JPH07118091A - Apparatus for growing semiconductor single crystal - Google Patents

Abstract

PURPOSE:To enable the extension of a seed moving stroke for pulling up a single crystal of length longer than heretofore with an apparatus for growing a semiconductor single crystal of a shaft system without having a cable winding up mechanism. CONSTITUTION:A wire 2 supporting a seed holder 3 in balance is connected to the bottom end of a short force bar connected to a load cell 1 in the case of the growth device having a crystal weight type diameter control system. Three pieces of pulleys 7, 8, 9 which are freely movable in a horizontal direction are disposed on the right and left outer sides of bellows 6 enclosing the upper space of a chamber 5. The bellows 6 is compressed upward to horizontally move the pulleys 7, 8 toward the left until the pulleys come into contact with the wire 2 at the time of taking the single crystal 4 out of the furnace. The pulley 9 is moved further horizontally toward the left after the pulley comes into contact with the wire 2. As a result, a part of the wire 2 is pulled toward a transverse direction between the pulley 7 and the pulley 8 and the single crystal 4 is correspondingly pulled upward and, therefore, the single crystal of the size longer than heretofore is taken out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaft type semiconductor single crystal growing apparatus having no cable winding mechanism.

[0002]

2. Description of the Related Art A Czochralski method (hereinafter referred to as CZ) for pulling a cylindrical single crystal from a raw material melt in a crucible is one of the methods for growing a silicon single crystal as a substrate of a semiconductor device.
Law) is used. In the CZ method, a crucible installed in a chamber of a single crystal growing apparatus is filled with polycrystalline silicon as a raw material, a raw material is heated and melted by a heater provided on the outer periphery of the crucible, and then a seed crystal attached to a seed holder. Is immersed in the melt, and the seed holder is pulled up while the seed holder and the crucible are rotated in the same direction or opposite directions to grow a single crystal. In order to control the diameter of a single crystal, a crystal weight type diameter control system using a load cell or an optical diameter control system for measuring the diameter with a television camera or the like is generally used.

FIG. 7 schematically shows a schematic structure of a main part of a conventional semiconductor single crystal growing apparatus of the shaft type. The pull-up shaft 21 is rotatably attached via a bearing to a carriage 23 that moves up and down along a guide rail 22, and a seed holder 3 is attached to the lower end of the pull-up shaft 21.
A gear 24 is fitted to the upper end of the pulling shaft 21, and the gear 24 and the pulling shaft 21 rotate through a gear train driven by a drive shaft 25, and finally a single crystal 4 grown from a seed crystal is obtained. Gives a rotational movement. Reference numeral 26 is a melt, 10 is a crucible, and 27 is a crucible shaft for rotating and moving the crucible 10 up and down. In the case of a shaft type semiconductor single crystal growing device having a crystal weight type diameter control system, a force bar is loosely inserted into a hollow pulling shaft, the upper end of this force bar is connected to the load applying part of the load cell, and the lower end is The seed holder is attached.

[0004]

In the shaft type semiconductor single crystal growing apparatus, the single crystal is pulled up together with the pulling shaft by raising the carriage. Therefore, if the length of the straight body portion of the single crystal is made longer than that of the conventional one, the total height of the semiconductor single crystal growing apparatus itself must be increased, resulting in an increase in equipment cost. Along with this, it is necessary to increase the height of the clean room accommodating the growing device, and the ratio of the equipment cost to the cost of the single crystal becomes extremely high. The present invention has been made in view of the above conventional problems, and in a shaft type semiconductor single crystal growing apparatus having no cable winding mechanism, a seed moving stroke is extended in order to pull a longer single crystal than before. It is an object of the present invention to provide a semiconductor single crystal growth apparatus capable of performing the above.

[0005]

In order to achieve the above object, in the first invention of the semiconductor single crystal growing apparatus according to the present invention, in the shaft type semiconductor single crystal growing apparatus, the pulling shaft or force having a shortened total length is used. A seed holder is attached to the lower end of the bar or the lower end of the load cell via a wire, and a mechanism is provided for laterally pulling a part of the wire above the seed holder. According to a second aspect of the invention, in a shaft type semiconductor single crystal growing apparatus, a wire pulling mechanism is provided at the lower end of a pulling shaft or force bar having a shortened overall length or the lower end of a load cell, and a wire having a seed holder supported at one end is provided. The other end is hooked on the wire pulling mechanism. In the third invention, in the shaft type semiconductor single crystal growing apparatus, the wire is attached to the lower end of the pulling shaft or force bar or the lower end of the load cell having a shortened overall length. The mechanism is characterized in that a seed holder is attached via the, and a mechanism for lifting the seed holder upward is provided.

[0006]

In the shaft type semiconductor single crystal growing apparatus, the first invention is such that, in the case of the single crystal growing apparatus using the optical diameter control system, the lower end of the pulling shaft or the lower end of the load cell, the weight of the crystal are shortened. In the case of a single crystal growth system that uses a diameter control system, the seed holder is attached to the lower end of the force bar whose length is shortened or the lower end of the load cell via a wire, and most or all of the conventional shaft or force bar is attached. Is replaced with a wire. By pulling part of this wire horizontally above the seed holder, the seed movement stroke can be made longer than before without raising the overall height of the single crystal growth apparatus, and the single crystal can be moved upward. Be lifted. Therefore, a single crystal longer than the conventional one can be taken out.

In the second invention, the wire pulling mechanism is provided at the lower end of the pulling shaft or the force bar or the lower end of the load cell, and the end of the wire for supporting the seed holder is hooked on the wire pulling mechanism. By pulling the end of the wire by using a means, the single crystal can be pulled up to a higher level than before. Further, in the third invention, since the wire is connected to the lower end of the pulling shaft or the force bar and the seed holder attached to the lower end of the wire is lifted upward, the lifting mechanism is driven to drive the seed holder. The crystal can be pulled up above the conventional one.

[0008]

Embodiments of the semiconductor single crystal growth apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing a schematic structure of a semiconductor single crystal growth apparatus according to the first embodiment of the first aspect, showing a state in which a grown single crystal is pulled above a chamber and cooled. This single crystal growing apparatus has a crystal weight type diameter control system, and a load cell 1 is provided on the top of the apparatus. The length of the force bar connected to the load cell 1 is extremely short, and the wire 2 is connected to the lower end of the force bar.
Alternatively, the wire 2 may be directly connected to the lower end of the load cell. A seed holder 3 is attached to the lower end of the wire 2, and a grown single crystal 4 is supported on the lower end of the seed crystal. Further, the upper space of the chamber 5 is covered with a bellows 6 to maintain a reduced pressure state. Two pulleys 7 and 8 are arranged on the left outer side of the bellows 6, and a pulley 9 is arranged on the right outer side thereof. These pulleys 7,
Both 8 and 9 can be moved in the horizontal direction by means not shown. In addition, 10 is a crucible which stores a melt.

When the cooled single crystal 4 is taken out of the furnace, the bellows 6 is compressed upward. At this time, the lower part is exposed from the pulleys 7, 8 and 9. Next, as shown in FIG. 2, the pulleys 7 and 8 are horizontally moved to the right until they come into contact with the wire 2, and even after the pulley 9 is brought into contact with the wire 2, they are further moved leftward. As a result, a part of the wire 2 is laterally pulled up while the upper part of the wire 7 and the lower part of the pulley 8 are kept vertically, and the single crystal 4 is pulled up by that much. Will be done. Therefore, it is possible to take out a single crystal having a straight body length longer than that of a conventional one.

FIG. 3 is a schematic diagram showing a schematic structure of a semiconductor single crystal growing apparatus according to the second embodiment of the present invention, and shows a state in which a grown single crystal is being cooled. This single crystal growing apparatus has a crystal weight type diameter control system, and the wire 2 is connected to the load cell 1 via a short force bar as in the first embodiment. Alternatively, the wire 2 may be directly connected to the lower end of the load cell. A pulley case 12 is provided between the magnetic fluid case 11 and the bellows 6. Inside the pulley case 12, there are two pulleys 7 and 8 on the left side near the wire 2 and a pulley 9 on the right side. Is also movably accommodated in the horizontal direction.

The grown single crystal 4 is pulled into the space surrounded by the bellows 6. However, in the case of a single crystal longer than the conventional one, the lower end of the single crystal is gated even if pulled up to the seed movement stroke limit. It may not rise above the valve. However, in the case of this embodiment, the pulleys 7 and 8 are horizontally moved to the right until they come into contact with the wire 2,
By further horizontally moving the wire 2 leftward after contacting the wire 2, a part of the wire 2 is laterally drawn in the pulley case 12, so that the lower end of the single crystal 4 moves above the gate valve. Can be raised. The cooled single crystal 4 is taken out after compressing the bellows 6 upward.

FIG. 4 is a schematic diagram showing a case where the grown single crystal is taken out in the semiconductor single crystal growing apparatus according to the first embodiment of the second aspect. A pulley 14 is axially attached to the lower end of the pulling shaft or the force bar 13 having a short length, and the upper end of the wire 2 is hooked by a stopper so as not to come off the pulley 14. The seed holder 3 is attached to the lower end of the wire 2, and the pulley 14 is attached so as to maintain the position where the wire 2 coincides with the vertical line passing through the center of the pulling shaft or the force bar 13 during single crystal growth. .

When the cooled single crystal 4 is taken out of the furnace, the bellows 6 is compressed upward to expose the lower part from the lower end of the pulling shaft or force bar 13. Next, a wire pulling means (not shown) is connected to the stopper at the upper end of the wire 2 to pull the wire 2 and pull the single crystal 4 to a height at which it can be taken out. By this operation, a longer single crystal than before can be taken out.

FIG. 5 is a schematic diagram showing a case where a grown single crystal is taken out in a semiconductor single crystal growing apparatus according to the second embodiment of the present invention. A single pulley 15 is pivotally mounted, and a pulley 16 is also pivotally mounted on the upper end of the seed holder 3. The wire 2 is stretched from the pulley 15 on one side to the pulley 15 on the other side via the pulley 16 and stoppers are attached to both left and right ends to prevent the wire 2 from falling off from the pulley 15. There is. By pulling both ends of the wire 2 by a wire pulling means (not shown), the single crystal 4 can be pulled up to a height at which it can be taken out.

FIG. 6 is a schematic diagram showing a case where the grown single crystal is taken out in the semiconductor single crystal growing apparatus according to the third embodiment. A constriction is provided on the upper portion of the seed holder 3, and a pull-up fitting 17 is fitted to the constricted portion. Wires 19 are stretched between the left and right ends of the pulling metal member 17 and two wire winding drums 18 installed at the top of the single crystal growing apparatus. The wire 19 is slackened during the growth of the single crystal 4, and the load is applied only to the wire 2 connected to the load cell via the force bar. The wire 2 may be directly connected to the load cell. The single crystal 4 that has been grown is pulled up together with the seed holder 3 into the space surrounded by the bellows 6 by driving the wire winding drum 18 and winding the two wires 19, and is cooled. When the cooling of the single crystal 4 is completed, the bellows 6 is compressed upward and taken out of the furnace.

[0016]

As described above, according to the present invention, the length of the pull-up shaft or the force bar is shortened, the wire is connected to the lower end of the pull-up shaft or the force bar, and a mechanism for pulling the wire laterally or upward is provided. Since the single crystal can be pulled up further by using the shaft-type semiconductor single crystal growing apparatus having no cable winding mechanism, it is possible to pull up a longer single crystal than before. Therefore, the following effects can be obtained. (1) The height of the semiconductor single crystal growing apparatus and the height of the clean room accommodating the growing apparatus can be made lower than in the case of the conventional shaft system, which leads to a reduction in equipment cost and a single crystal manufacturing cost. It is possible to reduce. Further, by making a small-scale improvement to the existing shaft type single crystal growing apparatus, it becomes possible to pull a single crystal longer than the conventional one. (2) When the present invention is applied, the seed movement stroke can be made larger, so that it is possible to increase the diameter of the crucible, that is, increase the charge amount, and improve the single crystal production efficiency.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a schematic configuration of a semiconductor single crystal growth apparatus based on a first embodiment of claim 1.

FIG. 2 is a schematic diagram showing a case where a single crystal is taken out in the semiconductor single crystal growth apparatus of FIG.

FIG. 3 is a schematic diagram showing a schematic configuration of a semiconductor single crystal growing apparatus based on a second embodiment of claim 1.

FIG. 4 is a schematic view showing a case where a single crystal is taken out in the semiconductor single crystal growing apparatus according to the first embodiment of claim 2.

FIG. 5 is a schematic view showing a case where a single crystal is taken out in the semiconductor single crystal growing apparatus according to the second embodiment of the present invention.

FIG. 6 is a schematic view showing a case where a single crystal is taken out in the semiconductor single crystal growing apparatus based on the embodiment of claim 3.

FIG. 7 is a schematic diagram showing a schematic configuration of a main part of a conventional semiconductor single crystal growth apparatus of a shaft type.

[Explanation of symbols]

 1 load cell 2,19 wire 3 seed holder 4 single crystal 7,8,9,14,15,16 pulley 12 pulley case 13 force bar 17 pulling metal fitting 18 wire winding drum

Claims (3)

[Claims] 1. In a shaft type semiconductor single crystal growing apparatus, a seed holder is attached to a lower end of a pulling shaft or a force bar having a reduced overall length or a lower end of a load cell via a wire, and a part of the wire is attached. An apparatus for growing a semiconductor single crystal, which is provided with a mechanism for laterally pulling above a seed holder. 2. In a shaft type semiconductor single crystal growing apparatus, a wire pulling mechanism is provided at the lower end of a pulling shaft or force bar having a shortened overall length or at the lower end of a load cell, and the other end of the wire with a seed holder supported at one end. An apparatus for growing a semiconductor single crystal, characterized in that: 3. In a shaft type semiconductor single crystal growing apparatus, a seed holder is attached to the lower end of a pulling shaft or force bar having a shortened overall length or the lower end of a load cell via a wire, and the seed holder is moved upward. A semiconductor single crystal growth apparatus having a lifting mechanism.