JP3288786B2 - Method and apparatus for cooling silicon single crystal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is intended to prevent the generation of oxidation-induced stacking faults (OSF) in a silicon single crystal when producing the silicon single crystal by the Czochralski method (CZ method) and to prevent oxygen precipitation. The present invention relates to a cooling method and a cooling device for controlling an amount.

[0002]

2. Description of the Related Art As a method for producing a single crystal, a CZ method in which a crystal is pulled from a melt in a crucible while growing the crystal is widely used. In this CZ method, a large amount of oxygen is mixed into a melt from a quartz crucible and is taken into a silicon single crystal ingot to be grown at a high concentration. As described above, since the above-described oxygen or other impurities that are taken in during the growth of the silicon single crystal ingot are present, the thermal history of the ingot during the crystal growth in the CZ method depends on the obtained silicon single crystal. It greatly affects the quality of the crystal.

[0003] That is, the thermal history at the time of growing a single crystal affects the rate of generation of OSF generated by high-temperature oxidation treatment in a device process. As described above, a large amount of impurities such as oxygen taken in during the growth of a single crystal are mixed into the melt, and the grown silicon single crystal ingot is taken in by the impurities to generate a point defect. This is because the nuclei grow by agglomeration due to the subsequent heat history, and stacking faults are precipitated from the nuclei in the high-temperature oxidation treatment of the device process.

[0004] The heat history changes the oxygen precipitation concentration in the silicon single crystal. The amount of deposition determines the magnitude of the warpage of the silicon wafer and also determines the intrinsic gettering (IG) effect.

Further, when oxygen in the crystal is subjected to a heat treatment at about 450 ° C., several atoms gather and emit one electron to generate a donor. This donor determines the amount of oxygen precipitation during high temperature heat treatment of the wafer. Conventionally, JP-A-58-12
After processing into a silicon wafer as disclosed in JP-A-0591 and JP-A-2-263792, a low-temperature heat treatment at 450 to 650 ° C. is performed to control the amount of oxygen precipitation. However, even if the above-mentioned low-temperature heat treatment is similarly performed along with the increase in the diameter of the silicon single crystal to be grown, oxygen precipitation on the silicon wafer will not occur between the small-diameter silicon single crystal and the large-diameter silicon single crystal. There are large differences in volume. This is because the small-diameter silicon single crystal and the large-diameter silicon single crystal have different thermal histories during single crystal growth.

Conventionally, in pulling a silicon single crystal by the CZ method, cooling of the grown single crystal ingot immediately after pulling is performed by an argon gas in a water-cooled stainless steel chamber. There is no method other than increasing the pressure in the furnace and the flow rate of argon gas, and the cooling rate is 0.5
３3 ° C./min. Under such cooling conditions, agglomeration of point defects and precipitation of impurities such as oxygen generally occur in a large amount as described above, and even when heat treatment is performed from a wafer, it occurs in a cooling process immediately after pulling up the single crystal ingot. Defective nuclei and the like cannot be eliminated, and when subjected to a device process, these become apparent as crystal defects, thereby lowering the yield.
Further, the increase in diameter of the silicon single crystal to be grown as described above further decreases the cooling rate immediately after pulling the single crystal, and such a problem has become more serious.

[0007] In the single crystal pulling apparatus, a cylindrical body which is suspended from the upper wall surface of the heating chamber portion of the single crystal pulling furnace and surrounds the silicon single crystal with the growing silicon single crystal as an axis is provided (for example, see Japanese Patent Application Laid-Open Publication No. H11-163873). Showa 47-26388
Japanese Patent Application Laid-Open No. 57-205397 and Japanese Patent Application Laid-Open No. 61-68389). Further, such a cylindrical body has a water-cooled structure (for example, Japanese Patent Application Laid-Open Nos. A cover comprising an upper flat annular rim protruding from the edge of the crucible and an inverted conical connecting part attached to the annular rim and having a lower end close to the silicon single crystal and the melt is provided (for example, Japanese Patent Publication No. -4
No. 0119) has been proposed, and by providing such a member, although a certain improvement in the cooling rate can be expected, a satisfactory result has not yet been obtained.

Accordingly, the present invention provides a method and a method for cooling a silicon single crystal which can obtain a high-quality silicon single crystal by improving the cooling rate of the single crystal ingot immediately after being pulled in the CZ method and improving the heat history. It is intended to provide a device. Another object of the present invention is to provide a cooling method and a cooling device capable of obtaining a silicon single crystal with less OSF generation in a device process.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above objects, the present invention provides a method of manufacturing a silicon single crystal by pulling a silicon single crystal from a melt in a crucible. A cooling rate in a temperature range from 350 ° C. to a normal temperature of 5 ° C./min to 200 ° C./min.

In the cooling method of the present invention, the cooling rate in the temperature range from 600 ° C. to 350 ° C. of the silicon single crystal pulled from the melt is set at 5 ° C./min to 100 ° C./min to further increase the cooling rate. A high quality silicon single crystal can be obtained.

The present invention is also a cooling device for cooling a silicon single crystal pulled from a melt in a crucible, comprising: a first cooling section for blowing a gas-liquid mist as a cooling medium onto the silicon single crystal; A second cooling section containing a liquid cooling medium in which the single crystal is immersed, the second cooling section being sequentially provided along the moving direction of the silicon single crystal.

Further, the present invention includes the above-described cooling device in which the first cooling section is provided above the second cooling section, and a single crystal pulling furnace for pulling a silicon single crystal from the melt in the crucible. An apparatus for producing a silicon single crystal, wherein the single crystal pulling furnace is provided with a heating chamber for housing a crucible for forming a melt and an upper end provided above the heating chamber and separable from the heating chamber . A chamber composed of a closed pulling chamber portion, and a wire installed on an upper end surface of the pulling chamber portion and winding a single crystal pulling linear body penetrating through the upper end surface of the pulling chamber portion and drooping into the chamber. And a pull-up chamber portion located above the heating chamber portion.
A transfer mechanism for moving the silicon single crystal from the position to a second position located above the cooling device, and introducing the silicon single crystal into the cooling device and moving the silicon single crystal from the first cooling section to the second cooling section in the device. After the pulling chamber portion is arranged at the second position, the movement can be performed by sending out a single crystal pulling linear body for suspending and holding a silicon single crystal by the linear body winding device. It is.

[0013]

According to the present invention, a single crystal ingot pulled from a melt is used in a temperature range from 350 ° C. to room temperature.
Cooling is actively performed using a spray flow of a liquid cooling medium such as water or a storage tank, and the cooling rate is 5 ° C./min or more and 200 ° C./min or less. The present inventors have conducted intensive studies on the thermal history immediately after pulling a silicon single crystal in order to reduce the OSF generated in the device process of a silicon single crystal obtained by the CZ method. Regardless of the cooling rate of the region, it has been found that when the cooling speed in the temperature region from 350 ° C. to room temperature is high, the occurrence of crystal defects is reduced. The detailed mechanism has not been fully elucidated yet, but it is considered that one of the factors is probably as follows. That is, the silicon single crystal becomes an impurity semiconductor when the temperature is 400 to 300 ° C. or lower, and takes a Fermi level inherent to the conductivity type (n-type or p-type). However, the temperature range from 350 ° C. to room temperature must be rapidly cooled. Thus, aggregation of point defects due to this can be suppressed to a low level.

Further, in the method for cooling a silicon single crystal of the present invention, it is desirable that the cooling rate in a temperature range from 600 ° C. to 350 ° C. be 5 ° C./min to 100 ° C./min. 450 ° C ± 100 ° C by increasing the cooling rate in the temperature range from
In this case, the amount of donors generated in the step is suppressed, and the aggregation of point defects and the generation of crystal defects caused by the donors can be prevented. In this specification, “normal temperature” means 50 ° C.
It refers to a temperature of about ± 50 ° C.

Hereinafter, the present invention will be described in more detail based on embodiments. FIG. 1 is a cross-sectional view schematically showing a configuration of a silicon single crystal manufacturing apparatus according to an embodiment of the present invention in use, and FIG. 2 is a plan view of the embodiment.

As shown in FIG. 1, the single crystal pulling apparatus 1 has a chamber 2 comprising a heating chamber 2a and a pulling chamber 2b. In the heating chamber 2a,
A quartz crucible 4 supported by a rotating shaft 3 extending through the bottom of the chamber from a driving device (not shown) located outside the chamber 2 is provided, and the crucible 4 is provided at a predetermined interval. A cylindrical heater 5 is provided to surround the heater 5, and a heat insulating material 6 is disposed outside the heater 5. In this example, the outer periphery of the quartz crucible 4 is protected by a graphite crucible 7, and the graphite crucible 7 is supported on the rotating shaft 3 via a graphite tray 8.

On the other hand, the pulling chamber 2b extends above the heating chamber 2a along the pulling axis of the single crystal ingot 10 pulled from the silicon melt 9 formed in the quartz crucible 4. , A portion having a smaller inner diameter than the heating chamber portion 2a. The heating chamber section 2a and the pulling chamber section 2b are structured to be separable at a connection section 11, and the heating chamber section 2a is located near the connection section 11 and has an opening at the upper end of the heating chamber section 2a. There is provided a gate valve 12 capable of closing the gate.

A pull-up wire 15 having a chuck 14 for holding a seed crystal 13 is disposed in the chamber 2 at a tip portion penetrating the upper wall of the chamber and hanging down from above. By the wire pulling device 16 provided above the pulling chamber 2b, the wire can be lifted and lowered while rotating.

As shown in FIGS. 1 and 2, an arm 19 of a hydraulic moving mechanism 18 fixed to a column 17 is connected to the outer peripheral wall surface of the pulling chamber 2b of the single crystal pulling apparatus 1. I have. The hydraulic moving mechanism 18 can be driven in the vertical direction and the turning direction.
9, the pulling chamber 2b is moved from a position (hereinafter, referred to as a first position) provided above the heating chamber 2a to a position provided above the cooling device 21 (described later). Hereinafter, this position is referred to as a second position.) Note that the moving mechanism provided in the single crystal manufacturing apparatus according to the present invention may be of a hydraulic type as in this embodiment as long as the pulling chamber unit 2b can be moved from the first position to the second position. It is not limited to anything, and may be a gear type, a crane type, or the like. As described above, the pulling chamber 2b moves from the first position to the second position immediately after the single crystal pulling operation. However, the argon gas supply pipe, the electric supply path, and the chamber connected to the pulling chamber 2b. The cooling water flow path and the like are made of a flexible member like the conventional single crystal manufacturing apparatus, and thus do not hinder such a moving operation at all.

In this single crystal manufacturing apparatus,
A cooling device 21 is provided in the turning range of the arm 19 of the hydraulic moving mechanism 18 at a distance from the single crystal pulling device 1. In the cooling device 21, the inside of a cylindrical container 22 having an opening at the upper end is divided into two in the vertical direction. In the upper region, the cooling medium pipe 23 extends through the wall surface of the container body 22 from the outside to the inside of the container body 22 and is installed along the inner peripheral surface near the inner peripheral surface of the container body 22. Are provided with a plurality of nozzles 24 that open toward the center in the radial direction of the container 22. Thereby, when the single crystal ingot 10 is disposed inside the cooling device 21, the first cooling section 25 in which the spray flow of the cooling medium is blown onto the single crystal ingot 10 is formed.
It has been.

On the other hand, the lower region is a second cooling section 26 for storing and storing the liquid cooling medium, immersing the single crystal ingot 10 in the liquid cooling medium and cooling it. Is provided with a liquid cooling medium inlet 27 and a liquid cooling medium outlet 28 on the bottom wall surface, and are connected to a liquid cooling medium inlet pipe 29 and a liquid cooling medium outlet pipe 30, respectively. Further, a second discharge port 31 for discharging the liquid cooling medium overflowing from the cooling section 26 is provided in the container body side wall surface located at the upper end of the cooling section 26, and the liquid cooling medium discharge pipe is provided. It is connected to the road 30.

The opening 32 provided at the upper end of the cooling device 21 only needs to have a diameter larger than the diameter of the single crystal ingot 10 to be cooled. As shown in the embodiment shown in FIG. Although it may be in a state where the opening is always large, preferably, as shown in FIGS. 3 (a) and 3 (b), a closed lid type lid body 33 which forms a small opening in the center when closed is provided. Single crystal ingot 1
0, the lid 33 is closed, and the vapor of the liquid cooling medium generated in the cooling device 21 when the single crystal ingot 10 is cooled is dissipated from the opening 32 and enters the clean room. It is desirable to prevent adhesion to the pulling chamber 2b and the chuck 14 disposed above the cooling device 21. When the lid 33 is provided in this manner, the exhaust port 3 is provided on the side wall surface of the container body in the first cooling section 25 of the cooling device 21 as shown in FIG.
It is desirable to provide an exhaust pump 4 and exhaust the air in the cooling device 21 by an exhaust pump (not shown) or the like connected to the exhaust port 34. The size of the small opening formed at the center when the lid 33 is closed is sufficient as long as it does not interfere with the seed crystal 13.

Further, in the vicinity of the outer peripheral surface of the upper end portion of the cooling device 21, a structure capable of mounting or fitting the lower peripheral surface of the lowering chamber portion 2a may be provided. Is supported by the moving mechanism 18 and is separated and held above the cooling device 21.
A cooling operation may be performed. When the lid 33 is provided in the opening 32 as described above, such a mounting or fitting structure naturally does not interfere with the opening / closing operation of the lid 33.

The growth and cooling of the silicon single crystal according to the present invention are performed as follows using the single crystal manufacturing apparatus having the above-described configuration. First, a silicon single crystal ingot 10 is grown in the single crystal pulling apparatus 1 based on a conventional method. Briefly, first, a predetermined amount of a raw material such as polycrystalline silicon and an optional dopant is loaded into a quartz crucible 4 and heated by a heater 5 to melt the raw material and melt 9. Form.
Then, the seed crystal 12 attached to the tip of the pulling wire 14 is immersed in the melt 9, and the quartz crucible 4 and the seed crystal 12
Is pulled while rotating to grow a single crystal ingot 10 at the lower end of the seed crystal 12. When the single crystal ingot 10 has a predetermined length, the single crystal ingot 10 is separated from the melt, the single crystal ingot 10 is further moved upward, and the entire single crystal ingot 10 is housed in the pulling chamber 2b. .

During the above operation, the grown single crystal ingot 10 is cooled by an inert gas such as argon gas introduced into the chamber 2. In the present invention, the argon gas in such a chamber 2 is cooled. May be continued until the temperature of the single crystal ingot 10 reaches a predetermined temperature range higher than 350 ° C., but as soon as the entire single crystal ingot 10 is accommodated in the pulling chamber portion 2b, As described later, the cooling device 21
The cooling may be switched to the cooling in the above.

Immediately after the entire single crystal ingot 10 is accommodated in the pulling chamber 2b, or when the single crystal ingot 10 reaches a predetermined temperature range higher than 350 ° C., the gate valve 12 is closed and heating is performed. The internal space of the chamber 2a is closed. Next, the hydraulic moving mechanism 1
8 to move the arm 19 vertically upward,
The heating chamber section 2b connected to the arm 19 is raised from the first position, and the pulling chamber section 2b is separated from the heating chamber section 2a at the connection section 11. Further arm 19
Is pivoted in the horizontal direction, and moved to a position where the axis of the container body 22 of the cooling device 21 and the axis of the pull-up chamber 2b substantially coincide with each other. Then, the arm 19 is displaced vertically downward, and the pulling chamber 2b is lowered to a predetermined position (second position) above the cooling device 21.

When the pulling chamber 2b is located at the second position, the lid 33 of the cooling device 21 is opened, and the wire pulling device 16 provided at the upper part of the pulling chamber 2b is operated to send out the pulling wire 15. The single crystal ingot 10 is lowered to enter the cooling device 21. When the entire single crystal ingot 10 is accommodated in the first cooling section 25 of the cooling device 21 (the lid 33 is closed as shown in FIG. 3B), the valve 36 on the cooling medium pipe 23 is opened, and the nozzle is opened. From 24, a cooling medium is sprayed toward the single crystal ingot 10. The spray amount of the cooling medium is monitored by a flow meter 35 on the cooling medium pipe 23, and the result is fed back to adjust the opening degree of the valve 36 to a predetermined amount. The cooling medium sprayed from the valve 36 toward the single crystal ingot may be water, gas-liquid mist (for example, water) depending on the temperature of the single crystal ingot 10 and the cooling rate to be applied to the single crystal ingot 10. And air), argon gas, helium gas, nitrogen gas and the like. In addition, these used cooling media can be heated or cooled in advance according to the cooling rate to be applied. When using a gas-liquid mist as a cooling medium, as shown in FIG.
It is desirable that a first conduit 23a for supplying a liquid cooling medium such as water and a second conduit 23b for supplying a gas such as air are provided as cooling medium conduits communicating with the nozzles 24, respectively. When a gas-liquid mist is generated by using such a configuration, fine droplet mist can be formed as compared with a case where only a liquid such as water is sprayed, and stress concentration and cracks on the surface of the single crystal ingot 10 can be reduced. The occurrence can be avoided.

In the first cooling section 25, when the single crystal ingot 10 is to be cooled from about 600 ° C. to about 350 ° C., or in the temperature range from about 350 ° C. to normal temperature. In this case, in order to achieve the desired cooling rate as described above, it is desirable to use a spray flow, a gas-liquid mist, or the like using a liquid cooling medium such as water as the cooling medium.

When the temperature of the single crystal ingot 10 is lowered to a predetermined temperature range by the cooling in the first cooling section 25, the wire pulling device 16 is operated to send out the pulling wire 15, and the single crystal ingot 10 is further cooled. It is lowered, moved to the second cooling section 26, and immersed in the liquid cooling medium stored in the second cooling section 26. Note that, depending on the temperature when the single crystal ingot 10 is introduced into the cooling device 21 or the cooling condition to be applied, the cooling is not directly performed in the first cooling section 25 but directly to the second cooling section 26. The single crystal ingot 10 may be fed, and the first cooling section 2
It is also possible to cool the single crystal ingot 10 to room temperature with only 5, and in this case, it is not necessary to send the single crystal ingot 10 to the second cooling section 26.

As the liquid cooling medium used in the second cooling section 26, water, various oils and the like can be used, and these used cooling mediums are added in advance according to the cooling rate to be applied. It can be warm or cooled. If the liquid cooling medium is heated in advance, the thermal shock at the time of dipping the single crystal ingot 10 can be reduced.

The first cooling section 25 of the cooling device 21 and / or
Alternatively, when the temperature of the single crystal ingot 10 becomes normal temperature by cooling in the second cooling section 26, the wire pulling device 16 is operated to wind up the pulling wire 15, and the single crystal ingot 10 is taken out from the cooling device 21.

In the present invention, the grown single crystal ingot 10 is cooled by the above-described operation, and the first cooling section 25 and / or the second cooling section 25 of the cooling device 21 are cooled from the cooling in the single crystal pulling apparatus 1. The operation is sequentially switched to cooling in the cooling section 26. Since the appropriate cooling conditions vary depending on the diameter, type, etc. of the single crystal ingot to be grown, the switching time cannot be specified unconditionally. However, cooling at least in the temperature range from 350 ° C. to room temperature is performed by cooling. The cooling is performed in the first cooling section 25 and / or the second cooling section 26 of the apparatus 21, and the cooling rate is 5 to 200 ° C./min, more preferably 10 to 200 ° C./min.
１２０120 ° C. In other words, it is difficult to achieve a cooling rate of 5 to 200 ° C./min in the single crystal pulling apparatus 1 in such a temperature range, and the diameter and type of the silicon single crystal and the cooling rate in the higher temperature range are limited. Whatever the cooling in the temperature range from 350 ° C. to room temperature is less than 5 ° C./min,
This is because there is a high possibility that the density of OSF generated in the device process of the obtained silicon single crystal increases.
If the cooling rate exceeds 200 ° C./min,
Because of too rapid cooling, single crystal ingot 1
This is because there is a high possibility that a crack may occur in 0.

More preferably, the temperature is from 600 ° C. to 3 ° C.
Cooling in a temperature range up to 50 ° C. is performed in the first cooling section 25 and / or the second cooling section 26 of the cooling device 21, particularly in the first cooling section 25, and the cooling rate is 5 to 10 ° C.
It is desirable that the temperature is 0 ° C / min, more preferably 10 to 60 ° C. That is, in such a temperature range, 5 to 10
It is difficult to achieve a cooling rate of 0 ° C./min in the single crystal pulling apparatus 1, and if the cooling in the temperature range from 600 ° C. to 350 ° C. is less than 5 ° C./min,
This is because, in many silicon single crystals, aggregation of point defects and occurrence frequency of crystal defects are likely to increase due to an increase in the amount of donors generated. When the cooling rate is 100
If the temperature exceeds ℃ / min, the cooling is too rapid, and the single crystal ingot 10 is likely to be cracked.

As described above, when the cooling device 21 according to the present invention is used, the cooling by the spray flow of the cooling medium and the cooling by immersion in the liquid cooling medium can be optionally performed according to the diameter of the single crystal ingot 10 to be grown. You can use them properly,
In many cases, both cooling by the spray flow of the cooling medium in the first cooling section 25 and cooling by immersion in the liquid cooling medium in the second cooling section 26 are sequentially performed, and the first cooling section 25 rapidly cools to a certain temperature. It is desirable to perform cooling in a pattern in which cooling is performed to room temperature more rapidly by the second cooling section 26 thereafter.

However, the optimum cooling conditions for the single crystal ingot 10 grown as described above vary depending on the type, diameter and the like of the single crystal ingot 10. Therefore,
If the cooling rate at least in the temperature range from 350 ° C. to room temperature can be within the range of 5 to 200 ° C./min, the cooling rate is increased within the range only in a certain specific temperature range within this temperature range, or It is also possible to lower the cooling rate, or to set the cooling rate within the above range from a temperature higher than 350 ° C. In such a case, when the temperature of the single crystal ingot 10 reaches the predetermined temperature, for example, switching from cooling by the first cooling section 25 of the cooling device 21 to cooling by the second cooling section 26, or first cooling Fine adjustment is made by changing the spray amount of the cooling medium, the gas-liquid mixing ratio, etc. while the cooling in the section 25 is in progress, and changing the temperature of the liquid cooling medium while the cooling in the second cooling section is in progress. It can be a pattern.

Although the present invention has been described based on the structure of the single crystal manufacturing apparatus shown in the drawings, the structure of the single crystal pulling apparatus used in the present invention is not particularly limited. The device may have a configuration in which a known cylindrical cooling cylinder, an inverted conical cover, and the like are disposed inside. Also, as the cooling device, it is not always necessary to provide the second cooling section below the first cooling section. The first cooling section in which the spray flow of the cooling medium is sprayed on the silicon single crystal, and the liquid cooling in which the silicon single crystal is immersed The second cooling section containing the medium may be arranged in parallel, and each may have an opening independently.

[0037]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. Examples 1 to 6 and Comparative Examples 1 to 3 A silicon single crystal ingot 10 having a diameter of 6 inches and a length of a straight body of about 600 mm was pulled up using a single crystal manufacturing apparatus as shown in FIG. .

After growing the silicon single crystal ingot 10 having the desired length, cooling was performed immediately after pulling the single crystal ingot by the methods and speeds shown in Table 1, respectively.

The presence or absence of cracks in the ingot during the production of the single crystal and the OS generated in the obtained silicon single crystal
The F density was evaluated. Table 1 shows the results. The evaluation of the OSF density was performed by heating a silicon wafer cut from a single crystal ingot at 1100 ° C. for 1 hour in a wet oxygen gas, etching it, and observing it with a microscope.

[0040]

[Table 1]

As is clear from the results shown in Table 1, the silicon single crystals obtained in Examples 1 to 6 according to the present invention have very little OSF generation in the device process and have good quality. No cracking of the ingot occurred.

[0042]

As described above, according to the present invention, when a silicon single crystal is manufactured by pulling a silicon single crystal from a melt in a crucible, the silicon single crystal pulled from the melt is removed.
By setting the cooling rate in the temperature range from 50 ° C. to room temperature to be 5 ° C./min or more and 200 ° C./min or less, more desirably, the cooling rate in the temperature range from 600 ° C. to 350 ° C.
/ Min. To 100 ° C./min. And a cooling rate in the temperature range from 350 ° C. to room temperature of 5 ° C./min. To 200 ° C./min. Since a single crystal ingot can be obtained, and cooling during the production of the single crystal ingot is completed in a short time, the productivity is improved. Furthermore, it is grown by using a cooling device having a first cooling section for performing cooling by a spray flow of a cooling medium according to the present invention and a second cooling section for performing cooling by immersing in a liquid cooling medium. Whatever the diameter of the single crystal ingot, cooling can be performed at a predetermined cooling rate within the above range, eliminating fluctuations in heat history due to enlargement of the diameter of the single crystal ingot, and achieving desired quality. A silicon single crystal can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a configuration in a use state of an embodiment of a single crystal manufacturing apparatus used in a method for cooling a silicon single crystal of the present invention,

2 is a plan view of the device shown in FIG. 1,

3A is a plan view showing the configuration of another embodiment of the cooling device of the present invention, FIG. 3B is a cross-sectional view of a main part showing the upper structure of the cooling device in use,

FIG. 4 is a cross-sectional view of a main part schematically showing a piping configuration in still another embodiment of the present invention.

[Explanation of symbols]

1. Silicon single crystal pulling device, 2. Chamber, 2a ...
Heating chamber part, 2b ... Pulling chamber part, 3 ... Rotary shaft, 4 ... Quartz crucible, 5 ... Heater, 6 ... Heat insulating material, 7
... graphite crucible, 8 ... graphite saucer, 9 ... silicon melt, 1
0: Single crystal ingot, 11: Connection between heating chamber and pulling chamber, 12: Gate valve, 13: Seed crystal, 14: Chuck, 15: Pulling wire, 16: Wire pulling device, 17: Support, 18 … Hydraulic moving mechanism,
19 ... arm, 21 ... cooling device, 22 ... container, 23 ...
Cooling medium line, 23a ... first line, 23b ... second line,
Reference numeral 24: nozzle, 25: first cooling section, 26: second cooling section, 27: liquid cooling medium inlet, 28: liquid cooling medium outlet, 29: liquid cooling medium introduction pipe, 30: liquid cooling medium discharge pipe Road, 31 ... overflow outlet, 32 ... opening, 33 ... lid, 34 ... exhaust port, 35 ... flow meter, 36 ...
valve.

Continuation of the front page (56) References JP-A-3-208879 (JP, A) JP-A-57-205397 (JP, A) JP-A-58-120593 (JP, A) JP-A-5-306191 (JP) JP-A-5-221773 (JP, A) JP-A-5-155700 (JP, A) JP-A-4-160088 (JP, A) JP-A-64-37490 (JP, A) 1-3313384 (JP, A) JP-A-63-319293 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C30B 1/00-35/00 H01L 21/208

Claims (4)

(57) [Claims] When a silicon single crystal is pulled from a melt in a crucible to produce a silicon single crystal, a cooling rate of the silicon single crystal pulled from the melt in a temperature range from 350 ° C. to room temperature is 5 ° C. / A method for cooling a silicon single crystal, which is performed at a temperature of at least 200 ° C./min. 2. A silicon single crystal 60 drawn from a melt.
The method for cooling a silicon single crystal according to claim 1, wherein a cooling rate in a temperature range from 0 ° C to 350 ° C is 5 ° C / min or more and 100 ° C / min or less . 3. A cooling device for cooling a silicon single crystal pulled from a melt in a crucible, comprising: a first cooling section for blowing a gas-liquid mist as a cooling medium onto the silicon single crystal; A cooling device comprising: a second cooling section containing a liquid cooling medium to be immersed in the moving direction of the silicon single crystal. 4. The cooling device according to claim 3, wherein the first cooling section is provided above the second cooling section, and a single crystal pulling furnace for pulling a silicon single crystal from a melt in a crucible. An apparatus for producing a silicon single crystal, comprising:
The single crystal pulling furnace, a heating chamber containing a crucible for forming a melt, and a chamber provided above the heating chamber and comprising a pulling chamber with an upper end closed and separable from the heating chamber ; A linear body winder installed on an upper end surface of the pulling chamber unit and winding a single crystal pulling linear body hanging through the upper end surface of the pulling chamber unit into the chamber; A transfer mechanism for moving the pulling chamber from a first position located above the heating chamber to a second position located above the cooling device, and introducing the silicon single crystal into the cooling device; The movement from the first cooling section to the second cooling section in the apparatus is for pulling a single crystal for suspending and holding a silicon single crystal after disposing the pulling chamber portion to the second position. Apparatus for producing a silicon single crystal, characterized in that perform the Jo body turned out by the linear body winding device.