JP2504550Y2 - Single crystal pulling device - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a raw material melt at an arbitrary height of a pedestal for supporting a crucible and moving it up and down in an apparatus for producing a single crystal by a pulling method, especially the Czochralski method (hereinafter referred to as CZ method). The present invention relates to a device provided with a saucer for falling.

[0002]

2. Description of the Related Art In recent years, semiconductor wafers, which are starting materials for semiconductor devices, are increasingly required to have a larger diameter in terms of area efficiency in manufacturing integrated circuits. Usually, a semiconductor wafer is cut out from a single crystal ingot grown by a pulling method, but naturally, a large amount of raw material must be charged in a crucible in order to manufacture a large diameter single crystal. Therefore, the heater power for heating and melting this, the time required for pulling, etc. are increasing more and more. The in-furnace parts of the pulling device are exposed to a harsh thermal atmosphere for a long time, and the quartz crucible holding the raw material melt is particularly damaged. As a result, deformation occurs, melt surface vibration occurs due to eccentricity, or the upper end of the crucible falls toward the center, and the adhering amorphous materials fall into the melt and inhibit single crystallization. Or In particular, in the latter half of the manufacturing process, the crucible is raised, the distance from the heater is increased, and the amount of melt is decreased to increase the heat dissipation area of the quartz crucible. Therefore, the growth temperature is maintained. Therefore, the heater power is increased, which further accelerates the above-described deterioration of the quartz crucible. The quartz crucible is so severely deteriorated that it must be replaced once for a child, and therefore, under the severe conditions as described above, the probability of breakage is high even during pulling. The fine air bubbles contained in the quartz crucible expand due to contact with the silicon melt at a temperature of 1000 ° C or higher, which causes the crucible to break. When the quartz crucible is cracked, the raw material melt exudes, but since the graphite crucible that accommodates the quartz crucible is porous, the exudation cannot be stopped. In this way, damage to the parts inside the furnace gradually progresses.

In addition to such a phenomenon, leakage of the melt from the crucible due to vibration or the like due to deterioration also causes damage to parts inside the furnace.

Conventionally, it is not always sufficient to secure the safety against melt leakage in the pulling device which is gradually increased in size.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to secure safety against melt leakage of a single crystal pulling apparatus which is becoming larger in size as described above.

[0006]

SUMMARY OF THE INVENTION The present invention is directed to a quartz crucible filled with a raw material, a graphite crucible for accommodating and protecting the quartz crucible, a crucible receiver integrally fixed and supported on the bottom of the graphite crucible, and a crucible. A pedestal that supports the receiver from the bottom and can move up and down, a heater that heats and melts the raw materials in the crucible surrounding them, and an insulating cylinder that is provided between the heater and the chamber side wall of the pulling device body to shield the radiant heat from the heater , A single crystal pulling device provided above the center of the crucible and having a pulling shaft for pulling the single crystal by immersing a seed crystal held at the tip of the molten raw material in the crucible into the raw material melt and gradually pulling it up In the above, the pedestal shaft is slidably pierced through its central portion, and a stopper for receiving and supporting the pedestal from the bottom is provided at an arbitrary height of the pedestal. It is characterized.

[0007]

The operation of the present invention will be described with reference to the drawings.
As shown in FIG. 1, a stopper 6 is provided at a constant height of a pedestal 5 which is connected to a crucible receiver 4 which supports a quartz crucible 2 and a graphite crucible 3 of a CZ single crystal pulling apparatus 1 from the bottom. Furthermore, above the stopper, a pan 7 concentrically surrounding the pedestal 5 is slidably attached to the pedestal. In the initial stage of pulling the single crystal 8, the crucible is descending and is in the state of FIG. Therefore, the receiving tray 7 is placed on the melt receiving tray 12 at the bottom of the chamber of the pulling apparatus. When the crucible rises as the pulling progresses, the stopper 6 eventually raises the crucible that pushes up the tray 7, and the tray also rises while maintaining a certain distance. If the tray is fixed to the pedestal, the crucible lowering position required at the initial stage of pulling up cannot be ensured, which causes a problem. Conventionally, there is a heater attached to such a space portion (see Japanese Patent Laid-Open No. 192486/1990), but it is difficult to take a structure in contact with the crucible receiver, so it is necessary to provide them at a certain distance. The stroke for this is limited. Conversely, the stroke is similarly limited even if it is provided far away from the crucible. The height of the tray can be set to be most suitable depending on the amount of melt to be filled and the state of the apparatus by forming a plurality of holes for supporting the stopper in the height direction.

As shown in FIG. 2, the stopper may be threaded at the base of the stopper and screwed into a screw hole formed in the shaft of the pedestal. As the material of the stopper, carbon having high heat resistance can be used. Further, the receiving tray may be made of carbon fiber or porous carbon that easily absorbs the melt.

[0009]

Example 1 A silicon single crystal was grown using the single crystal pulling apparatus shown in FIG. 1 which is an example of the present invention.

The raw material silicon was filled in the quartz crucible 8 and the heater 9 was energized to melt the raw material silicon. Seed crystal 10
Was immersed in the melt and gradually pulled up to grow a silicon single crystal in the usual manner. The physical properties of the obtained single crystal were comparable to those of the conventional one, and no adverse effect due to the provision of the saucer was observed.

[0011]

[Effect] According to the present invention, the capacity of the receiver is increased against the leakage of the melt due to vibration or accident, so that the safety is improved.
Furthermore, the saucer is slidable with respect to the pedestal, and the stopper supports the saucer as the crucible rises, so a sufficient stroke necessary for crystal growth can be secured, and the stopper can be mounted in the pedestal height direction. If a plurality of holes are provided, the saucer can be installed at an optimum arbitrary height.

Furthermore, the single crystal production apparatus of the present invention is
It is easy to apply because it does not require extensive modification of conventional equipment.

If a heat insulating material is loaded in the saucer,
Since the heat retention effect is obtained, the power supplied to the heater is also saved,
The effect of blocking the heat radiation from the bottom to the crucible and protecting it can be expected.

[Brief description of drawings]

FIG. 1 is a sectional view of a single crystal manufacturing apparatus showing an embodiment of the present invention.

FIG. 2 is a partial perspective view of an example of components used in the single crystal production apparatus of the present invention.

[Explanation of symbols]

 1 Pulling device 2 Quartz crucible 3 Graphite crucible 4 Crucible receiver 5 Pedestal 6 Stopper 7 Saucepan 8 Single crystal 9 Heater 10 Seed crystal 11 Screw hole 12 Melt receiver

Claims (1)

(57) [Scope of utility model registration request] 1. A quartz crucible filled with a raw material, a graphite crucible for accommodating and protecting the quartz crucible, a crucible receiver for integrally fixing and supporting the bottom of the graphite crucible, and a crucible receiver supported from the bottom and capable of moving up and down. The pedestal, a heater that heats and melts the raw materials in the crucible around these, a heat insulation tube that is provided between the heater and the chamber side wall of the pulling device body to shield radiant heat from the heater, and further above the center of the crucible. , A single crystal pulling device having a pulling shaft for pulling a single crystal by immersing a seed crystal grasped at the tip from a molten raw material in a crucible into a raw material melt and gradually pulling it up, and a central portion of the pedestal A single crystal pulling apparatus, wherein a saucer through which a shaft slidably passes and a stopper that receives and supports the saucer are provided at an arbitrary height of a pedestal.