JPH07126095A - Single crystal growing device - Google Patents

Abstract

PURPOSE:To provide the device enabling even a small-sized seed crystal to be used and a continuous single crystal of uniform inner quality to be grown by attaching a load cell of special structure for measuring the weight of a crystal under pull. CONSTITUTION:In a single crystal pull unit of resistance or induction heating type, in order to grow a single crystal while measuring its weight without dissolving a small seed crystal, a jig for attaching seed crystal is fed from above through a cooling medium and a gas is also fed via an inlet 1 for cooling gas so as to cool the seed crystal. The gas then flows from the outside of a load cell to the lower part thereof, being stopped at the oil seal 8 and O-ring 7 on the lower side of a flange attached to the load cell; part of the gas then goes upward, enters the inside via a side hole of a joint 4 and flows downward. A hollow force bar 5 is fixed on the inside of the lower part of the joint 4, and the gas is allowed to flow through the hollow to the seed crystal. And, a feedstock is designed to feed continuously from a feedstock vessel to a melt section under heating.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resistance heating type or induction heating type single crystal growing apparatus, and in particular, due to physical properties of an object to be heated, a temperature gradient that is somewhat slow (and partially steep) It can be used for a single crystal growing apparatus in a field where it is necessary to grow a single crystal at a medium temperature or a constant temperature.

[0002]

2. Description of the Related Art In a resistance heating type or induction heating type single crystal growing apparatus, an electric furnace for pulling a single crystal has a preset temperature of one or a plurality of heating portions at arbitrary temperatures. Is set so that a certain temperature gradient and a certain temperature distribution can be created. A seed crystal is attached to the lower portion of the single crystal pulling device.

However, conventionally, for the physical reason of seed crystals,
When only small seed single crystals can be obtained, when seed crystals were added to the dissolved raw material, the seed crystals were easily dissolved by heat conduction from the solution, and it was difficult to grow the crystals. Therefore, conventionally, the seed crystal attachment jig is usually cooled to prevent the dissolution of the seed crystal.

On the other hand, it is important to measure the weight of a single crystal, and a weight measurement signal can be used to control the diameter for keeping the crystal grain size constant. However, if the seed crystal mounting jig is cooled, it is structurally difficult to mount the weight measuring load cell on the upper pulling shaft.

Regarding the raw material supply method in the single crystal growing apparatus, conventionally, when a relatively large crystal is manufactured by the pulling down method, the grooved rotary drum 4 as shown in FIG. 2 is used.
3 is used to supply a raw material having a constant weight through the groove. In the figure, 41 is a raw material container,
42 is a powder raw material, 44 is a motor, 45 is a funnel, 46 is a guide pipe, and 47 is a funnel. However, strictly speaking, this method is a discontinuous raw material supply method, and when the crystal growth rate is slow, when small crystals are grown, or when the pulling method is used, the discontinuity causes the growth. It had bad influences such as microscopic defects such as stripes and non-uniformity of components.

In particular, in the case of the pulling method, the raw material once placed in the crucible is melted and pulled from there, so that if the raw material cannot be supplied midway, only crystals of a fixed length can be obtained. However, heretofore, there has been only a device for supplying the raw material discontinuously, and much less has been found for a device that combines the weight measurement and the continuous supply of the raw material.

Under such circumstances, the present invention can be applied to the case where a small seed crystal is used in the pulling method, or a long single crystal is grown to have a constant quality of internal components. It is an object of the present invention to provide a single crystal growth apparatus that can be used.

As a means for solving the above problems, the present invention provides a resistance heating type or induction heating type single crystal pulling apparatus having a structure in which a seed crystal mounting jig and a seed crystal are cooled by a refrigerant from above, It is characterized in that a load cell for pulling crystal weight measurement having a structure in which the refrigerant can be introduced from one side and discharged from the other side is attached.

Another aspect of the present invention is, in a resistance heating type or induction heating type single crystal growing apparatus, a raw material container having a hole at the lowermost tip, and a metal belt rotating below the hole in a conveyor type. And a funnel provided below one end of the belt, and the raw material is continuously supplied from the container to the heated and melted liquid surface in the electric furnace through the metal belt and the funnel. It is characterized by having done.

[0010]

The present invention will be described in more detail below.

In the conventional pulling apparatus, it was possible to easily obtain a seed crystal of a certain size, and it was easy to obtain a crystal of such a length that the seed portion did not melt. It was easy to provide a lifting device in which a load cell for measuring the weight was mounted on the upper part of the lifting shaft, and a rotation mechanism could be equipped. However, when this technique is applied to the single crystal pulling method in which the seed crystal cannot be made large for the physical reason of the seed crystal, the seed crystal is easily dissolved and it becomes difficult to grow the crystal.

Therefore, in order to grow a single crystal while measuring the weight of the crystal and rotating the crystal without dissolving the small seed crystal, in the present invention, in addition to the conventional pulling mechanism, Measure the weight of the pulled crystal without melting the seed crystal by making the structure such that the seed crystal can be cooled by flowing the gas to the vicinity of the crystal mounting jig and by treating the cooling gas so as not to hinder the crystal growth. It was designed so that it could be pulled up.

FIG. 1 shows an example of the specific example.

That is, gas is supplied from the gas inlet 1 at the upper part of the load cell 2, flows from the outside inside the load cell to the lower part, and below the flange attached to the load cell,
The gas is stopped by the oil seal 8 and the O-ring 7, one end of which goes upward, enters inside the lateral hole of the joint 4, and the gas flows downward. Inside the bottom of the joint,
The hollow force bar 5 is stopped, and through this inside,
Gas will flow to the seed crystal part below.

In addition to the structure in which the refrigerant passes through the inside of the load cell itself, the structure may be such that an outer member capable of forming a refrigerant passage is provided outside the load cell itself.

On the other hand, in order to continuously supply the powder raw material to the heating and melting section, it is necessary that the raw material coming out of the raw material container has a certain continuity.

FIG. 3 shows an example of the specific example. A hard resin lid 23 is attached to the lower end of the raw material container 21, a hole is made in the center thereof, and a conveyor made of a metal belt 24 is arranged below the hole. The spring 26 at the lower position of the hole is for maintaining the adhesion between the raw material container and the metal belt. The roller shaft on one side of the belt is equipped with a rotary pulley 28, and rotation is transmitted from a nearby motor 32 through a timing belt 30. When the conveyor moves, the material is supplied to a funnel 34 provided below the one side. Is supplied, and the raw material is continuously supplied to the heating and melting part inside the electric furnace through the guide pipe thereunder.

According to this raw material supply system, the raw materials 25 lined up at the center of the belt can be continuously supplied by the powder being aligned in the lateral direction and the belt moving. By adjusting the width and height of this hole, the rotation speed of the motor can be varied according to the state of the powder of the raw material, so that a small amount to a large amount of the powder raw material can be continuously supplied. This method can be applied to both the raising method and the lowering method.

When such a powder raw material continuous feeding device is mounted, a long single crystal having a high quality and a uniform composition can be produced. If this device has a structure capable of producing a gas atmosphere, it can be stabilized against changes in the environment. Also,
Weigh the entire device with a scale, measure the amount of reduction of raw materials, input the amount of change with time to the program controller,
It is also possible to control the rotation speed of the motor based on this program.

Of course, it is also possible to use this continuous powder raw material supply device together with the above-mentioned load cell for measuring the crystal weight. A long crystal whose crystal diameter is controlled to be constant by the crystal weight measurement signal of the load cell can be grown with high quality. Further, this continuous powder raw material supply device is capable of accurately measuring and supplying a small amount of raw material, and is also applicable to the fields of medicine and cosmetics.

[0021]

As described above, according to the present invention,
The pulling method can prevent the dissolution of a small seed crystal, and can grow a long single crystal of high quality with a constant internal component.

[Brief description of drawings]

FIG. 1 is a view showing an upper pulling mechanism of a pulling device according to the present invention.

FIG. 2 is a diagram showing a conventional raw material supply device.

FIG. 3 is a diagram showing a raw material continuous supply device according to the present invention.

[Explanation of symbols]

 1 Gas Inlet 2 Load Cell 3 Flange 4 Joint 5 Force Bar 6 Gas Stopper 7 O-ring 8 Oil Seal 9 Flange 10 Rotating Pulley 11 Lifting Shaft 21 Raw Material Container 22 Powder Raw Material 23 Lower Lid 24 Metal Belt 25 Aligned Powder Raw Material 26 Spring 27 Spring Support Plate 28 Rotating Pulley 29 Pulley Holding Flange 30 Timing Belt 31 Motor Stop Plate 32 Motor 33 Stop Bottom Plate 34 Funnel

Claims (3)

[Claims] 1. A resistance heating type or induction heating type single crystal pulling apparatus, wherein a structure for cooling a seed crystal attachment jig and a seed crystal by a refrigerant from above, a structure in which a refrigerant can be introduced from one side and discharged from the other side A single crystal growing apparatus characterized in that a load cell for measuring the weight of the pulled crystal is attached. 2. A resistance heating type or induction heating type single crystal growing device, and a raw material container having a hole at the lowermost tip,
A metal belt that rotates in a conveyor manner is provided below the hole, and a funnel provided below one end of the belt. The raw material is continuously fed from the container through the metal belt and the funnel inside the electric furnace. A single crystal growth apparatus characterized in that it is configured to supply to the surface of a liquid that has been heated and melted. 3. The single crystal growing device according to claim 2, wherein a load cell for measuring the weight of the pulled crystal is attached to a device for cooling the seed crystal mounting jig with a refrigerant.