JPS61242981A - Production of single crystal - Google Patents

Abstract

PURPOSE:To produce a large-sized high-quality single crystal having long length and free of impurities at a low cost, by replenishing a solid crystal raw material to the part where the top surface of the molten liquid in a crucible is almost solidified by the temperature gradient of a heating furnace. CONSTITUTION:The crystal raw material in the crucible 2 is melted with the heating furnace 1, and the single crystal 3 is grown from the molten liquid 4 by lowering the crucible 2 at a definite rate. The crucible 2 is replenished with the solid crystal raw material 10 by the replenishing means 8 through the pipe 9 corresponding to the growth of the single crystal 3. The furnace 1 has a temperature gradient having a peak at the center and decreasing toward the upper and the lower ends. The slid crystal raw material 10 is supplied to the part where the top surface 7 of the molten liquid 4 is almost solidified by the temperature gradient. The evaporation of the molten substance from the top surface 7 of the molten liquid 4 and the blow-up of air by thermal convection in the liquid can be suppressed, the blockage of the pipe 9 is prevented, the disturbance of the molten liquid 4 is minimized, and the reaction of the molten liquid 4 and the crucible 2 is suppressed by this process.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は種結晶と固体結晶原料が充填されたるつぼに固
体結晶原料を連続的に補給しながら融液から長尺の単結
晶を製造する方法に関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention produces a long single crystal from a melt while continuously replenishing a crucible filled with seed crystals and solid crystal raw materials with solid crystal raw materials. Regarding the method.

〔従来の技術〕[Conventional technology]

上述の如き単結晶製造装置による単結晶の作製法は、ブ
リッジマン法として知られている。The method for producing a single crystal using the above-mentioned single crystal production apparatus is known as the Bridgman method.

この方法で長尺の大型単結晶を作成する場合には長尺で
大型のるつぼを用い、該るつぼに上方から固体結晶原料
を単位時間当り一定量ずつ連続的に供給しながら単結晶
を成長させる。When creating a long, large single crystal using this method, a long and large crucible is used, and the single crystal is grown while continuously supplying solid crystal raw material from above at a constant rate per unit time to the crucible. .

具体的には、るつぼの中に一部装填した固体の結晶原料
を溶融し、所定の温度分布をもつ加熱炉内でるつぼを下
方（二移動させることによって、るつぼ底部で生じた結
晶をもとじ結晶を成長させ、他方、結晶の成長に合せて
粉末状、顆粒状、あるいはペレット状等の固体結晶原料
をるつぼ上方からパイプを通して供給することによって
単結晶を作製する。Specifically, a solid crystal raw material partially charged in a crucible is melted, and the crucible is moved downward (two times) in a heating furnace with a predetermined temperature distribution, so that the crystals formed at the bottom of the crucible are undone. A single crystal is produced by growing a crystal and supplying a solid crystal raw material in the form of powder, granules, or pellets through a pipe from above the crucible in accordance with the growth of the crystal.

〔発明が解決しようとする問題点〕[Problem that the invention seeks to solve]

このように、るつぼ内に固体結晶原料を単位時間当り一
定量ずつ連続的に添加しながら、溶融させて、長尺の大
型単結晶を製造する際に。In this way, solid crystal raw materials are continuously added in a fixed amount per unit time into the crucible and melted to produce a long, large single crystal.

原料供給を長時間続けると、溶融物質の蒸発。If the raw material supply is continued for a long time, the molten material will evaporate.

熱対流による空気の吹きあげ等により、パイプが閉塞し
、連続供給ができなくなる傾向があった。また、固体結
晶原料を溶融しながら、結晶成長を行なうことにより、
融液面での温度の擾乱が大きくなる。そのため、融液と
るつぼ材との反応が起こりやすくなる。この現象が顕著
な場合は、るつぼ材料の破断まで引き起こす原因となっ
ている。There was a tendency for pipes to become clogged due to air blowing up due to thermal convection, making continuous supply impossible. In addition, by performing crystal growth while melting the solid crystal raw material,
Temperature disturbances at the melt surface become larger. Therefore, a reaction between the melt and the crucible material is likely to occur. If this phenomenon is significant, it may even cause breakage of the crucible material.

本発明の目的は、長尺で大型の不純物の入らない高品質
の単結晶製造方法を提供し、長尺で大型のるつぼ材の入
らない高品質単結晶素材を安価な値段での提供を可能（
ニすること（二ある。The purpose of the present invention is to provide a method for producing a high-quality single crystal that does not contain long and large impurities, and to provide a high-quality single crystal material that does not contain long and large crucible materials at a low price. (
There are two things to do.

〔問題点を解決するための手段〕[Means for solving problems]

本発明によれば、るつぼの中に一部充填した固体の結晶
原料を溶融し、所定の温度分布をもつ電気炉の如き加熱
炉内でるつぼを下方に移動させることによって、るつぼ
底部で生じた結晶をもとじ結晶を成長させ、他方、結晶
の成長に合せて粉末状、顆粒状、あるいはペレット状等
の固体結晶原料をるつぼ上方から供給する際に。According to the present invention, by melting a solid crystal raw material partially filled in a crucible and moving the crucible downward in a heating furnace such as an electric furnace having a predetermined temperature distribution, When starting a crystal and growing the crystal, and on the other hand, supplying solid crystal raw materials such as powder, granules, or pellets from above the crucible as the crystal grows.

融液の上面だけ凝固するような位置を電気炉の温度分布
から選ぶ。そして、その部分に固体結晶原料を供給しな
がら結晶を育成する。供給パイプを、中心部に設置した
従来法では、融液の対流、熱の放散により、融液面での
温度の擾乱が起きやすくなる。本願発明による方法では
。Select a position from the temperature distribution of the electric furnace so that only the upper surface of the melt solidifies. Then, crystals are grown while supplying a solid crystal raw material to that part. In the conventional method in which the supply pipe is installed in the center, the temperature on the surface of the melt tends to fluctuate due to convection of the melt and heat dissipation. In the method according to the present invention.

融液の上面がほぼ凝固しているので、固体結晶原料が、
融液の上面に供給される際に、凝固層がバリヤーになっ
て固体結晶原料が直接融液に入り込むことがなくなる。Since the upper surface of the melt is almost solidified, the solid crystal raw material
When supplied to the upper surface of the melt, the solidified layer acts as a barrier and prevents the solid crystal raw material from directly entering the melt.

その結果として、融液面での温度の擾乱が小さくなる。As a result, the temperature disturbances at the melt surface are reduced.

そのため。Therefore.

融液とるつぼ材との反応が制御される。その結果として
、長尺で大型のるつぼ材の入らない高品質の単結晶が得
られる。The reaction between the melt and the crucible material is controlled. As a result, a high-quality single crystal can be obtained without the need for long and large crucible materials.

〔実施例〕〔Example〕

次に本発明に依る単結晶の製造方法を図面を参照して説
明する。Next, a method for manufacturing a single crystal according to the present invention will be explained with reference to the drawings.

第１図は本発明を実施する（；当っての製造装置を示す
。１は加熱炉で図中右側の温度分布図に示す如く炉内上
下方向位置の中央部で最高温度となり、該中央部から上
下方向に離れるに従って温度が下がっている。電気炉１
の最高温部は固体の結晶原料を溶融して融液にすること
ができる温度である。Figure 1 shows a manufacturing apparatus for carrying out the present invention. 1 is a heating furnace, and as shown in the temperature distribution diagram on the right side of the figure, the highest temperature is at the center of the vertical position in the furnace, and The temperature decreases as it moves away from the top and bottom.Electric Furnace 1
The highest temperature part is the temperature at which the solid crystal raw material can be melted into a melt.

第１図の状態では、るっぽ２の中に融液４が入っており
、上述した温度分布をもった加熱炉１の中を、るつぼ２
を所定の速度で下方へ移動させることによって単結晶３
が成長しつつある。In the state shown in Fig. 1, the melt 4 is contained in the crucible 2, and the crucible 4 is passed through the heating furnace 1 having the above-mentioned temperature distribution.
By moving the single crystal 3 downward at a predetermined speed,
is growing.

５はるつぼ支持具、６はるつぼ移動機構である。5 is a crucible supporter, and 6 is a crucible moving mechanism.

この際、粉末状、顆粒状あるいはペレット状の固体結晶
原料１０を、原料供給機構８によって。At this time, the solid crystal raw material 10 in the form of powder, granules, or pellets is supplied by the raw material supply mechanism 8.

単結晶３の成長速度に合せて供給パイプ９を介してるっ
ぽ２の中に、単位時間当り一定量ずつ連続的に供給する
。A fixed amount per unit time is continuously supplied into the Luppo 2 via the supply pipe 9 in accordance with the growth rate of the single crystal 3.

以下９本発明を例えば磁気ヘッド等の磁性材料として使
用されるＭｎ　−Ｚｎフェライト単結晶の育成について
従来の方法と比較して説明する。The present invention will be described below in comparison with conventional methods for growing Mn--Zn ferrite single crystals used as magnetic materials for magnetic heads and the like.

先ず、従来法でフェライト単結晶を育成した場合につい
て説明する。この方法で、原料を供給するとき、長時間
（１００時間以上）続けると、原料供給パイプ９が溶融
物質の蒸発、熱対流による空気の吹き上げのために閉塞
され、連続供給が不可能となることがしばしばあった。First, a case in which a ferrite single crystal is grown using a conventional method will be described. If this method is used to supply raw materials for a long time (more than 100 hours), the raw material supply pipe 9 will become blocked due to evaporation of the molten material and air blowing up due to thermal convection, making continuous supply impossible. was often the case.

得られた結晶をみるとるつぼ材がかなりの量検出された
。この原因は、固体結晶原料を溶融しながら、結晶成長
を行なうこと：；より、融液４面での温度の擾乱が大き
くなる。そのため、融液とるつぼ材との反応が起こりや
すくなる。When looking at the obtained crystals, a considerable amount of crucible material was detected. The reason for this is that crystal growth is performed while the solid crystal raw material is melted; therefore, temperature fluctuations on the four sides of the melt become large. Therefore, a reaction between the melt and the crucible material is likely to occur.

次に本発明では９例えば、Ｍｎ−Ｚｎフェライトの溶融
原料から単結晶に成長させていくときに、融液４の上面
７の部分がほぼ凝固するように電気炉の温度勾配を選択
する。そうすると。Next, in the present invention, for example, when growing a single crystal from a molten raw material of Mn--Zn ferrite, the temperature gradient of the electric furnace is selected so that the upper surface 7 of the melt 4 is almost solidified. Then.

融液の上面からの溶融物質の蒸発、熱対流による空気の
吹き上げを抑制することができる。また、その結果とし
て、原料供給パイプ９の先端は、溶融原料の融点以下に
おさえられる。よって、パイプが閉塞されることが少な
くなる。そして、融液４の上面は、凝固物でふたをされ
た状態になるので、固体結晶原料１０は、い、ったん凝
固物に達する。その結果、直接固体結晶原料１０が融液
４にチャージされて融液面での温度の擾乱が大きくなる
ことがなくなる。そのため、融液とるつぼ材との反応が
抑制される。Evaporation of the molten substance from the upper surface of the melt and blowing up of air due to thermal convection can be suppressed. Moreover, as a result, the tip of the raw material supply pipe 9 is kept below the melting point of the molten raw material. Therefore, the pipe is less likely to be blocked. Then, since the upper surface of the melt 4 is covered with the solidified material, the solid crystal raw material 10 reaches the solidified material at once. As a result, the solid crystal raw material 10 is not directly charged into the melt 4 and the temperature disturbance at the melt surface is not increased. Therefore, the reaction between the melt and the crucible material is suppressed.

〔発明の効果〕〔Effect of the invention〕

以上説明したように９本発明は９種結晶と少量の固体結
晶原料が充填されたるつぼを加熱炉との相対的位置関係
を連続して変化させ加熱し。As explained above, in the present invention, a crucible filled with nine types of crystals and a small amount of solid crystal raw material is heated by continuously changing the relative positional relationship with the heating furnace.

前記るつぼ内で溶融凝固した単結晶に前記固体結晶原料
を連続的に補給し融液から単結晶を製造する際に、電気
炉の温度勾配から融液の上面がほぼ固まるような場所を
選んで、そこに前記固体結晶原料を補給することで結晶
成長を行なう。その結果、長尺で大型の不純物の入らな
い高品質単結晶素材を低コストで製造することが可能と
なる。When producing a single crystal from the melt by continuously supplying the solid crystal raw material to the single crystal melted and solidified in the crucible, select a location where the upper surface of the melt will almost solidify due to the temperature gradient of the electric furnace. , crystal growth is performed by replenishing the solid crystal raw material therein. As a result, it becomes possible to produce a long, high-quality single crystal material free of large impurities at low cost.

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

第１図は本発明に使用した単結晶製造装置並び冨二従来
法：二よるときの温度分布図を示す。第２図は本発明を
実施した場合の温度分布図を示す。 図において、１は加熱炉、２はるつぼ、３は単結晶、４
は融液、５はるつぼ支持具、６はるつぼ移動機構、７は
融液の上面、８は原料供給機構、９は供給パイプ、１０
は結晶原料である。 ＩＯ：固体結晶原料FIG. 1 shows a temperature distribution diagram of the single crystal production apparatus used in the present invention and the Fuji conventional method. FIG. 2 shows a temperature distribution diagram when the present invention is implemented. In the figure, 1 is a heating furnace, 2 is a crucible, 3 is a single crystal, and 4
5 is a melt, 5 is a crucible support, 6 is a crucible moving mechanism, 7 is an upper surface of the melt, 8 is a raw material supply mechanism, 9 is a supply pipe, 10
is the crystal raw material. IO: solid crystal raw material

Claims (1)

【特許請求の範囲】[Claims] １、種結晶と少量の固体結晶原料が充填されたるつぼを
加熱炉との相対的位置関係を連続して変化させて加熱し
、前記るつぼ内で溶融凝固した単結晶に前記固体結晶原
料を連続的に補給し融液から単結晶を製造する方法にお
いて、加熱炉の温度勾配から融液の上面がほぼ固まるよ
うな場所を選んで、そこに前記固体結晶原料を補給する
ことを特徴とする単結晶の製造方法。1. A crucible filled with a seed crystal and a small amount of solid crystal raw material is heated by continuously changing its relative position with the heating furnace, and the solid crystal raw material is continuously applied to the single crystal melted and solidified in the crucible. A method for producing a single crystal from a melt by replenishing the solid crystal raw material at a location where the upper surface of the melt is almost solidified due to the temperature gradient of the heating furnace, and replenishing the solid crystal raw material there. Method of manufacturing crystals.