JPH0354187A - Single crystal producing device - Google Patents

Abstract

PURPOSE:To make possible to melt raw material without using special cover and eliminate pollution with impurities from outside by installing a coracle for pulling up single crystal from raw material melt at inside of vessel as capable of going up and down. CONSTITUTION:A groove 4a containing sealant 8 is formed along outer periphery of crucible-receiving vessel 4 installed at top end of lower shaft 6 and a crucible 5 containing lumpy raw material 7 is received in said vessel 4, then a coracle 9 supported by coracle-supporting part 12 set inside of the vessel 3 in freely going up and down is installed over the raw material 7. Thus, weights 10 are laid on arm parts 9a and 9b formed at outer periphery part of said coracle 9 and inserted into guide groove 12a of supporting part, then lower end of the vessel 3 is dipped into the sealant 8. Thus, the raw material 7 is melted in a state of coracle 9 attaching to and staying on the raw material 7 and the coracle 9 is lowered by empty weight and weight of the weight 10 corresponding to reduction of bulk of the raw material 7, then the coracle is attached to lower end of the guide groove 12a and stopped, thus seed crystal 11 attached to upper shaft 2 is introduced into the raw material 7 through communicating hole 9c and singe crystal 13 is pulled up by the upper shaft.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is applicable to oxidation of group I compound semiconductors such as GaAs and InP, group compound semiconductors such as Cd and ZnTe, and oxidation of BSO and BG0. Things 11
The present invention relates to an apparatus for producing a single crystal containing an element with high H-separation property, such as a single crystal.

[Conventional technology]

As a device for manufacturing single crystals containing highly dissociable elements such as GaAs, Betucell is used to form a closed space.
An apparatus is known that grows a single crystal while controlling the solid-liquid interface by raising and lowering the position of a crucible that controls the vapor pressure in the lowest temperature part of the space.

In addition, there is a device that floats a coracle in the raw material melt in the crucible, introduces the raw material melt from the crucible into the coracle through the communication hole of this coracle, and pulls a single crystal from the raw material melt introduced into the coracle. In known and conventional devices, such a coracle is attached to a vessel for forming a closed space.

FIG. 6 is a sectional view showing such a conventional device.

Referring to FIG. 6, there is a crucible 2 in the crucible storage container 24.
5 is stored. On the outer periphery of the crucible storage container 24,
A total of 24 a is formed.

This F? A sealant 28 is placed inside 24a, and the lower end of the vessel 23 is immersed in this sealant 28, thereby forming a closed space within the vessel 23.

A melted raw material 27 is placed in the crucible 25, and a coracle 29 is floated on the raw material 27. The coracle 29 is attached to the inner wall surface of the vessel 23. The melt in the crucible 25 is introduced into the two coracles through the communication hole 29a, and the single crystal 33 is pulled up from the raw material melt in the two coracles.

Such pulling of the single crystal 33 is performed by pulling up the seed crystal 31 attached to the tip of the upper shaft 22.

[Problems to be Solved by the Invention] As described above, in the conventional single crystal manufacturing apparatus, the coracle is fixedly attached inside the vessel. When melting the raw materials in the crucible, it is necessary to make the crucible a closed space in order to suppress volatilization of highly volatile elements in the compound. However, since the raw material before melting is bulky, if you try to use the vessel 23 used for single crystal growth to form a closed space during melting of this raw material, it will be fixed inside the vessel. The lower end of the vessel cannot be immersed in the sealant due to the bulky material in the attached coracle crucible. For this reason, conventional devices use a lid 21 as shown in FIG.

Referring to FIG. 4, the lower end of the lid 21 is immersed in the sealant 28 in the '/R 24 a of the crucible storage container 24 to form a closed space. After forming a closed space with the lid 21 in this way, the inside of the melting hole 25 is heated and the raw material 2
Melt 7. FIG. 5 is a sectional view showing the state after melting the raw materials. After melting the raw material 27 using the lid 21 in this way, the lid 21 is pulled up and the sealant 27 is melted.
8, and then remove it from Bethel 23 as shown in FIG.
Dip the tip of the needle into the glue 28.

In this way, conventional single crystal manufacturing equipment requires the process of melting the raw material in the crucible and setting the coracle on top of the molten raw material melt, which is complicated and reduces production efficiency. It wasn't desirable. In addition, since it is necessary to remove the lid and set the coracle, and once the closed space is opened, the temperature must be adjusted to prevent highly dissociable elements from volatilizing, or when removing the lid and setting the coracle. There was a problem in that control, etc. had to be carried out.

The present invention solves the problems of such conventional devices, allows raw materials to be melted without using a special lid for the raw material melting process, and is capable of efficiently manufacturing single crystals. The goal is to provide equipment.

[Means for Solving the Problems] The single crystal manufacturing apparatus of the present invention includes a crucible storage container that houses a crucible for containing a raw material melt and has a groove formed along the outer periphery for containing a sealant. , a vessel whose interior is sealed by fully immersing the tip of the crucible storage container, and a vessel that is floated on top of the melted raw material in the crucible and is introduced from the melted raw material through the communication hole into the inside of the crucible. The device is equipped with a coracle for pulling up crystals, and is characterized in that the coracle is installed inside the Bethel so that it can be moved up and down.

[Function] In the LJ product manufacturing apparatus of the present invention, the coracle is installed inside the vessel so as to be movable up and down. Therefore, by positioning the coracle upward when placed on top of a bulky lump of raw material before melting, the lower end of the vessel can be immersed in the sealant, thereby sealing the inside of the vessel. be able to.

When the raw material melts, its bulk decreases, and accordingly, the coracle moves downward and is placed in a state where it is floating in the raw material melt. At this time, a weight such as quartz can be placed on the coracle so that the melt floats at an appropriate position in the raw material melt.

In the single crystal manufacturing apparatus of this invention, since the coracle is installed so that it can be raised and lowered inside the vessel, it is possible to carry out sushi 1 [disease melting and crystal growth as one process, and by extrusion of highly dissociable elements. Problems such as contamination or impurity contamination from the outside when replacing the lid and attaching the vessel after melting the raw materials can be alleviated, and productivity can be improved.

[Example] FIG. 1 is a sectional view showing an example of the present invention, and shows a state before the raw material in the crucible is eluted. Referring to FIG. 1, a crucible 5 is housed in a crucible storage container 4. As shown in FIG. A groove 4a is formed along the outer periphery of the rutsuho storage container 4. A sealant 8 is placed in the chamber 4a. The crucible storage container 4 is attached to and supported by the tip of the lower shaft 6.

A lumpy raw material 7 is placed in the crucible 5, and a coracle 10 is placed above the raw material 7. The coracle 9 is a coracle support part 12 provided inside the vessel 3.
It is supported so that it can be raised and lowered. Coracle support part 1
2 is formed with a guide groove 12a. Coracle 9
Arm parts 9a and 9b are formed on the outer periphery of the body, and a weight 10 is placed on the arm parts 9a and 9b. The arm portions 9a and 9b are pushed into the guide 12a of the coracle support portion 12.

The lower end of the vessel 3 is immersed in a sealant 8.

A hole is formed above the vessel 3, and the upper shaft 2 is passed through this hole. A seed crystal 11 is attached to the lower end of the upper part 2. A heater 1 is provided around the vessel 3 to heat the inside.

The raw material 7 in the crucible 5 is bulky and therefore bulky, so the coracle 9 is in contact with the raw material 7 and positioned above. When the raw material 7 is heated and melted in this state, it becomes liquid and its bulk decreases, so the coracle 9 moves downward under its own weight and the weight of the weight lO, and stops when it comes into contact with the lower end of the guide 12a. .

FIG. 2 is a sectional view showing such a state, and shows the poor state after melting the raw material in the crucible. As shown in FIG. 2, the raw material 7, which has become a W liquid, is introduced into the coracle 9 through a communication hole 9C formed at the ψ center of the rutsuho 9.
From the introduced raw material melt in the coracle 9, 11) crystals] 3 are pulled up and crystallized or lengthened.

As described above, in the apparatus of the embodiment according to the present invention, a closed space can be formed using a beth cell in the process of melting the raw material, and unlike the conventional apparatus, the process of melting the raw material and crystallization or lengthening can be performed in stages. There is no need to do it separately.

FIG. 3 is a perspective view showing how the coracle is mounted in another embodiment according to the present invention. Referring to FIG. 3, a communication hole 9C is formed in the center of the coracle 9. Also, arm portions 9a are located at two opposing locations on the periphery of the coracle 9.
and 9b are provided. Note that in FIG. 3, the arm portion 9b has the same structure as the arm portion 9a, so it is cut away and not shown. The arm portion 9a extends vertically upward and its tip is bent outward to form a tip 9d. Is this tip portion 9d a guide for the coracle support portion 12? It is pushed into g 1 2 a. Also, the tip 9
A weight 10 made of quartz is placed on top of d. The coracle 9 is supported by the coracle support portion 12, and the tip portion 9d moves up and down in the guide groove 12a within a vertically movable range. Further, like the arm part 9a, the arm part 9b is also provided with a tip, and a weight is placed on the tip.
They are passed through the guide groove of the coracle support.

Using the manufacturing apparatus of the embodiment shown in FIG.
s crystal was grown. 1500 g of GaAs polyphonic crystal and As for applying As pressure were placed in a 4-inch diameter PBN tube.
50g of polygonal crystals and 30Og of B2O were placed in the crucible, and the crucible was placed on top of a crucible storage container. Ruri was filled with 500 g of B20 into a container formed along the outer periphery of the storage container. B,,0, as a sealant put in this groove
The tip of a quartz vessel was immersed in the water.

The coracle used had an opening angle of 150 @ and a diameter of 4 m in the center.
m communicating holes are formed, and the diameter of the upper part of the coracle is 90 mm. Arms are provided at three locations on the outer periphery of the coracle, and on top of these arms there are 8
A 0g quartz weight is placed on it. These arm portions are inserted and supported by the guide l14 of the coracle support section. The length of the guide groove in the vertical direction is 50 mm. Note that the coracle was made of carbon.

Before the raw materials in the crucible were melted, the coracle was located about 30 mm above the lower end of the guide of the coracle support. B203, which is the sealing agent inside the crucible storage container, completely melts at 800° C., and the inside is sealed at a temperature higher than this temperature. Further increase the temperature to approx.
At a temperature of 250°C, the raw materials in the crucible melted. This melting of the raw material caused the raw material to liquefy and become bulky, so the coracle moved downward along the guide groove. The coracle was floated in the raw material melt, and after adjusting the position of the lower shaft, that is, the crucible, so that the melt diameter of the raw material in the coracle was 5 mm, the upper shaft speed was 10 mm/h, and the rotation was 3.
rpm, lower shaft speed 12-20 mm/h,
(100) growth was performed at a rotation speed of 2 rpm.

As a result, a single crystal having a crystal diameter of 2 inches could be stably grown. The obtained single crystal had an average EPD of 5000 cm-2, a resistivity of 10'Ω"cm or more, and a mobility of 6000 cm2V-S-1, indicating that it was a single crystal with good electrical properties.

[Effects of the Invention] As explained above, in the monoviscous crystal production apparatus of the present invention,
Since the coracle is installed so that it can be raised and lowered inside the vessel, a closed space can be formed by the vessel used during crystal growth without having to create a closed space with a separate lid etc. when melting raw materials. , whereas conventionally raw material melting and crystal growth were performed as separate steps,
It can be done in one step. Therefore, it is possible to prevent contamination by external impurities and to produce a high-quality single crystal, and it is also possible to improve productivity and reduce costs.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, and shows the state before the raw material in the crucible is melted. FIG. 2 is a sectional view showing an embodiment of the present invention, showing the state after the raw materials in the crucible have been melted. FIG. 3 is a perspective view showing a coracle mounting structure in another embodiment of the invention. FIG. 4 is a sectional view for explaining a method using a conventional apparatus, and shows a state before the raw material is melted. FIG. 5 is a sectional view for explaining a method using a conventional apparatus, showing a state after melting the raw material and before setting a vessel. FIG. 6 is a cross-sectional view for explaining a method using a conventional apparatus, showing a state in which a vessel is set and a single crystal is grown. In the figure, 1 is the heater, 2 is the upper shaft, 3 is the vessel, and 4
Crucible storage container, 4a is a groove, 5 is a crucible, 6 is a lower shaft,
7 is a raw material, 8 is a sealant, 9 is a coracle, 9a, 9b are arm parts, 9C is a communication hole, 10 is a weight, 11 is a single crystal,
12 is a coracle support portion, and 13 is a single crystal. Fig. 3 7 '/c Fig. si) faction

Claims (1)

[Claims] (1) A crucible storage container that stores a crucible for storing the raw material melt and has a groove formed along the outer periphery for storing a sealant, and the inside can be opened by dipping the tip into the groove of the crucible storage container. A single crystal manufacturing apparatus comprising a vessel to be sealed and a coracle floating above the raw material melt in the crucible and for pulling the single crystal from the raw material melt introduced into the inside from the crucible through a communication hole. . A single crystal manufacturing apparatus, characterized in that the coracle is mounted so as to be movable up and down inside the vessel.