JPH11116389A - Apparatus for pulling single crystal - Google Patents
Apparatus for pulling single crystalInfo
- Publication number
- JPH11116389A JPH11116389A JP27896597A JP27896597A JPH11116389A JP H11116389 A JPH11116389 A JP H11116389A JP 27896597 A JP27896597 A JP 27896597A JP 27896597 A JP27896597 A JP 27896597A JP H11116389 A JPH11116389 A JP H11116389A
- Authority
- JP
- Japan
- Prior art keywords
- single crystal
- graphite
- quartz crucible
- cylindrical barrier
- carbon
- 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.)
- Granted
Links
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- Crystals, And After-Treatments Of Crystals (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】この発明は、石英ルツボの周
囲に位置する黒鉛ヒーターでその石英ルツボ内のSi（シ
リコン）を加熱して溶融させ、その溶融Si中からSi単結
晶を引き上げる単結晶引き上げ装置に関するものであ
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single crystal pulling method in which Si (silicon) in a quartz crucible is heated and melted by a graphite heater located around the quartz crucible, and a Si single crystal is pulled out of the molten Si. It concerns the device.
【０００２】[0002]
【従来の技術】上述の如き装置としては従来、例えば特
開平1-160894号公報にて開示されたものが知られてお
り、この装置は、炉本体中央部内に黒鉛サセプタを昇降
および回転可能に配置してその黒鉛サセプタで石英ルツ
ボを保持するとともに、炉本体中央部内のその黒鉛サセ
プタの周囲に黒鉛ヒーターを配置し、炉本体の首状にす
ぼまった上部から炉本体中央部内にワイヤを昇降および
回転可能に吊り下げてなるものである。2. Description of the Related Art As a device as described above, for example, a device disclosed in Japanese Patent Application Laid-Open No. 1-160894 is known. This device enables a graphite susceptor to be moved up and down and rotated in a central portion of a furnace body. While placing and holding the quartz crucible with the graphite susceptor, a graphite heater was placed around the graphite susceptor in the central part of the furnace main body, and a wire was inserted into the furnace main part central part from the upper part narrowed in a neck shape of the furnace main part. It is lifted up and down and rotatably suspended.
【０００３】かかる単結晶引き上げ装置によれば、チョ
クラルスキー法に基づき、炉本体内の空気をアルゴンガ
スで置換するとともに、石英ルツボ内の多結晶Siを黒鉛
ヒーターで加熱して溶融させ、その溶融Si中に、ワイヤ
の下端にて保持した種結晶を浸漬させ、その後、溶融Si
の温度を単結晶成長に適した所定温度に維持するととも
に溶融Si内に不純物が混入しないよう炉本体内にアルゴ
ンガスを供給しつつ、石英ルツボとワイヤとを互いに逆
方向に回転させながらワイヤを少しずつ引き上げ、それ
に伴って、単結晶成長による溶融Siの減少で結晶成長界
面の位置が変化しないように石英ルツボも少しずつ上昇
させることにより、種結晶の下端にSi単結晶を順次成長
させることができる。According to the single crystal pulling apparatus, the air in the furnace body is replaced with argon gas based on the Czochralski method, and the polycrystalline Si in the quartz crucible is heated and melted by a graphite heater. The seed crystal held at the lower end of the wire is immersed in the molten Si, and then the molten Si
While maintaining the temperature at a predetermined temperature suitable for single crystal growth and supplying argon gas into the furnace body so that impurities do not mix into the molten Si, the quartz crucible and the wire are rotated while rotating By gradually raising the quartz crucible gradually so that the position of the crystal growth interface does not change due to the decrease in molten Si due to single crystal growth, the Si single crystal is grown sequentially at the lower end of the seed crystal Can be.
【０００４】[0004]
【発明が解決しようとする課題】ところで上記従来の装
置にあっては、Si単結晶成長に適した温度が1500℃程度
と極めて高温であることから、Si単結晶の引き上げ中に
石英ルツボのSiO2と溶融Siとが反応して SiO（一酸化珪
素）ガスが発生する（SiO2＋Si→2SiO）。In the above-mentioned conventional apparatus, since the temperature suitable for growing a Si single crystal is extremely high at about 1500 ° C., the SiO crucible of quartz crucible is pulled during the pulling of the Si single crystal. 2 reacts with the molten Si to generate SiO (silicon monoxide) gas (SiO 2 + Si → 2SiO).
【０００５】しかしながら上記従来の装置では、発生し
た SiOガスが、アルゴンガスの流れに乗って黒鉛ヒータ
ーの発熱部に接触して、そこの高温になっている黒鉛と
反応し、これによりその発熱部を形成している黒鉛の一
部が SiC（炭化珪素）に変質してしまう（ SiO＋2C→ S
iC＋CO↑）。そしてこの SiCは、黒鉛とは熱膨張係数が
異なることから、装置の稼働時の加熱と非稼働時の冷却
との繰り返しにより黒鉛ヒーターから次第に剥離し、こ
れにより、黒鉛ヒーターの発熱部は減肉してしまう。However, in the above-mentioned conventional apparatus, the generated SiO gas comes into contact with the heat generating portion of the graphite heater on the flow of the argon gas and reacts with the high-temperature graphite there. Part of the graphite that forms the carbon is transformed into SiC (silicon carbide) (SiO + 2C → S
iC + CO ↑). Since the SiC has a different coefficient of thermal expansion from graphite, the SiC gradually peels off from the graphite heater by repeating heating during operation and cooling during non-operation, thereby reducing the heat-generating portion of the graphite heater. Resulting in.
【０００６】しかして発熱部が減肉消耗すると、発熱部
の抵抗が上がって発熱部がさらに高温になり、さらに上
記反応が進行して減肉が進んでしまう。これがため上記
従来の装置では、Si単結晶の引き上げ条件が次第に変化
してしまい、引き上げ条件を長期間に亘って安定させる
ために黒鉛ヒーターを頻繁に新品と交換することとする
と、黒鉛ヒーターは比較的高価なものゆえ、装置の維持
費が嵩んでしまうという問題があった。[0006] When the heat-generating portion is reduced in thickness and consumed, the resistance of the heat-generating portion increases and the temperature of the heat-generating portion further rises. For this reason, in the above-described conventional apparatus, the conditions for pulling the Si single crystal gradually change, and if the graphite heater is frequently replaced with a new graphite heater in order to stabilize the pulling condition over a long period of time, the graphite heater is compared with the conventional heater. There is a problem that the maintenance cost of the apparatus is increased due to the high cost.
【０００７】また、上記従来の装置では通常、溶融Siの
温度管理のために炉本体中央部内に黒鉛ヒーターを囲繞
するように断熱材を設けるとともに、その断熱材を保護
するためにその断熱材と黒鉛ヒーターとの間に黒鉛製の
インナーシールドを設けてあるが、このインナーシール
ドも、黒鉛ヒーターで加熱されるため黒鉛ヒーターと同
様に一部が SiOガスによりSiC に変質して、黒鉛ヒータ
ー程ではないが減肉消耗してしまうという問題があっ
た。In the above-mentioned conventional apparatus, a heat insulating material is usually provided around the graphite heater in the central portion of the furnace body for temperature control of molten Si, and the heat insulating material is provided to protect the heat insulating material. A graphite inner shield is provided between the graphite heater and the inner shield.This inner shield is also heated by the graphite heater, and a part of the inner shield is transformed into SiC by SiO gas, similar to the graphite heater. However, there was a problem that the meat wasted and consumed.
【０００８】[0008]
【課題を解決するための手段およびその作用・効果】こ
の発明は、上記課題を有利に解決した単結晶引き上げ装
置を提供することを目的とするものであり、この発明の
単結晶引き上げ装置は、石英ルツボの周囲に位置する黒
鉛ヒーターでその石英ルツボ内のSiを加熱して溶融さ
せ、その溶融Si中からSi単結晶を引き上げる単結晶引き
上げ装置において、前記黒鉛ヒーターと前記石英ルツボ
との間に筒状障壁を設け、その筒状障壁の表面に熱分解
炭素またはガラス状炭素の被膜を形成したことを特徴と
するものである。SUMMARY OF THE INVENTION An object of the present invention is to provide a single crystal pulling apparatus which advantageously solves the above-mentioned problems. In a single crystal pulling apparatus that heats and melts Si in the quartz crucible with a graphite heater located around the quartz crucible and pulls up a Si single crystal from the molten Si, between the graphite heater and the quartz crucible A cylindrical barrier is provided, and a coating of pyrolytic carbon or glassy carbon is formed on the surface of the cylindrical barrier.
【０００９】かかる装置にあっては、Si単結晶の引き上
げ中に石英ルツボのSiO2と溶融Siとが反応して発生した
SiOガスが、黒鉛ヒーターと石英ルツボとの間に設けた
筒状障壁で遮られて、黒鉛ヒーターにはほとんどもしく
は全く接触しなくなる。従ってこの装置によれば、黒鉛
ヒーターの発熱部の一部が SiCに変質してその発熱部が
減肉消耗するのを有効に防止し得て、黒鉛ヒーターの寿
命を従来よりも大幅に延長することができ、ひいては、
多額の費用を費やして黒鉛ヒーターを頻繁に新品に交換
することなしにSi単結晶の引き上げ条件を長期間に亘っ
て安定させることができる。In such an apparatus, SiO 2 of the quartz crucible reacts with molten Si during the pulling of the Si single crystal and is generated.
The SiO gas is blocked by the cylindrical barrier provided between the graphite heater and the quartz crucible, and hardly or not comes into contact with the graphite heater. Therefore, according to this apparatus, it is possible to effectively prevent a part of the heating part of the graphite heater from being transformed into SiC and to reduce the thickness of the heating part, thereby prolonging the life of the graphite heater more than before. Can, in turn,
The pulling condition of the Si single crystal can be stabilized for a long period of time without frequently replacing the graphite heater with a new one at a great expense.
【００１０】またこの装置にあっては、断熱材と黒鉛ヒ
ーターとの間に黒鉛製のインナーシールドを設けてある
場合に、Si単結晶の引き上げ中に石英ルツボのSiO2と溶
融Siとが反応して発生した SiOガスが、黒鉛ヒーターと
石英ルツボとの間に設けた筒状障壁で遮られて、そのイ
ンナーシールドにもほとんどもしくは全く接触しなくな
る。従ってこの装置によれば、そのインナーシールドの
減肉消耗も有効に防止し得て、装置の維持費を安価なも
のとすることができる。Further, in this apparatus, when a graphite inner shield is provided between the heat insulating material and the graphite heater, the SiO 2 of the quartz crucible reacts with the molten Si during the pulling of the Si single crystal. The generated SiO gas is blocked by the cylindrical barrier provided between the graphite heater and the quartz crucible, and hardly or not at all contacts the inner shield. Therefore, according to this device, the thinning of the inner shield can be effectively prevented and the maintenance cost of the device can be reduced.
【００１１】しかもこの装置にあっては、前記筒状障壁
の表面に熱分解炭素またはガラス状炭素の被膜を形成す
るので、前記筒状障壁を例えば炭素材料で形成した場合
に、炭素材料自体は多孔質であるのでそのままでは SiO
ガスが貫流する可能性があるが、共にガス不浸透性を持
つ熱分解炭素またはガラス状炭素の被膜を表面に形成す
ることで、 SiOガスの貫流を確実に防止することができ
る。Further, in this apparatus, since a coating of pyrolytic carbon or glassy carbon is formed on the surface of the cylindrical barrier, when the cylindrical barrier is formed of, for example, a carbon material, the carbon material itself is not formed. SiO as it is porous
The gas may flow through, but by forming a coating of pyrolytic carbon or glassy carbon having gas impermeability on the surface, it is possible to reliably prevent the flow of SiO gas.
【００１２】なお、この発明の装置においては、前記筒
状障壁は、好ましくは炭素材料からなるものとする。炭
素材料は耐熱性が極めて高いので、筒状障壁を炭素材料
からなるものとすれば、その筒状障壁も充分に寿命の長
いものとすることができる。また炭素材料は高温で焼成
することからその成形物は高純度のものになるので、筒
状障壁を炭素材料からなるものとすれば、炉内の雰囲気
中ひいてはSi単結晶中への不純物の混入を有効に防止す
ることができる。そしてこの発明においては、その炭素
材料を黒鉛材料としても良く、そのようにすれば、黒鉛
材料は特に高温で焼成するので、筒状障壁の耐熱性およ
び純度の点で特に有利である。しかして筒状障壁を黒鉛
材料からなるものとする場合には、それを等方性黒鉛材
料としても良く、そのようにすれば、装置の稼働時の加
熱と非稼働時の冷却との繰り返しによる膨張収縮の際に
も全方向に均等に膨張収縮を生ずるので、表面に形成し
た被膜に剪断力を発生させることがなく、それゆえ被膜
を長期間確実に保持することができる。なお、等方性黒
鉛材料を高密度のものとした場合には、それ自体の開気
孔率が低くなるので、表面に熱分解炭素またはガラス状
炭素の被膜を設けなくても SiOガスの貫流をある程度防
止することができる。In the apparatus according to the present invention, the cylindrical barrier is preferably made of a carbon material. Since the carbon material has extremely high heat resistance, if the cylindrical barrier is made of a carbon material, the cylindrical barrier can have a sufficiently long life. In addition, since the carbon material is fired at a high temperature, the molded product has a high purity.If the cylindrical barrier is made of a carbon material, impurities may be mixed into the furnace atmosphere and eventually into the Si single crystal. Can be effectively prevented. In the present invention, the carbon material may be a graphite material. In such a case, the graphite material is fired at a particularly high temperature, which is particularly advantageous in terms of heat resistance and purity of the cylindrical barrier. However, when the cylindrical barrier is made of a graphite material, it may be made of an isotropic graphite material, and by doing so, the heating during the operation of the device and the cooling during the non-operation are repeated. Since expansion and contraction occur evenly in all directions during expansion and contraction, no shearing force is generated in the film formed on the surface, and therefore the film can be reliably held for a long period of time. If the isotropic graphite material has a high density, the open porosity of the material itself is low, so that the flow of SiO gas can be prevented without providing a coating of pyrolytic carbon or glassy carbon on the surface. It can be prevented to some extent.
【００１３】さらに、この発明の装置においては、炭素
材料からなる前記筒状障壁の表面に熱分解炭素またはガ
ラス状炭素の被膜を形成する場合に、前記筒状障壁を、
好ましくは平均細孔半径が 20000オングストローム以下
のものとする。筒状障壁の平均細孔半径が 20000オング
ストロームを越えると、熱分解炭素またはガラス状炭素
の通常の厚さの被膜では気孔を完全には塞ぐことができ
なくなり、それらの被膜を厚くかつ均一に形成するの
は、安定性および経済性の点で困難であるが、筒状障壁
の平均細孔半径が 20000オングストローム以下であれ
ば、安定性および経済性の点で有利な通常の厚さの熱分
解炭素またはガラス状炭素の被膜で、炭素材料からなる
筒状障壁の気孔を完全に塞ぐことができる。Further, in the apparatus according to the present invention, when a coating of pyrolytic carbon or glassy carbon is formed on the surface of the cylindrical barrier made of a carbon material, the cylindrical barrier is formed by:
Preferably, the average pore radius is less than 20000 Å. If the average pore radius of the cylindrical barrier exceeds 20000 Angstroms, the normal thickness of pyrolytic carbon or glassy carbon will not be able to completely close the pores, making those films thick and uniform. This is difficult in terms of stability and economy, but if the average pore radius of the cylindrical barrier is less than 20000 Angstroms, pyrolysis of normal thickness is advantageous in terms of stability and economy. The pores of the tubular barrier made of carbon material can be completely closed by the carbon or glassy carbon coating.
【００１４】[0014]
【発明の実施の形態】以下に、この発明の実施の形態を
実施例によって、図面に基づき詳細に説明する。ここ
に、図１は、この発明の単結晶引き上げ装置の一実施例
を示す縦断面図であり、また図２は、その実施例の装置
における筒状障壁の設置構造を示す拡大縦断面図であ
る。Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Here, FIG. 1 is a longitudinal sectional view showing an embodiment of the single crystal pulling apparatus of the present invention, and FIG. 2 is an enlarged longitudinal sectional view showing an installation structure of a cylindrical barrier in the apparatus of the embodiment. is there.
【００１５】図１に示す単結晶引き上げ装置では、炉本
体１の中央部内に黒鉛サセプタ２を昇降および回転可能
に配置してその黒鉛サセプタ２で石英ルツボ３を保持す
るとともに、炉本体１の中央部内のその黒鉛サセプタ２
の周囲に筒状の黒鉛ヒーター４を配置し、また、炉本体
１の首状に窄まった上部から炉本体１の中央部内に、前
述した従来装置のワイヤに代えてシャフト５を昇降およ
び回転可能に吊り下げてあり、さらに、石英ルツボ３内
の溶融Siの温度管理のために炉本体１の中央部内に黒鉛
ヒーター４を囲繞するように断熱材６を配設するととも
に、その断熱材６を黒鉛ヒーターの熱から保護するため
にその断熱材６と黒鉛ヒーター４との間に黒鉛製の筒状
インナーシールド７を設けてある。In the single crystal pulling apparatus shown in FIG. 1, a graphite susceptor 2 is arranged in a central portion of a furnace main body 1 so as to be able to move up and down and rotate, and the graphite susceptor 2 holds a quartz crucible 3 and a central portion of the furnace main body 1. The graphite susceptor 2 in the department
A cylindrical graphite heater 4 is disposed around the furnace, and a shaft 5 is moved up and down and rotated from the upper part of the furnace body 1 constricted in a neck shape into the center of the furnace body 1 in place of the wire of the above-described conventional apparatus. In order to control the temperature of the molten Si in the quartz crucible 3, a heat insulating material 6 is provided in the central portion of the furnace body 1 so as to surround the graphite heater 4. A graphite inner shield 7 is provided between the heat insulator 6 and the graphite heater 4 in order to protect the heater from the heat of the graphite heater.
【００１６】加えてこの実施例の装置では、黒鉛ヒータ
ー４と石英ルツボ３との間に等方性黒鉛材料からなる筒
状障壁８を設けてあり、ここにおけるインナーシールド
７と筒状障壁８との設置構造は、図２にその詳細に示す
ように、これも炭素材料製の円盤状の底板９の上面にそ
の底板９の中心軸線Ｃを中心として二重に形成した環状
溝9a, 9b内にそれらインナーシールド７と筒状障壁８と
の下端部をそれぞれ嵌め合わせることでそれらインナー
シールド７と筒状障壁８とを底板９により位置決めして
支持し、またそれらインナーシールド７と筒状障壁８と
の上端部を、これも炭素材料製の環状の上板10の下面に
その上板10の中心軸線Ｃを中心として二重に形成した環
状溝10a および環状段部10b 内にそれぞれ嵌め合わせる
ことでそれらインナーシールド７と筒状障壁８とを互い
に結合した、簡易かつ堅牢なものとなっており、これに
より黒鉛ヒーター４は、その半径方向内外方を筒状障壁
８およびインナーシールド７により囲繞されるととも
に、その上方を上板10により覆われ、さらにその下方
も、電極が貫通する部分を除いて底板９により囲繞され
ている。なお、上記中心軸線Ｃは、黒鉛サセプタ２の中
心軸線と一致するものである。In addition, in the apparatus of this embodiment, a cylindrical barrier 8 made of an isotropic graphite material is provided between the graphite heater 4 and the quartz crucible 3, and the inner shield 7 and the cylindrical barrier 8 here are provided. As shown in detail in FIG. 2, the installation structure of this is formed in annular grooves 9a and 9b which are also formed on the upper surface of a disc-shaped bottom plate 9 made of carbon material and centered on the center axis C of the bottom plate 9. The lower ends of the inner shield 7 and the cylindrical barrier 8 are fitted to each other to position and support the inner shield 7 and the cylindrical barrier 8 by the bottom plate 9. Are fitted into the annular groove 10a and the annular stepped portion 10b which are formed on the lower surface of the annular upper plate 10 also made of carbon material and centered on the central axis C of the upper plate 10. With those inners The graphite heater 4 has a simple and robust structure in which the graphite heater 4 and the cylindrical barrier 8 are connected to each other, whereby the graphite heater 4 is surrounded inside and outside in the radial direction by the cylindrical barrier 8 and the inner shield 7. The upper part is covered by an upper plate 10, and the lower part is also surrounded by a bottom plate 9 except for a portion through which an electrode passes. The central axis C is coincident with the central axis of the graphite susceptor 2.
【００１７】さらにこの実施例の装置では、筒状障壁８
の内周側表面に、熱分解炭素またはガラス状炭素からな
る被膜11を形成してある。熱分解炭素からなる被膜11を
黒鉛材料からなる筒状障壁８の表面に形成する方法とし
ては、通常使用される各種化学蒸着法(CVD) を用いるこ
とができ、例えば、筒状障壁８の表面を 800〜2600℃に
加熱しておき、炭化水素ガスもしくはハロゲン化炭化水
素ガスを水素ガス共存下で筒状障壁８の表面に接触させ
て、多数の気孔を有するその筒状障壁８の表面上に熱分
解炭素の緻密な層を形成する。これらの反応は、常圧も
しくは減圧下で行われるが、熱分解炭素被膜の均一性お
よび平滑性のためには減圧下、特に 300Torr以下で行う
ことが望ましい。また、熱分解炭素の被膜の厚さは10μ
m 〜 500μm が望ましい。その理由は、10μm 未満では
十分なガス不浸透性が得られない一方、 500μm を越え
ると筒状障壁８の黒鉛材料との熱膨張率の差により被膜
にクラックが生ずる可能性が大きくなるからである。Further, in the apparatus of this embodiment, the cylindrical barrier 8
A coating film 11 made of pyrolytic carbon or glassy carbon is formed on the inner peripheral surface of the substrate. As a method of forming the coating 11 made of pyrolytic carbon on the surface of the cylindrical barrier 8 made of a graphite material, various types of commonly used chemical vapor deposition (CVD) can be used. Is heated to 800 to 2600 ° C., and a hydrocarbon gas or a halogenated hydrocarbon gas is brought into contact with the surface of the cylindrical barrier 8 in the coexistence of hydrogen gas. To form a dense layer of pyrolytic carbon. These reactions are carried out under normal pressure or reduced pressure. However, it is desirable to carry out the reaction under reduced pressure, particularly 300 Torr or less, in order to make the pyrolytic carbon coating uniform and smooth. The thickness of the pyrolytic carbon coating is 10μ.
m to 500 μm is desirable. The reason is that if it is less than 10 μm, sufficient gas impermeability cannot be obtained, while if it exceeds 500 μm, the possibility of cracks in the coating increases due to the difference in the coefficient of thermal expansion between the cylindrical barrier 8 and the graphite material. is there.
【００１８】またガラス状炭素は、フラン樹脂や、塩化
ビニール樹脂、ポリビニルアルコール、油溶性フェノー
ル樹脂等の有機重合体を不活性雰囲気中で焼成すること
で得られ、耐熱性や、強度、耐蝕性、ガスの非吸着性お
よび不浸透性等に優れたものであり、ガラス状炭素から
なる被膜11を黒鉛材料からなる筒状障壁８の表面に形成
する方法としては、例えば、塩化ビニール樹脂をアルゴ
ン雰囲気下にて、 380℃で40分間処理して不完全熱分解
生成物を得、これをトリクレン中にトリクレン１リット
ルに対し 200グラムの割合で溶解させて溶液とし、その
溶液を黒鉛材料からなる筒状障壁８の内周表面に塗布
し、あるいはその溶液中に筒状障壁８を浸すことで、そ
の筒状障壁８の少なくとも内周表面に上記不完全熱分解
生成物の被膜を形成し、これを真空中にて1400℃で１時
間焼成する。これにより、10μm の厚さを持つガラス状
炭素からなる被膜11を、筒状障壁８の少なくとも内周表
面に形成することができる。Glassy carbon is obtained by baking an organic polymer such as a furan resin, a vinyl chloride resin, polyvinyl alcohol, and an oil-soluble phenol resin in an inert atmosphere, and has heat resistance, strength, and corrosion resistance. The method of forming the coating 11 made of glassy carbon on the surface of the cylindrical barrier 8 made of a graphite material is, for example, a method in which vinyl chloride resin is coated with argon. An incomplete pyrolysis product was obtained by treating at 380 ° C for 40 minutes in an atmosphere, and this was dissolved in tricrene at a rate of 200 grams per liter of tricrene to form a solution, and the solution was made of a graphite material. By coating on the inner peripheral surface of the cylindrical barrier 8 or immersing the cylindrical barrier 8 in the solution, a coating of the incomplete thermal decomposition product is formed on at least the inner peripheral surface of the cylindrical barrier 8, Les baked 1 hour at 1400 ° C. in vacuo. As a result, the coating 11 made of glassy carbon having a thickness of 10 μm can be formed on at least the inner peripheral surface of the cylindrical barrier 8.
【００１９】なお、等方性黒鉛材料からなる上記筒状障
壁８は、上記熱分解炭素またはガラス状炭素からなる被
膜11を長期間確実に保持するためには、熱膨張係数の異
方比が1.25以下で、20〜 400℃の平均熱膨張係数が 1.5
×10-6℃-1〜 6.5×10-6℃-1のものとすることが好まし
い。また上記筒状障壁８は、被膜11で気孔を完全に塞ぐ
ために、平均細孔半径が20000 オングストローム以下の
ものとする。ここに、「平均細孔半径」とは、水銀圧入
法により細孔半径75オングストローム〜 75000オングス
トロームの範囲で細孔容積を累積測定し、その最終累積
容積の1/2 の容積に対応する細孔半径を求めたものをい
う。The cylindrical barrier 8 made of an isotropic graphite material has an anisotropic ratio of a coefficient of thermal expansion in order to reliably hold the coating 11 made of the pyrolytic carbon or the glassy carbon for a long period of time. 1.25 or less, average coefficient of thermal expansion between 20 and 400 ° C is 1.5
It is preferable that the temperature is from × 10 -6 ° C -1 to 6.5 × 10 -6 ° C -1 . The cylindrical barrier 8 has an average pore radius of 20,000 angstroms or less in order to completely close the pores with the coating 11. Here, the "average pore radius" is defined as the pore volume corresponding to one-half of the final cumulative volume obtained by cumulatively measuring the pore volume in the range of 75 Å to 75,000 Å by the mercury intrusion method. Refers to the radius obtained.
【００２０】かかる等方性黒鉛材料からなる筒状障壁８
は、例えば、平均粒径15ミクロンの骨材コークス 100部
に対しコールタールピッチ56部をニーダーで加熱捏混し
た後それを粉砕し、得られた炭素前駆体をラバーバック
に充填してラバープレスで面圧1.3ton/cm2にて加圧する
ことにより円筒状成形体を形成し、それを1200℃まで一
次焼成した後、得られた一次焼成品を誘導加熱炉のコイ
ル内に断熱材とともに置いて、3KHz、300KW のサイリス
タ−インバーター電源により 300℃/hr の昇温速度で28
00℃まで直接加熱し、黒鉛化した後放冷するという方法
によって製造することができる。なお、この実施例の装
置では、その筒状障壁８の寸法を、外径450mm、厚さ 5m
m、高さ 850mmとした。A cylindrical barrier 8 made of such an isotropic graphite material
For example, 100 parts of aggregate coke having an average particle size of 15 microns is kneaded with 56 parts of coal tar pitch in a kneader and then crushed, and the obtained carbon precursor is filled in a rubber bag and rubber pressed. in forming the cylindrical molded body by applying pressure at a surface pressure of 1.3 ton / cm 2, after primary firing it to 1200 ° C., at with heat insulating material in the coil of the induction heating furnace primary sintered product obtained With a 3KHz, 300KW thyristor-inverter power supply at a heating rate of 300 ° C / hr.
It can be manufactured by directly heating to 00 ° C., graphitizing, and then allowing to cool. In the apparatus of this embodiment, the dimensions of the cylindrical barrier 8 are set to an outer diameter of 450 mm and a thickness of 5 m.
m and height 850 mm.
【００２１】この実施例の単結晶引き上げ装置によれ
ば、チョクラルスキー法に基づき、炉本体１内の空気を
不活性ガス、例えばアルゴンガスArで置換するととも
に、石英ルツボ３内の多結晶Siを黒鉛ヒーター４で加熱
して溶融させ、その溶融Si中にアンチモンを所定量加え
てから、シャフト５の下端にて保持した種結晶をそのそ
の溶融Si中に浸漬させ、その後、溶融Siの温度を単結晶
成長に適した所定温度に維持するとともに溶融Si内に不
純物が混入しないよう炉本体１内に上方からアルゴンガ
スArを供給し、同時に炉本体１内のアルゴンガスArや前
述した SiOガス、COガスを下方へ排気しつつ、石英ルツ
ボ３とシャフト５とを互いに逆方向に回転させながらシ
ャフト５を少しずつ引き上げ、それに伴って、単結晶成
長による溶融Siの減少で結晶成長界面の位置が変化しな
いように石英ルツボ３も少しずつ上昇させることによ
り、図１に示すように種結晶の下端にSi単結晶12を順次
成長させることができる。According to the single crystal pulling apparatus of this embodiment, based on the Czochralski method, the air in the furnace body 1 is replaced with an inert gas, for example, argon gas Ar, and the polycrystalline Si in the quartz crucible 3 is replaced. Is heated and melted by a graphite heater 4, a predetermined amount of antimony is added to the molten Si, and the seed crystal held at the lower end of the shaft 5 is immersed in the molten Si. Is maintained at a predetermined temperature suitable for single crystal growth, and argon gas Ar is supplied from above into the furnace main body 1 so as to prevent impurities from being mixed in the molten Si. At the same time, the argon gas Ar in the furnace main body 1 and the SiO gas described above are supplied. The shaft 5 is pulled up little by little while rotating the quartz crucible 3 and the shaft 5 in the opposite directions while exhausting the CO gas downward. By the position of the interface is the quartz crucible 3 so as not to change is increased little by little, it is possible to successively grow a Si single crystal 12 at the lower end of the seed crystal, as shown in FIG.
【００２２】しかもこの実施例の装置にあっては、Si単
結晶の引き上げ中に石英ルツボ３のSiO2と溶融Siとが反
応して発生した SiOガスが、黒鉛ヒーター４と石英ルツ
ボ３との間に設けた筒状障壁８と上板10とで遮られて、
黒鉛ヒーター４には全く接触しなくなる。従って、この
実施例の装置によれば、黒鉛ヒーター４の発熱部の一部
が SiCに変質してその発熱部が減肉消耗するのを確実に
防止し得て、黒鉛ヒーター４の寿命を従来よりも大幅に
延長することができ、ひいては、多額の費用を費やして
黒鉛ヒーターを頻繁に新品に交換することなしにSi単結
晶の引き上げ条件を長期間に亘って安定させることがで
きる。なお、この筒状障壁８は、黒鉛ヒーター４の減肉
に伴うパーティクルの発生を防止するとともに炉内の石
英ルツボ３の周辺の気流の流れを整える機能も果たすの
で、従来の装置ではSi単結晶内に微量の炭素が混入する
場合があった処、この実施例の装置によれば、石英ルツ
ボ３の周辺のパーティクル量を減らし得て、Si単結晶内
への炭素の混入を確実に防止することができる。Further, in the apparatus of this embodiment, the SiO 2 gas generated by the reaction between the SiO 2 of the quartz crucible 3 and the molten Si during the pulling of the Si single crystal generates the SiO gas between the graphite heater 4 and the quartz crucible 3. Blocked by the cylindrical barrier 8 and the upper plate 10 provided between them,
There is no contact with the graphite heater 4 at all. Therefore, according to the apparatus of this embodiment, it is possible to reliably prevent a part of the heat generating portion of the graphite heater 4 from being changed into SiC and the heat generating portion being reduced in thickness and consumed. Therefore, the conditions for pulling the Si single crystal can be stabilized for a long period of time without frequent replacement of the graphite heater with a new one at a great expense. The cylindrical barrier 8 prevents the generation of particles due to the thinning of the graphite heater 4 and also regulates the flow of air around the quartz crucible 3 in the furnace. According to the apparatus of this embodiment, the amount of particles around the quartz crucible 3 can be reduced, and the mixing of carbon into the Si single crystal can be reliably prevented. be able to.
【００２３】またこの実施例の装置にあっては、断熱材
６と黒鉛ヒーター４との間に黒鉛製のインナーシールド
７を設けてある処、Si単結晶の引き上げ中に石英ルツボ
３のSiO2と溶融Siとが反応して発生した SiOガスが、黒
鉛ヒーター４と石英ルツボ３との間に設けた筒状障壁８
と上板10とで遮られて、そのインナーシールド７にも全
く接触しなくなる。従って、この実施例の装置によれ
ば、そのインナーシールド７の減肉消耗も有効に防止し
得て、装置の維持費を安価なものとすることができる。In the apparatus of this embodiment, the inner shield 7 made of graphite is provided between the heat insulating material 6 and the graphite heater 4, and the SiO 2 of the quartz crucible 3 is pulled during the pulling of the Si single crystal. SiO gas generated as a result of the reaction between the silica and the molten Si forms a cylindrical barrier 8 provided between the graphite heater 4 and the quartz crucible 3.
And the upper plate 10 so as not to contact the inner shield 7 at all. Therefore, according to the device of this embodiment, the thinning of the inner shield 7 can be effectively prevented, and the maintenance cost of the device can be reduced.
【００２４】さらにこの実施例の装置によれば、筒状障
壁８を、耐熱性および純度が高い炭素材料、なかでも特
に耐熱性および純度の点で優れた黒鉛材料からなるもの
としてあるので、筒状障壁８を充分に寿命の長いものと
することができるとともに、炉内の雰囲気中ひいてはSi
単結晶中への不純物の混入を有効に防止することができ
る。Further, according to the apparatus of this embodiment, the cylindrical barrier 8 is made of a carbon material having high heat resistance and purity, and especially a graphite material having excellent heat resistance and purity. Barrier 8 can have a sufficiently long life, and the atmosphere in the furnace and thus Si
Incorporation of impurities into the single crystal can be effectively prevented.
【００２５】またこの実施例の装置によれば、筒状障壁
８の表面に熱分解炭素またはガラス状炭素の被膜11を形
成してあるので、筒状障壁８に対する SiOガスの貫流を
確実に防止することができる。なお、本願発明者が実験
した結果では、筒状障壁８を持たない従来の装置での黒
鉛ヒーターの寿命は概ね3000時間であったのに対し、上
記実施例の装置において、なにも被膜を設けていない黒
鉛性筒状障壁８を用いた場合には、黒鉛ヒーター４の寿
命は概ね8500時間に延び、またガラス状炭素の被膜11を
設けた黒鉛性筒状障壁８を用いた場合には、黒鉛ヒータ
ー４の寿命は概ね 17000時間に延び、そして熱分解炭素
の被膜11を設けた黒鉛性筒状障壁８を用いた場合には、
黒鉛ヒーター４の寿命は概ね 20000時間にまで延びた。
従って、黒鉛性筒状障壁８そのものによる優れた黒鉛ヒ
ーター寿命延長効果と、そこに被膜11を設けた場合のさ
らに優れた黒鉛ヒーター寿命延長効果とが確認された。Further, according to the apparatus of this embodiment, since the coating 11 of pyrolytic carbon or glassy carbon is formed on the surface of the cylindrical barrier 8, the flow of SiO gas through the cylindrical barrier 8 is reliably prevented. can do. According to the results of experiments conducted by the inventor of the present invention, the life of the graphite heater in the conventional apparatus having no cylindrical barrier 8 was approximately 3000 hours, whereas in the apparatus of the above embodiment, no coating was formed. In the case where the graphite tubular barrier 8 not provided is used, the life of the graphite heater 4 is extended to approximately 8500 hours, and in the case where the graphite tubular barrier 8 provided with the glassy carbon coating 11 is used. The service life of the graphite heater 4 is extended to approximately 17,000 hours, and when the graphite tubular barrier 8 provided with the coating 11 of pyrolytic carbon is used,
The service life of the graphite heater 4 has been extended to about 20,000 hours.
Thus, it was confirmed that the graphite heater 8 itself has an excellent effect of extending the service life of the graphite heater, and that the coating 11 has a further excellent effect of extending the service life of the graphite heater.
【００２６】さらにこの実施例の装置によれば、筒状障
壁８を等方性黒鉛材料からなるものとして、装置の稼働
時の加熱と非稼働時の冷却との繰り返しによる膨張収縮
の際に全方向に均等に膨張収縮を生ずるようにしたの
で、表面に形成した被膜11に剪断力を発生させることが
なく、それゆえ被膜11を長期間確実に保持することがで
きる。Further, according to the apparatus of this embodiment, the cylindrical barrier 8 is made of an isotropic graphite material, so that when the apparatus is expanded and contracted due to repetition of heating during operation and cooling during non-operation, the entire barrier is formed. Since the expansion and contraction occur evenly in the directions, no shearing force is generated in the coating 11 formed on the surface, and therefore the coating 11 can be reliably held for a long period of time.
【００２７】さらにこの実施例の装置によれば、筒状障
壁８を、平均細孔半径が 20000オングストローム以下の
ものとしたので、安定性および経済性の点で有利な通常
の厚さの熱分解炭素またはガラス状炭素の被膜11で筒状
障壁８の気孔を完全に塞ぎ得て、黒鉛ヒーター４の寿命
を確実かつ安価に延ばすことができる。Further, according to the apparatus of this embodiment, since the cylindrical barrier 8 has an average pore radius of 20000 Å or less, it has a normal thickness and is advantageous in terms of stability and economy. The pores of the cylindrical barrier 8 can be completely closed by the carbon or glassy carbon coating 11, and the life of the graphite heater 4 can be reliably and inexpensively prolonged.
【００２８】以上、図示例に基づき説明したが、この発
明は上述の例に限定されるものでなく、例えば、前記筒
状障壁を形成するための炭素材料として、上記実施例の
等方性黒鉛材料に代えて、押し出し成形黒鉛材料や、炭
素結合炭素繊維複合材料、発泡性炭素黒鉛材料等を用い
ることもできる。また、前記筒状障壁を形成するための
等方性黒鉛材料を、高密度等方性黒鉛材料としても良
い。そして、前記筒状障壁の設置構造も、上記実施例に
限定されず所要に応じて適宜に変更することができる。Although the present invention has been described with reference to the illustrated examples, the present invention is not limited to the above examples. For example, as the carbon material for forming the cylindrical barrier, the isotropic graphite of the above embodiment is used. In place of the material, an extruded graphite material, a carbon-bonded carbon fiber composite material, an expandable carbon graphite material, or the like can be used. Further, the isotropic graphite material for forming the cylindrical barrier may be a high-density isotropic graphite material. Also, the installation structure of the cylindrical barrier is not limited to the above embodiment, and can be appropriately changed as needed.
【図１】この発明の単結晶引き上げ装置の一実施例を示
す縦断面図である。FIG. 1 is a longitudinal sectional view showing one embodiment of a single crystal pulling apparatus of the present invention.
【図２】上記実施例の装置における筒状障壁の設置構造
を示す拡大縦断面図である。FIG. 2 is an enlarged vertical sectional view showing an installation structure of a cylindrical barrier in the apparatus of the embodiment.
１ 炉本体 ２ 黒鉛サセプタ ３ 石英ルツボ ４ 黒鉛ヒーター ５ シャフト ６ 断熱材 ７ インナーシールド ８ 筒状障壁 ９ 底板 10 上板 11 被膜 12 Si単結晶 DESCRIPTION OF SYMBOLS 1 Furnace main body 2 Graphite susceptor 3 Quartz crucible 4 Graphite heater 5 Shaft 6 Insulation material 7 Inner shield 8 Cylindrical barrier 9 Bottom plate 10 Top plate 11 Coating 12 Si single crystal
Claims (5)
ーでその石英ルツボ内のSiを加熱して溶融させ、その溶
融Si中からSi単結晶を引き上げる単結晶引き上げ装置に
おいて、 前記黒鉛ヒーターと前記石英ルツボとの間に筒状障壁を
設け、その筒状障壁の表面に熱分解炭素またはガラス状
炭素の被膜を形成したことを特徴とする、単結晶引き上
げ装置。1. A single crystal pulling apparatus for heating and melting Si in a quartz crucible with a graphite heater positioned around the quartz crucible and pulling a Si single crystal from the molten Si, wherein the graphite heater and the quartz A single crystal pulling apparatus, characterized in that a cylindrical barrier is provided between a crucible and a film of pyrolytic carbon or glassy carbon is formed on the surface of the cylindrical barrier.
を特徴とする、請求項１記載の単結晶引き上げ装置。2. The single crystal pulling apparatus according to claim 1, wherein the cylindrical barrier is made of a carbon material.
特徴とする、請求項２記載の単結晶引き上げ装置。3. The single crystal pulling apparatus according to claim 2, wherein said carbon material is a graphite material.
とを特徴とする、請求項３記載の単結晶引き上げ装置。4. The single crystal pulling apparatus according to claim 3, wherein the graphite material is isotropic.
オングストローム以下のものとしたことを特徴とする、
請求項３または請求項４記載の単結晶引き上げ装置。5. The method according to claim 5, wherein the cylindrical barrier has an average pore radius of 20000.
Angstroms or less,
The single crystal pulling apparatus according to claim 3 or 4.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27896597A JP3636873B2 (en) | 1997-10-13 | 1997-10-13 | Single crystal pulling device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27896597A JP3636873B2 (en) | 1997-10-13 | 1997-10-13 | Single crystal pulling device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH11116389A true JPH11116389A (en) | 1999-04-27 |
| JP3636873B2 JP3636873B2 (en) | 2005-04-06 |
Family
ID=17604544
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP27896597A Expired - Fee Related JP3636873B2 (en) | 1997-10-13 | 1997-10-13 | Single crystal pulling device |
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| Country | Link |
|---|---|
| JP (1) | JP3636873B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102653880A (en) * | 2012-04-20 | 2012-09-05 | 镇江环太硅科技有限公司 | Casting device |
| WO2016010040A1 (en) * | 2014-07-14 | 2016-01-21 | 株式会社福田結晶技術研究所 | Lithium tantalate single crystal growth device and growth method |
| CN107840329A (en) * | 2017-12-16 | 2018-03-27 | 江西正拓新能源科技股份有限公司 | A kind of high performance Delanium stove |
| JP2023509531A (en) * | 2020-06-05 | 2023-03-08 | 西安奕斯偉材料科技有限公司 | Hot zone structure of single crystal furnace, single crystal furnace and crystal bar |
-
1997
- 1997-10-13 JP JP27896597A patent/JP3636873B2/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102653880A (en) * | 2012-04-20 | 2012-09-05 | 镇江环太硅科技有限公司 | Casting device |
| WO2016010040A1 (en) * | 2014-07-14 | 2016-01-21 | 株式会社福田結晶技術研究所 | Lithium tantalate single crystal growth device and growth method |
| JPWO2016010040A1 (en) * | 2014-07-14 | 2017-04-27 | 株式会社福田結晶技術研究所 | Apparatus and method for growing lithium tantalate single crystal |
| CN107840329A (en) * | 2017-12-16 | 2018-03-27 | 江西正拓新能源科技股份有限公司 | A kind of high performance Delanium stove |
| JP2023509531A (en) * | 2020-06-05 | 2023-03-08 | 西安奕斯偉材料科技有限公司 | Hot zone structure of single crystal furnace, single crystal furnace and crystal bar |
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