JPS641405B2 - - Google Patents
Info
- Publication number
- JPS641405B2 JPS641405B2 JP16728481A JP16728481A JPS641405B2 JP S641405 B2 JPS641405 B2 JP S641405B2 JP 16728481 A JP16728481 A JP 16728481A JP 16728481 A JP16728481 A JP 16728481A JP S641405 B2 JPS641405 B2 JP S641405B2
- Authority
- JP
- Japan
- Prior art keywords
- monosilane
- impurities
- ethane
- monochlorosilane
- gas
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 claims description 52
- 239000012535 impurity Substances 0.000 claims description 30
- 238000011282 treatment Methods 0.000 claims description 11
- 229910021536 Zeolite Inorganic materials 0.000 claims description 9
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 claims description 9
- 239000010457 zeolite Substances 0.000 claims description 9
- VXEGSRKPIUDPQT-UHFFFAOYSA-N 4-[4-(4-methoxyphenyl)piperazin-1-yl]aniline Chemical compound C1=CC(OC)=CC=C1N1CCN(C=2C=CC(N)=CC=2)CC1 VXEGSRKPIUDPQT-UHFFFAOYSA-N 0.000 claims description 7
- 239000005049 silicon tetrachloride Substances 0.000 claims description 7
- 239000011148 porous material Substances 0.000 claims description 6
- HJXBDPDUCXORKZ-UHFFFAOYSA-N diethylalumane Chemical compound CC[AlH]CC HJXBDPDUCXORKZ-UHFFFAOYSA-N 0.000 claims description 3
- CMFFRNMPXYSZIX-UHFFFAOYSA-N [C+4] Chemical class [C+4] CMFFRNMPXYSZIX-UHFFFAOYSA-N 0.000 claims 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 26
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 20
- KOPOQZFJUQMUML-UHFFFAOYSA-N chlorosilane Chemical compound Cl[SiH3] KOPOQZFJUQMUML-UHFFFAOYSA-N 0.000 description 20
- 238000000034 method Methods 0.000 description 17
- 229910003902 SiCl 4 Inorganic materials 0.000 description 13
- 239000003638 chemical reducing agent Substances 0.000 description 8
- 238000006722 reduction reaction Methods 0.000 description 8
- 238000001179 sorption measurement Methods 0.000 description 7
- 238000001816 cooling Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 239000002904 solvent Substances 0.000 description 5
- -1 etc. Chemical compound 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 238000000746 purification Methods 0.000 description 4
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 3
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 3
- 229940057995 liquid paraffin Drugs 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 235000013162 Cocos nucifera Nutrition 0.000 description 2
- 244000060011 Cocos nucifera Species 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- IMNFDUFMRHMDMM-UHFFFAOYSA-N N-Heptane Chemical compound CCCCCCC IMNFDUFMRHMDMM-UHFFFAOYSA-N 0.000 description 2
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 2
- 239000006227 byproduct Substances 0.000 description 2
- 239000003610 charcoal Substances 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- MROCJMGDEKINLD-UHFFFAOYSA-N dichlorosilane Chemical compound Cl[SiH2]Cl MROCJMGDEKINLD-UHFFFAOYSA-N 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- HCWCAKKEBCNQJP-UHFFFAOYSA-N magnesium orthosilicate Chemical compound [Mg+2].[Mg+2].[O-][Si]([O-])([O-])[O-] HCWCAKKEBCNQJP-UHFFFAOYSA-N 0.000 description 2
- 229910052919 magnesium silicate Inorganic materials 0.000 description 2
- 235000019792 magnesium silicate Nutrition 0.000 description 2
- 239000000391 magnesium silicate Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 239000005046 Chlorosilane Substances 0.000 description 1
- 229910003910 SiCl4 Inorganic materials 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 239000003463 adsorbent Substances 0.000 description 1
- 150000001338 aliphatic hydrocarbons Chemical class 0.000 description 1
- 150000004945 aromatic hydrocarbons Chemical class 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- HRYZWHHZPQKTII-UHFFFAOYSA-N chloroethane Chemical compound CCCl HRYZWHHZPQKTII-UHFFFAOYSA-N 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 235000019441 ethanol Nutrition 0.000 description 1
- 150000002170 ethers Chemical class 0.000 description 1
- 229960003750 ethyl chloride Drugs 0.000 description 1
- KCWYOFZQRFCIIE-UHFFFAOYSA-N ethylsilane Chemical compound CC[SiH3] KCWYOFZQRFCIIE-UHFFFAOYSA-N 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000012280 lithium aluminium hydride Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000003595 mist Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- FDNAPBUWERUEDA-UHFFFAOYSA-N silicon tetrachloride Chemical compound Cl[Si](Cl)(Cl)Cl FDNAPBUWERUEDA-UHFFFAOYSA-N 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 1
- ZDHXKXAHOVTTAH-UHFFFAOYSA-N trichlorosilane Chemical compound Cl[SiH](Cl)Cl ZDHXKXAHOVTTAH-UHFFFAOYSA-N 0.000 description 1
- 239000005052 trichlorosilane Substances 0.000 description 1
- QQQSFSZALRVCSZ-UHFFFAOYSA-N triethoxysilane Chemical compound CCO[SiH](OCC)OCC QQQSFSZALRVCSZ-UHFFFAOYSA-N 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Silicon Compounds (AREA)
Description
本発明は、モノシランの精製方法に関し、さら
に詳しくは、四塩化ケイ素（SiCl4）をジエチル
アルミニウムハイドライド（AlEt2H）で還元し
て、モノシランガスを製造するに当り、得られる
モノシランガス中に副生随伴するモノクロルシラ
ン、及びエタン並びに未反応のSiCl4を極めて効
率的に除去する方法に関する。
上記のモノシランの合成反応は次式で示される
が、この反応を、そのまま実施して得たモノシラ
ンガス中には、各種不純物、特にモノクロルシラ
ンとエタンが多量に副生する。
SiCl4＋4AlEt2H→SiH4＋4AlEt2Cl
このモノシランは、半導体製造に不可欠な物質
であり、その純度に対する要求は非常に厳しい。
それゆえ、その要求を満足する精製方法の開発が
望まれている。
従来モノシラン中の不純物を除去する方法とし
ては、モノシランガスを活性炭と細孔直径５〜９
Åの合成ゼオライトの両者を使つて吸着精製する
方法（特開昭50−9598号）が提案されている。し
かしながら、この方法はトリエトキシシランを原
料としたモノシランガス中の不純物を吸着除去す
るのに適した方法であり、エチルシラン、塩化エ
チル、エチルアルコール、ジエチルエーテルなど
の吸着除去に有効であるけれども、モノクロルシ
ランやエタンの吸着除去に効果がない。また、多
孔性粒状木炭と多孔性粒状ケイ酸マグネシウムの
両者を使つてモノシランガスの精製を行う方法が
知られている（特開昭53−76200号）。しかしこの
方法によれば、クロルシランは吸着除去されるけ
れども、エタンは多孔性粒状木炭、多孔性粒状ケ
イ酸マグネシウムのいずれによつても吸着されな
い。
したがつて上記２件の従来法は、AlEt2Hと
SiCl4から合成される。SiCl4、モノクロルシラン
及びエタンを主な不純物として含有するモノシラ
ンガスの精製方法としては効果が無く不適当であ
つた。
本発明者らは、こうした従来の、モノシランガ
スの精製法の欠点を克服するため種々検討を重ね
た結果、所定の還元工程、冷却工程及び吸着工程
をそれぞれ選択し、これを特定の順序で行うこと
により、上記３不純物（SiCl4、モノクロルシラ
ン、エタン）が極めて効率良く除去できることを
見出した。
すなわち本発明は、四塩化ケイ素をジエチルア
ルミニウムハイドライドで還元して得た不純物を
含むモノシランを精製するに当り、このモノシラ
ンを(i)還元処理する(ii)−20℃以下に冷却処理する
(iii)活性炭で処理する(iv)細孔直径４〜4.5Åの合成
ゼオライトで処理する、の各処理に順に付すこと
により、その中の不純物を除去することを特徴と
するモノシランの精製方法を提供するものであ
る。
本発明方法において(i)の工程では還元剤によつ
て、モノシランに混在する四塩化ケイ素がモノシ
ランに還元され、主な不純物の一つが消去され
る。
不純物を含むモノシランガスと還元剤の接触方
法としては、不純物を含むモノシランガスを還元
剤の液又は溶液中を通過させる気液接触方式をと
つてもよく、また、還元剤を吸収させた多孔質体
中を通過させるような気固接触方式をとつてもよ
い。気液接触方式の場合の装置の型式は、スクラ
バー型式、段塔型式など気液接触を行えるもので
あればいずれの型式でもよいが、設備が安価であ
る気泡塔型式が好ましい。
還元剤としてはAlEt2Hが最も好ましい。これ
は、本発明で対象としているモノシランの製造に
用いられているからである。しかし、リチウムア
ルミニウムハイドライドやナトリウムアルミニウ
ムハイドライドも用いることができる。
還元処理は、溶媒を用いてもよいが、モノシラ
ンと反応せず、また沸点が高く、蒸気圧の低いも
のがよい。その例としては、脂肪族炭化水素、芳
香族炭化水素及びエーテル類があり、具体例とし
ては、ヘプタン、トルエン、テトラヒドロフラ
ン、流動パラフインなどがあげられ、特に流動パ
ラフインが好ましい。
還元温度は、あまりに高いと、還元反応はよく
進むが溶媒の蒸気圧が高くなるので好ましくな
い。また低すぎた場合は、還元反応が進まない。
一般に、−10〜60℃の範囲が好ましく、０〜40℃
の範囲がより好ましい。
以上のようにしてSiCl4をモノシランに変化さ
せて除去することにより、後段の(iii)の工程で使用
する吸着剤である活性炭の負荷を大幅に低減でき
る。
すなわち、活性炭は、四塩化ケイ素とモノクロ
ルシランを非常によく吸着するけれども、エタン
はほとんど吸着しない。そして四塩化ケイ素をモ
ノクロルシランより優先的に吸着する。そこで、
この(i)の工程により四塩化ケイ素が消滅して吸着
除去する必要が無くなるので、活性炭のモノクロ
ルシランに対する吸着容量は、最大限に発揮され
る。
なお、(i)の工程の還元処理により、モノシラン
中に微量混在するジクロルシラン、トリクロルシ
ランもモノシランに還元され消去される。また還
元剤の溶液を用いた場合、用いた溶液の溶解効果
による不純物の除去も達成される。
(i)の工程を終えた、モノクロルシランとエタン
を主な不純物として含むモノシランガスは(ii)の工
程に導入される。
(ii)の工程は、モノシランガスを−20℃以下に冷
却した不純物を凝縮トラツプする工程である。こ
のため温度はできるかぎり低くすることが必要で
あるが、モノシランの露点以上としなければなら
ない。冷却温度をあまりに低くすることは設備上
の制約があり好ましくない。また高むぎると、凝
縮効果が落ちる。そこで操作時の圧力との関係に
よるが−20〜−75℃の範囲が好ましい。
この工程で用いられる装置は、モノシランガス
を所定の温度まで冷却できれば、いずれの型式の
冷却器でもよいが、冷却により凝縮した不純物が
霧状となりモノシランガス中に浮遊するため、こ
の液滴を捕集できる構造とすることが望まれる。
(ii)の工程で除去される不純物は、モノクロルシ
ランの一部と、(i)の工程で混入する還元剤と溶媒
である。
以上のようにして(i)の工程でSiCl4を消去する
結果として、(i)の工程で用いた還元剤と溶媒を、
モノクロルシランの一部と共に除去するため(ii)の
工程が必要となるのであり、(ii)の工程は(i)の工程
に引き続いて行われなければならない。
そうすると、後に続く、(iii)の工程及び(iv)の工程
を導入されるモノシランガス中の主な不純物は、
モノクロルシランとエタンになる。これらの不純
物は、(iii)の工程と(iv)の工程で、以下に示すように
別個に除去される。
(ii)の工程を終えた、残余の不純物を含むモノシ
ランガスは(iii)の工程へ導入される。(iii)の工程は活
性炭を充填した塔に上記モノシランガスを通すこ
とにより実施される。
使用する活性炭は、粒状高比表面積のものがよ
く、必要であれば、活性化処理してもよい。活性
炭の粒子の大きさは４〜32メツシユの範囲が好ま
しい。
(iii)の工程の温度は、特に制限は無いが、あまり
に低いと装置が高価になり、またモノシランの吸
着ロスが大きくなり、あまりに高いと不純物の吸
着除去効果が落ちるので−20〜−75℃の範囲が好
ましい。
(iii)の工程で吸着除去される不純物は、モノクロ
ルシランの残り全部であり、同時に、極微量存在
しているジクロルシランも吸着除去される。
(iii)の工程を終えた残りの不純物を含むモノシラ
ンガスは、(iv)の工程へ導入される。
(iv)の工程は、合成ゼオライト４Ａを充填した塔
に上記モノシランガスを通過させて実施すること
ができる。
合成ゼオライトの細孔直径は、エタンの分子直
径が４Åなので、それ以下ではエタンが吸着され
ない。また細孔直径が4.5Å以上ではモノシラン
も吸着されるのでモノシランのロスが多くなる。
それ故、好ましい細孔直径は４Å以上4.5Å未満
の範囲である。
合成ゼオライトの大きさは、４メツシユから32
メツシユの範囲が好ましい。また、必要に応じ、
加熱処理、減圧処理などの活性化処理を行うこと
ができる。
(iv)の工程の温度は、特に制限は無いが、あまり
に低いと装置が高価になり、あまりに高いと不純
物の吸着除去効果が落ちるので−20〜−75℃の範
囲が好ましい。
(iii)の工程、(iv)の工程共、−20〜−75℃の範囲で
は、操作する圧力によつて決定されるモノシラン
の露点以上であるかぎり、できるだけ低い温度が
好ましい。
(iv)の工程で吸着除去される不純物は、エタンで
あり、同時に極微量存在しているメタンも吸着除
去される。
本発明においては、(iii)の工程の次に(iv)の工程を
行うことが必要であり、この順に逆にすると除去
操作が効率的に行えない。
例えば、不純物として、モノクロルシランを
800ppm、エタンを1000ppm含むモノシランガス
を(iii)の工程の活性炭層を通過させたのち(iv)の工程
の合成ゼオライト４Ａ層に通過させた場合（実験
No.１）及びこの順序を逆にした場合（実験No.２）
について、通過後の精製ガスに未吸着のエタンが
混入すると、いわゆる破過点までのモノシランの
流出量を測定した結果は第１表の通りである。明
らかに本発明の順序がすぐれていることがわか
る。
The present invention relates to a method for purifying monosilane, and more specifically, when silicon tetrachloride (SiCl 4 ) is reduced with diethylaluminum hydride (AlEt 2 H) to produce monosilane gas, by-products are present in the monosilane gas obtained. The present invention relates to a method for extremely efficiently removing monochlorosilane, ethane, and unreacted SiCl 4 . The above monosilane synthesis reaction is shown by the following formula, but in the monosilane gas obtained by carrying out this reaction as it is, a large amount of various impurities, especially monochlorosilane and ethane, are produced as by-products. SiCl 4 +4AlEt 2 H→SiH 4 +4AlEt 2 Cl This monosilane is an essential substance for semiconductor manufacturing, and the requirements for its purity are very strict.
Therefore, it is desired to develop a purification method that satisfies these requirements. The conventional method for removing impurities in monosilane is to mix monosilane gas with activated carbon and pores with a diameter of 5 to 9.
A method of adsorption purification using both synthetic zeolite and zeolite has been proposed (Japanese Unexamined Patent Publication No. 1983-9598). However, although this method is suitable for adsorbing and removing impurities in monosilane gas made from triethoxysilane as a raw material, and is effective for adsorbing and removing ethylsilane, ethyl chloride, ethyl alcohol, diethyl ether, etc., monochlorosilane It is not effective in adsorbing and removing ethane or ethane. Furthermore, a method for purifying monosilane gas using both porous granular charcoal and porous granular magnesium silicate is known (Japanese Unexamined Patent Publication No. 76200/1983). However, according to this method, although chlorosilane is adsorbed and removed, ethane is not adsorbed by either porous granular charcoal or porous granular magnesium silicate. Therefore, the above two conventional methods are suitable for AlEt 2 H and
Synthesized from SiCl4 . This method was ineffective and inappropriate as a method for purifying monosilane gas containing SiCl 4 , monochlorosilane, and ethane as main impurities. In order to overcome the drawbacks of the conventional monosilane gas purification method, the present inventors have conducted various studies, and as a result, have selected a predetermined reduction step, cooling step, and adsorption step, and conducted them in a specific order. It has been found that the above three impurities (SiCl 4 , monochlorosilane, and ethane) can be removed extremely efficiently. That is, in the present invention, when purifying monosilane containing impurities obtained by reducing silicon tetrachloride with diethylaluminium hydride, this monosilane is (i) subjected to a reduction treatment, and (ii) is subjected to a cooling treatment to below -20°C.
A method for purifying monosilane characterized by removing impurities therein by sequentially subjecting it to the following treatments: (iii) treatment with activated carbon and (iv) treatment with synthetic zeolite with a pore diameter of 4 to 4.5 Å. This is what we provide. In step (i) of the method of the present invention, silicon tetrachloride mixed in monosilane is reduced to monosilane by a reducing agent, and one of the main impurities is eliminated. As a method of contacting the monosilane gas containing impurities with the reducing agent, a gas-liquid contact method may be used in which the monosilane gas containing impurities is passed through a liquid or solution of the reducing agent, or a porous body in which the reducing agent is absorbed. It is also possible to use a gas-solid contact method that allows the material to pass through. In the case of a gas-liquid contact system, the type of apparatus may be any type that can perform gas-liquid contact, such as a scrubber type or a tray column type, but a bubble column type is preferable because of its inexpensive equipment. AlEt 2 H is most preferred as the reducing agent. This is because it is used in the production of monosilane, which is the subject of the present invention. However, lithium aluminum hydride and sodium aluminum hydride can also be used. Although a solvent may be used in the reduction treatment, it is preferable to use a solvent that does not react with monosilane, has a high boiling point, and has a low vapor pressure. Examples thereof include aliphatic hydrocarbons, aromatic hydrocarbons, and ethers, and specific examples include heptane, toluene, tetrahydrofuran, liquid paraffin, and the like, with liquid paraffin being particularly preferred. If the reduction temperature is too high, the reduction reaction will proceed well, but the vapor pressure of the solvent will increase, which is not preferable. If it is too low, the reduction reaction will not proceed.
Generally, a range of -10 to 60°C is preferred, and 0 to 40°C.
The range is more preferable. By converting SiCl 4 into monosilane and removing it as described above, the load on activated carbon, which is an adsorbent used in the subsequent step (iii), can be significantly reduced. That is, activated carbon adsorbs silicon tetrachloride and monochlorosilane very well, but hardly adsorbs ethane. It adsorbs silicon tetrachloride more preferentially than monochlorosilane. Therefore,
By this step (i), silicon tetrachloride disappears and there is no need to remove it by adsorption, so the adsorption capacity of activated carbon for monochlorosilane is maximized. In addition, by the reduction treatment in step (i), dichlorosilane and trichlorosilane present in trace amounts in monosilane are also reduced to monosilane and eliminated. Furthermore, when a solution of a reducing agent is used, removal of impurities is also achieved due to the dissolution effect of the solution used. After completing step (i), the monosilane gas containing monochlorosilane and ethane as main impurities is introduced into step (ii). Step (ii) is a step in which monosilane gas is cooled to −20° C. or lower and impurities are condensed and trapped. For this reason, it is necessary to keep the temperature as low as possible, but it must be at least the dew point of monosilane. It is not preferable to set the cooling temperature too low because of restrictions on equipment. Also, if the temperature is too high, the condensation effect will decrease. Therefore, the temperature is preferably in the range of -20 to -75°C, depending on the relationship with the operating pressure. The equipment used in this process can be any type of cooler as long as it can cool the monosilane gas to a predetermined temperature, but since the impurities condensed by cooling become mist and float in the monosilane gas, these droplets can be collected. It is desirable to have a structure. The impurities removed in step (ii) are a portion of monochlorosilane and the reducing agent and solvent mixed in in step (i). As a result of eliminating SiCl 4 in step (i) as described above, the reducing agent and solvent used in step (i) are
Step (ii) is necessary to remove some of the monochlorosilane, and step (ii) must be performed subsequent to step (i). Then, the main impurities in the monosilane gas introduced into the subsequent steps (iii) and (iv) are:
It becomes monochlorosilane and ethane. These impurities are removed separately in steps (iii) and (iv) as shown below. After completing the step (ii), the monosilane gas containing remaining impurities is introduced into the step (iii). Step (iii) is carried out by passing the monosilane gas through a column filled with activated carbon. The activated carbon used is preferably granular and has a high specific surface area, and may be activated if necessary. The particle size of the activated carbon is preferably in the range of 4 to 32 mesh. There is no particular limit to the temperature in step (iii), but if it is too low, the equipment will become expensive and the adsorption loss of monosilane will increase, and if it is too high, the adsorption and removal effect of impurities will decrease, so -20 to -75℃. A range of is preferred. The impurities adsorbed and removed in step (iii) are all the remaining monochlorosilane, and at the same time, the extremely small amount of dichlorosilane present is also adsorbed and removed. The monosilane gas containing impurities remaining after the step (iii) is introduced into the step (iv). Step (iv) can be carried out by passing the monosilane gas through a tower filled with synthetic zeolite 4A. Since the pore diameter of synthetic zeolite is 4 Å, which is the molecular diameter of ethane, ethane cannot be adsorbed below that diameter. Furthermore, if the pore diameter is 4.5 Å or more, monosilane will also be adsorbed, resulting in a large loss of monosilane.
Therefore, the preferred pore diameter is in the range of 4 Å or more and less than 4.5 Å. The size of synthetic zeolite is from 4 mesh to 32
A mesh range is preferred. In addition, if necessary,
Activation treatments such as heat treatment and reduced pressure treatment can be performed. The temperature in step (iv) is not particularly limited, but if it is too low, the equipment will become expensive, and if it is too high, the effect of adsorption and removal of impurities will be reduced, so it is preferably in the range of -20 to -75°C. In both steps (iii) and (iv), in the range of -20 to -75°C, the temperature is preferably as low as possible, as long as it is above the dew point of monosilane determined by the operating pressure. The impurity adsorbed and removed in step (iv) is ethane, and at the same time, methane present in a very small amount is also adsorbed and removed. In the present invention, it is necessary to perform step (iv) after step (iii), and if this order is reversed, the removal operation cannot be performed efficiently. For example, monochlorosilane is used as an impurity.
When monosilane gas containing 800 ppm of ethane and 1000 ppm of ethane was passed through the activated carbon layer in step (iii) and then through the synthetic zeolite 4A layer in step (iv) (experimental
No. 1) and when this order is reversed (Experiment No. 2)
Table 1 shows the results of measuring the amount of monosilane flowing out up to the so-called breakthrough point when unadsorbed ethane is mixed into the purified gas after passing through. It is clearly seen that the order of the present invention is superior.
【表】
＊１；やし殻活性炭
＊２；栗田工業社製モレキユライト
以上のように、本発明方法によれば、SiCl4を
AlEt2Hで還元して得たモノシランガスから
SiCl4、モノクロルシラン、エタンなどを極めて
効率よく除去することができる。
次に本発明を実施例に基づきさらに詳細に説明
する。
実施例
AlEt2を還元試薬としてSiCl4から、不純物とし
て、SiCl41％、モノクロルシラン900ppm及びエ
タン1000ppmを含有するモノシランガスを得た。
これを、順次、次の第１〜４工程を通過させた。
（第１工程）
35℃、１Kg/cm2−Ｇの条件下でAlEt2Hと
AlEt2Clのモル比１：１の混合物の20wt％流動パ
ラフイン溶液中にモノシランガスを通す。
（第２工程）
−70℃、１Kg/cm2−Ｇの条件下でSUS製充填剤
層中をモノシランガスを通す。
（第３工程）
−70℃、１Kg/cm2−Ｇの条件下で、活性化した
やしがら活性炭（粒度８〜32メツシユ）層中を、
モノシランガスを通す。
（第４工程）
−70℃、１Kg/cm2−Ｇの条件下で、活性化した
合成ゼオライト４Ａ（栗田工業社製、粒径1.5mm
φ）層中を、モノシランガスを通す。
第２工程を通過させたのち、第３工程に導入す
る前の不純物を含むモノシランガスの組成を第２
表に示す。[Table] *1: Coconut shell activated carbon *2: Moleculite manufactured by Kurita Water Industries, Ltd. As described above, according to the method of the present invention, SiCl 4
From monosilane gas obtained by reduction with AlEt 2 H
SiCl 4 , monochlorosilane, ethane, etc. can be removed extremely efficiently. Next, the present invention will be explained in more detail based on examples. Example A monosilane gas containing 1% SiCl 4 , 900 ppm of monochlorosilane, and 1000 ppm of ethane as impurities was obtained from SiCl 4 using AlEt 2 as a reducing reagent.
This was sequentially passed through the following 1st to 4th steps. (1st step) AlEt 2 H under the conditions of 35℃ and 1Kg/cm 2 -G.
Monosilane gas is passed through a 20 wt % liquid paraffin solution of a 1:1 molar mixture of AlEt 2 Cl. (Second step) Monosilane gas is passed through the SUS filler layer under the conditions of −70° C. and 1 Kg/cm 2 −G. (Third step) Under the conditions of -70℃ and 1Kg/cm 2 -G, in the activated coconut shell activated carbon (particle size 8 to 32 mesh) layer,
Pass monosilane gas through. (4th step) Synthetic zeolite 4A (manufactured by Kurita Kogyo Co., Ltd., particle size 1.5 mm) was activated under the conditions of -70°C and 1 Kg/cm 2 -G.
φ) Pass monosilane gas through the layer. After passing through the second step, the composition of the monosilane gas containing impurities before being introduced into the third step is changed to the second step.
Shown in the table.
【表】
上記第２表の組成のガスを第３工程、第４工程
に順次通して精製したところ、モノシランガス中
の主な不純物であるSiCl4、モノクロルシラン及
びエタンは、FID、ECD検出器を有するガスクロ
マトグラフで測定しても、全く検出されなかつ
た。
比較例
実施例と同様の、不純物としてSiCl41％、モノ
クロルシラン900ppm及びエタン1000ppmを含む
モノシランガスを実施例の第１工程と同様の条件
で精製し、冷却温度−60℃の第２工程を通過させ
た後、活性炭20ｇを精製に用いる第３工程へと導
入した。そして通過後の精製ガスに未吸着のモノ
クロルシランが混入するいわゆる破過点までのモ
ノシランの流出量を測定した。
比較として、同じ組成のガスを、第１の工程を
通さないで、他は、上記と同様にして、破過点を
求めた。
この結果をそれぞれ実験No.１、２として第３表
に示す。第３表より、第１の工程が第３の工程の
活性炭に対する負荷を大幅に低下させる効果があ
ることがわかる。[Table] When the gas with the composition shown in Table 2 was purified by sequentially passing it through the third and fourth steps, the main impurities in monosilane gas, SiCl 4 , monochlorosilane, and ethane, were detected using FID and ECD detectors. Even when measured using a gas chromatograph, it was not detected at all. Comparative Example A monosilane gas containing 1% SiCl 4 , 900 ppm monochlorosilane, and 1000 ppm ethane as impurities was purified under the same conditions as the first step of the example, and passed through the second step at a cooling temperature of -60°C. After this, 20 g of activated carbon was introduced into the third step used for purification. Then, the amount of monosilane flowing out up to the so-called breakthrough point where unadsorbed monochlorosilane is mixed into the purified gas after passing was measured. For comparison, the breakthrough point was determined using a gas having the same composition but not passing it through the first step, but in the same manner as above. The results are shown in Table 3 as Experiment Nos. 1 and 2, respectively. Table 3 shows that the first step has the effect of significantly reducing the load on the activated carbon in the third step.
Claims (1)
ライドで還元して得た不純物を含むモノシランを
精製するに当り、このモノシランを(i)還元処理す
る(ii)−20℃以下に冷却処理する(iii)活性炭で処理す
る(iv)細孔直径４〜4.5Åの合成ゼオライトで処理
する、の各処理に順に付すことにより、その中の
不純物を除去することを特徴とするモノシランの
精製方法。1 In purifying monosilane containing impurities obtained by reducing silicon tetrachloride with diethylaluminum hydride, this monosilane is (i) subjected to reduction treatment (ii) cooled to below -20°C (iii) treated with activated carbon (iv) treatment with a synthetic zeolite having a pore diameter of 4 to 4.5 Å, in order to remove impurities therein.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16728481A JPS5869715A (en) | 1981-10-21 | 1981-10-21 | Purification of monosilane |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16728481A JPS5869715A (en) | 1981-10-21 | 1981-10-21 | Purification of monosilane |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5869715A JPS5869715A (en) | 1983-04-26 |
| JPS641405B2 true JPS641405B2 (en) | 1989-01-11 |
Family
ID=15846895
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16728481A Granted JPS5869715A (en) | 1981-10-21 | 1981-10-21 | Purification of monosilane |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5869715A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4554141A (en) * | 1984-05-14 | 1985-11-19 | Ethyl Corporation | Gas stream purification |
| JPS6163514A (en) * | 1984-09-03 | 1986-04-01 | Mitsui Toatsu Chem Inc | Method of purifying monosilane |
| FR2652346B1 (en) * | 1989-09-22 | 1991-11-29 | Air Liquide | PROCESS FOR THE PREPARATION OF DISILANE. |
| JP4843553B2 (en) * | 2007-05-09 | 2011-12-21 | 株式会社コロナ | Integrated air conditioner |
| KR101159674B1 (en) * | 2009-11-16 | 2012-06-25 | 주식회사 케이씨씨 | Process for purification of monosilane |
-
1981
- 1981-10-21 JP JP16728481A patent/JPS5869715A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5869715A (en) | 1983-04-26 |
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