JPH071072U - Single crystal pulling device - Google Patents

Abstract

(57) [Abstract] [Purpose] The quenching region of the pulled single crystal can be limited, and an appropriate cooling effect can be given according to the diameter of the pulled single crystal, and therefore the single crystal Provided is a single crystal pulling apparatus capable of maintaining good quality. In a single crystal pulling apparatus for pulling and growing a single crystal 9 from a raw material melt 6 in a crucible 4 by the Czochralski method, a chamber accommodating the crucible 4 can be vertically divided into a plurality of chambers. A cooling cylinder 10 for cooling the single crystal 9 while surrounding the single crystal 9 is detachably provided via an attachment portion 11 on the upper end surface of the upper flange 2a of the lower chamber 2.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a single crystal pulling apparatus for pulling and growing a single crystal from a raw material melt in a crucible by the Czochralski method.

[0002]

[Prior art]

 Conventionally, as this type of single crystal pulling apparatus, 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 insulating cylinder are respectively provided around the graphite susceptor, and the quartz quartz is used. Above the crucible, cooling means for cooling the single crystal pulled from the silicon melt in the quartz crucible is provided, and the cooling means forcibly cools the single crystal under pulling and growing. We are trying to quickly obtain good quality single crystals with few crystal defects.

[0003]

[Problems to be solved by the device]

 By the way, in the former single crystal pulling apparatus (Japanese Patent Laid-Open No. 57-205397), the mounting structure of the cooling means arranged around the single crystal is not specified. In the latter single crystal pulling apparatus (Japanese Patent Laid-Open No. 61-68389), the cooling means is fixed to the inner wall of a water cooling jacket that covers the quartz crucible, the graphite susceptor, the heater, the heat retaining cylinder and the like. Therefore, the distance between the single crystal and the cooling means changes depending on the size of the pulled single crystal, so that there is a problem that the cooling conditions change and the cooling effect becomes different.

The present invention has been made in view of the above circumstances, and it is possible to limit the quenching region of a single crystal to be pulled, and it is appropriate 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 that can provide a cooling effect and therefore can maintain good single crystal quality.

[0005]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention employs the following single crystal pulling apparatus. That is, in a single crystal pulling apparatus for pulling up and growing a single crystal from a raw material melt in a crucible by the Czochralski method, the chamber containing the crucible can be vertically divided into a plurality of chambers. It is characterized in that a cooling cylinder for cooling while enclosing the single crystal is detachably provided on the upper end surface of the upper flange of the chamber through a mounting portion.

[0006]

[Action]

 In the single crystal pulling apparatus of the present invention, the chamber for housing the crucible can be vertically divided into a plurality of chambers, and the upper crystal of the upper flange of the lower chamber of the chamber is surrounded by the single crystal and is cooled with cooling. Since the cylinder is detachably provided via the mounting portion, the cooling cylinder is installed in conformity with the quenching region of the pulled single crystal, and limits the quenching region of the single crystal. In addition, since the cooling cylinder is attachable to and detachable from the upper surface of the upper flange of the lower chamber, a cooling cylinder with an appropriate diameter is selected and arranged according to the diameter of the single crystal to be pulled, and the appropriate cooling effect for the single crystal is obtained. give. As a result, the quality of the single crystal is kept good.

[0007]

【Example】

 A single crystal pulling apparatus according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing, for example, a single crystal pulling apparatus used for pulling a single crystal having a diameter of 100 mm. In the figure, 1 is a furnace body, and this furnace body 1 is a lower chamber 2, It is composed of a middle chamber 3 and an upper chamber (not shown), each of which has a water cooling jacket structure. Further, a quartz crucible 4 is provided substantially in the center of the inside of the furnace body 1, and the quartz crucible 4 is attached to a lower shaft 5 which is vertically movable and rotatable via a graphite susceptor (not shown). It is included. A heater 7 for heating and holding the silicon melt 6 in the quartz crucible 4 at a predetermined temperature is installed around the quartz crucible 4, and heat insulation is provided between the heater 7 and the furnace body 1. The cylinder 8 is arranged.

In the vicinity of the single crystal 9 pulled from the silicon melt 6, the single crystal 9 is cooled in a state in which the single crystal 9 is surrounded so as to limit the region where the single crystal 9 is rapidly cooled. A cylindrical cooling cylinder 10 having a slightly larger diameter is arranged, and a mounting portion 11 extending outward in the horizontal direction is provided at an upper end portion of the cooling cylinder 10. The mounting portion 11 is located above the lower chamber 2. The upper end surface of the flange portion 2a and the lower end surface of the lower flange portion 3a of the middle chamber 3 are detachably attached to each other. A wire 12 for holding and pulling the single crystal 9 is suspended in the center of the middle chamber 3 and the cooling cylinder 10 so as to be vertically movable and rotatable.

In order to pull up a single crystal using the single crystal pulling apparatus configured as described above, first, the silicon piece (raw material) 13 to be the silicon melt 6 is housed in the quartz crucible 4 and pulled up. The cooling cylinder 10 is arranged above the central portion of the quartz crucible 4 according to the diameter of the single crystal 9 to be formed, and the mounting portion 11 provided at the upper end of the cooling cylinder 10 is attached to the upper flange portion 2a of the lower chamber 2. It is clamped by the upper end surface of the lower chamber and the lower end surface of the lower flange portion 3a of the middle chamber 3. Next, after the air in the furnace body 1 is sufficiently replaced with argon gas, the silicon piece 13 is melted by the heater 7 to form the silicon melt 6, and the temperature of the silicon melt 6 is adjusted to a temperature suitable for pulling a single crystal. Hold.

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, the seed crystal held on the lower end of the wire 12 via the chuck is lowered from above and immersed in the silicon melt 6. Then, the wire 12 is rotated at a predetermined rotation speed in a direction opposite to the rotation direction of the quartz crucible 4, and the seed crystal is pulled at a predetermined speed, whereby the single crystal 9 is grown and pulled.

In this apparatus for pulling a single crystal, a 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. Since it is detachably installed, an appropriate cooling cylinder 10 is selectively arranged according to the diameter of the single crystal 9 to be pulled and the region to be rapidly cooled, and the region to be rapidly cooled of the single crystal 9 is limited to obtain an appropriate cooling effect. give. As a result, 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 body 1 is composed of the lower chamber 2, the middle chamber 3 and the upper chamber, and the upper flange 2 a of the lower chamber 2 is formed. Since the cooling cylinder 10 is detachably provided on the upper end surface via the mounting portion 11, the cooling cylinder 10 is selected according to the diameter of the single crystal 9 to be pulled and the region of the cooling profile of the single crystal 9 that requires rapid cooling. The single crystal 9 can be arranged, 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 the occurrence of lattice irregularities or lattice defects in the pulled single crystal 9, improve the crystal uniformity of the single crystal 9, and easily and satisfactorily maintain the quality of the single crystal 9. be able to. Moreover, since the cooling cylinder 10 is short, it is possible to effectively cool only the region of the single crystal 9 that requires rapid cooling.

Further, by simply attaching and detaching the attaching 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 causing a large-scale disassembly of the chamber. It is possible to improve the work efficiency.

[0014]

[Effect of device]

 As described above, according to the single crystal pulling apparatus of the present invention, the chamber containing the crucible can be divided into a plurality of upper and lower chambers, and the single chamber pulling apparatus is provided on the upper surface of the upper flange of the lower chamber of the chamber. Since the cooling cylinder that cools the crystal in the surrounding state is attached and detached via the mounting part, the cooling cylinder that matches the diameter of the single crystal to be pulled and the cooling profile of the single crystal that requires rapid cooling Can be selectively arranged, the region where the single crystal is rapidly cooled can be limited, and an appropriate cooling effect can be provided. Therefore, it is possible to prevent the occurrence of lattice irregularities, lattice defects, etc. in the pulled single crystal, improve the crystal uniformity of the single crystal, and easily and satisfactorily maintain the quality of the single crystal. it can.

Further, by simply attaching and detaching the attaching portion to the upper end surface of the upper flange of the lower chamber, the cooling cylinder can be easily exchanged without causing a large-scale disassembly of the chamber, resulting in high work efficiency. Has the effect of improving.

[Brief description of drawings]

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

[Explanation of symbols]

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

Claims (1)

[Scope of utility model registration request] 1. 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 while surrounding the single crystal is detachably provided via an attachment portion on the upper end surface of the upper flange of the lower chamber.