JPS61183113A - Process and device for preparing polycrystalline silicon - Google Patents

Abstract

PURPOSE:To prevent deposition of silicon on a heating surface and to improve reaction efficiency by fluidizing particulate silicon powder heated at high temp. with gaseous H2 in a reaction vessel, and introducing an inorg. silane compd. into the fluidized bed. CONSTITUTION:An internal cylinder 3 is inserted concentrically to a cylindrical vessel main body 1. Specified particulate Si powder of high purity is charged from a charging port 12 and heated at a specified temp. with an electric heater 11. On one hand, gaseous H2 is fed from gas introducing ports 5, 8 through gas straightening device 4, 7 to fluidize the silicon, and a gaseous inorg. silane compd. is introduced simultaneously through an introducing pipe 9 into the fluidized bed of silicon in the internal cylinder 3 and dispersed in the fluidized bed. The gaseous inorg. silane compd. contacts with particulate silicon powder at high temp. while rising up through the fluidized bed depositing fresh silicon on the surface of silicon particles by reduction or thermal decomposition. The silicon particles are circulated in the vessel 1 through an annular section 14, and particulate silicon powder having increased particle size are discharged through a discharging pipe 6 of product.

Description

【発明の詳細な説明】 産業上の利用分野 この発明は、高温度の粉粒状シリコンを水素ガスによっ
て流動化する流動層の中に無機シラン化合物を送入して
行なう多結晶Ｓ／ＩＪコンの製造方法及びその装置に関
する。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to the production of polycrystalline S/IJ composites, which is carried out by introducing an inorganic silane compound into a fluidized bed in which high-temperature granular silicon is fluidized by hydrogen gas. This invention relates to a manufacturing method and its apparatus.

従来技術 粉粒状シリコンを流動層状態（以丁流動層と称す）に保
って製造する方法としては、底部に多孔板などの整流器
を有する反応装置に高純度の粉粒状５／リコンを入れて
高温度に保ち、四塩化けい素、トリクロルシラン、ジク
ロルシラン、モノクロルシラン及びモノシランなどの精
製された無機シラン化合物と水素の混合気体を装置の底
部にある整流器を通して送入することによシ高純度シリ
コン粒子を流動化させ、温度４００〜１２００℃、圧力
１〜３気圧の条件下で還元度広又は熱分解反応を進行さ
せ、流動化しているシリコン粒子の表面にシリコンを析
出させる方法が知られている。Conventional technology A method for manufacturing powdered and granular silicon while maintaining it in a fluidized bed state (referred to as a fluidized bed) is to place high-purity powdered and granular 5/recon into a reactor equipped with a rectifier such as a perforated plate at the bottom. High purity silicon particles are produced by maintaining the temperature and feeding a mixed gas of hydrogen and purified inorganic silane compounds such as silicon tetrachloride, trichlorosilane, dichlorosilane, monochlorosilane and monosilane through the rectifier at the bottom of the device. There is a known method in which silicon is precipitated on the surface of the fluidized silicon particles by fluidizing the silicon particles and allowing a wide reduction or thermal decomposition reaction to proceed under conditions of a temperature of 400 to 1200°C and a pressure of 1 to 3 atmospheres. .

この方法によれば、流動状態にあるシリコン粒子群が気
体流と接触する表面積は極めて大きく、しかも流動層状
態での大きな攪拌効果によって粒子相互の凝固を防止で
きるので、多結晶シリコンを効率よく製造できる。According to this method, the surface area where the silicon particles in the fluidized state come into contact with the gas flow is extremely large, and the large stirring effect in the fluidized bed state prevents the particles from coagulating, so polycrystalline silicon can be produced efficiently. can.

従来技術の問題点 上記方法での反応容器内における反応は、前記のように
４００〜１２００℃の高温で行なわれるので加熱装置が
必要である。そのため、従来は反応装置の外側に電気加
熱器を設置し、反応装置の外壁面から熱伝達を行なって
いた。Problems with the Prior Art The reaction in the reaction vessel in the above method is carried out at a high temperature of 400 to 1200° C., so a heating device is required. Therefore, in the past, an electric heater was installed outside the reactor, and heat was transferred from the outer wall surface of the reactor.

そのため、反応装置の内壁面は流動層よシも高い温度に
あり、一方上記還元反応又は熱分解反応の速度は温度に
対し極めて敏感であるため、流動層中を上昇する気流中
の無機シラン化合物ガスが高温の又応装置内壁面に接触
してシリコンを析出し、その析出層厚は連続操作の時間
に従って増大する。このようなシリコン析出は、反応装
置の定常的連続操作を妨げ、生産性を著しく低下させる
。Therefore, the inner wall surface of the reactor is at a higher temperature than the fluidized bed, and the rate of the above-mentioned reduction reaction or thermal decomposition reaction is extremely sensitive to temperature. The gas contacts the hot inner walls of the reactor to deposit silicon, and the thickness of the deposited layer increases with the time of continuous operation. Such silicon deposition interferes with regular continuous operation of the reactor and significantly reduces productivity.

又、反応装置の構成材料は、その熱膨張係数がシリコン
とは異なるため、上記析出シリコン層ができると、昇温
時又は冷却時に大きな熱応力が発生し、これにより装置
が破壊される恐れがあった。In addition, since the material forming the reactor has a coefficient of thermal expansion different from that of silicon, if the precipitated silicon layer is formed, a large thermal stress will be generated during heating or cooling, which may cause the equipment to be destroyed. there were.

このよう壜反応容器内壁面へのシリコン析出を防止する
ため、従来より種々の工夫がなされておシ、例えば反応
容器の底中央に内管が外管よシ高い二重管ノズルを設け
、内管からクロロシランガスを、外管から水素ガスを送
入する方法（特開昭５７−１３５７０８）　、ｆｆ応容
器内壁面にシリコンが析出するのを防止又は抑制するガ
スを内壁面近傍に存在させる方法（特開昭５８−１８５
４２６）、及び反応容器内に内筒を設け、底中央よシ送
入される無機シラン化合物ガスと水素との混合ガスを上
記内筒の下方位置に設けたガス分散板を通して供給し、
内筒内で反応を行なわせたのち粉粒状シリコンを内筒の
外周に循環させる方法（特開昭５９−４５９１７）など
が提案されている。In order to prevent such silicon precipitation on the inner wall surface of the bottle reaction vessel, various measures have been taken in the past. A method of feeding chlorosilane gas from a tube and hydrogen gas from an outer tube (Japanese Patent Application Laid-Open No. 57-135708), a method of causing a gas to exist near the inner wall surface to prevent or suppress the precipitation of silicon on the inner wall surface of the FF reaction vessel. (Unexamined Japanese Patent Publication No. 58-185
426), and an inner cylinder is provided in the reaction vessel, and a mixed gas of inorganic silane compound gas and hydrogen is supplied from the center of the bottom through a gas distribution plate provided at a lower position of the inner cylinder,
A method has been proposed (Japanese Patent Laid-Open No. 59-45917) in which silicon powder is circulated around the outer circumference of the inner cylinder after a reaction takes place within the inner cylinder.

しかしながら、流動層中での気体流は激しく混合するか
ら、上記第１の方法では底部から噴出する混合ガスが内
壁面に接触して反応するのを防止することは困難である
。又、第２の方法では内壁に沿ってシリコンの析出を防
止する多孔質内筒が設けられる丸め、反応容器の外周に
設けた加熱器から流動層への熱伝導が低下し、反応効率
が低下する。更に、第３の方法はガス分散板を通して流
動層に送入された混合ガスの全部が内筒内部の流動層中
を上昇することはなく、一部の混合ガスは内筒外側を移
動層状態でゆつくシ下降する粉粒状シリコン中にはいり
こんで上昇する。そのため、内筒外側を上昇する混合ガ
ス中の無機シラン化合物ガスが高温の反応容器内壁面に
接触して反応しシリコンを内壁面に析出するのを完全に
防止することはできない。However, since the gas flow in the fluidized bed mixes violently, it is difficult in the first method to prevent the mixed gas ejected from the bottom from contacting and reacting with the inner wall surface. In addition, in the second method, a porous inner cylinder is provided along the inner wall to prevent the precipitation of silicon, which reduces heat conduction from the heater provided around the outer periphery of the reaction vessel to the fluidized bed, reducing reaction efficiency. do. Furthermore, in the third method, all of the mixed gas sent into the fluidized bed through the gas distribution plate does not rise in the fluidized bed inside the inner cylinder, and some of the mixed gas moves outside the inner cylinder in a moving bed state. It gets stuck in the descending powdery silicone and rises. Therefore, it is not possible to completely prevent the inorganic silane compound gas in the mixed gas rising on the outside of the inner cylinder from contacting and reacting with the high-temperature inner wall surface of the reaction vessel and depositing silicon on the inner wall surface.

そこで、本発明者は先に、無機シラン化合物ガスが高温
の加熱面に接触する可能性を皆無とするために、反応容
器中に二つの内筒を同心して設置し、底部よシ送入され
る水素ガスによって粉粒状高純度シリコンを反応容器中
で循環させる方法を提案した（特願昭５９−１５１７６
０）。Therefore, in order to eliminate the possibility that the inorganic silane compound gas would come into contact with the high-temperature heating surface, the inventor installed two inner cylinders concentrically in the reaction vessel, and the gas was introduced from the bottom. proposed a method of circulating powdered and granular high-purity silicon in a reaction vessel using hydrogen gas (Japanese Patent Application No. 59-15176).
0).

その方法は、二つの内筒と反応容器内壁面によって又応
答器内空間を二つの帯域に分け、粉粒状シリコンを両帯
域内に流動層状態で循環させ、内側内筒の内部に設置し
た加熱器によって内側内筒の外表面を高温に保ち、これ
に沿って流動層状態で下降する粉粒状クリコンを必要温
度に加熱し、底部に設置した整流器を通して送入される
水素ガスの作用によって加熱された粉粒状シリコンを反
応容器内壁面に沿って流動層状部で上方に移動させ、内
筒の下端よシ上方にある基準位置で度広容器外側から粉
粒状シリコン中に無機シラン化合物ガスを送入するので
あり、無機シフン化合物ガスが高温の加熱面に接触する
機会は皆無であるから、加熱面におけるシリコンの析出
を完全に防止できる。This method divides the interior space of the reactor into two zones by two inner cylinders and the inner wall surface of the reaction vessel, circulates powdered silicon in a fluidized bed state in both zones, and heats the reactor by placing it inside the inner cylinder. The outer surface of the inner inner cylinder is kept at a high temperature by a container, and the powdery granular cricon, which descends along it in a fluidized bed state, is heated to the required temperature, and is heated by the action of hydrogen gas fed through a rectifier installed at the bottom. The powdered granular silicon is moved upward in a fluidized bed along the inner wall surface of the reaction vessel, and an inorganic silane compound gas is introduced into the powdered silicone from the outside of the expanded container at a reference position above the lower end of the inner cylinder. Since there is no opportunity for the inorganic siphon compound gas to come into contact with the high-temperature heating surface, precipitation of silicon on the heating surface can be completely prevented.

しかしながら、上記方法は二つの内筒を同心して設置し
、かつ加熱器を内筒内部に設けるため・反応装置として
の構造が複雑で設備費が高くなると共に加熱器の保守、
点検が不便である。However, in the above method, since the two inner cylinders are installed concentrically and the heater is installed inside the inner cylinder, the structure of the reactor is complicated, which increases equipment costs and requires maintenance of the heater.
Inspection is inconvenient.

発明の目的 この発明は、前記の現状にかんがみ、流動層を用いて多
結晶シリコンを製造する場合において、反応容器の高温
壁面へのｙリコン析出を完全に防止すると共に、無機シ
ラン化合物の反応率をほぼ理論値近くまで向上させ、し
かも加熱のための電力消費量を低減するための内部循環
流動層を用いた多結晶シリコンの製造方法及びその装置
を提案するものである。Purpose of the Invention In view of the above-mentioned current situation, the present invention completely prevents the precipitation of ylicon on the high-temperature walls of a reaction vessel when producing polycrystalline silicon using a fluidized bed, and improves the reaction rate of an inorganic silane compound. This paper proposes a method and apparatus for manufacturing polycrystalline silicon using an internally circulating fluidized bed, which improves the temperature to almost the theoretical value and reduces power consumption for heating.

発明の構成 この発明は、上下端を開放して同心挿入した内筒を有す
る反応容器の底部及び容器周壁の内筒下端よりやや上方
位置に対向した部分より水素ガス金送入し、反応容器内
に充填した粉粒状シリコンを流動化すると共に、内筒内
側を濃厚流動層状態で上昇し、内筒外側に容器周壁との
間に形成した環状部を濃厚流動層状態で下降して循環流
動せしめ、内筒内側の濃厚流動層状態にある粉粒状シリ
コン中に、内筒下端よりやや上方位置より無機Ｖく矛 ラン化合物を送入し、内筒内側の流動層内で無機シラン
化合物の還元反応又は熱分解反応を行なわせ、容器周壁
外側に設けた加熱器によシ容器周壁を高温に保持し、内
筒外側の環状部を下降する粉粒状シリコンを加熱するこ
とを要旨とする多結晶シリコンの製造方法、及び周壁外
面に加熱器を設け、上下端を開放した内筒を同心挿入し
た反応容器の底部及び上記内筒下端よりやや上方位置に
対向する容器周壁に気体整流器を介して水素ガスを送入
する送入口を設け、かつ容器外から内筒内に挿入した無
機シラン化合物ガスの送入管の送入口を内筒下端よりや
や上方位置に設け、容器の上端に粉粒状シリコン装入口
とガス排出口を、容器の底部に製品取出し口をそれぞれ
設けてなり、内筒内側を上昇流動層とし、内筒外側を下
降流動層とする循環流動層を形成することを特徴とする
多結晶シリコンの製造装置である。Structure of the Invention This invention provides hydrogen gas to be introduced into the reaction vessel from the bottom of a reaction vessel having an inner cylinder inserted concentrically with the upper and lower ends open, and from a portion of the vessel circumferential wall located slightly above the lower end of the inner cylinder. At the same time, the powdered silicon filled in the container is fluidized, and the inside of the inner cylinder rises in a dense fluidized bed state, and the annular part formed between the outer side of the inner cylinder and the peripheral wall of the container descends in a dense fluidized bed state, creating a circulating fluid. An inorganic silane compound is introduced into the powdered silicon in a dense fluidized bed inside the inner cylinder from a position slightly above the lower end of the inner cylinder, and a reduction reaction of the inorganic silane compound occurs in the fluidized bed inside the inner cylinder. Or polycrystalline silicon, which undergoes a thermal decomposition reaction, maintains the peripheral wall of the container at a high temperature with a heater installed outside the peripheral wall of the container, and heats the powdered silicon that descends through the annular portion outside the inner cylinder. A method for producing hydrogen gas is provided at the bottom of a reaction vessel in which a heater is provided on the outer surface of the peripheral wall, and an inner cylinder with open upper and lower ends is concentrically inserted, and on the peripheral wall of the container slightly above the lower end of the inner cylinder, through a gas rectifier. In addition, the inlet for the inorganic silane compound gas is inserted into the inner cylinder from outside the container at a position slightly above the lower end of the inner cylinder, and the powder and granular silicon charging port is provided at the upper end of the container. Multis crystal is characterized by the fact that the gas exhaust port is provided with a product removal mouth at the bottom of the container, the inside of the inner cylinder is a rising flow layer, and a circulatory flow layer is formed on the outside of the inner cylinder. This is silicon manufacturing equipment.

次に、この発明の詳細を図面に基づいて説明する。Next, details of the present invention will be explained based on the drawings.

第１図は、この発明の一実施例における反応容器の縦断
面図であり、容器本体は長い筒状本体（１）と短かい筒
状下部材（２）の組合せからなり、本体より小径で上下
端を開放した内筒（３）を本体に同心挿入して支持し、
筒状下部材（２）の下端に気体整流器（４）を設け、こ
の気体整流器（４）を通して水素ガスを送入するように
送入口（５）を有するガス送入部材（５−１）を筒状下
部材（２）に接続して容器底部を形成し、この容器底部
を貫通して上端を気体整流器（４）に接合した製品取出
し管（６）を設ける。又、筒状本体（１）と筒状下部材
（２）の対向する端間に気体整流器（７）を設け、かつ
環状箱体のガス送入部材（８−１）で上記気体整流器（
７）を色囲し、送入口（８）より水素ガスを送入するよ
うに設ける。この気体整流器（７）は内筒（３）の下端
よりやや上方位置に対向せしめ、ここから送入した水素
ガスは内筒（３）の外側に容器周壁との間に形成した環
状空間を上昇するようにする。FIG. 1 is a longitudinal cross-sectional view of a reaction vessel in one embodiment of the present invention, and the vessel main body consists of a combination of a long cylindrical main body (1) and a short cylindrical lower member (2), and is smaller in diameter than the main body. An inner cylinder (3) with open upper and lower ends is inserted concentrically into the main body and supported,
A gas rectifier (4) is provided at the lower end of the cylindrical lower member (2), and a gas feed member (5-1) having an inlet port (5) is provided to feed hydrogen gas through the gas rectifier (4). A product take-out pipe (6) is provided which is connected to the cylindrical lower member (2) to form the bottom of the container, passes through the bottom of the container, and has its upper end joined to the gas rectifier (4). Further, a gas rectifier (7) is provided between the opposing ends of the cylindrical main body (1) and the cylindrical lower member (2), and the gas rectifier (
7) is circled in color and provided so that hydrogen gas is introduced through the inlet port (8). This gas rectifier (7) is opposed to the inner cylinder (3) at a position slightly above the lower end, and the hydrogen gas fed from here rises through the annular space formed between the outer side of the inner cylinder (3) and the peripheral wall of the container. I'll do what I do.

そして、無機Ｖフン化合物ガスの送入管（９）を容器上
端より内筒（３）内に挿入し、その下端にガス分散器を
取付けて形成した送入口α０を内筒（３）の下端よりや
や上方位置に設け、送入された無機シラン化合物ガスは
内筒（３）内を上昇するようにする。なお、上記送入口
α０の位置は内筒（３）の高さの半分よシ下方とするこ
とが望ましい。さらに、容器周壁の外側には電気加熱器
αＩ）を設置し、容器上端に粉粒状シリコンの装入口（
２）とガス排出口（至）を設ける。Then, the inlet pipe (9) for the inorganic V-dung compound gas is inserted into the inner cylinder (3) from the upper end of the container, and the inlet port α0 formed by attaching the gas disperser to the lower end of the inlet pipe (9) is inserted into the lower end of the inner cylinder (3). It is provided at a slightly higher position so that the inorganic silane compound gas introduced rises inside the inner cylinder (3). Note that the position of the inlet port α0 is preferably about half the height of the inner cylinder (3) below. Furthermore, an electric heater αI) is installed outside the peripheral wall of the container, and a charging port for powdered silicon (
2) and a gas exhaust port (to).

上記装置において、装入口＠より平均粒径２０μ〜４Ｂ
の粉粒状高純度シリコンを装入し容器内に充填する。そ
して、無機Ｖ”）ン化合物を含有しない気体、例えば水
素ガスを底部の送入口（５）から送入し、気体整流器（
４）上にある粉粒状高純度シリコン層を流動化する。こ
の際、送入されるガスの大部分は内筒（３）内の粉粒状
シリコン層中を上昇するが、一部のガスは内筒（３）の
外側に容器周壁との間に形成した環状部α４にある粉粒
状シリコン層中を上昇する。In the above device, the average particle size is 20 μ to 4 B from the charging port @.
of high-purity silicon powder is charged and filled into a container. Then, a gas that does not contain an inorganic V'') compound, such as hydrogen gas, is fed through the inlet port (5) at the bottom, and the gas rectifier (
4) Fluidize the overlying granular high purity silicon layer. At this time, most of the gas fed rises in the powdery silicon layer inside the inner cylinder (3), but some of the gas is formed outside the inner cylinder (3) between it and the peripheral wall of the container. It rises in the powdery silicon layer in the annular portion α4.

一方、無機Ｓ／′ｙン化合物ガスあるいは無機７ラン化
合物ガスと水素ガスとの混合ガスは送入管（９）を経て
送入口α１よシ内筒（３）内の粉粒状高純度シリコン流
動層中に分散送入され、ここで流動層中を上昇する間に
高温の粉粒状シリコンに接触して還元反応又は熱分解を
起し、シリコン粒子の表面に新たなシリコンが析出する
。On the other hand, the mixed gas of inorganic S/'yn compound gas or inorganic 7-ranium compound gas and hydrogen gas flows through the inlet pipe (9) to the inlet α1 and into the powder and granular high-purity silicon in the inner cylinder (3). It is dispersed and fed into the bed, and while rising through the fluidized bed, it comes into contact with the high temperature granular silicon to cause a reduction reaction or thermal decomposition, and new silicon is deposited on the surface of the silicon particles.

そして、無機シラン化合物を含まない気体、例えば水素
ガスを送入口（８）より環状部α◆にある粉粒状シリコ
ン流動層中に送入し、これを濃厚流動層状態に保持する
。Then, a gas that does not contain an inorganic silane compound, such as hydrogen gas, is introduced from the inlet (8) into the granular silicon fluidized bed located in the annular portion α♦, and is maintained in a dense fluidized bed state.

この際、送入管（９）を通して送入する気体の流量及び
送入口（８）を通して送入する気体の流量を調節して、
内筒（３）内の流動層の平均空隙率が環状部α→にある
流動層の平均空隙率よりも大きく保つことによシ、環状
部α→内の粉粒状シリコンが環状部下端より内筒（３）
内に回シ込む起動力を生じ、これにより内筒（３）内の
粉粒状シリコンは流動層状態のまま上昇し、環状部α４
内の粉粒状シリコンは流動層状態のｔま下降して、粉粒
状シリコンは容器内を循環する。At this time, adjust the flow rate of the gas fed through the feed pipe (9) and the flow rate of the gas fed through the feed port (8),
By keeping the average porosity of the fluidized bed in the inner cylinder (3) larger than the average porosity of the fluidized bed in the annular part α→, the powdered and granular silicon in the annular part α→ becomes more inward than the lower end of the annular part. Tube (3)
This generates a starting force that causes the silicon powder inside the inner cylinder (3) to rise while remaining in a fluidized bed state, and the annular part α4
The granular silicon in the container descends to a fluidized bed state, and the granular silicon circulates within the container.

前記無機シラン化合物ガスの還元反応及び熱分解反応は
４００〜１２００℃の高温で行なわれるので、反応系を
高温に保持し反応を進行させるのに必要な熱エネμギー
は電気加熱器（ロ）から供給される。Since the reduction reaction and thermal decomposition reaction of the inorganic silane compound gas are carried out at a high temperature of 400 to 1200°C, the thermal energy required to maintain the reaction system at a high temperature and advance the reaction can be obtained using an electric heater (b). Supplied from.

すなわち、環状部０４″ｆｔ下降する粉粒状シリコンが
高温の容器周壁内面に接触し、反応温度よシ高い温度に
加熱される。そして、加熱された粉粒状シリコンが内筒
（３）内に循環流動することにより反応に必要な熱エネ
ルギーが運搬される。この際の運搬能力は粉粒状シリコ
ンの循環速度に比例し、その循環速度はガス送入量を変
えることにより制御することができる。That is, the powdered and granular silicon that descends through the annular portion 04'' comes into contact with the inner surface of the high-temperature container peripheral wall and is heated to a temperature higher than the reaction temperature.Then, the heated powdered and granular silicon is circulated into the inner cylinder (3). The thermal energy required for the reaction is transported by the flow.The transport capacity at this time is proportional to the circulation speed of the silicon powder, and the circulation speed can be controlled by changing the amount of gas fed.

送入口ａＯから内筒（３）内に送入された無機シラン化
合物ガスは流動層中の高温の粉粒状高純度シリコンと接
触し、還元反応又は熱分解反応を起してシリコン粒子の
表面に新たなシリコンを析出する。The inorganic silane compound gas fed into the inner cylinder (3) from the inlet port aO comes into contact with the high-temperature powder-like high-purity silicon in the fluidized bed, causes a reduction reaction or thermal decomposition reaction, and decomposes on the surface of the silicon particles. Deposit new silicon.

この際の反応は吸熱反応であシ、反応に要する熱エネル
ギーは環状部α◆で反応温度以上に加熱された粉粒状シ
リコンが内筒（３）内に循環し、反応温度まで温度が低
下する際放出される顕熱によって与えられる。The reaction at this time is an endothermic reaction, and the thermal energy required for the reaction is such that the silicon powder heated above the reaction temperature in the annular part α◆ circulates inside the inner cylinder (3) and the temperature decreases to the reaction temperature. This is given by the sensible heat released during the process.

温度が゛低下し、かつ表面に新たなシリコンが析出した
粉粒状シリコンは内筒（３）内を上昇し、内筒上端で環
状部α→側へ回シ込み、流動層状態で環状部α４を下降
し再び加熱される。なお、反応を終つ九ガス流は容器内
の上部空間（至）で粉粒状シリコンの大部分を分離した
のちガス排出口（至）から次工程に送られる。The granular silicon, whose temperature has decreased and new silicon has precipitated on the surface, rises in the inner cylinder (3), flows into the annular part α→ side at the upper end of the inner cylinder, and flows into the annular part α4 in a fluidized bed state. is lowered and heated again. The nine gas streams that have completed the reaction are sent to the next step from the gas outlet after separating most of the powdered silicon in the upper space of the container.

一方、流動層中を循環する間に表面に新たなシリコンを
析出して粒径を増大した粉粒状シリコンは製品取出し管
（６）を経て取出される。この際、気体整流器の分級作
用により、取出される製品シリコン粒は粒径の大きなも
のが多く、粒径の小さいシリコン粒は流動層中を循環す
る。又、取出された製品シリコンは別途分級して粒径の
小さいものを分離し装入口υから再装入する。On the other hand, the powdered silicon, which has increased in particle size by depositing new silicon on its surface while circulating in the fluidized bed, is taken out through the product take-out pipe (6). At this time, due to the classification action of the gas rectifier, many of the product silicon particles taken out have large particle sizes, and silicon particles with small particle sizes circulate in the fluidized bed. In addition, the product silicon taken out is separately classified to separate those with small particle sizes, and then re-charged from the charging port υ.

前記容器周壁から気体を送入する九めの送入口（８）は
第１図に示す構造のものに限ることなく他の構造のもの
が使用できる。例えば、第２図に示すように、筒状下部
材（２）を小径とし、筒状本体（１）との接続部に形成
される環状スリットに気体整流器（７）を設けたもの、
又第３図に示すように、小径の筒状下部材（２）を筒状
本体（１）の下部に挿入し、筒状下部材（２）の上端と
筒状本体（１）の内周壁との間に気体整流器（７）を設
けたものなどが使用できる。The ninth inlet port (8) for introducing gas from the peripheral wall of the container is not limited to the structure shown in FIG. 1, but other structures can be used. For example, as shown in FIG. 2, the cylindrical lower member (2) has a small diameter and a gas rectifier (7) is provided in the annular slit formed at the connection with the cylindrical main body (1);
Further, as shown in Fig. 3, a small-diameter cylindrical lower member (2) is inserted into the lower part of the cylindrical main body (1), and the upper end of the cylindrical lower member (2) and the inner peripheral wall of the cylindrical main body (1) are connected. A device with a gas rectifier (7) installed between it and the like can be used.

又、無機シラン化合物ガスは、内筒（３）内の流動層中
で還元反応又は熱分解反応を起させるために、内筒（３
）内の下部に送入する必要がある。しかし、その送入口
αＱは第１図に示すガス分散器に限ることは々い。要は
、内筒（３）内の粉粒状シリコン流動層中に無機シラン
化合物ガスをほぼ均一に分散させ得る構造であればよい
。したがって、その送入管（９）は第１図及び第４図に
示すように１本を内筒（３）に同心挿入してもよく、又
第５図に示すように管内で熱分解反応を起すのを防止す
るため断熱材Ｑ・を内嵌することが望ましい。Further, the inorganic silane compound gas is supplied to the inner cylinder (3) in order to cause a reduction reaction or a thermal decomposition reaction in the fluidized bed in the inner cylinder (3).
). However, the inlet port αQ is not limited to the gas distributor shown in FIG. In short, any structure may be used as long as it can disperse the inorganic silane compound gas almost uniformly in the powdery silicon fluidized bed within the inner cylinder (3). Therefore, one feed pipe (9) may be inserted concentrically into the inner cylinder (3) as shown in Figs. 1 and 4, or the pyrolysis reaction may occur within the pipe as shown in Fig. 5. In order to prevent this from occurring, it is desirable to insert a heat insulating material Q.

以上は送入管（９）を容器上部より下方へ挿入した場合
について説明したが、第６図及び第７図く示すように容
器底部よシ上方へ挿入することもできる。この場合、無
機シラン化合物ガスの均一分散をより効果的にするため
第７図に示すように、分校状に分散管を配置したガス分
散器α力を使用することができる。Although the case where the feed pipe (9) is inserted below the top of the container has been described above, it can also be inserted above the bottom of the container as shown in FIGS. 6 and 7. In this case, in order to more effectively disperse the inorganic silane compound gas, it is possible to use a gas disperser α force in which dispersion tubes are arranged in a branched manner, as shown in FIG.

又、図示しないが、容器の周壁より送入管を挿入し、無
機シラン化合物ガスを送入する送入口を横向けに設ける
こともできる。Although not shown, an inlet pipe may be inserted through the peripheral wall of the container to provide a sideways inlet port for injecting the inorganic silane compound gas.

前記の反応において流動層を構成する粉粒状シリコンは
、表面に新たなシリコンが析出して次第に粒径が大きく
なるから、反応を長期間安定して連続的に進行させ、連
続操業を可能とするには、粗粒を選択的に取出すことが
望ましい。例えば、第１図に示し九気体整流器（４）は
、それ自体が粉粒層に対し分級効果を有するが、その効
果は不十分であり、取出された製品中には相轟量の微粉
が混入しており、別工程により分級処理し微粉を分離す
る必要がある。In the above reaction, the particle size of the granular silicon that constitutes the fluidized bed gradually increases as new silicon precipitates on the surface, allowing the reaction to proceed stably and continuously for a long period of time, making continuous operation possible. It is desirable to selectively extract coarse particles. For example, the nine-gas rectifier (4) shown in Figure 1 has a classification effect on the powder layer, but its effect is insufficient, and a large amount of fine powder remains in the product taken out. It is necessary to separate the fine powder by classifying it in a separate process.

その別工程による分級処理を除くには反応容器の製品取
出し口に分級処理装置を付設すればぷい。In order to eliminate this separate classification process, a classification device can be attached to the product outlet of the reaction vessel.

今、その−例を第８図に示す。気体整流器（４）に逆円
錐状の分級管（至）と粗粒分級排出器Ｑ嗜からなる分級
処理装置を設ける。すなわち、分級管（至）内において
粉粒状シリコンは、送入口−から送入される水素ガスに
よって成る程度の分級が行なわれる。An example of this is now shown in FIG. The gas rectifier (4) is provided with a classification processing device consisting of an inverted conical classification tube (1) and a coarse particle classification/discharge device (Q). That is, in the classification tube (through), the powdery silicon is classified to the extent that the hydrogen gas is introduced from the inlet.

そして、多孔板から構成したスクリュー状の粗粉分級排
出器α傷を下降する間に微粒子は、そのほとんどが分級
管（至）側へ押しもどされ微粉シリコンのみが製品取出
し管（６］より取出すことができる。Most of the fine particles are pushed back to the classification tube (end) side while descending through the screw-shaped coarse powder classification ejector alpha wound made of a perforated plate, and only the fine silicon powder is taken out from the product take-out tube (6). be able to.

実　　施　　例 実施例１ 第１図に示す形状で、高さ１５００ｆｉ、内径１７０ｎ
１厚さ１４ｆｌの不透明石英管の内面に厚さ５Ｍのシリ
コン層を内張すした筒状本体（１）を有する反応容器で
、外径１２０ｆｉ、厚さ５　ｓｍ、高さ１２００ｆｌの
５／リスン製内筒（３）と外径５０鰭の送入管（９）を
設置し、容器周壁の外側に８ｋＷのテコランダム（５ｔ
Ｃ）製電気加熱器を設置した装置を用い、装置内の循環
流動層部分に平均粒度８８０μの高純度シリコン１３．
６ｋｐを装入し、底部の送入口（５）から水素ガス５０
　Ｎ＄／ｍｉｎ　、周壁の送入口（８）から水素ガス１
８Ｎｌ／ｍｉｎを送入して粉粒状シリコンを濃厚流動層
状順で反応容器内を循環流動させ、電気加熱器からの加
熱によって環状部α→にある流動層を９６５℃に保ち、
送入管（９）を通して送入口σ１よりトリクロロンラン
１７　Ｎｌ／ｍｉｎ　、水素ガス１２．８　Ｎｌ／ｍ１
ｔｔの混合ガスを内筒内の流動層中に送入分散させ、又
装入口υより平均粒度３５０μの高純度シリコン粒子７
．６５ｙ／Ｈｒを装入し、製品取出し管（６）を経て平
均粒度１１７０μの多結晶シリコン粗粒子を２３０ｙ／
Ｈｒで取出す運転を行ない多結晶シリコンを製造した。Examples Example 1 Shape shown in Figure 1, height 1500fi, inner diameter 170n
1 A reaction vessel having a cylindrical body (1) with a 14 fl thick opaque quartz tube lined with a 5 M thick silicon layer on the inner surface, an outer diameter of 120 fi, a thickness of 5 sm, and a height of 1200 fl. A manufactured inner cylinder (3) and an inlet pipe (9) with an outer diameter of 50 fins were installed, and an 8kW Tecorundum (5t) was installed on the outside of the container peripheral wall.
Using a device equipped with an electric heater manufactured by C), high-purity silicon 13. with an average particle size of 880 μm was placed in the circulating fluidized bed section of the device.
6kp, and 50 ml of hydrogen gas is charged from the bottom inlet (5).
N$/min, hydrogen gas 1 from the inlet (8) on the peripheral wall
8 Nl/min was fed to circulate and flow the powdered silicon in the reaction vessel in the order of a dense fluidized bed, and the fluidized bed in the annular part α was maintained at 965°C by heating from an electric heater.
Trichlorone run 17 Nl/min, hydrogen gas 12.8 Nl/m1 from the inlet port σ1 through the inlet pipe (9)
A mixed gas of tt is introduced into the fluidized bed in the inner cylinder and dispersed, and high purity silicon particles 7 with an average particle size of 350μ are introduced from the charging port υ.
．． 65y/Hr is charged, and polycrystalline silicon coarse particles with an average particle size of 1170μ are charged 230y/Hr through the product take-out pipe (6).
Polycrystalline silicon was produced by performing an extraction operation at hr.

そして、５２０時間の連続定常運転を行なったのち、運
転を停止し装置内を点検したが、反応容器の電気加熱器
により加熱される周壁の内面にはシリコンの析出は全く
認められなかつ九。After 520 hours of continuous steady operation, the operation was stopped and the inside of the apparatus was inspected, but no silicon precipitation was observed on the inner surface of the peripheral wall heated by the electric heater of the reaction vessel.

実施例２ 実施例１と同じ装置内に平均粒度５９０μの高純度シリ
コン１３．６ｋｆを装入し、送入口（５）から水素ガス
４９　Ｎｌ／ｍｉｎ　、　　送入口（８）から水素ガス
１４ＮＡ！／ｌＸ１ｉｔｌ　ｔ−送入して粉粒状高純度
シリコンを循環流動させ、電気加熱器からの加熱によシ
環状部α々内の流動層を７００℃に保ち、送入口αΦよ
シ内筒内にモノシランガス４７．６　Ｎｌ／ｗｉｎを送
入分散サセ、装入口（２）よｉ平均粒度３５０μの高純
度シリコン粒子を１２０　Ｐ／Ｈｒで供給し、製品取出
し管（６）を通して平均粒度１０２０μの多結晶シリコ
ン粗粒子を３７００　ｐ／Ｈｒで取出す運転を行ない多
結晶シリコンを製造した。そして、８０時間の定常運転
を行なったのち、運転を停止し装置内を点検したが、加
熱される周壁内面にはシリコンの析出は全く認められな
かった。Example 2 13.6 kf of high-purity silicon with an average particle size of 590 μm was charged into the same equipment as in Example 1, and hydrogen gas was supplied at 49 Nl/min from the inlet (5) and 14 NA from the inlet (8). /l Monosilane gas 47.6 Nl/win was fed into the dispersion tank, and high-purity silicon particles with an average particle size of 350μ were supplied through the charging port (2) at a rate of 120 P/Hr, and polycrystalline silicon particles with an average particle size of 1020μ were passed through the product take-out pipe (6). Polycrystalline silicon was produced by operating to extract silicon coarse particles at 3700 p/hr. After 80 hours of steady operation, the operation was stopped and the inside of the apparatus was inspected, but no silicon precipitation was observed on the inner surface of the heated peripheral wall.

発明の効果 この発明は、反応容器内に内側上昇部と外側下降部から
なる粉粒状シリコンの循環流動層を形成し、内側上昇部
の流動層中に無機シラン化合物ガスを送入分散して還元
反応又は熱分解反応を起させ粉粒状シリコンの表面に新
たにシリコンを析出させ高純度シリコンを製造するもの
であシ、加熱によシ高温に保持される容器周壁内面には
無機シラン化合物ガスは接触しない状態で運転されるた
め、容器周壁内面でのシリコン析出が皆無で長期間の連
続定常運転が可能である。又、内径に対し十分に高さの
高い反応容器を作ることができるので、無機シラン化合
優魯還元反応又は熱分解度広する上昇流動層を長くでき
反応効率を向上でき、製造コストを低減できる。Effects of the Invention This invention forms a circulating fluidized bed of granular silicon consisting of an inner rising part and an outer falling part in a reaction vessel, and injects and disperses an inorganic silane compound gas into the fluidized bed in the inner rising part for reduction. High-purity silicon is produced by causing a reaction or thermal decomposition reaction to newly precipitate silicon on the surface of powdered silicon.Inorganic silane compound gas is not present on the inner surface of the peripheral wall of the container, which is kept at a high temperature by heating. Since it is operated without contact, there is no silicon precipitation on the inner surface of the container peripheral wall, and long-term continuous steady operation is possible. In addition, since a reaction vessel with a sufficiently high height relative to the inner diameter can be made, the ascending fluidized bed for the reduction reaction of inorganic silane compounds or the degree of thermal decomposition can be made longer, improving reaction efficiency and reducing manufacturing costs. .

【図面の簡単な説明】[Brief explanation of drawings]

第１図はこの発明の一実施例における反応容器の要部を
示す縦断面図、第２図及び第３図は反応容器の周壁下部
に設けた気体整流器の他の実施例を示す反応容器下部の
縦断面図、第４図は第１図の上部の貢断平面図、第５図
は無機シラン化合物ガヌの送入管を複数設置した場合の
一例を示す横断平面図、第６図はこの発明の他の実施例
における反応容器の要部を示す縦断面図、第７図は第６
図の実施例における無機シラン化合物ガスの送入口の変
形を示す反応容器の横断平面図（１１）及び一部縦断面
図（ｂ）、第８図は製品取出し口に分級袋ｇ１を付設し
た場合を示す反応容器下部の縦断面図である。 １・・・筒状本体、２・・・筒状下部材、３・・・内筒
、４．７・・・気体整流器、５．８．１０．２０−・・
送入口、９・・・送入管、１１−・・電５ＩｃｔｘＪｓ
器、１２−・・装入口、１３・・・ガス排出口、　１４
・・・環状部、１５・・・上部空間、１６−・・断熱材
、１８・・・汗級管、１９・・・粗粒分級排出器。 出願人　　大阪チタニクム製造株式会社第１図 ＮＩ２図 第３図 第６図 第７図 （ａ） （ｂ）、７FIG. 1 is a longitudinal sectional view showing the main parts of a reaction vessel in one embodiment of the present invention, and FIGS. 2 and 3 are lower parts of the reaction vessel showing other embodiments of a gas rectifier provided at the lower part of the peripheral wall of the reaction vessel. Fig. 4 is a cross-sectional view of the upper part of Fig. 1, Fig. 5 is a transverse plan view showing an example of a case where a plurality of inorganic silane compound inlet pipes are installed, and Fig. 6 is a cross-sectional view of the upper part of Fig. 1. A vertical cross-sectional view showing the main parts of a reaction vessel in another embodiment of the present invention, FIG.
A cross-sectional plan view (11) and a partial longitudinal cross-sectional view (b) of the reaction vessel showing the deformation of the inorganic silane compound gas inlet in the example shown in the figure, and Figure 8 show the case where a classification bag g1 is attached to the product outlet. FIG. DESCRIPTION OF SYMBOLS 1... Cylindrical main body, 2... Cylindrical lower member, 3... Inner cylinder, 4.7... Gas rectifier, 5.8.10.20-...
Inlet port, 9... Inlet pipe, 11-... Electric 5IctxJs
container, 12-... charging port, 13... gas discharge port, 14
. . . Annular portion, 15. Upper space, 16.. Insulating material, 18.. Sweat class pipe, 19.. Coarse particle classification discharge device. Applicant Osaka Titanicum Manufacturing Co., Ltd. Figure 1 NI 2 Figure 3 Figure 6 Figure 7 (a) (b), 7

Claims (1)

【特許請求の範囲】 １　上下端を開放して同心挿入した内筒を有する反応容
器の底部及び容器周壁の内筒下端よりやや上方位置に対
向した部分より水素ガスを送入し、反応容器内に充填し
た粉粒状シリコンを流動化すると共に、内筒内側を濃厚
流動層状態で上昇し、内筒外側に容器周壁との間に形成
した環状部を濃厚流動層状態で下降して循環流動せしめ
、内筒内側の濃厚流動層状態にある粉粒状シリコン中に
、内筒下端よりやや上方位置より無機シラン化合物を送
入し、内筒内側の流動層内で無機シラン化合物の還元反
応又は熱分解反応を行なわせ、容器周壁外側に設けた加
熱器により容器周壁を高温に保持し、内筒外側の環状部
を下降する粉粒状シリコンを加熱することを特徴とする
多結晶シリコンの製造方法。 ２　周壁外面に加熱器を設け、上下端を開放した内筒を
同心挿入した反応容器の底部及び上記内筒下端よりやや
上方位置に対向する容器周壁に気体整流器を介して水素
ガスを送入する送入口を設け、かつ容器外から内筒内に
挿入した無機シラン化合物ガスの送入管の送入口を内筒
下端よりやや上方位置に設け、容器の上端に粉粒状シリ
コン装入口とガス排出口を、容器の底部に製品取出し口
をそれぞれ設けてなり、内筒内側を上昇流動層とし、内
筒外側を下降流動層とする循環流動層を形成することを
特徴とする多結晶シリコンの製造装置。[Scope of Claims] 1. Hydrogen gas is introduced from the bottom of a reaction vessel having an inner cylinder inserted concentrically with its upper and lower ends open, and from a portion of the vessel peripheral wall located slightly above the lower end of the inner cylinder, and hydrogen gas is introduced into the reaction vessel. At the same time, the powdered silicon filled in the container is fluidized, and the inside of the inner cylinder rises in a dense fluidized bed state, and the annular part formed between the outer side of the inner cylinder and the peripheral wall of the container descends in a dense fluidized bed state, creating a circulating fluid. , an inorganic silane compound is introduced into the powdered silicon in a dense fluidized bed inside the inner cylinder from a position slightly above the lower end of the inner cylinder, and a reduction reaction or thermal decomposition of the inorganic silane compound occurs in the fluidized bed inside the inner cylinder. A method for producing polycrystalline silicon, which comprises causing a reaction, maintaining the container peripheral wall at a high temperature with a heater provided on the outside of the container peripheral wall, and heating powdery silicon that descends through an annular portion outside the inner cylinder. 2. A heater is provided on the outer surface of the peripheral wall, and hydrogen gas is delivered via a gas rectifier to the bottom of the reaction vessel into which an inner cylinder with open upper and lower ends is concentrically inserted, and to the peripheral wall of the container located slightly above the lower end of the inner cylinder. An inlet is provided, and the inlet of the inorganic silane compound gas inlet pipe inserted from outside the container into the inner cylinder is located slightly above the lower end of the inner cylinder, and a powder and granular silicon charging port and a gas outlet are provided at the upper end of the container. An apparatus for manufacturing polycrystalline silicon, characterized in that a product outlet is provided at the bottom of the container, and a circulating fluidized bed is formed with an ascending fluidized bed on the inside of the inner cylinder and a descending fluidized bed on the outside of the inner cylinder. .