JP2533864Y2 - Single crystal pulling device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single crystal pulling apparatus for growing a single crystal from a raw material melt in a crucible by the Czochralski method.

[0002]

2. Description of the Related Art Conventionally, as a single crystal pulling apparatus of this kind, those described in, for example, JP-A-57-205397 and JP-A-61-68389 are known. In these single crystal pulling apparatuses, a silicon melt is contained in a quartz crucible held by a graphite susceptor,
A heater and a heat retaining cylinder are provided around the graphite susceptor, and a cooling means for cooling a single crystal pulled from a silicon melt in the quartz crucible is provided above the quartz crucible. By forcibly cooling the single crystal being pulled and grown by means, a single crystal of good quality with few crystal defects can be obtained quickly.

[0003]

The conventional single crystal pulling apparatus is the former (Japanese Patent Laid-Open No. 57-20439).
No. 7) does not disclose the mounting structure of the cooling means arranged around the single crystal. Further, in the latter single crystal pulling apparatus (Japanese Patent Application Laid-Open No. 61-68389), the cooling means comprises the quartz crucible, the graphite susceptor,
Since it is fixed to the inner wall of the water cooling jacket that covers the heater and the heat retaining cylinder, the distance between the single crystal to be pulled and the cooling means changes depending on the diameter of the single crystal to be pulled, so that the cooling condition changes and the cooling effect differs. However, there is a problem that a problem occurs.

The present invention has been made in view of the above circumstances, and it is possible to limit a region where a single crystal to be pulled is quenched, and to perform appropriate cooling according to the diameter of the single crystal to be pulled. It is an object of the present invention to provide a single crystal pulling apparatus which can provide an effect and can maintain good quality of a single crystal.

[0005]

In order to solve the above-mentioned problems, the present invention employs the following single crystal pulling apparatus. That is, in a single crystal pulling apparatus that pulls and grows a single crystal from a raw material melt in a crucible by the Czochralski method, the chamber containing the crucible can be divided into a plurality of upper and lower sections, and the lower chamber of the chamber is On the upper end surface of the upper flange, a cooling cylinder that cools the single crystal while surrounding the single crystal is detachably provided via a mounting portion.

[0006]

In the single crystal pulling apparatus of the present invention, the chamber for accommodating the crucible can be divided into a plurality of upper and lower chambers, and the upper surface of the upper flange of the lower chamber of the chamber is cooled while surrounding the single crystal. By providing the cooling cylinder to be detachably attached via the mounting portion, the cooling cylinder is set in accordance with the region where the single crystal to be pulled is rapidly cooled, and the region where the single crystal is rapidly cooled is limited. In addition, since the cooling cylinder is detachable on the upper end surface of the upper flange of the lower chamber, a cooling cylinder having an appropriate diameter is selected and arranged according to the diameter of the single crystal to be pulled, and an appropriate cooling effect for the single crystal is obtained. give. Thereby, the quality of the single crystal is favorably maintained.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A single crystal pulling apparatus according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows, for example, 100
1 is a schematic configuration diagram showing a single crystal pulling apparatus used when pulling a single crystal having a diameter of 1 mm, in which 1 is a furnace body, and the furnace body 1 has a lower chamber 2, a middle chamber 3, and an upper chamber. (Not shown), each of which has a water-cooled jacket structure. A quartz crucible 4 is provided at a substantially central portion inside the furnace body 1.
The quartz crucible 4 is attached to a vertically movable and rotatable lower shaft 5 via a graphite susceptor (not shown). A heater 7 for heating and holding the silicon melt 6 in the quartz crucible 4 at a predetermined temperature is provided around the quartz crucible 4, and a heat insulating cylinder is provided between the heater 7 and the furnace body 1. 8 are arranged.

In the vicinity of the single crystal 9 pulled up from the silicon melt 6, in order to limit the region where the single crystal 9 is quenched, the single crystal 9 is slightly cooled in a state surrounding the single crystal 9. A large-diameter cylindrical cooling cylinder 10 is arranged at the upper end of the cooling cylinder 10, and a mounting portion 11 extending outward in the horizontal direction is provided at the upper end portion. And is detachably attached in a state of being sandwiched between the upper end surface of the inner chamber 3 and the lower end surface of the lower flange portion 3a of the middle chamber 3. A wire 12 for holding and pulling up the single crystal 9 is suspended from the middle chamber 3 and the center of the cooling cylinder 10 so as to be able to move up and down and rotate freely.

In order to pull up a single crystal using the single crystal pulling apparatus constructed as described above, first, a silicon piece (raw material) 13 to be a silicon melt 6 is stored in a quartz crucible 4 and pulled up. Cooling cylinder 1 according to the diameter of single crystal 9
0 is placed above the center of the quartz crucible 4 and the cooling cylinder 10
Of the lower chamber 2 and the lower end of the lower flange 3 a of the middle chamber 3. Then, after sufficiently replacing the air in the furnace body 1 with argon gas, the silicon piece 13 is melted by the heater 7 to form a silicon melt 6, and the temperature of the silicon melt 6 is maintained at a temperature suitable for pulling a single crystal. I do.

Next, the lower shaft 5 is rotated at a predetermined rotation speed, and the quartz crucible 4 is rotated at a predetermined rotation speed together with the graphite susceptor. In this state, wire 1
The seed crystal held at the lower end of 2 via a chuck is lowered and immersed in silicon melt 6. And wire 1
The seed crystal is pulled up at a predetermined speed while rotating the crystal 2 at a predetermined rotation speed in a direction opposite to the rotation direction of the quartz crucible 4, thereby pulling up the single crystal 9 while growing it.

In this single crystal pulling apparatus, the furnace body 1 is composed of a lower chamber 2, a middle chamber 3 and an upper chamber, and a cooling cylinder 10 is mounted on an upper end surface of an upper flange 2a of the lower chamber 2 via a mounting portion 11. By being detachably provided, an appropriate cooling cylinder 10 is selectively arranged in accordance with the diameter of the single crystal 9 to be pulled and the region to be quenched, restricting the region of the single crystal 9 to be quenched, and giving an appropriate cooling effect. . Than this,
The quality of the single crystal 9 to be pulled is kept good.

As described above, according to the single crystal pulling apparatus of this embodiment, the furnace main body 1 is composed of the lower chamber 2, the middle chamber 3, and the upper chamber.
Since the cooling cylinder 10 is detachably provided on the upper end surface of the upper flange 2a via the mounting portion 11, the cooling cylinder 10 is adapted to the diameter of the single crystal 9 to be pulled up and the region where the cooling profile of the single crystal 9 requires rapid cooling. The cooling cylinder 10 can be selectively arranged, so that the region where the single crystal 9 is rapidly cooled can be limited, and an appropriate cooling effect can be provided. Therefore, it is possible to prevent lattice irregularities and lattice defects from being generated in the single crystal 9 to be pulled, and to improve the uniformity of the single crystal 9.
Can easily and satisfactorily be maintained. Moreover, since the cooling cylinder 10 is short, only the region where the single crystal 9 needs to be rapidly cooled can be effectively cooled.

Further, by simply attaching and detaching the mounting portion 11 to and from the upper end surface of the upper flange portion 2a of the lower chamber 2, the cooling cylinder 10 can be easily replaced without major disassembly of the chamber. This has the effect of improving work efficiency.

[0014]

As described above, according to the single crystal pulling apparatus of the present invention, the chamber accommodating the crucible can be divided into a plurality of upper and lower portions, and the upper end surface of the upper flange of the lower chamber among the chambers. Since the cooling cylinder for cooling the single crystal in a state surrounding the single crystal is detachably provided through the mounting portion, the cooling is adapted to the diameter of the single crystal to be pulled up and the area which requires rapid cooling of the cooling profile of the single crystal. The tube can be selectively arranged, and the region where the single crystal is rapidly cooled can be limited, and an appropriate cooling effect can be given. Therefore, it is possible to prevent lattice irregularities and lattice defects from being generated in the single crystal to be pulled, to improve the uniformity of the single crystal, and to easily and satisfactorily maintain the quality of the single crystal. .

Further, by simply attaching and detaching the mounting portion to and from the upper end surface of the upper flange of the lower chamber, the cooling cylinder can be easily replaced without large-scale disassembly of the chamber, thereby improving work efficiency. Has the effect of doing

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a single crystal pulling apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 2 Lower chamber 2a Upper flange part 3 Middle chamber 3a Lower flange part 4 Quartz crucible 6 Silicon melt 9 Single crystal 10 Cooling cylinder 11 Mounting part

Claims (1)

(57) [Scope of request for utility model registration] In a single crystal pulling apparatus for pulling and growing a single crystal from a raw material melt in a crucible by the Czochralski method, a chamber accommodating the crucible can be vertically divided into a plurality of chambers. A single crystal pulling apparatus, wherein a cooling cylinder for cooling the single crystal in a state surrounding the single crystal is detachably provided on an upper end surface of an upper flange of the lower chamber via a mounting portion.