JP3428626B2 - Apparatus and method for pulling silicon single crystal - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silicon single crystal pulling apparatus for pulling and growing a silicon single crystal rod and a pulling method thereof.

[0002]

2. Description of the Related Art As a method for growing a silicon single crystal ingot, the Czochralski method (hereinafter referred to as CZ) for growing a high purity silicon single crystal ingot for a semiconductor from a silicon melt in a crucible.
The law) is known. In this CZ method, the silicon melt in the quartz crucible is heated by a carbon heater provided around the quartz crucible and maintained at a predetermined temperature, and the mirror-etched seed crystal is brought into contact with the silicon melt.
The seed crystal is pulled up to grow a silicon single crystal ingot. In this silicon single crystal ingot growing method, after pulling up the seed crystal to produce a seed throttle from the silicon melt, the shoulder is formed by gradually thickening the crystal to the diameter of the target silicon single crystal ingot. Then, it is further pulled up to form the straight body portion of the silicon single crystal ingot.

In order to improve the quality and productivity of silicon single crystal rods in the CZ method, conventionally, in this type of apparatus, a crucible for raising or lowering a quartz crucible for storing a silicon melt is provided in a chamber. There is known one provided with an elevating means and a cylindrical heat shield member surrounding a silicon single crystal ingot grown from a silicon melt. The crucible lifting means prevents the surface of the silicon melt from being lowered due to the pulling of the silicon single crystal rod by raising the quartz crucible, and maintains the surface of the silicon melt at a predetermined position to obtain a uniform silicon single crystal rod. In addition, the heat shielding member surrounds the silicon single crystal rod to shield the heat of the silicon melt from reaching the grown silicon single crystal rod,
The cooling rate of the silicon single crystal ingot is increased to increase the pulling rate and the productivity of the silicon single crystal ingot is improved.

[0004]

However, in the conventional pulling of a silicon single crystal, the heat shielding effect of the heat of the silicon melt by the heat shielding member is poor, and particularly the cooling of the silicon single crystal rod in the vicinity of the silicon melt is insufficient. There wasn't. Therefore, there is a problem that the temperature gradient in the vicinity of the solid-liquid interface in the axial direction at the center of the silicon single crystal ingot varies. On the other hand, if the diameter of the silicon single crystal ingot increases, it is expected that the fluctuation of the temperature gradient in the axial direction of the central portion of the silicon single crystal ingot will further increase. Therefore, there is a possibility that thermal stress may occur in the silicon single crystal ingot due to the fluctuation of the temperature gradient. An object of the present invention is to uniformize the temperature gradient in the vicinity of the solid-liquid interface in the axial direction of the central portion of the silicon single crystal rod being pulled from the silicon melt, thereby suppressing the occurrence of thermal stress in the silicon single crystal rod. An object of the present invention is to provide a silicon single crystal pulling apparatus and a pulling method thereof that can suppress the pulling.

[0005]

The invention according to claim 1 is
As shown in FIG. 1, a quartz crucible 13 provided in a chamber 11 in which a silicon melt 12 is stored, and a quartz crucible 1
The heater 18 that surrounds the outer peripheral surface of the silicon melt 3 and heats the silicon melt 12, and the outer peripheral surface of the silicon single crystal rod 25 pulled up from the silicon melt 12 and the lower end of the silicon melt 1
The present invention is an improvement of a silicon single crystal pulling apparatus provided with a heat shield member 26 which is configured to be positioned above and spaced apart from two surfaces and which shields radiant heat from the heater 18. Its characteristic configuration is that a cone-shaped heat radiation suppressing portion 26c inclined downward so that the opening diameter becomes smaller as it goes downward is formed below the heat shielding member 26, and the plurality of heat radiation plates 27 are made of silicon single crystal rods. The heat radiation suppressing portion 26c so as to surround 25
The outer peripheral portions of the plurality of heat radiating plates 27 arranged above are pivotally supported by the heat shield member 26, respectively, and the plurality of heat radiating plates 27 are respectively rotated to dissipate heat of the plurality of heat radiating plates 27c. Heat radiation plate rotating means 4 for changing the angle θ with respect to
It is equipped with 1.

In the apparatus for pulling a silicon single crystal according to the present invention, the plurality of heat radiation plates 27 arranged on the heat radiation suppressing portion 26c are radiant heat from the silicon melt 12 or from the silicon single crystal rod 25. Reflects heat dissipation. The heat radiation plate 27 is rotated so as to fall on the heat radiation suppressing portion 26c, thereby preventing the heat of the silicon melt 12 from being dissipated into the chamber 11, and the heat of the silicon single crystal rod 25 grown together with the heat radiation suppressing portion 26c is prevented. Cooling is promoted to maintain a high temperature gradient in the axial direction of the silicon single crystal ingot 25.

The invention according to claim 2 is the invention according to claim 1, wherein the heat radiation plate rotating means 41 is a drive gear provided on the upper part of the chamber 11 and a drive gear provided on the upper part of the chamber 11. A drive motor 46 for driving the motor, and a support rod 42 around which a rack gear that is suspended from the upper portion of the chamber 11 and meshes with the drive gear is formed.
And a connecting wire 44 that connects the lower end of the support rod 42 and the heat radiation plate 27 to each other. In the apparatus for pulling a silicon single crystal according to the second aspect of the invention, the support rod 42 moves up and down by the rotation of the drive gear that meshes with the rack gear, so that the heat radiation plate 27 can be easily rotated.

According to a third aspect of the present invention, a silicon single crystal rod 25 grown from the silicon melt 12 stored in the quartz crucible 13 is formed into a cylindrical heat shield member 26 and a downward face formed below the heat shield member 26. It is surrounded by a cone-shaped heat radiation suppressing portion 26c inclined to a plurality, and a plurality of heat radiation plates 27 are arranged on the heat radiation suppressing portion 26c so as to surround the silicon single crystal rod 25, and the outer peripheral portions of the plurality of heat radiation plates 27 are surrounded. In this method, the silicon single crystal ingots 25 are pulled up by being pivotally supported by the heat shield members 26, respectively. The characteristic point is that when the shoulder portion 25b of the silicon single crystal rod 25 is formed, a plurality of heat radiation plates 27 are erected at positions separated from the shoulder portion 25b, and the straight body portion 2 of the silicon single crystal rod 25 is formed.
When the 5c is formed, the plurality of heat radiation plates 27 are rotated from the standing position.
It is about to be rolled over and laid down on the heat radiation suppressing portion 26c .

In the method of pulling up the silicon single crystal according to the present invention, the heat of the silicon melt 12 is raised by raising the plurality of heat radiation plates 27 at positions separated from the shoulder portions 25b when forming the shoulder portions 25b. Is actively dissipated to the shoulder portion 25b in the process of forming, and the shoulder portion 25b is quickly formed. On the other hand, when forming the straight body portion 25c, a plurality of heat radiation plates 27 are erected.
The silicon single crystal rod grown together with the heat shield member 26 is rotated from the above position and laid down on the heat dissipation suppressing portion 26c to prevent the heat of the silicon melt 12 from being directly dissipated to the straight body portion 25c. By cooling 25, the temperature gradient in the axial direction of the central portion of the silicon single crystal ingot 25 at the time of forming the straight body portion 25c is maintained as high as that at the time of forming the shoulder portion 25b.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, a quartz crucible 13 for storing a silicon melt 12 is provided in a chamber 11 of a silicon single crystal pulling apparatus 10, and an outer surface of the quartz crucible 13 is covered with a graphite susceptor 14. To be done. The lower surface of the quartz crucible 13 is the above graphite susceptor 14.
It is fixed to the upper end of the support shaft 16 via, and the lower part of the support shaft 16 is connected to the crucible drive means 17. Although not shown, the crucible driving means 17 has a first rotation motor for rotating the quartz crucible 13 and an elevating motor for elevating the quartz crucible 13, and these motors can rotate the quartz crucible 13 in a predetermined direction. At the same time, it can move vertically. The outer peripheral surface of the quartz crucible 13 is a quartz crucible 13.
A heater 18 surrounds the heater 18 at a predetermined distance from the heater 18. Heater 1
Numeral 8 heats and melts a high-purity silicon polycrystal material put in a quartz crucible 13 to form a silicon melt.

A cylindrical casing 21 is connected to the upper end of the chamber 11. The casing 21 is provided with pulling up means 22. The pulling means 22 is a pulling head (not shown) provided on the upper end of the casing 21 so as to be horizontally rotatable, a second rotation motor (not shown) for rotating the head, and a quartz crucible 13 from the head.
A wire cable 23 hanging toward the center of rotation of
A pulling motor (not shown) provided in the head for winding or unwinding the wire cable 23. A seed crystal 24 for dipping in the silicon melt 12 and pulling up the silicon single crystal ingot 25 is attached to the lower end of the wire cable 23.

A heat shield member 26 surrounding the outer peripheral surface of the silicon single crystal rod 25 is provided between the outer peripheral surface of the silicon single crystal rod 25 and the inner peripheral surface of the quartz crucible 13. The heat shield member 26 has a cylindrical portion 26a which is formed in a cylindrical shape and shields the radiant heat from the heater 18, and a flange portion 26b which is connected to the upper edge of the cylindrical portion 26a and projects outward in a substantially horizontal direction. By placing the flange portion 26b on the heat insulating cylinder 19, the heat shield member 2 is arranged so that the lower edge of the cylinder portion 26a is located above the surface of the silicon melt 12 by a predetermined distance.
6 is fixed in the chamber 11.

Further, the chamber 11 includes the chamber 11
A gas supply / discharge means 28 for supplying an inert gas to the silicon single crystal rod side and discharging the inert gas from the inner peripheral surface side of the crucible of the chamber 11 is connected. The gas supply / discharge means 28 has one end connected to the peripheral wall of the casing 21 and the other end connected to a supply pipe 29 connected to a tank (not shown) for storing the inert gas, and one end connected to the lower wall of the chamber 11. Discharge pipe 30 whose other end is connected to a vacuum pump (not shown)
Have and. The supply pipe 29 and the discharge pipe 30 are provided with first and second flow rate adjusting valves 31, 32 for adjusting the flow rates of the inert gas flowing through these pipes 29, 30, respectively.

At the lower part of the tubular portion 26a which is the heat shield member 26, there is formed a cone-shaped heat radiation suppressing portion 26c inclined downward so that the opening diameter becomes smaller as it goes downward, and a plurality of heat radiation suppressing portions 26c are provided. A heat radiation plate 27 is arranged so as to surround the silicon single crystal ingot 25. As shown in FIG. 3, the heat dissipation suppressing portion 26c according to the present embodiment has a cylindrical portion 26.
It is formed to be inclined downward by 120 ° with respect to a, and six heat radiation plates 27 are used as shown in FIG. The six heat radiation plates 27 are each made of carbon, and are arranged on the heat radiation suppressing portion 26c at equal angles with the silicon single crystal rod 25 (FIG. 1) as the center. The outer peripheral portions of the plurality of heat radiation plates 27 arranged on the heat radiation suppressing portion 26c are pivotally supported at the lower portions of the tubular portion 26a which is the heat shielding member 26.

One end of a connecting wire 44 of a heat radiating plate rotating means 41 (FIGS. 1 and 2), which will be described later, is connected to each of the six heat radiating plates 27, and the wires 44 are pulled so that the broken lines in FIG. Rotate the wire 44 as indicated by the arrow
Is rotated to rotate as shown by the solid line arrow in the figure, and the angles θ of the plurality of heat radiation plates 27 with respect to the heat radiation suppressing portion 26c can be changed. The heat radiation plate 27 reflects the heat radiation from the silicon melt 12, and the heat radiation plate 27 rotates so as to fall on the heat radiation suppressing portion 26c, whereby the heat of the silicon melt 12 is dissipated into the chamber 11. And promotes cooling of the silicon single crystal rod 25 grown together with the heat dissipation suppressing portion 26c, and particularly, when forming the straight body portion 25c (FIG. 1), the temperature gradient in the axial direction of the silicon single crystal rod 25 is reduced to the shoulder portion 25b. It is designed to be kept as high as when it was formed (Fig. 2).

Returning to FIG. 1 and FIG. 2, a pair of heat radiation plate rotating means 41 is provided above the chamber 11 so as to sandwich the casing 21. The heat radiation plate rotating means 41 includes a drive gear provided on the upper part of the chamber 11, a drive motor 46 provided on the upper part of the chamber 11 and driving the drive gear,
It has a support rod 42 around which a rack gear that is suspended from the upper portion of the chamber 11 and meshes with a drive gear is formed, and a connecting wire 44 that connects the lower end of the support rod 42 and the heat radiation plate 27. The drive gear is built in a gear box 43 provided in the upper part of the chamber 11, and the connecting wire 44 is provided in the turning roller 2 provided outside the tubular portion 26a.
6e (FIG. 3) changes the direction and is installed.
In the heat radiation plate rotating means 41, a drive gear (not shown) contained in the gear box 43 is rotated by the rotation of the rotation shaft 46a by the drive motor 46, and the support rod 42 is moved up and down to radiate heat through the connecting wire 44. Each of the plates 27 is rotated so that the angles of the plurality of heat radiation plates 27 with respect to the heat radiation suppressing portion 26c can be changed from the state shown by the solid line to the state shown by the broken line in FIG.

On the other hand, a rotary encoder (not shown) is provided on the output shaft (not shown) of the pulling motor in the pulling means 22, and the weight of the silicon melt 12 in the quartz crucible 13 is provided in the crucible lifting means 17. There is provided a weight sensor (not shown) for detecting the position and a linear encoder (not shown) for detecting the vertical position of the support shaft 16. Each detection output of the rotary encoder, the weight sensor and the linear encoder is connected to a control input of a controller (not shown),
The control output of the controller is connected to the pulling motor of the pulling means 22, the raising / lowering motor of the crucible raising / lowering means 17, and the drive motor 46 of the heat radiation plate rotating means 41, respectively.
In addition, the controller is provided with a memory (not shown),
In this memory, the winding length of the wire cable 23 with respect to the detection output of the rotary encoder, that is, the pulling length of the silicon single crystal rod 25 is stored as a first map, and the silicon melting inside the quartz crucible 13 with respect to the detection output of the weight sensor is stored. The liquid level of the liquid 12 is stored as the second map.
The controller controls the raising / lowering motor of the crucible raising / lowering means 17 so that the liquid level of the silicon melt 12 in the quartz crucible 13 is always kept at a constant level based on the detection output of the weight sensor, and the plurality of heat radiation plates It is configured to control the drive motor 46 of the heat radiation plate rotating means 41 to rotate 27.

A method for pulling a silicon single crystal according to the present invention using the apparatus thus constructed will be described. As shown in FIG. 2, a high-purity silicon polycrystal is put into a quartz crucible 13, and the high-purity silicon polycrystal is heated and melted by a carbon heater 18 to form a silicon melt 12. When the silicon polycrystalline body is melted, the heat radiation plate rotating means 41 moves the support rod 42 upward to move the heat radiation plate 27.
Is rotated as shown by the broken line arrow in FIG. 3 to stand up as shown by the broken line (θ = 0 °). After the silicon polycrystal melts and the silicon melt 12 is stored in the quartz crucible 13, the inert gas is supplied into the casing 21 by opening the first and second flow rate adjusting valves 31 and 32. 12
The gas evaporated from the surface of is discharged from the discharge pipe 30 together with this inert gas.

Next, the wire 19 is fed out by a pulling motor (not shown) of pulling means to lower the seed crystal 24, and the tip of the seed crystal 24 is brought into contact with the silicon melt 12. After that, the seed crystal 24 is gradually pulled up and the seed diaphragm 25a
After forming, the seed crystal 24 is further pulled up to grow the shoulder portion 25b under the seed narrowing portion 25a. Even when the shoulder portion 25b is formed, the heat radiation plate rotating means 4
1 stands up the plurality of heat radiation plates 27 at a position separated from the shoulder portion 25b. For this reason, the heat of the silicon melt 12 is positively dissipated to the shoulder portion 25b in the process of formation, and the shoulder portion 2b quickly
5b is formed.

After the shoulder portion 25b is grown, the shoulder portion 2 is further pulled up by pulling up the seed crystal 24, as shown in FIG.
A straight body portion 25c is formed below 5b. This straight body part 25
In forming c, the heat radiating plate rotating means 41 moves the support rod 42 downward to rotate the plurality of heat radiating plates 27 as shown by the solid line arrows in FIG. 3, and from the state shown by the dashed line in FIG. As shown, the plurality of heat radiation plates 27 are connected to the heat radiation suppressing section 2
Lie on 6c (θ = 120 °). Heat dissipation suppressing section 26
The plurality of heat radiating plates 27 laid down on c are the silicon melt 1
2 heat is prevented from being dissipated in the chamber 11,
Silicon single crystal rod 2 grown together with heat dissipation suppressing portion 26c
The cooling of No. 5 is promoted, and the temperature gradient in the axial direction of the silicon single crystal ingot 25 at the time of forming the straight body portion 25c is maintained as high as that at the time of forming the shoulder portion 25b (FIG. 2). In addition, the straight body part 25
With the growth of c, the surface of the silicon melt 12 lowers, and a lifting motor (not shown) raises the crucible 13 in accordance with the amount of the melt 12 decreasing, and the silicon melt 12 lowers as the seed crystal 24 is pulled up. To keep the surface in place.

[0021]

EXAMPLES Next, examples of the present invention will be described in detail together with comparative examples. <Example 1> As shown in FIG. 1, the inner diameter is 400 to 600.
mm quartz crucible 13 and the inner diameter of the tubular portion 26a is 300 to
Heat shield member 2 having a height of 500 mm and a height of 300 to 600 mm
In the silicon single crystal pulling apparatus 10 having the above-mentioned No. 6, a cone-shaped heat dissipation suppressing unit 31 was formed in the lower portion of the cylindrical portion 26a. Six heat radiation plates 27 are arranged in the heat radiation suppressing portion 31, and the outer peripheral portions of the respective heat radiation plates 27 are covered by the heat shielding member 26.
To each of them. One end of the connecting wire 44 was connected to the radiation plate 27, and the other end of the connecting wire 44 was connected to the lower end of the support rod 42 of the heat radiation plate rotating means 41. The heat radiation plate 27 is made of carbon and has a thickness of about 50 to 80 mm. The pulling device 10 configured as described above
Was set as Example 1.

<Comparative Example 1> Although not shown, the pulling device was constructed in the same manner as in Example 1 except that the heat radiation plate 27 was not provided. This pulling device is referred to as Comparative Example 1.

<Comparison Test and Evaluation> With each of the pulling devices of Example 1 and Comparative Example 1, the diameter of the straight body part is 300 to 350 mm.
Pulling speed of the silicon single crystal rod 25 of 0.1 to 1.0 m
The temperature gradient in the vicinity of the solid-liquid interface in the axial direction of the silicon single crystal ingot 25 when pulled up at m / min was simulated and calculated by a heat conduction analysis program in consideration of radiative heat transfer for comparison. The pulling amount of the silicon single crystal rod 25 is represented by a solidification rate, and the solidification rate is 100 obtained by dividing the weight of the pulled silicon single crystal rod 25 by the weight of the silicon melt 12 initially stored in the quartz crucible 13. Expressed as a multiplied value. Further, in the first embodiment, when the angle of the heat radiation plate 27 with respect to the heat radiation suppressing portion 26c is θ (FIG. 3), the plurality of heat radiation plates 27 are arranged at the angle (θ) shown in FIG. 5 in relation to the solidification rate. It was rotated so as to fall on the heat radiation suppressing portion 26c. The result is shown in FIG.

As is apparent from FIG. 6, in Comparative Example 1, the silicon single crystal ingot 2 was initially pulled up and then the silicon single crystal ingot 2 was pulled up.
The temperature gradient in the vicinity of the solid-liquid interface in the axial direction of 5 showed the maximum value, then showed the minimum value at the time when the solidification rate was 43%, and the temperature gradient slightly increased by further raising. On the other hand, in Example 1, the silicon single crystal rod 2
At the beginning of pulling up No. 5, the temperature gradient showed the maximum value as in Comparative Example 1, and then at the time when the solidification rate was 43%, Comparative Example 1
It shows the minimum value with a higher value. It can be seen that even if the value is further raised after that, the value does not change and is almost uniform.

In the first embodiment, the heat radiation plate 27 prevents the heat of the silicon melt 12 from radiating into the chamber, prevents the heat of the silicon melt 12 from directly radiating to the straight body portion 25c, and shields the heat. Silicon single crystal rod 25 grown together with member 26
However, in Comparative Example 1, heat was dissipated from the silicon melt 12 into the chamber, and this heat reduced the temperature gradient near the solid-liquid interface in the axial direction at the center of the straight body portion 25c. it is conceivable that.

[0026]

As described above, according to the present invention, a cone-shaped heat radiation suppressing portion inclined downward so that the opening diameter becomes smaller as it goes downward is formed in the lower portion of the heat shielding member, and a plurality of heat radiation suppressing members are formed. The heat radiation plate is arranged on the heat dissipation suppressing portion so as to surround the silicon single crystal rod, and the outer peripheral portions of the arranged heat radiation plates are pivotally supported by the heat shielding member, respectively, and the plurality of heat radiation plates are rotated respectively. Since the heat radiation plate rotating means for changing the angle of the plurality of heat radiation plates with respect to the heat radiation suppressing portion is provided, by rotating the heat radiation plate by the heat radiation plate rotating means so as to fall on the heat radiation suppressing portion, It prevents the heat of the silicon melt from radiating into the chamber, accelerates the cooling of the silicon single crystal rod grown with the heat shield, and reduces the temperature gradient in the axial direction of the central part of the single crystal rod when the straight body is formed. Keep as high as when forming the shoulder It can be. Further, the heat radiation plate rotating means includes a drive gear provided on the upper part of the chamber, a drive motor provided on the upper part of the chamber to drive the drive gear, and a drive gear that is suspended from the upper part of the chamber into the chamber and meshes with the drive gear. If there is a supporting rod around which the rack gear is formed and a connecting wire that connects the lower end of the supporting rod and the heat radiation plate, the supporting rod moves up and down by the rotation of the drive gear that meshes with the rack gear, so it is easy. The heat radiation plate can be rotated.

Furthermore, when a plurality of heat radiation plates are erected at positions apart from the shoulders when forming the shoulders, the heat of the silicon melt is positively dissipated to the shoulders during the formation, and the heat of the shoulders is rapidly increased. Forming can be performed, and by rotating multiple heat radiation plates so as to lie down on the heat dissipation suppressing part when forming the straight body part, it is possible to prevent the heat of the silicon melt from radiating directly to the straight body part, By promoting cooling of the silicon single crystal ingot grown with the shielding member, it is possible to maintain the temperature gradient in the axial direction of the central part of the silicon single crystal ingot at the time of forming the straight body as high as that at the time of forming the shoulder. .
As a result, the temperature gradient in the vicinity of the solid-liquid interface in the axial direction at the center of the silicon single crystal rod can be made uniform, and the occurrence of thermal stress in the silicon single crystal rod can be suppressed.

[Brief description of drawings]

FIG. 1 is a cross-sectional configuration diagram showing a pulling device of the present invention in which a straight body portion of a silicon single crystal ingot is pulled up.

FIG. 2 is a sectional configuration diagram corresponding to FIG. 1, showing a state in which a shoulder portion is pulled up.

FIG. 3 is a cross-sectional view of a heat shield member in which a heat radiation plate is arranged on the heat radiation suppressing portion.

FIG. 4 is a cross-sectional view taken along the line AA of FIG. 1 showing an arrangement state of the heat radiation plate.

FIG. 5 is a diagram showing a relationship between an angle of a heat radiation plate with respect to a heat radiation suppressing portion and a solidification rate.

FIG. 6 is a diagram showing the relationship between the temperature gradient and the solidification rate in the vicinity of the solid-liquid interface in the axial direction at the center of the silicon single crystal ingot.

[Explanation of symbols]

10 Lifting device 11 chambers 12 Silicon melt 13 Quartz crucible 18 heater 25 Silicon single crystal rod 25b shoulder 25c straight body 26 Heat shield 26c Heat dissipation suppressing section 27 Heat radiation plate 41 Heat radiation plate rotating means 42 Support rod 44 connecting wire 46 Drive motor

─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Yasushi Shimanuki 1-5-1, Otemachi, Chiyoda-ku, Tokyo Mitsubishi Materials Silicon Co., Ltd. (56) Reference JP-A-9-132496 (JP, A) JP 1-100086 (JP, A) JP 5-330975 (JP, A) JP 6-256084 (JP, A) JP 9-227272 (JP, A) JP 9-309789 (JP , A) JP-A-9-315882 (JP, A) JP-A-11-157993 (JP, A) JP-A-11-263692 (JP, A) International Publication 93/00462 (WO, A1) (58) Survey Areas (Int.Cl. ⁷ , DB name) C30B 1/00-35/00

Claims (3)

(57) [Claims] 1. A silicon melt provided in the chamber (11).
(12) is stored in the quartz crucible (13), and the quartz crucible (1
A heater (18) that surrounds the outer peripheral surface of 3) and heats the silicon melt (12), and a lower end that surrounds the outer peripheral surface of the silicon single crystal rod (25) pulled from the silicon melt (12). A silicon single crystal pulling device provided with a cylindrical heat shield member (26) configured to be positioned above the surface of the silicon melt (12) with a space between them and shield the radiant heat from the heater (18). In the above, the cone-shaped heat dissipation suppressing portion (26c) inclined downward so that the opening diameter becomes smaller as it goes downward is the heat shielding member.
A plurality of heat radiation plates (27) formed on the lower part of (26) are arranged on the heat dissipation suppressing part (26c) so as to surround the silicon single crystal rod (25), and the plurality of heat dissipation plates arranged. The outer peripheral portion of the radiation plate (27) is pivotally supported by the heat shielding member (26), respectively, and the plurality of heat radiation plates (27) are rotated to rotate the heat radiation plates (27). Angle (θ) with respect to (26c)
A device for pulling a silicon single crystal, comprising a heat radiation plate rotating means (41) for changing the temperature. 2. A heat radiation plate rotating means (41) is provided in the chamber.
The drive gear provided on the upper part of (11) and the chamber (11)
A drive motor (4
6), a support rod (42) around which a rack gear that is suspended from the upper part of the chamber (11) and meshes with the drive gear is formed, and the lower end of the support rod (42) And a connecting wire (44) for connecting the heat radiation plate (27).
The apparatus for pulling a silicon single crystal described. 3. A cylindrical heat shield member (26) is provided with a silicon single crystal rod (25) grown from a silicon melt (12) stored in a quartz crucible (13) and a lower portion of the heat shield member (26). Surrounded by a downwardly inclined cone-shaped heat dissipation suppressing portion (26c) formed, a plurality of heat radiation plates (27) to surround the silicon single crystal rod (25) the heat dissipation suppressing portion (26c). A method of pulling up the silicon single crystal rod (25) by arranging the silicon single crystal rods (25) on the heat shielding member (26) by pivotally supporting the outer peripheral portions of the plurality of heat radiation plates (27). When forming the shoulder portion (25b) of the crystal rod (25), the plurality of heat radiation plates (27) are erected at a position apart from the shoulder portion (25b), and the straight body portion of the silicon single crystal rod (25) ( 25c) by rotating the plurality of heat radiation plates (27) from the upright position during formation
A method for pulling a silicon single crystal, which is characterized in that the heat dissipation suppressing portion (26c) is laid down.