JPH09165290A - Graphite crucible for lifting device for semiconductor single crystal and handling method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for handling a graphite crucible enabling the carrying in and out of the graphite crucible having a large capacity and a heavy weight safely and quickly for a lifting device for a semiconductor single crystal by the CZ (Czochralski) method. SOLUTION: This graphite crucible for a lifting device for a semiconductor single crystal is constituted by installing plural screw holes at the top edge surface of the graphite crucible 1 dividable into two and restraining the graphite crucible 1 by clamping a ring 13 consisting of a carbon fiber reinforced carbon composite material with bolts 21. After housing a quartz crucible 22 into the graphite crucible 1 and filling a polycrystalline silicone 23 into the quartz crucible, the top surface of the quartz crucible 22 is covered by using a cover 17 and the pressure of the inside of the quartz crucible is reduced. The graphite crucible 1 is hanged by a hanging tool 24 for carrying in, which is hooked to the protruded part of the ring 13, carried into a device for lifting a semiconductor single crystal, and set. After the completion of the lifting of the semiconductor single crystal and for carrying out the graphite crucible, bolts for hanging are screwed into at least two each screw holes provided near the divided surface 2 of the graphite crucible 1 and the graphite crucible is hanged by a hanging tool hooked to the bolts for hanging.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a graphite crucible used for a semiconductor single crystal pulling apparatus and a crucible handling method.

[0002]

2. Description of the Related Art A high-purity single crystal silicon is mainly used for a substrate of a semiconductor device. One of the manufacturing methods thereof is a CZ method for pulling a cylindrical single crystal silicon from a raw material melt in a crucible. It has been known. In the case of manufacturing a semiconductor single crystal by the CZ method, a graphite crucible is placed in a pedestal that can be rotated and moved up and down provided in a main chamber of a semiconductor single crystal pulling apparatus, and a quartz crucible is stored in the graphite crucible. Polycrystalline silicon which is a raw material of single crystal silicon is loaded. When pulling the single crystal silicon, the polycrystalline silicon is heated and melted by a heater provided around the graphite crucible to form a melt, and then the seed crystal attached to the seed chuck is immersed in the melt to remove the seed chuck and the graphite crucible. The seed chuck is pulled up while rotating in the same direction or in opposite directions to grow single crystal silicon.

When the grown single crystal silicon is stored in the pull chamber connected above the main chamber, the pulling of the single crystal is completed. Here, the inside of the furnace is cooled in vacuum and then opened to the atmosphere, and then the single crystal silicon ingot is carried out from the pull chamber. The graphite crucible is cleaned and inspected after removing the quartz crucible and the remaining polycrystalline silicon solidified in the quartz crucible and then carrying it out of the main chamber.

The graphite crucible which has been cleaned and inspected is placed on the pedestal again for the next pulling of the single crystal.
After housing the quartz crucible, a predetermined amount of polycrystalline silicon is loaded.

[0005]

Conventionally, the work of loading and installing a graphite crucible in a semiconductor single crystal pulling apparatus and the work of carrying out a graphite crucible from the apparatus have been carried out manually. On the other hand, single crystal ingots pulled by the CZ method are becoming larger year by year, and single crystals having a diameter of 8 inches are becoming mainstream. Along with this, the amount of polycrystalline silicon loaded has increased, and the capacity and weight of the graphite crucible have also increased, so the loading and unloading of the graphite crucible has become a difficult task. Furthermore, the work of unloading the graphite crucible is difficult to carry out until the parts inside the furnace are cooled to a temperature that can withstand the work manually, so a down time is required to cool the semiconductor single crystal pulling device, Cycle time is prolonged and productivity is reduced.

[0006] It is possible to attach a suspending tool to the graphite crucible and carry it in and out without relying on human power. However, the suspending tool may contaminate the graphite crucible and other parts in the furnace and the semiconductor single crystal pulling apparatus. However, since the hanger must be easy to put on and take off, there is no choice but to rely on manpower.

The present invention has been made in view of the above-mentioned conventional problems, and it is possible to safely and quickly carry in and carry out a large capacity and heavy graphite crucible. In particular, after pulling a semiconductor single crystal, An object of the present invention is to provide a graphite crucible for a semiconductor single crystal pulling apparatus and a method for handling the crucible so that the graphite crucible can be carried out without being sufficiently cooled.

[0008]

In order to achieve the above object, the graphite crucible of the semiconductor single crystal pulling apparatus according to the present invention has a two-divided graphite crucible used for pulling a semiconductor single crystal by the CZ method. A position in which a plurality of screw holes are provided, and at least two screw holes of each of these screw holes are located closer to the split surface than the plane parallel to the split surface through the center of gravity of each of the graphite crucibles divided into two. It is provided in.

Further, the crucible handling method according to the present invention is such that a graphite crucible and a quartz crucible are installed in a semiconductor single crystal pulling apparatus, and a screw provided on the graphite crucible in the work of loading polycrystalline silicon into the quartz crucible. After tightening the ring made of carbon fiber reinforced carbon composite material using the bolt made of carbon fiber reinforced carbon composite material in the hole, store the quartz crucible in the graphite crucible, load the polycrystalline silicon into the quartz crucible, and cover it. Was used to cover the upper surface of the quartz crucible and the inside of the quartz crucible was depressurized. Then, the graphite crucible was supported by a suspender hooked on the ring and carried into the semiconductor single crystal pulling apparatus.

Further, in carrying out the crucible after pulling the semiconductor single crystal by using the semiconductor single crystal pulling apparatus, at least two screw holes provided at the upper end in the vicinity of the dividing surface of the graphite crucible are provided with carbon fiber reinforced carbon composite. A hanging bolt made of a material was screwed on, and a graphite crucible was supported by a hanging tool hooked on the hanging bolt to be carried out from the semiconductor single crystal pulling apparatus.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION According to the present invention, a plurality of screw holes are provided in the upper end portion of a graphite crucible divided into two parts used for pulling a semiconductor single crystal by the CZ method, and a hanging tool or a hanging device is provided in these screw holes. By tightening bolts and supporting a graphite crucible, it is intended to save labor and facilitate handling.

When a graphite crucible is installed in a semiconductor single crystal pulling apparatus, a ring made of carbon fiber reinforced carbon composite material is fastened to the graphite crucible by using a screw hole provided in the graphite crucible before installation. A quartz crucible housed in a graphite crucible is loaded with polycrystalline silicon. In this method, the loading operation is easier than the conventional method of loading the crucible installed in the semiconductor single crystal pulling apparatus. Then, the graphite crucible is supported by a suspender hooked on the ring and carried into and installed in the semiconductor single crystal pulling apparatus, but the divided graphite crucible is constrained by the ring and is not separated. Further, since the carbon fiber reinforced carbon composite material is used for the ring and the bolt that come into contact with the graphite crucible, there is no risk of contamination. Furthermore, since the polycrystalline silicon is covered and sealed by the cover, the inclusion of impurities is avoided.

When the graphite crucible is carried out from the semiconductor single crystal pulling apparatus after pulling the semiconductor single crystal, a hanging bolt is screwed into at least two screw holes provided at the upper end of the graphite crucible in the vicinity of the dividing surface. If a graphite crucible is supported by a suspender hooked on these suspension bolts, it can be easily carried out of the semiconductor single crystal pulling apparatus.
Since the screwing position of the suspension bolt is near the dividing surface of the graphite crucible, the graphite crucible is not separated even if the ring for restraining the graphite crucible is not fastened. Further, when the graphite crucible is not cooled to a temperature at which it can be manually handled, it can be safely carried out together with the quartz crucible and the polycrystalline silicon residual material.

Next, embodiments of a graphite crucible and a crucible handling method of a semiconductor single crystal pulling apparatus according to the present invention will be described with reference to the drawings. 1 is a perspective view of a graphite crucible in a first embodiment of the present invention, and FIG. 2 is a top view of the same. The graphite crucible 1 is of a two-part type and is divided into a left half part 3 and a right half part 4 with a vertical parting surface 2 as a boundary. The halves 3, 4
Four screw holes are provided on the upper end surface of each. Of these screw holes, the screw holes 5 and 6 provided in the half-divided portion 3 pass through the center of gravity G3 of the half-divided portion 3 as shown in FIG. The screw holes 7 and 8 provided at the position close to the surface 2 and provided in the half-divided portion 4 pass through the center of gravity G4 of the half-divided portion 4 and are parallel to the divided surface 2.
It is provided at a position closer to the dividing surface 2 than -B.
The other screw holes 9, 10 and 11, 12 are provided on the circumference at substantially equal pitches.

FIG. 3 is a perspective view of a ring fastened to the upper end surface of the graphite crucible. The ring 13 is made of carbon fiber reinforced carbon composite material, and bolt holes 14 are formed at positions corresponding to the eight screw holes 5 to 12 provided on the upper end surface of the graphite crucible 1 shown in FIGS. 1 and 2. ing. The inner diameter and outer diameter of the ring 13 are the same as the inner diameter and outer diameter of the graphite crucible 1. In addition, the protrusions 1 are provided at least at three locations on the outer peripheral surface of the ring.
5 are provided, and these projecting portions 15 are provided with hooking holes 16 for hooking hooks of a hanging tool.

FIG. 4 is a partially fragmented side view of the cover covering the polycrystalline silicon loaded in the quartz crucible. This cover 1
7 is a cylindrical shape with its upper end closed, and its inner and outer diameters are the same as the inner and outer diameters of the quartz crucible. A coupler 18 that can be connected to a vacuum pump is attached to the upper surface of the cover 17. A lining 19 that improves the airtightness of the contact surface may be attached to the lower end surface of the cover 17 that contacts the upper end surface of the quartz crucible.

The carrying-in hanging device used when the graphite crucible is carried into the main chamber of the semiconductor single crystal pulling apparatus and the carrying-out hanging device used when carrying out from the main chamber are hooked to the lifting mechanism. It consists of metal fittings, lifting wires, hooks, etc., which are made of stainless steel.

Next, a crucible handling method in the work of loading the graphite crucible, the quartz crucible and the polycrystalline silicon into the semiconductor single crystal pulling apparatus will be described.
FIG. 5 is a partially crushed side view showing a state in which a carrying hanger is attached to a graphite crucible.

As a preparatory work for pulling a semiconductor single crystal, a graphite crucible is carried in and installed in a semiconductor single crystal pulling apparatus, and the crucible handling method in that case is as follows. (1) Eight bolts 21 made of a carbon fiber reinforced carbon composite material on the upper end surfaces of the half-divided portions 3 and 4 constituting the graphite crucible 1.
The ring 13 is fastened by using, and the quartz crucible 22 is housed in the graphite crucible 1. (2) A predetermined amount of polycrystalline silicon 23 is placed in the quartz crucible 22.
And the cover 17 is placed on the upper end surface of the quartz crucible 22. (3) A vacuum pump (not shown) is connected to the coupler 18 provided on the upper surface of the cover 17, and the cover 17 and the quartz crucible 2 are connected.
The space surrounded by 2 is reduced to a predetermined pressure. (4) The carrying-in hanging tool 24 is hooked on a hoisting mechanism (not shown), and the protrusion of the ring 13 (the protrusion 15 in FIG. 3).
The hook 2 of the carrying-in hanging tool 24 is fitted into a hook hole provided in the
The graphite crucible 1 is lifted by hooking 5 and carried into the main chamber of the semiconductor single crystal pulling apparatus. (5) After placing the graphite crucible 1 on the pedestal, the graphite crucible 1 is hooked with the hook 25 of the carrying suspender 24 and the bolt 2.
1. Remove the ring 13 and the cover 17.

Since the carbon fiber reinforced carbon composite material is used for the ring and the bolts which are fastened to the graphite crucible, the graphite crucible is not contaminated, and the graphite crucible, the quartz crucible and the polycrystalline silicon can withstand the total weight. It has strong strength. Further, the loading operation of the polycrystalline silicon can be efficiently performed at a place suitable for the loading operation before the graphite crucible and the quartz crucible are installed in the semiconductor single crystal pulling apparatus, so that the loading operation efficiency is improved. Since the charged polycrystalline silicon is covered and sealed with a cover, it can be avoided from being contaminated by dust or the like.

The crucible handling method after the pulling of the single crystal is as follows. FIG. 6 shows a state in which the graphite crucible is lifted by using the carry-out hanging tool. (1) After the pull chamber of the single crystal pulling apparatus is separated from the main chamber and swung, the hanging bolts 26 are respectively placed in the screw holes 5 to 8 of the half halves 3 and 4 of the graphite crucible 1 shown in FIGS. 1 and 2. Screw together. (2) The carrying-out hanging tool 27 is hooked on the four hanging bolts 26, and the upper part of the carrying-out hanging tool 27 is hooked on a lifting mechanism (not shown) to lift the graphite crucible 1. Due to thermal deformation of the quartz crucible 22 when pulling the single crystal, the graphite crucible 1 is in a state in which the upper end surfaces of the half-split portions 3 and 4 are open to the left and right of the split surface 2 as shown in FIG. Since 26 is located closer to the dividing surface 2 than the center of gravity of the half-divided portions 3 and 4, the half-divided portions 3 and 4 are not separated and the quartz crucible 22 and the polycrystalline silicon solidified on the bottom of the quartz crucible 22 are separated. The remaining material 28 is discharged from the main chamber. (3) The graphite crucible 1 that has been carried out is lowered to a predetermined place,
After removing the carry-out hanging tool 27 and the hanging bolt 26, the residual material 28 and the quartz crucible 22 are removed, and the graphite crucible 1 is cleaned and inspected.

As described above, the graphite crucible 1 can be safely and easily carried out of the furnace even if it is not cooled to a temperature suitable for being carried out manually, and the work efficiency of cleaning and inspection of the main chamber is also improved. . Further, since the carbon fiber reinforced carbon composite material is used for the hanging bolt, the graphite crucible is not contaminated.

FIG. 7 is a side view of the graphite crucible according to the second embodiment of the present invention. Four screw holes along the radial direction are formed on the outer peripheral surface near the upper end of the two-part split type graphite crucible 31.
Each is provided. Of these screw holes, the screw holes 35 (and the screw holes 36 at symmetrical positions) provided in the half-cut portion 33 are the same as those of the graphite crucible of the first embodiment shown in FIGS. 1 and 2. It is provided at a position closer to the dividing surface 32 than the plane AA parallel to the dividing surface 32 through the center of gravity of the half-split portion 33. Further, the screw hole 37 (and the screw hole 38 at a position symmetrical to this) provided in the half-divided portion 34 passes through the center of gravity of the half-divided portion 34 and is more divided than the plane BB parallel to the divided surface 32. It is installed at a position close to. The other four screw holes 39, 41 and the like are provided on the outer periphery at substantially equal pitches.

FIG. 8 is a perspective view of a ring that is fastened to the graphite crucible 31. The ring 43 is made of a carbon fiber reinforced carbon composite material and has an inner diameter of a size that allows loose fitting to the outer periphery of the graphite crucible 31 shown in FIG. 7. Eight bolt holes 44 are formed in the outer peripheral surface of the ring 43 in the radial direction, and the positions of these bolt holes 44 coincide with the eight screw holes provided in the graphite crucible 31. Further, the protrusions 45 are provided at least at three positions on the upper end surface of the ring 43, and these protrusions 4
A hooking hole 46 for hooking a hook of the hanging tool is provided in the numeral 5.

The graphite crucible handling method using the graphite crucible shown in FIG. 7 and the ring shown in FIG.
The description is omitted because it is the same as the case of the embodiment.

[0026]

As described above, according to the present invention, the following effects can be obtained. (1) Since a plurality of screw holes are provided on the upper end surface of the graphite crucible or on the outer peripheral surface close to the upper end surface, and the suspending tool is fastened using these screw holes, it is not necessary for a semiconductor single crystal pulling apparatus to be large. It becomes possible to efficiently carry in and out a large capacity and heavy graphite crucible without relying on human power and without contaminating the semiconductor single crystal pulling apparatus and parts in the furnace. (2) When the graphite crucible is loaded into the semiconductor single crystal pulling apparatus, the quartz crucible and polycrystalline silicon are hoisted together and loaded, but the graphite crucible is prevented from being separated by tightening the ring. Can be easily lifted. (3) The loading operation of polycrystalline silicon can be efficiently performed in a place suitable for the loading operation before the graphite crucible and the quartz crucible are loaded into the semiconductor single crystal pulling apparatus.
The loading work efficiency is improved. Further, since the loaded polycrystalline silicon is covered and hermetically sealed with a cover, it is possible to reliably prevent contamination by dust or the like. (4) When carrying out the graphite crucible from the semiconductor single crystal pulling apparatus, since it is sufficient to screw the hanging bolts into the at least four screw holes provided in the vicinity of the dividing surface of the graphite crucible to lift the graphite crucible, it is sufficiently cooled. Even a graphite crucible that has not been made easy to carry out. Therefore, it is possible to carry out safely and swiftly as compared with the conventional method. Moreover, the down time of the semiconductor single crystal pulling apparatus is shortened, and the productivity of the semiconductor single crystal is improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a graphite crucible according to a first embodiment of the present invention.

FIG. 2 is a top view of the graphite crucible according to the first embodiment of the present invention.

FIG. 3 is a perspective view of a ring.

FIG. 4 is a partially broken side view of the cover.

FIG. 5 is a partially crushed side view showing a state in which a graphite crucible is lifted up using a carry-in hanging tool.

FIG. 6 is a side view showing a state in which a graphite crucible is lifted up using a carry-out hanging tool.

FIG. 7 is a side view of a graphite crucible according to a second embodiment of the present invention.

FIG. 8 is a perspective view of a ring according to a second embodiment of the present invention.

[Explanation of symbols]

1,31 Graphite crucible 2,32 Dividing surface 3,4,33,34 Half-divided portion 5,6,7,8,9,10,11,12,35,36,
37,38,39,41 Screw hole 13,43 Ring 14,44 Bolt hole 15,45 Projection part 16,46 Locking hole 17 Cover 21 Bolt 22 Quartz crucible 23 Polycrystalline silicon 24 Carrying suspender 26 Lifting bolt 27 Carrying out Hanging equipment

Claims (3)

[Claims] 1. A graphite crucible divided into two parts used for pulling a semiconductor single crystal by the CZ method is provided with a plurality of screw holes at an upper end portion, and at least two of these screw holes are provided.
A graphite crucible for a semiconductor single crystal pulling apparatus, characterized in that each screw hole is provided at a position closer to a dividing surface than a plane parallel to the dividing surface, passing through respective centers of gravity of the graphite crucible divided into two. . 2. A carbon fiber reinforced in a screw hole provided in the graphite crucible according to claim 1, in a work of installing a graphite crucible and a quartz crucible in a semiconductor single crystal pulling apparatus and loading polycrystalline silicon into the quartz crucible. After tightening the ring made of carbon fiber reinforced carbon composite material using the bolt made of carbon composite material, the quartz crucible was stored in the graphite crucible, the quartz crucible was loaded with polycrystalline silicon, and the quartz crucible was used with the cover. The method for handling a crucible is characterized in that the upper surface of the quartz crucible is covered and the inside of the quartz crucible is decompressed, and then the graphite crucible is supported by a hanging tool hooked on the ring and carried into a semiconductor single crystal pulling apparatus. 3. In carrying out the crucible after pulling the semiconductor single crystal using the semiconductor single crystal pulling apparatus, at least two screw holes provided at the upper end in the vicinity of the dividing surface of the graphite crucible according to claim 1. A crucible handling method, characterized in that a hanging bolt made of a carbon fiber reinforced carbon composite material is screwed, and a graphite crucible is supported by a hanging tool hooked on the hanging bolt and is carried out from a semiconductor single crystal pulling apparatus. .