JP4857920B2 - Method for producing silicon single crystal - Google Patents

Description

  The present invention relates to a method for producing a silicon single crystal by the Czochralski method (hereinafter referred to as “CZ method”) or by the MCZ method (Magnetic field applied Czochral crystal growth method) in which a magnetic field is applied to a pulling apparatus of the CZ method. Specifically, following the dipping process in which the seed crystal is immersed in the melt, the improvement in the neck process for forming the neck part shortens the formation length of the neck part necessary for non-dislocation and improves the crystal quality. The present invention relates to a method for producing a silicon single crystal that can be achieved.

  Usually, in a single crystal manufacturing apparatus used for the CZ method, an inert gas (Ar) gas is flowed by reducing the pressure in a high pressure-tight airtight chamber to about 10 torr, and a crystal raw material in a crucible provided below the chamber The seed crystal is immersed in the surface of the melt from above, the crucible containing the seed crystal and the melt is rotated, and the seed crystal is pulled up while moving up and down, so that a conical shoulder is formed below the seed crystal. A silicon single crystal comprising a portion, a cylindrical body portion, and a conical tail portion protruding from the lower end is grown.

  In this growth method, in the initial stage of pulling, after the dipping process of immersing the seed crystal in the melt, a neck process of pulling up the seed crystal to form a neck portion is performed.

  FIG. 1 is a partially enlarged view schematically showing a dip process, a neck process, and a shoulder part forming process performed in the initial pulling stage of the CZ method, (a) is a dip process, (b) is a neck process, And (c) has shown the process of shoulder part formation.

  In the dipping process shown in FIG. 1A, the seed crystal 1 is lowered while being rotated, and the tip thereof is immersed in the surface of the melt 2. After dipping the tip of the seed crystal 1, the descent of the seed crystal 1 is stopped and the melt 2 is sufficiently blended.

  Usually, when the seed crystal 1 is brought into contact with the melt 2, a meniscus is formed at the contact interface due to the surface tension of the melt 2. However, the temperature of the melt immediately after melting the crystal raw material has a large local temperature fluctuation, and the temperature of the melt as a whole greatly varies and becomes unstable.

  For this reason, the dip process is carried out after the crystal raw material has been melted and a predetermined time has elapsed. If the surface temperature of the melt when the seed crystal 1 is brought into contact with the melt 2 is too high, the seed crystal 1 is melted and separated from the melt 2. On the other hand, if the melt surface temperature is too low, the crystal grows from the tip of the seed crystal 1 and the crystal protrudes on the surface side of the melt 2. When shifting to the step (b), a new dislocation is generated in the neck portion.

  For this reason, when shifting from the dipping step (a) to the neck step (b), it is necessary that the temperature of the melt is stabilized, and the tip of the seed crystal 1 is placed on the surface of the melt 2. It is immersed and sufficiently blended with the melt 2 to confirm that the melt temperature has been stabilized, and then transferred.

  Therefore, “familiarization” means that the melt surface temperature is estimated by observing the shape of the contact interface when the seed crystal 1 is brought into contact with the melt 2, and the heater power is controlled based on this to melt the melt. The amount of heat input to the liquid 2 is adjusted. In other words, “familiarization” means adjusting the heater power so that a meniscus 3 having a predetermined shape is formed around the tip of the seed crystal 1 when the growth rate of the seed crystal 1 is 0 (zero). Then, the melt surface temperature is adjusted and stabilized. The meniscus 3 is not formed only at the time of acclimatization, but is also formed at the interface between the crystal and the melt at the time of crystal growth such as a neck process following the acclimatization.

  The neck step shown in FIG. 1B is a process for obtaining a dislocation-free single crystal. By pulling the seed crystal 1 upward at a high speed while rotating the seed crystal 1, the melt 2 is added to the tip of the seed crystal 1. The neck portion 4 is formed in which the diameter of the substantially cylindrical portion is made as thin as possible. Although the required diameter varies depending on the thermal environment of the manufacturing apparatus, the dislocation can be removed by forming the neck portion 4 having a crystal diameter reduced to about 3 to 6 mm. This method is called the dash method (or dash neck method).

  In the step of forming the shoulder portion 5 shown in FIG. 1C, the pulling speed of the seed crystal 1 is reduced, and the diameter of the neck portion 4 is grown to the diameter of the body portion to form the shoulder portion 5. Further, through the formation process of the body part following the formation of the shoulder part 5, the single crystal is pulled up to the formation of the tail part.

  In this dash method, in order to pull up the single crystal with a thin diameter, it is easily affected by the thermal environment in the manufacturing apparatus, and it is not possible to control the growth conditions such as the pulling speed to the rapid fluctuation of the melt temperature, There are cases where troubles such as fracture of the neck portion occur or dislocation-free cannot be achieved. For this reason, various methods for producing silicon single crystals have been proposed.

  For example, in Patent Document 1, when pulling up the seed crystal, the length of the tapered narrowed portion that follows the seed crystal is kept 2.5 to 15 times the thickness of the seed crystal, The diameter of the long, substantially cylindrical aperture is 0.09 to 0.9 times the thickness of the seed crystal, and the variation of the aperture diameter is 1 mm or less. A method of pulling up while maintaining the thickness in the range of 200 mm to 600 mm is proposed.

  However, the method proposed in Patent Document 1 responds to the demand for larger diameter and higher weight of the silicon single crystal. In order to suppress the risk of crystal falling due to fracture of the neck portion, the diameter of the neck portion is reduced. It is possible to make dislocation-free even if the thickness is increased. Therefore, in the manufacturing method of Patent Document 1, since it is necessary to secure a length for forming the neck portion from the seed crystal portion to the lower end of the neck portion, it is necessary to take a long time to form the neck portion. Become. Furthermore, there is a problem that the body portion of the single crystal cannot be secured sufficiently due to the length of the neck portion.

Japanese Patent No. 2822904

  As described above, in the dash method, since the single crystal is pulled up with a small diameter, if the fluctuation of the melt temperature is large in the neck process, it is difficult to properly control the pulling speed against the sudden fluctuation, and the neck part is separated. May cause trouble. For this reason, in order to form a neck part stably, it is necessary to suppress the fluctuation | variation of the melt temperature in a neck process.

  When the amount of the melt increases with the increase in the size of the production apparatus, natural convection is strongly generated in the melt in the crucible, and the fluctuation of the melt temperature in the neck process becomes more remarkable. In order to suppress the fluctuation of the melt temperature, for example, a method of suppressing a convection of the melt by applying a magnetic field such as a transverse magnetic field to the melt is effective. That is, by applying a transverse magnetic field to the melt, natural convection can be suppressed, fluctuations in the melt temperature can be suppressed, and the neck portion can be formed stably.

  However, when a transverse magnetic field is applied to the melt in the crucible, the cause is not clarified, but it becomes difficult to eliminate dislocation in the neck process, and a neck portion is formed in order to achieve dislocation elimination. It is necessary to make the length to be longer than when no magnetic field is applied.

  The pull chamber that constitutes the manufacturing apparatus has a finite length for housing the pulled single crystal. Therefore, when the neck portion is formed longer than a predetermined length, the pulled single crystal cannot be stored. It will be. Also, from the viewpoint of production efficiency, there is a need to lengthen the single crystal to be pulled up in order to increase the number of product wafers per single crystal, but if the neck portion is formed longer, the length of the single crystal will increase. There is a problem that a restriction occurs.

  The present invention has been made in view of such a situation, and when pulling up a silicon single crystal, the neck portion is formed after the seed crystal is sufficiently blended in a dipping process in which the seed crystal is immersed in the melt. A method for manufacturing a silicon single crystal that can improve the crystal quality while reducing the formation length of the neck portion necessary for dislocation-free, regardless of the CZ method or the MCZ method, by improving the neck process The purpose is to provide.

  As a result of various studies to solve the above problems, the present inventors have made dislocation-free in the dash method shown in FIG. 1 when the seed crystal cannot be sufficiently adapted to the melt. Focused on the difficulty. As a result, regardless of the CZ method or the MCZ method, the seed crystal is adapted to the melt in the dipping process, the neck part having a predetermined length is formed in the neck process, and then the formed neck part is adapted to the melt again. Thus, it has been found that by continuously forming the neck portion, it is possible to shorten the neck length necessary for non-dislocation and improve the non-dislocation rate.

The present invention has been completed on the basis of the above findings, and the gist thereof is the following method for producing a silicon single crystal.
(1) After the crystal raw material in the crucible is melted by the CZ method, the seed crystal is immersed in a melt held in the crucible and the seed crystal is adapted at the dip temperature. In the single crystal manufacturing method for forming the shoulder portion and the body portion of the single crystal after the neck step to be formed, after the neck portion is formed to have a length of 20 mm or more in the neck step, the neck portion is heated to a dip temperature. Is a method for producing a silicon single crystal, wherein the neck portion is formed by acclimating the substrate to a melt and subsequently lowering the temperature to a temperature suitable for neck formation .
(2) Melt the crystal raw material in the crucible by MCZ method, soak the seed crystal in the melt held in the crucible and let the seed crystal adapt at the dip temperature, then pull up the seed crystal to form the neck part In the single crystal manufacturing method for forming the shoulder portion and the body portion of the single crystal after the neck step, the neck portion is formed to have a length of 20 mm or more in the neck step, and then the neck portion is heated to a dip temperature. It is a method for producing a silicon single crystal, which is characterized in that the neck portion is formed by adjusting to a melt and subsequently lowering the temperature to a temperature suitable for neck formation .

When the MCZ method is applied, it is desirable that the transverse magnetic field applied to the melt is in the range of 2000 to 4000 G.
(3) In the method for producing a silicon single crystal of (1) and (2) above, it is desirable that the length of the neck portion formed first in the neck step is 20 mm or more. Further, in the neck step, it is preferable that the neck portion is adapted to the melt after being raised to a temperature higher than the melt temperature when the neck portion is formed. Furthermore, it is desirable to measure the heater temperature for melting the crystal material in the crucible and to control the heater temperature based on the temperature measurement result to adjust the melt temperature.

  In the present invention, “seeding of the seed crystal” and “fitting of the neck portion” are performed by observing the meniscus shape of the contact interface when the crystal is brought into contact with the molten liquid, for example, by observing the protrusion of the habit line. This is an operation of estimating the temperature of the liquid surface, controlling the heater power (electric power) based on this, adjusting the amount of heat input to the melt, and stabilizing the temperature of the melt surface.

  According to the method for producing a silicon single crystal of the present invention, when the silicon single crystal is pulled, it is necessary for dislocation-free by performing a dip process of “seed crystal fitting” and “neck fitting” twice. As a result, the formation length of the neck portion can be shortened, and the crystal quality can be improved by increasing the dislocation-free rate. As a result, the manufacturing cost can be greatly reduced, and it can be widely applied as an efficient dash method regardless of the CZ method or the MCZ method.

  FIG. 2 is a flowchart for explaining a dipping process and a neck process in the method for producing a silicon single crystal of the present invention. The “dip temperature” shown in FIG. 2 is a melt temperature in a state where the melt temperature is stabilized by “seed crystal soaking” and “neck soaking”, and “neck temperature” is a narrow diameter in the neck process. It is a melt temperature suitable for pulling up the neck portion.

As is apparent from FIG. 2, in the method for producing a silicon single crystal according to the present invention, the crystal raw material in the crucible is melted by the CZ method, and the seed crystal is immersed in a molten liquid held in the crucible. Following the neck process of pulling up the seed crystal and forming the neck part after acclimating at the dip temperature, the target is a single crystal manufacturing method for forming the shoulder part and body part of the single crystal . After forming the length to 20 mm or more, the temperature is raised to the dip temperature, the neck portion is adjusted to the melt, and then the temperature is lowered to a temperature suitable for neck formation to form the neck portion.

  In the production method of the present invention, the crystal raw material in the crucible is melted and transferred to the dipping process, and then the seed crystal is brought into contact with the melt to be adapted. The melt temperature is stabilized by fully acclimatizing the seed crystal.

  When moving from the dip process to the neck process, the melt temperature is high and the neck part is grown if the melt temperature remains at the dip temperature, that is, the temperature distribution of the melt is stabilized by seed crystal acclimation. Therefore, it is necessary to lower the temperature to a neck temperature, that is, a temperature suitable for neck formation. For this reason, the heater power (electric power) is lowered, the heater temperature is controlled to lower the melt temperature in the range of 4 to 5 ° C., the seed crystal is pulled up at a high speed, and the melt is added to the tip under the seed crystal. The first neck is formed to a predetermined length while solidifying. Usually, dislocations can be removed by forming a neck portion having a crystal diameter reduced to about 3 to 6 mm.

  In the production method of the present invention, the melt surface temperature is stabilized by the operations of “seed crystal soaking” and “neck soaking”, but the melt surface temperature is stabilized when the melt surface temperature is stabilized. Cannot be determined uniquely. That is, if the pulling device used is different, the temperature at which the melt temperature stabilizes will be different, and even if the seed crystal (diameter) to be used and the target neck diameter are different, the melt will be stable. The melt surface temperature at the time of conversion is different.

  Therefore, in the manufacturing method of the present invention, it is necessary to accurately grasp the melt temperature when the above-mentioned “familiarization” operation is performed and control the melt temperature. Generally, as a means for controlling the melt temperature, there is a method of controlling the melt temperature by adjusting the heater power (electric power) based on the data obtained by optically measuring the melt temperature. is there.

  However, the method of detecting the temperature of the melt surface with an optical temperature measuring means such as a monochromatic thermometer or a two-color thermometer is affected by disturbance factors such as SiO evaporation generated during crystal growth during the measurement temperature. The measurement temperature varies depending on the measurement point on the melt surface due to the influence of the melt heat convection. For this reason, the reliability of the measured temperature is poor, and it cannot be applied to a neck process that requires accurate temperature control.

  For this reason, in the manufacturing method of the present invention, as shown in a control process described later, the heater temperature for melting the crystal raw material in the crucible is measured, and the heater power (electric power) is adjusted based on the temperature measurement result. It is desirable to control the temperature to adjust the melt temperature. There is a one-to-one correspondence between the heater temperature and the melt temperature. Even if the heater temperature is measured with a radiation thermometer or two-color thermometer, the effects of disturbance factors such as SiO evaporation and the effects of melt convection Since it does not receive, melt temperature can be controlled accurately.

In the production method of the present invention shall be the least 20mm in length of the neck portion initially formed. If it is less than 20 mm, there is no effect of removing dislocations, and the length of the neck portion cannot be shortened. To remove reliably dislocations to the length of the neck portion is formed with more than 50mm is desirable. Even if the neck part is formed longer than that, the effect of removing the dislocation is saturated, and forming the neck part longer takes time to form the neck part. Is desirable.

  Further, it is not always necessary to reduce the diameter of the neck portion formed first to about 3 to 6 mm. This is because the diameter of the seed crystal is usually 20 to 10 mm, and advanced technology is required to pull it up to about 20 mm and reduce the diameter to 3 to 6 mm.

  Therefore, the diameter of the first neck portion may be a diameter range that does not steadily become larger than the diameter of the seed crystal and approximates the target neck diameter (3 to 6 mm). Here, “not constantly thickening” means that the diameter of the neck portion temporarily exceeds the diameter of the seed crystal when the melt temperature and the pulling speed are not stable immediately after the neck formation starts. Meaning.

  In the manufacturing method of the present invention, in the neck step, the temperature is raised to a temperature higher than the melt temperature when the neck portion is formed, and then the first neck portion is adapted to the melt. In the initial stage of pulling up a silicon single crystal, the length of the neck required to eliminate dislocations can be shortened without causing new dislocations in the neck by applying the crystal twice. It becomes possible to do.

  After the neck portion formed first is adjusted to the melt, the heater power is reduced to lower the melt temperature in the range of 4 to 5 ° C. in order to lower the melt temperature to the neck temperature again. . In the manufacturing method of the present invention, after the melt is stabilized, formation of a neck portion is newly started, dislocation is eliminated at the neck portion, and then the shoulder portion where the diameter of the single crystal gradually increases is passed. As a result, the body part corresponding to the product diameter is moved up.

  In the manufacturing method of the present invention, a more remarkable effect can be exhibited in the method for manufacturing a silicon single crystal in which the neck portion is formed by the MCZ method. In order to stably form the neck portion, it is effective to apply a transverse magnetic field to the melt and suppress the melt convection in order to suppress fluctuations in the melt. When the method is applied, it becomes difficult to dislocation-free in the neck process, and it is necessary to form a long neck portion. However, by applying the manufacturing method of the present invention, it is possible to reduce the formation length of the neck portion necessary for the non-dislocation and to improve the non-dislocation rate.

  The MCZ method applied in the present invention is a method in which a conductive coil is provided on the outer periphery of a crucible containing a melt and a transverse magnetic field is applied to the melt. The transverse magnetic field to be applied varies depending on the size of the crucible and the amount of the melt, but it is desirable to apply in this range because the occurrence of natural convection can be effectively suppressed, particularly when the crucible is 2000 to 4000 G. .

  As described above, in the manufacturing method of the present invention, regardless of the CZ method or the MCZ method, the temperature of the heater that melts the crystal raw material in the crucible is measured, and the heater temperature is controlled based on the temperature measurement result. It is desirable to adjust the temperature. Regarding the adjustment of the melt temperature by this heater temperature control, a control process that can be specifically operated will be described in detail below.

  Usually, in the CZ method and the MCZ method, the heater temperature can be used as an index temperature for process control. The heater temperature is measured by a radiation thermometer or a two-color thermometer installed outside the furnace, through a measurement window installed on the furnace wall, with the temperature of the heater or the furnace internal structure heated by the heater.

  When measuring through the measurement window, the measurement window can be installed in a place that avoids dirt such as SiO due to the measurement position compared to the temperature measurement of the melt in the crucible, and it can be measured from a location relatively close to the heater. Therefore, if the measurement accuracy can be ensured and the in-furnace structure is the same, it is possible to obtain measurement data used in common between the furnaces and between batches.

  That is, the obtained heater temperature is approximately 1 between the same batches or approximate batches except for the transition period immediately after changing the heater power when the amount of the melt in the crucible and the crucible position are the same. One-to-one correspondence. The heater temperature also corresponds to the melt temperature obtained by flattening the fluctuation due to thermal convection by the time average of several minutes to several tens of minutes.

  Assuming such a correspondence relationship between the heater temperature and the melt temperature, (1) record the heater temperature in “seeding of seed crystal” in the dip process, and (2) next, from the past examples Change the heater temperature so that it becomes the neck temperature obtained empirically. (3) After the change, grow the predetermined neck part, (4) Stop the pulling speed, and for the "neck part familiarization" If the heater temperature recorded in (1) is changed, the temperature of the melt in the crucible can be adjusted efficiently.

The effects of the method for producing a silicon single crystal of the present invention will be described based on specific Examples 1 and 2.
Example 1
In Example 1, tests were conducted on the formation length of the neck portion necessary for dislocation-free using the present invention example by the MCZ method, the comparative example 1 by the CZ method, and the comparative example 2 by the MCZ method.

  FIG. 3 is a view showing a neck portion formation sample produced in Example 1, (a) is a sample formed in the present invention example, (b) is a sample formed in Comparative Example 1, and (c) is a comparison. 2 shows the sample formed in Example 2.

  In the example of the present invention, an 8-inch silicon single crystal was grown by the MCZ method in which a transverse magnetic field was applied at 4000 G. First, 140 kg of polycrystalline silicon as a crystal raw material was filled in a 24-inch quartz crucible, and the crystal raw material in the crucible was melted. In the dipping process, the seed crystal was lowered while being rotated and immersed in the melt, and then the descent of the seed crystal was stopped and the blending operation was performed to stabilize the melt temperature. After visually confirming that a predetermined meniscus shape was formed at the lower end of the seed crystal, the heater power was adjusted so that the melt temperature was lowered by 4 to 5 ° C. to the neck temperature.

  In the neck process, the seed crystal is pulled up to start the formation of the neck portion, the neck portion is grown 50 mm, the pulling up of the seed crystal is stopped, the heater power is changed so that the melt temperature becomes the dip temperature, and the seed crystal is again formed. Was blended into the melt. In FIG. 3A, the length of the neck portion formed first is indicated by L.

  Next, after adjusting the heater power so that the melt temperature is lowered by 4 to 5 ° C. to the neck temperature, the seed crystal is pulled up again to start the formation of the neck portion, and the neck shown in FIG. The part formation sample was pulled up.

  In Comparative Example 1, an 8-inch silicon single crystal was grown by the CZ method. Similarly to the example of the present invention, polycrystalline silicon as a crystal raw material was filled in a 24-inch quartz crucible, and the crystal raw material in the crucible was melted. In the dipping process, the seed crystal was lowered while being rotated and immersed in the melt, and then the descent of the seed crystal was stopped and the blending operation was performed to stabilize the melt temperature. After visually confirming that a predetermined meniscus shape is formed at the lower end of the seed crystal, the melt temperature is lowered by 4 to 5 ° C. and the heater power is adjusted to the neck temperature. The formation of the neck portion was started, and the neck portion formation sample shown in FIG.

  In Comparative Example 2, an 8-inch silicon single crystal was grown by the MCZ method in which a transverse magnetic field was applied at 4000 G. Similarly to the example of the present invention, polycrystalline silicon as a crystal raw material was filled in a 24-inch quartz crucible, and the crystal raw material in the crucible was melted. In the dipping process, the seed crystal was lowered while being rotated and immersed in the melt, and then the descent of the seed crystal was stopped and the blending operation was performed to stabilize the melt temperature. After visually confirming that a predetermined meniscus shape is formed at the lower end of the seed crystal, the melt temperature is lowered by 4 to 5 ° C. and the heater power is adjusted to the neck temperature. The formation of the neck portion was started, and the neck portion formation sample shown in FIG.

  After the completion of the crystal pulling, the neck portion was collected and subjected to an etching treatment, and a portion where no dislocation was formed in the neck portion was observed, and the formation length N of the neck portion required for it was determined. Table 1 shows the formation length N of the neck portion required for dislocation-free according to the present invention example and Comparative Examples 1 and 2.

(Example 2)
In Example 2, using the example of the present invention by the MCZ method and the comparative example 1 by the CZ method, the body part was pulled up and a dislocation-free rate test was performed.

  In the example of the present invention, an 8-inch silicon single crystal was grown by the MCZ method in which a transverse magnetic field was applied at 4000 G. First, 140 kg of polycrystalline silicon as a crystal raw material was filled in a 24-inch quartz crucible, and the crystal raw material in the crucible was melted. In the dipping process, the seed crystal was lowered while being rotated and immersed in the melt, and then the descent of the seed crystal was stopped and the blending operation was performed to stabilize the melt temperature. After visually confirming that a predetermined meniscus shape was formed at the lower end of the seed crystal, the heater power was adjusted so that the melt temperature was lowered by 4 to 5 ° C. to the neck temperature.

  In the neck process, the seed crystal is pulled up to start the formation of the neck portion, the neck portion is grown 50 mm, the pulling up of the seed crystal is stopped, the heater power is changed so that the melt temperature becomes the dip temperature, and the seed crystal is again formed. Was blended into the melt.

  Next, after adjusting the heater power so that the melt temperature is lowered by 4 to 5 ° C. to reach the neck temperature, the seed crystal is pulled up again to start the formation of the neck portion, and the neck portion is formed to 250 mm. Raised shoulder, body and tail.

  The test was conducted for 20 pulls, and the dislocation-free rate was 90% (18/20).

  In Comparative Example 1, an 8-inch silicon single crystal was grown by the CZ method. Similarly to the example of the present invention, polycrystalline silicon as a crystal raw material was filled in a 24-inch quartz crucible, and the crystal raw material in the crucible was melted. In the dipping process, the seed crystal is adjusted to the melt, the melt temperature is lowered by 4 to 5 ° C., the heater power is adjusted to the neck temperature, the seed crystal is pulled up, and formation of the neck portion is started. The portion was formed to 500 mm, and the shoulder portion, body portion and tail portion were subsequently raised.

  The test was carried out for 18 pulls, but the dislocation-free rate was 56% (10/18).

  According to the method for producing a silicon single crystal of the present invention, when the silicon single crystal is pulled, it is necessary for dislocation-free by performing a dip process of “seed crystal fitting” and “neck fitting” twice. As a result, the formation length of the neck portion can be shortened, and the crystal quality can be improved by increasing the dislocation-free rate. As a result, the manufacturing cost can be greatly reduced, and it can be widely applied as an efficient dash method regardless of the CZ method or the MCZ method.

It is the elements on larger scale which showed typically the process of dip process, neck process, and shoulder part formation performed at the pulling initial stage of CZ method, (a) is a dip process, (b) is a neck process, and (c). Indicates a step of forming a shoulder portion. It is a flowchart explaining the dipping process and the neck process in the manufacturing method of the silicon single crystal of this invention. It is a figure which shows the formation sample of the neck part produced in Example 1, (a) is the sample formed in the example of this invention, (b) is the sample formed in the comparative example 1, (c) is formed in the comparative example 2. Shows the sample.

Explanation of symbols

1: Seed crystal 2: Melt 3: Meniscus 4: Neck 5: Shoulder

Claims (5)

Using the Czochralski method, melt the crystal raw material in the crucible, immerse the seed crystal in the melt held in the crucible and let the seed crystal adapt at the dip temperature, then pull up the seed crystal to form the neck part In the single crystal manufacturing method for forming the shoulder portion and the body portion of the single crystal after the neck step, the neck portion is formed to have a length of 20 mm or more in the neck step, and then the neck portion is heated to a dip temperature. A method for producing a silicon single crystal, characterized in that the neck portion is formed by immersing in a melt and subsequently lowering the temperature to a temperature suitable for neck formation . After melting the crystal raw material in the crucible by the Czochralski method of pulling up by applying a transverse magnetic field, soaking the seed crystal in the melt held in the crucible and allowing the seed crystal to adapt at the dip temperature , In the single crystal manufacturing method for forming the shoulder portion and the body portion of the single crystal after the neck step of pulling up the seed crystal to form the neck portion, after forming the neck portion length to 20 mm or more in the neck step, the dip A method for producing a silicon single crystal, wherein the neck portion is formed by heating to a temperature, allowing the neck portion to conform to the melt, and subsequently lowering the temperature to a temperature suitable for neck formation .   The method for producing a silicon single crystal according to claim 2, wherein the transverse magnetic field is applied in a range of 2000 to 4000G. In the neck step, it was raised to a temperature higher than the melt temperature for forming the neck portion, according to any one of claims 1 to 3, characterized in that adapt the neck portion into the melt A method for producing a silicon single crystal. Said measuring raised the heater temperature to melt the crystal raw material in the crucible, according to any one of claims 1 to 4, by controlling the heater temperature based on the temperature measurement result and adjusts the melt temperature A method for producing a silicon single crystal.

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