrogenated For example , it is preferable that the solid - liquid separa silane (particularly cyclohexasila e ) in an appropriate con tion is carried out at least two times after reducing the cyclic tent is collected ( first distillation ), the collected fraction is halosilane. For example , a solution or a solid containing the 35 again distilled under the reduced pressure to collect an hydrogenated silane composition is subjected to solid -liquid appropriate fraction containing the cyclic hydrogenated separation ( first separation ), the solution containing the silane (particularly cyclohexasilane ) in an appropriate con hydrogenated silane composition is preferably concentrated , tent ( second distillation ) , and the second distillation may be the hydrocarbon solvent such as hexane is added as a solvent repeated if necessary. for dilution thereto , the hydrogenated silane composition is 40 In the case where the distillation under reduced pressure preferably concentrated , a precipitated solid is again sub is carried out two or more times , a temperature of a solution jected to solid - liquid separation ( second separation ), and (an inner temperature ) at the previous distillation under operations from the first separation to the second separation reduced pressure is preferably 25 to 65 ° C., more preferably may be repeated if necessary . After the first separation , the 30 to 60 ° C., even preferably 55 ° C. or lower , and a solvent dilution , the concentration , and the solid - liquid 45 temperature of a solution (an inner temperature ) at the post separation are more preferably carried out one or more distillation under reduced pressure is preferably 20 to 65 ° C., times . Thesemay be repeated multiple times. Thus, when the more preferably 30 to 60 ° C., and even preferably 50 ° C. or solid -liquid separation is carried out at least two times, lower. Further , the temperature of the solution at the previ byproducts of the linear hydrogenated silane and the cyclic ous distillation under reduced pressure may be the same as hydrogenated silane having a branched structure can be 50 the temperature of the solution at the post distillation under controlled , and a content of the linear hydrogenated silane reduced pressure . When the inner temperature becomes and the cyclic hydrogenated silane having a branched struc high , normal hexasilane and the like are increased in some ture of the hydrogenated silane composition can be cases . decreased . Thus, when the content of the linear hydroge In the case where the distillation under reduced pressure nated silane and the cyclic hydrogenated silane having a 55 is carried out two or more times , the previous distillation branched structure is decreased , cyclohexasilane can be under reduced pressure may be carried out at preferably 5 to distilled without requiring useless energy . 400 Pa, more preferably 10 to 300 Pa, even preferably 50 to The solid - liquid separation may be two times or three or 250 Pa , even more preferably 100 to 220 Pa , and the post times. The number of the solid - liquid separation is not distillation under reduced pressure may be carried out at limited particularly , and the upper limit of the solid - liquid 60 preferably 5 to 300 Pa ,more preferably 10 to 200 Pa, even separation is about five times in the viewpoint of the preferably 20 to 150 Pa, and even more preferably 30 to 120 productivity . Pa . The pressure of the previous distillation under reduced Next, if necessary , a solution containing the hydrogenated pressure may be the same as the pressure of the post silane composition obtained by the solid - liquid separation is distillation under reduced pressure . When the pressure is too concentrated , and the hydrogenated silane composition 65 much low , the impurities are hardly separated in some cases. (preferably cyclohexasilane ) having high concentration is The temperature and the pressure of the previous distil preferably distilled . The distillation is preferably distillation lation under reduced pressure are preferably higher than the US 10,676,365 B2 17 18 temperature and the pressure of the post distillation under Gas Chromatography (GC ) Analysis Method reduced pressure in the viewpoint of improving the purify Measurement Method : GC FID method ing degree of the cyclic hydrogenated silane . Analyzing device: GC2014 manufactured by Shimadzu Cor The pressure used in the first fraction of the post distil poration lation under reduced pressure is preferably higher than the 5 (Column Film ) x0.25 : Agilent mm (Diam J & W )x30 GC m column(Length )DB ( Agilent - 5MS Technolo0.25 ?m pressure used in the fractions other than the first fraction of gies) the post distillation under reduced pressure in the viewpoint Temperature of vaporization chamber : 250 ° C. of removing the linear hydrogenated silane ( for example Temperature of detector: 280º C. normal hexasilane ) . Temperature elevating conditions : at 50 ° C. for 5 minutes, The distillation under reduced pressure may be carried out 10 elevation of temperature up to 250 ° C. at a temperature in batch because impurities having a higher boiling point elevating rate of 20 ° C./minute , elevation of temperature up than that of cyclohexasilane and impurities having a lower to 280º C. at a temperature elevating rate of 10 ° C./minute , boiling point than that of cyclohexasilane are separated , and and at 280 ° C. for 10 minutes. a content of the linear hydrogenated silane and the cyclic hydrogenated silane having a branched structure is 15 Production Example 1 (Production of Cyclic decreased in the hydrogenated silane composition . Halosilane ) Fractions obtained in the distillation under reduced pres The inside of a 3 L four -necked flask equipped with a sure ( particularly second distillation under reduced pressure ) thermometer , a condenser, a dropping funnel and a stirrer may be divided into 1 to 20 fractions, 2 to 15 fractions , or 20 was replaced with nitrogen gas, and 155 g ( 0.591 mol) of 3 to 10 fractions. triphenylphosphine as a coordination compound , 458 g It is preferable that fractions are obtained by dividing into (3.54 mol) of diisopropylethylamine as a basic compound multiple fractions while the temperature of the inner solution and 1789 g of 1,2 -dichloroethane as a solvent were then and the pressure are controlled within the above temperature charged therein , to prepare a solution . Subsequently , while and the above pressure, and it is more preferable that 25 trichlorosilanethe solution in asthe a halosilaneflask was compoundstirred, 481 was g (slowly3.54 mol added ) of fractions are obtained by dividing into multiple fractions dropwise from the dropping funnel in the condition of 25 ° C. while a maximum pressure is gradually decreased within the After the completion of dropwise addition , the cyclization above pressure range and a minimum temperature of the coupling reaction was carried out by continuously stirring inner solution is gradually increased within the above tem the mixture for 2 hours and subsequently heating and stirring perature . 30 the mixture at 60 ° C. for 8 hours to give a homogeneous It is preferable that a first fraction is removed from all reaction solution . The resultant reaction solution was con distilled fractions in the distillation under reduced pressure . densed and 7200 g of chloroform was added thereto , a mixture was stirred at room temperature for one hour , the In at least one embodiment of the present disclosure , the mixture was washed and filtered , and filtered residue was storage stability of cyclohexasilane may be evaluated with 35 dried under reduced pressure to give a crude product of the the following formula in the case where the cyclohexasilane cyclic halosilane as a white solid . is restored at 20 ° C. for five months in a container (for Subsequently , to the white solid obtained in the above, example , SUS container , preferably surface- polished SUS five times volume of dehydrated hexane on a mass basis was container, more preferably electro -polished SUS container ) added , a mixture was stirred for 24 hours at room tempera having the light shielding property and the pressure resis- 40 ture , washed and filtered . The resultant filtered residue was tance . again subjected to washing and filtration using hexane in the same manner as the above , and the resultant filtered residue (GC purity ( Y ) of sample restored at 20 ° C. for five was dried under reduced pressure to obtain a purified cyclic months/ GC purity ( X ) of sample )x100 ( Z ) halosilane compound (bis ( triphenylphosphine )dodecachlo A value of the formula ( 2 ) is preferably 97.8 % or more , 45 rocyclohexasilane ( [ Ph3P ] 2[ Si ,Cl 2 ] )) . All steps of from more preferably 98.0 % or more , even preferably 98.3 % or washing to drying were carried out in nitrogen atmosphere . more , and even more preferably 98.5 % or more in the When the resultant purified product was objected to gas viewpoint of the storage stability for long time of cyclohex chromatography, 1 % by mass of chloroform as halogenated asilane. The upper limit of the formula ( Z ) may be 99.999 % , hydrocarbon and 1 % by mass of amine salt (amine hydro or 99.99 % . 50 chloride ) were contained in the purified product . In the at least one embodiment of the present disclosure , the hydrogenated silane composition is characterized in that Example 1-1 (Production of Crude Cyclic a content ratio of normal hexasilane and silylcyclopentasi Hydrogenated Silane ) lane to cyclohexasilane is decreased by 0.0020 or less on a 55 To a 10 L flask under nitrogen atmosphere, 1099 g of the mass basis . Therefore , the storage stability of the cyclohex purified cyclic halosilane obtained in the above Production asilane can be improved . Example 1 and 5226 g of diethyl ether were charged and stirred at -40 ° C. Then , 2005 g of a 1M diethyl ether solution EXAMPLE of LiAlH4 as a reducing agent was added dropwise from the 60 dropping funnel . After the completion of the addition , a The present disclosure will be more specifically described solution was stirred at -40 ° C. for three hours , and the below with reference to Examples, but the present disclosure reduction reaction was carried out. Then , a reaction solution is not limited to the following Examples , and can be was heated to a room temperature , the solution was sub implemented with appropriate modifications within the jected to solid - liquid separation by decantation under nitro scope conforming to the purport of what is mentioned above 65 gen atmosphere , diethyl ether solvent was distilled off under and below herein . All of such modifications are included in reduced pressure from 6974 g of the resultant solution , and the technical scope of the present disclosure. 3810 g of dehydrated hexane was added thereto . After the US 10,676,365 B2 19 20 addition of the hexane , diethyl ether and hexane were GC purity was 98.1 % . In addition , 29Si- NMR was measured distilled off under reduced pressure to concentrate the solu for two times -distilled cyclohexasilane and the production of tion , and the solution was subjected to solid - liquid separa the polymer component was not observed . tion by the filtration at 0 ° C. to remove a precipitated solid . On the other hand, for two times -distilled cyclohexasilane After a solvent was further distilled off from a filtrate, the 5 described in Table 1 , the fraction 1 of Lot.C (GC purity resultant solution was filtered to obtain 160 g of crude ( Area % ) 98.9 % ) was charged in a stainless (SUS ) container cyclohexasilane as a filtrate . having a pressure resistance and stored at a room tempera ture (20 ° C.) within a glove box under nitrogen atmosphere . Example 1-2 (Production of Purified Cyclic At the time when five months were passed , GC purity of Hydrogenated Silane ) 10 cyclohexasilane was measured using a gas chromatography device , and GC purity was 96.6 % . In addition , 29Si- NMR Under light shielding condition , 139 g of crude cyclohex was measured for two times- distilled cyclohexasilane and asilane was subjected to a distillation under reduced pressure ( conditions: temperature of inner solution of 41 to 53 ° C., a the production of the polymer component was observed . pressure of 120 to 200 Pa ) using a distillation equipment 15 These results are shown in Table 2 . which was made of glass and was equipped with a vigreux column, a flask , a fractionating column, a condenser ( a TABLE 2 cooling pipe ), and a receiver to 51 g of roughly distilled Initial Purity after Production cyclohexasilane ( fractions 1 to 5 , GC purify ( Area % ) : Content ratio of purity five of 95.4 % to 98.1 % ). Then , 114 g of roughly distilled cyclo- 20 ( n -HS + Si -CPS )/ CHS ( % ) months ( % ) polymer hexasilane was subjected to a distillation under reduced Lot. A 0.0011 99.0 97.8 No pressure ( conditions: temperature of inner solution of 35 to ( Example ) Lot.B 0.0007 99.0 98.1 No 43 ° C., a pressure of 60 to 97 Pa ) using a distillation (Example ) equipment which was made of glass and was equipped with 0.0030 a vigreux column, a flask , a fractionating column, a con- 25 Lot.C(Comparative 98.9 96.6 Yes denser ( a cooling pipe) , and a receiver under light shielding Example ) condition to 106 g of two times- distilled cyclohexasilane ( fractions 1 to 5 , GC purify ( Area % ) : 98.0 % to 99.1 % ) . According to measured results of gas chromatography, Example 2-1 (Production of Crude Cyclic contents of normal hexasilane (n -HS ) of the linear hydro- 30 Hydrogenated Silane ) genated silane and silylcyclopentasilane (Si - CPS ) of the cyclic hydrogenated silane having a branched structure of To a 10 L flask under nitrogen atmosphere in the same the two times -distilled cyclohexasilane are shown in Table 1 . manner as in Example 1-1, 1099 g of the purified cyclic In addition , conditions for obtaining each fractions are also halosilane obtained in the above Production Example 1 and shown in Table 1 . 35 5217 g of diethyl ether were charged and stirred at -40 ° C. Then , 2000 g of a 1M diethyl ether solution of LiAlH4 as a TABLE 1 reducing agent was added dropwise from the dropping Two - times Temperature ( n -HS + funnel . After the completion of the addition , a solution was distilled Pres of inner CHS n -HS Si - CPS Si- CPS ) / stirred at -40 ° C. for three hours, and the reduction reaction cyclo sure solution ( area- ( area- (area CHS 40 was carried out. Then , a reaction solution was heated to a hexasilane ( Pa) (° C . ) % ) % ) % ) ( area- % ) room temperature , the solution was subjected to solid - liquid Fraction 1 74-97 35 98.9 0.21 0.09 0.0030 separation by decantation under nitrogen atmosphere , Fraction 2 65-77 36 99.0 0.15 0.08 0.0023 diethyl ether solvent was distilled off under reduced pressure Fraction 3 62-69 35-36 99.1 0.11 0.09 0.0020 from 6273 g of the resultant solution , and 3344 g of Fraction 4 60-71 36-39 99.0 0.03 0.08 0.0011 45 dehydrated hexane was added thereto . After the addition of Fraction 5 65-80 40-43 98.0 0.004 0.07 0.0008 the hexane, diethyl ether and hexane were distilled off under reduced pressure to concentrate the solution , and the solu tion was subjected to solid -liquid separation by the filtration Test Example 1 (Evaluation of Storage Stability ) at 0 ° C. to remove a precipitated solid . After a solvent was 50 further distilled off from a filtrate , the resultant solution was For two times -distilled cyclohexasilane obtained in filtered to obtain 72 g of crude cyclohexasilane as a filtrate . Example 1-2 , the fraction 4 of Lot.A (GC purity ( Area % ) 99.0 % ) was charged in a stainless (SUS ) container having a Example 2-2 (Production of Purified Cyclic pressure resistance and stored at a room temperature (20 ° C.) Hydrogenated Silane ) within a glove box under nitrogen atmosphere . At the time 55 when five months were passed , GC purity of cyclohexasi Under light shielding condition , 71 g of crude cyclohex lane was measured using a gas chromatography device , and asilane was subjected to a distillation under reduced pressure GC purity was 97.8 % . In addition , 29Si- NMR was measured ( conditions: temperature of inner solution of 40 to 50 ° C., a for two times -distilled cyclohexasilane and the production of pressure of 130 to 190 Pa ) using a distillation equipment the polymer component was not observed . 60 which was made of glass and was equipped with a vigreux For another two times- distilled cyclohexasilane obtained column, a flask , a fractionating column , a condenser (a in Example 1-2 , the fraction 4 of Lot.B (GC purity ( Area % ) cooling pipe ), and a receiver to 50 g of roughly distilled 99.0 % ) was charged in a stainless ( SUS) container having a cyclohexasilane ( fractions 1 to 5 , GC purify ( Area % ): pressure resistance and stored at a room temperature (20 ° C.) 97.3 % to 99.2 % ) . Then , 44 g of roughly distilled cyclohex within a glove box under nitrogen atmosphere . At the time 65 asilane was subjected to a distillation under reduced pressure when five months were passed , GC purity of cyclohexasi ( conditions: temperature of inner solution of 33 to 42 ° C., a lane was measured using a gas chromatography device , and pressure of 63 to 73 Pa ) using a distillation equipment which US 10,676,365 B2 21 22 was made of glass and was equipped with a vigreux column, asilane and the production of the polymer component was a flask , a fractionating column , a condenser (a cooling pipe ), observed . These results are shown in Table 4 . and a receiver under light shielding condition to 41 g of two times- distilled cyclohexasilane ( fractions 1 to 5 , GC purify TABLE 4 (Area % ): 99.1 % to 99.6 % ) . According to measured results 5 Purity of gas chromatography , contents of normal hexasilane after ( n - HS ) of the linear hydrogenated silane and silylcyclopen Initial five tasilane (Si - CPS ) of the cyclic hydrogenated silane having a Content ratio of purity months Production of branched structure of the two times -distilled cyclohexasi ( n - HS + Si- CPS ) / CHS ( % ) ( % ) polymer lane are shown in Table 3. In addition , conditions for 10 Lot.D 0.0005 99.6 99.2 No obtaining each fractions are also shown in Table 3 . ( Example ) Lot . E 0.0008 99.6 98.7 No TABLE 3 (Example ) Lot.F 0.0029 99.1 97.0 Yes (Comparative Two times Temperature ( n -HS + 15 distilled Pres of inner CHS n - HS Si - CPS Si- CPS ) / Example ) cyclo sure solution ( area- ( area- ( area CHS hexasilane (Pa ) (° C .) % ) % ) % ) ( area- % ) Fraction 1 68-73 33-34 99.1 0.23 0.06 0.0029 The invention claimed is : Fraction 2 71-75 35-36 99.6 0.11 0.06 0.0017 Fraction 3 65-69 35-36 99.6 0.06 0.05 0.0010 20 1. A hydrogenated silane composition , wherein a content Fraction 4 63-70 34-37 99.6 0.01 0.04 0.0005 ratio of linear hydrogenated hexasilane and silylcyclopen Fraction 5 62 37-42 99.1 0.01 0.04 0.0004 tasilane to cyclohexasilane is 0.00001 or more and 0.0020 or less on a mass basis . Test Example 2 (Evaluation of Storage Stability ) 25 2. The hydrogenated silane composition according to claim 1 , wherein a content of silylcyclopentasilane is 0.0001 For two times -distilled cyclohexasilane obtained in to 0.5 % by mass per 100 % by mass of the hydrogenated Example 2-2, the fraction 4 of Lot.D (GC purity ( Area % ) silane composition . 99.6 % ) was charged in a stainless (SUS ) container having a 3. The hydrogenated silane composition according to pressure resistance and stored at a room temperature ( 20 ° C.) 30 claim 1 ,wherein a content of linear hydrogenated hexasilane within a glove box under nitrogen atmosphere . At the time is 0.5 % by mass or less per 100 % by mass of the hydroge when five months were passed , GC purity of cyclohexasi nated silane composition . lane was measured using a gas chromatography device , and 4. The hydrogenated silane composition according to GCfor twopurity times was -distilled 99.2 % . cyclohexasilaneIn addition , 29Si -and NMR the was production measured of 35 claim 2, wherein a content of linear hydrogenated hexasilane the polymer component was not observed . is 0.5 % by mass or less per 100 % by mass of the hydroge In addition , the fraction 4 of Lot.E (GC purity (Area % ) nated silane composition . 99.6 % ) of two times- distilled cyclohexasilane obtained in 5. The hydrogenated silane composition according to the same manner as in Example 2-2 was charged in a claim 1 , wherein a content of cyclohexasilane is 97 % by stainless (SUS ) container having a pressure resistance and 40 mass or more per 100 % by mass of the hydrogenated silane stored at a room temperature (20 ° C.) within a glove box composition . under nitrogen atmosphere . At the time when five months were passed , GC purity of cyclohexasilane was measured 6. The hydrogenated silane composition according to using a gas chromatography device , and GC purity was claim 2 , wherein a content of cyclohexasilane is 97 % by 98.7 % . In addition , 29Si- NMR was measured for two times- 45 mass or more per 100 % by mass of the hydrogenated silane distilled cyclohexasilane and the production of the polymer composition . component was not observed . 7. The hydrogenated silane composition according to On the other hand , the fraction 1 of Lot.F (GC purity claim 3 , wherein a content of cyclohexasilane is 97 % by ( Area % ) 99.1 % ) of two times - distilled cyclohexasilane mass or more per 100 % by mass of the hydrogenated silane described in Table 3 was charged in a stainless (SUS ) 50 composition . container having a pressure resistance and stored at a room temperature (20 ° C.) within a glove box under nitrogen 8. The hydrogenated silane composition according to atmosphere . At the timewhen five months were passed , GC claim 4 , wherein a content of cyclohexasilane is 97 % by purity of cyclohexasilane was measured using a gas chro mass or more per 100 % by mass of the hydrogenated silane matography device , and GC purity was 97.0 % . In addition , 55 composition . 29Si- NMR was measured for two times -distilled cyclohex