JP5805527B2 - Method for producing silicon single crystal - Google Patents

Description

  The present invention relates to a silicon single crystal manufacturing method for growing a silicon single crystal without performing a dash necking method by the Czochralski method.

A silicon wafer, which is a substrate material for forming a semiconductor device, grows a silicon single crystal by the Czochralski method (hereinafter also referred to as CZ method), and processes (polished) the silicon wafer obtained by slicing the silicon single crystal. Etc.) are manufactured. When the silicon single crystal is grown by the CZ method, thermal shock dislocation occurs in the seed crystal due to thermal shock generated when the seed crystal is brought into contact with a high-temperature silicon melt.
Therefore, in order to remove the generated dislocations, a dash necking method in which a diameter of a crystal grown below the seed crystal is once reduced to about 3 to 5 mm to form a neck portion having a length of about 200 mm is generally used. Are known.

  However, the dash necking method decreases in productivity, and in recent years, a large diameter for obtaining a silicon wafer having a large diameter (for example, a diameter of 300 mm or more) with high integration of semiconductor devices, cost reduction, and improvement in production efficiency. It is required to grow a silicon single crystal with a straight body part. The neck part with a small diameter as in the conventional case breaks without being able to withstand the high weight of the silicon single crystal, and the silicon single crystal falls into the silicon melt. However, there was a risk of major accidents such as leaking water.

  In order to solve the above problems, Patent Document 1 uses a single crystal pulling seed crystal having a cylindrical body and a conical tip, and melting the tip of the single crystal pulling seed crystal. A single crystal pulling method is disclosed in which a single crystal is pulled without forming a neck portion after being immersed and dissolved in a liquid.

  Patent Document 2 discloses a method for producing a silicon single crystal by the Czochralski method in which a seed crystal is brought into contact with a silicon melt and then slowly pulled up while being rotated to grow a silicon single crystal rod. Using a seed crystal whose tip is in contact with the silicon melt of the seed crystal or having a pointed shape or a shape in which the sharp tip is cut off, first contact the tip of the seed crystal with the silicon melt. After that, the seed crystal is melted by lowering the seed crystal at a low speed until the tip of the seed crystal reaches a desired thickness, and then the seed crystal is slowly lifted up to a desired diameter without performing necking. A method for producing a silicon single crystal for growing a silicon single crystal rod is disclosed.

  Further, in Patent Document 3, a seed crystal having a tip angle of 28 ° or less is used, the temperature fluctuation of the silicon melt surface is kept at ± 5 ° C. or less, and a silicon single crystal using a dash necking method is used. The seed crystal is brought into contact with the silicon melt and submerged at a silicon melt temperature that is 10 to 20 ° C. higher than the temperature suitable for contacting the seed crystal with the silicon melt in the production method. At least the seed crystal In the formation of the diameter-reduced portion immediately after the start of the lowering of the crystal and the start of the pulling up, the crystal diameter formed under the seed crystal begins to grow, and the silicon single crystal with a pulling speed of 0.5 mm / min or less is manufactured. A method is disclosed.

JP-A-9-235186 Japanese Patent Laid-Open No. 10-203898 International Publication No. 2003/91483 Pamphlet

  However, since the generation mechanism of heat shock dislocation when the seed crystal is immersed in the silicon melt is complicated, even when the methods disclosed in Patent Documents 1 to 3 are used, the heat shock is not performed without performing the dash necking method. There was a limit to suppressing dislocations.

  The present invention has been made in view of the above-mentioned circumstances, suppresses the occurrence of heat shock dislocation when the seed crystal is brought into contact with the silicon melt, and is immersed, and performs no dislocation without performing a dash necking method. An object of the present invention is to provide a method for producing a silicon single crystal that can increase the probability of obtaining a single crystal of silicon.

A method for producing a silicon single crystal according to the present invention is a method for producing a silicon single crystal by growing a silicon single crystal by the Czochralski method, which extends from a cylindrical cylindrical portion and one end of the cylindrical portion, and And using a seed crystal comprising a conical portion having a small diameter and a sharp tip or a chamfered sharp tip, and before contacting the tip of the conical portion with the silicon melt, the surface of the silicon melt from after preheating at the following positions above 10 mm, the tip of the conical portion is brought into contact with the silicon melt, and a portion in contact with the silicon melt of the seed crystal is melted without immersed in the silicon melt And immersing the seed crystal to a predetermined position while forming a melt phase having a diameter smaller than the diameter of the solid phase between the solid phase as the seed crystal portion and the silicon melt, and then pulling it up Flip, characterized in that the silicon single crystal is grown without performing dash necking method.

  The melt phase is formed by controlling at least the temperature of the silicon melt, the contact speed when the tip of the conical portion is brought into contact with the silicon melt, and the immersion speed when the seed crystal is immersed to a predetermined position. Preferably it is done.

  According to the present invention, after the seed crystal is brought into contact with the silicon melt, the occurrence of heat shock dislocation during immersion is suppressed, and the probability of obtaining a dislocation-free silicon single crystal without performing the dash necking method is increased. A method for producing a silicon single crystal is provided.

It is an expansion conceptual diagram which shows the silicon melt vicinity in each step for demonstrating the manufacturing method of the silicon single crystal concerning embodiment of this invention concretely. It is a conceptual perspective view which shows the specific aspect of the seed crystal 50 shown in FIG. FIG. 1 is an enlarged conceptual diagram showing a state in the vicinity of the seed crystal 50 when the tip 50b of the seed crystal 50 is brought into contact with the silicon melt 16 and then immersed to a predetermined position. It is an expansion conceptual diagram which shows the generation | occurrence | production state of the heat shock dislocation at the time of contact with the silicon melt 16 in the case of using the seed crystal which does not have the cone part 50c as shown to Fig.1 (a). It is an expansion conceptual diagram which shows the state at the time of immersion of the seed crystal 50 in the case of immersing without forming the melt phase Lp as shown in FIG. 3, and the generation | occurrence | production state of a heat shock dislocation. 1 is a conceptual sectional view showing an example of a silicon single crystal pulling apparatus to which a method for producing a silicon single crystal according to the present invention is applied. It is an expansion conceptual diagram which shows the state at the time of the immersion of the seed crystal 50 when the temperature of the silicon melt 16 is too high.

  As a result of intensive studies on the generation mechanism of the heat shock dislocation of the seed crystal, the present inventors immerse the seed crystal in the silicon melt in addition to the heat shock dislocation generated when the seed crystal is brought into contact with the silicon melt. Depending on the contact state between the seed crystal and the silicon melt, heat shock dislocation was newly generated, and the present invention was completed.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is an enlarged conceptual diagram showing the vicinity of a silicon melt in each step for specifically explaining a method for producing a silicon single crystal according to an embodiment of the present invention. FIG. 2 is a conceptual perspective view showing a specific embodiment of the seed crystal 50 shown in FIG.

A method for producing a silicon single crystal according to an embodiment of the present invention is a method for producing a silicon single crystal by growing a silicon single crystal by a CZ method, and extends from a cylindrical cylindrical portion 50a and one end of the cylindrical portion 50a. A seed crystal 50 having a diameter smaller than that of the cylindrical portion 50a and having a sharp tip 50b or a conical portion 50c having a sharp tip 50b is disposed on the silicon melt 16 (FIG. 1A). ).
Next, the seed crystal 50 is lowered, and the tip 50b of the conical part 50c is brought into contact with the liquid surface of the silicon melt 16 at a predetermined contact speed (FIG. 1 (b)). Thereafter, the seed crystal 50 is immersed in the silicon melt 16 to a predetermined position at a predetermined immersion speed. The predetermined position is when holding a heavy silicon single crystal (for example, a silicon single crystal having a straight body having a diameter of 300 mm or more) at a position where the seed crystal 50 is immersed and then pulled up. What is necessary is just to provide the diameter (preferably 6 mm or more) which has the intensity | strength of the grade which does not fracture | rupture. That is, the predetermined position may be the conical portion 50c (FIG. 1 (c)) or the cylindrical portion 50a (FIG. 1 (d)) as long as it has a diameter having the strength. . Hereinafter, in this embodiment, it demonstrates by the aspect (mode performed to FIG.1 (d)) immersed to the cylindrical part 50a.

FIG. 3 is an enlarged conceptual diagram showing a state in the vicinity of the seed crystal 50 when the tip 50b of the seed crystal 50 in FIG. 1 is brought into contact with the silicon melt 16 and then immersed to a predetermined position.
After the tip 50b of the conical portion 50c of the seed crystal 50 is brought into contact with the silicon melt 16, until the seed crystal 50 is immersed to a predetermined position, as shown in FIG. The portion in contact with the silicon melt 16 is melted without being immersed in the silicon melt 16, and the solid phase Sp 1 is between the solid phase Sp 1 as the seed crystal 50 portion and the silicon melt 16. It is carried out while forming a melt phase Lp having a minimum diameter H2 that is smaller than the diameter H1.

  Finally, after immersing the seed crystal 50 to a predetermined position, the diameter is increased and the desired diameter (for example, 310 mm) is expanded without performing the dash necking method, and the desired diameter is maintained. A silicon single crystal Ig (not shown except for the enlarged diameter portion) having a straight body portion and a reduced diameter portion that is reduced from the desired diameter is grown (FIG. 1 (e)). At this time, a solid phase Sp2 having a minimum diameter H2 smaller than the diameter H1 of the solid phase Sp1 solidified by the molten phase Lp formed during the immersion is formed at the lower end of the seed crystal 50.

  In the method for producing a silicon single crystal according to the present invention, as described above, in order to immerse the seed crystal 50 to a predetermined position while forming the melting phase Lp, the seed crystal is brought into contact with the silicon melt and then immersed. It is possible to suppress the occurrence of heat shock dislocation during the process. Therefore, the probability of obtaining a dislocation-free silicon single crystal without performing the dash necking method can be increased.

FIG. 4 is an enlarged conceptual diagram showing a state of occurrence of heat shock dislocation at the time of contact with the silicon melt 16 in the case of using a seed crystal that does not include the conical portion 50c as shown in FIG.
As shown in FIG. 4, a seed crystal 50A that does not have a conical portion 50c as shown in FIG. 1A (for example, a seed crystal of only the cylindrical portion 50a or a diameter smaller than that of the cylindrical portion 50a, but the tip 50c). When using a seed crystal having a conical portion (50Ac as shown in FIG. 4) (which is the latter in FIG. 4) having a pointed or chamfered shape, the seed crystal 50A and the silicon melt 16 Since the contact area increases, the heat shock dislocation 30 tends to occur in the seed crystal 50A.

FIG. 5 is an enlarged conceptual diagram showing a state when the seed crystal 50 is immersed and a state of occurrence of heat shock dislocation in the case where the seed crystal 50 is immersed without forming the melting phase Lp as shown in FIG.
As shown in FIG. 5, in the case of dipping without forming the melt phase Lp as shown in FIG. 3, the silicon melt 16 causes the side surface α of the seed crystal 50 by the force PP that pushes the seed crystal 50 into the silicon melt 16. It is thought that it will crawl up (Fig. 5 (a)). As a result, the temperature distribution in the radial direction at the side surface α portion of the seed crystal 50 where the silicon melt 16 has risen becomes non-uniform, so that when the seed crystal 50 is immersed, the heat shock dislocation 30 is generated particularly from the side surface α side. This is considered to be easier (FIG. 5B).

FIG. 6 is a conceptual cross-sectional view showing an example of a silicon single crystal pulling apparatus to which the method for producing a silicon single crystal according to the present invention is applied.
A silicon single crystal pulling apparatus 10 to which the method for producing a silicon single crystal according to the present invention is applied is arranged in a furnace body 12 and a furnace body 12 as shown in FIG. A crucible 14 that holds silicon), a heater 18 that is provided on the outer periphery of the crucible 14, heats the crucible 14, and melts the silicon raw material held in the crucible 14 to form a silicon melt 16; A cylindrical heat shield 20 is provided which is disposed above 16 and shields radiant heat to the silicon single crystal Ig (not shown) pulled from the silicon melt 16 by the CZ method.

The crucible 14 includes a quartz crucible 14a that holds the silicon melt 16 and a carbon crucible 14b that accommodates the quartz crucible 14a.
A first heat retaining member 22 is provided on the outer periphery of the heater 18, and a second heat retaining member 24 is provided above the first heat retaining member 22 with a certain distance from the heater 18.
Above the heat shield 20, it passes between the inner periphery of the heat shield 20, between the heat shield 20 and the silicon melt 16, and from the discharge port 26 located below the crucible 14 to the outside of the furnace body 12. A carrier gas supply port 28 for supplying the discharged carrier gas G1 is provided.
Above the crucible 14 is provided a pulling wire 34 to which a seed chuck 32 for holding a seed crystal 50 used for growing a silicon single crystal Ig (not shown) is attached. The pulling wire 34 is attached to a wire rotating / lifting mechanism 36 provided outside the furnace body 12 and capable of rotating and lifting.

The crucible 14 passes through the bottom of the furnace body 12 and is attached to a crucible rotating shaft 40 that can be rotated up and down by a crucible rotation lifting mechanism 38 provided outside the furnace body 12.
The heat shield 20 is held above the crucible 14 via a heat shield support member 42 attached to the upper surface of the second heat retaining member 24.
A carrier gas supply unit 44 that supplies a carrier gas G <b> 1 into the furnace body 12 is connected to the carrier gas supply port 28 via a mass flow controller 43. A carrier gas discharge part 48 that discharges the carrier gas G1 that passes between the heat shield 20 and the silicon melt 16 is connected to the discharge port 26 via a butterfly valve 46. Has been. By adjusting the mass flow controller 43, the supply amount of the carrier gas G1 supplied into the furnace body 12 is adjusted. The exhaust gas discharged from the furnace body 12 by adjusting the butterfly valve 46 (from the carrier gas G1 and the silicon melt 16). The amount of generated SiOx gas etc. is also controlled.

  When the seed crystal 50 is immersed, the molten phase Lp is formed by using the imaging means 60 such as a CCD camera from the monitoring window 12A provided in the furnace body 12 to form the contact interface between the seed crystal 50 and the silicon melt 16. It is preferable to carry out monitoring. This is preferable because it can always be confirmed whether or not the melt phase Lp is formed when the seed crystal 50 is immersed.

Next, an example of a method for manufacturing a silicon single crystal using the silicon single crystal pulling apparatus 10 as shown in FIG. 6 will be described.
First, a silicon raw material (for example, 350 kg) is loaded into the crucible 14, a carrier gas G 1 (preferably argon gas) is supplied into the furnace body 12 from the carrier gas supply unit 44, and further, the crucible 14 is heated by the heater 18. The silicon raw material held in 14 is melted to obtain a silicon melt 16.
Next, the wire rotation elevating mechanism 36 and the crucible rotation elevating mechanism 38 are operated to rotate the crucible 14 and lower the seed crystal 50 held by the seed chuck 32 while rotating it in the direction opposite to the crucible 14.
Next, while rotating the seed crystal 50, the tip 50b is brought into contact with the silicon melt 16, and as described above, the seed crystal 50 is immersed to a predetermined position while forming the melt phase Lp. Thereafter, the silicon single crystal Ig is grown without pulling up and performing the dash necking method.

The melt phase Lp is formed by at least the temperature of the silicon melt 16, the contact speed when the tip 50b of the conical portion 50c is brought into contact with the silicon melt 16, and the immersion when the seed crystal 50 is immersed to a predetermined position. It is preferable to control each speed.
That is, by controlling the temperature of the silicon melt 16, it is possible to form the melt phase Lp as shown in FIG. Further, by controlling the contact speed, it is possible to suppress the occurrence of heat shock dislocation when the seed crystal 50 is in contact with the silicon melt 16. Furthermore, by controlling the immersion rate, it is possible to suppress the creeping of the silicon melt 16 to the side surface α of the seed crystal 50 as shown in FIG.
The “temperature of the silicon melt” here refers to the outer periphery from the contact interface between the seed crystal 50 and the silicon melt 16 when the surface of the silicon melt 16 is measured by thermography (not shown in FIG. 6). It is the maximum temperature of the liquid surface of the silicon melt 16 within 10 mm in the direction.

  The temperature of the silicon melt 16 can be controlled by controlling the output of the heater 18. The contact speed and the dipping speed can be controlled by controlling the lowering speed of the pulling wire 34 by the wire rotation lifting mechanism 36.

When the temperature of the silicon melt 16 is too low, the viscosity of the silicon melt 16 increases (is easy to solidify), so that the silicon melt 16 is formed of the seed crystal 50 as shown in FIG. There is a case where heat shock dislocation is likely to occur due to easy climbing to the side surface α.
FIG. 7 is an enlarged conceptual diagram showing a state when the seed crystal 50 is immersed when the temperature of the silicon melt 16 is too high.
When the temperature of the silicon melt is too high, the viscosity of the silicon melt 16 becomes small, so that the minimum diameter of the melt phase Lp becomes small as shown in FIG. May be easy to tear.

If the contact speed is too slow, productivity may be reduced. When the contact speed is too high, heat shock dislocation may occur when the seed crystal 50 contacts.
When the immersion rate is too slow, productivity may be reduced, and the diameter of the melt phase Lp may be reduced as shown in FIG. 7, and the crystal may be easily broken when the seed crystal 50 is immersed. When the immersion speed is too high, as shown in FIG. 5 (a), the silicon melt 16 tends to creep up to the side surface α of the seed crystal 50, and heat shock dislocation is likely to occur.

  Therefore, the control specifically includes a temperature of the silicon melt of 1418 ° C. or higher and 1428 ° C. or lower, the contact speed of 1 mm / min or higher and 10 mm / min or lower, and the immersion speed of 2 mm / min or higher and 10 mm / min or lower. It is preferable that

The seed crystal 50 is preheated at a position 10 mm or less above the liquid surface of the silicon melt 16 (preferably a position of 3 mm or more and 10 mm or less) before bringing the tip 50 b of the conical part 50 c into contact with the silicon melt 16. It is preferable to make it.
By doing in this way, generation | occurrence | production of the heat shock dislocation which generate | occur | produces when the front-end | tip 50b of the said seed crystal 50 is made to contact can be suppressed more.
The time for preheating the seed crystal 50 is not particularly limited, but is preferably 3 minutes or more and 1 hour or less in terms of productivity.

The rotation speed of the seed crystal 50, the rotation speed of the crucible 14, the supply amount of the carrier gas G1 supplied into the furnace body 12, and the furnace pressure when the seed crystal 50 is brought into contact with the silicon melt 16 and immersed to a predetermined position. Although there is no particular limitation, it is preferable to carry out the setting under conditions that do not interfere with the formation of the melt phase Lp.
For example, the rotation speed of the seed crystal 50 is 5 rpm to 30 rpm, the rotation speed of the crucible 14 is 0.5 rpm to 15 rpm, and the supply amount of the carrier gas G1 is 30 L / min. The pressure is 150 L / min or less, and the furnace pressure is 20 mbar or more and 100 mbar or less.

The minimum diameter (H2 in FIG. 3) of the melt phase Lp is preferably controlled to 6 mm or more.
By adopting such a diameter, even when holding a heavy silicon single crystal (for example, a silicon single crystal having a straight body having a diameter of 300 mm or more), it is possible to obtain a strength that does not break. it can.
The minimum diameter H2 is more preferably 8 mm or more.

EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limitedly interpreted by the following Example.
(Example 1)
Using a silicon single crystal pulling apparatus 10 as shown in FIG. 6, a silicon raw material was filled in a quartz glass crucible 14 a having a diameter of 32 inches and dissolved by a heater 18 to obtain a silicon melt 16. Next, the diameter (H1 in FIG. 2) of the cylindrical portion 50a is 12.5 mm, the length (D1 in FIG. 2) is 100 mm, the length of the conical portion 50c (D2 in FIG. 2) is 51 mm, and the conical portion. As shown in FIG. 1A, using the seed crystal 50 in which the angle (θ in FIG. 2) of the sharp tip 50b of 50c is 14 °, a position 5 mm high from the liquid surface of the silicon melt 16 Then, the seed crystal 50 was preheated for 30 minutes, and then the tip 50b of the seed crystal 50 was brought into contact with the silicon melt 16 as shown in FIG. Next, the seed crystal 50 is dipped to the position of the cylindrical portion 50a (position shown in FIG. 1 (d)), and then the diameter is increased to 310 mm without turning to pulling and performing the dash necking method. A silicon single crystal having a straight body portion having a length of 1800 mm was grown while forming a portion (crown portion) and maintaining the diameter at 310 mm.

  When the seed crystal 50 is brought into contact with the silicon melt 16, the temperature and contact speed of the silicon melt 16 are adjusted, and when the seed crystal 50 is immersed in the silicon melt 16, the imaging means 60 is used. While monitoring the contact interface between the seed crystal 50 and the silicon melt 16 and adjusting the temperature and immersion speed of the silicon melt 16, the portion of the seed crystal 50 in contact with the silicon melt 16 is adjusted to the silicon melt 16. As shown in FIG. 3, a melt phase Lp having a diameter smaller than the diameter of the solid phase Sp1 is interposed between the solid phase Sp1 and the silicon melt 16 as the seed crystal 50 portion. While forming. In addition, the immersion speed was controlled so that the minimum diameter (H2 in FIG. 3) of the melt phase Lp at this time was 8 mm.

The specific manufacturing conditions of Example 1 are as follows.
-Silicon melt temperature: 1418 ° C
・ Contact speed: 6mm / min
・ Immersion speed: After gradually decreasing from 6 mm / min to a range of 2 mm / min to 3 mm / min, adjustment is made within the range. ・ Carrier gas G1: Argon gas ・ Supply amount of carrier gas G1: 50 L / min
-Furnace pressure: 90-100mbar
・ Rotation speed of seed crystal: 10 rpm
・ Crucible rotation speed: 5rpm
-Rotation direction of seed crystal and crucible: reverse direction-Pulling speed of seed crystal 50 at the enlarged diameter portion (crown portion): 1.0 mm / min to 1.5 mm / min

(Example 2)
A silicon single crystal was grown under the same conditions as in Example 1 except that the temperature of the silicon melt 16 was 1420 ° C.

(Example 3)
A silicon single crystal was grown under the same conditions as in Example 1 except that the temperature of the silicon melt 16 was 1422 ° C.

Example 4
A silicon single crystal was grown under the same conditions as in Example 1 except that the temperature of the silicon melt 16 was 1424 ° C.

(Example 5)
A silicon single crystal was grown under the same conditions as in Example 1 except that the temperature of the silicon melt 16 was 1426 ° C.

(Example 6)
A silicon single crystal was grown under the same conditions as in Example 1 except that the temperature of the silicon melt 16 was 1428 ° C.

(Comparative Example 1)
By increasing the immersion speed (by making the contact speed 6 mm / min, which is the same as the contact speed), the seed crystal 50 is immersed in the state shown in FIG. A silicon single crystal was grown under the same conditions.

(Comparative Example 2)
By setting the temperature of the silicon melt 16 to 1414 ° C., the state when the seed crystal 50 is immersed is changed to a state as shown in FIG. Single crystals were grown.

Next, the straight body part of each silicon single crystal grown in Examples 1 to 6 and Comparative Examples 1 and 2 is sliced in parallel to the growth direction (long axis direction), and the sliced cut surface The occurrence of slip dislocation was evaluated using an X-ray topograph.
As a result, no dislocation was observed in all the silicon single crystals obtained in Examples 1 to 6. On the other hand, in the silicon single crystals obtained in Comparative Examples 1 and 2, the occurrence of slip dislocations was observed on almost the entire sliced cut surface.

(Comparative Example 3)
A silicon single crystal was grown under the same conditions as in Example 1 except that the temperature of the silicon melt 16 was 1430 ° C.
As a result, when the seed crystal 50 is immersed, the molten layer Lp is in a state as shown in FIG. 7 (the minimum diameter H2 is less than 2 mm), and the seed crystal 50 and the silicon melt 16 are torn off during the immersion. Was confirmed.

16 Silicon melt 50 Seed crystal 50a Cylindrical portion 50b Conical portion 50c Tip Sp1 Solid phase Sp2 Solid phase Lp Liquid phase

Claims (2)

A silicon single crystal manufacturing method for growing a silicon single crystal by the Czochralski method,
Using a seed crystal comprising a cylindrical cylindrical portion and a conical portion extending from one end of the cylindrical portion and having a diameter reduced from the cylindrical portion and having a sharp tip or a chamfered sharp tip, the tip of the conical portion the prior to contacting with the silicon melt, after preheated at a following position above 10mm from the surface of the silicon melt, the tip of the conical portion is brought into contact with the silicon melt, the silicon melt of the seed crystal A portion in contact with the liquid is melted without being immersed in the silicon melt, and a melt phase having a diameter smaller than the diameter of the solid phase is formed between the solid phase as the seed crystal portion and the silicon melt. A method for producing a silicon single crystal comprising immersing the seed crystal to a predetermined position and then growing the silicon single crystal without performing a dash necking method.   The melt phase is formed by controlling at least the temperature of the silicon melt, the contact speed when the tip of the conical portion is brought into contact with the silicon melt, and the immersion speed when the seed crystal is immersed to a predetermined position. The method for producing a silicon single crystal according to claim 1, wherein the method is performed.

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