JP4725752B2 - Single crystal manufacturing method - Google Patents

Description

  The present invention relates to a method for producing a silicon single crystal and an apparatus for producing a silicon single crystal used therefor, and more specifically, while applying a horizontal magnetic field to a silicon raw material melt in a crucible by a magnetic field application device, The present invention relates to a horizontal magnetic field applied CZ method for pulling up crystals (Horizontal magnetic field applied CZ method: hereinafter referred to as “HMCZ method”).

  It is well known that the HMCZ method is superior in various respects to the normal CZ method (Czochralski method). The apparatus used for carrying out this HMCZ method is an improvement of the ordinary CZ method, and a magnetic field applying device for applying a magnetic field is placed coaxially across the quartz crucible outside the heater for heating the quartz crucible. Deployed.

FIG. 7 is a diagram schematically showing a main configuration of a manufacturing apparatus suitable for carrying out a conventional method for manufacturing a silicon single crystal by the HMCZ method.
This manufacturing apparatus includes a silicon single crystal pulling apparatus 41 and a magnetic field applying apparatus 40 disposed outside the apparatus. The pulling device 41 includes a hollow cylindrical chamber 31, and a crucible is disposed at the center thereof. This crucible has a double structure, and is an inner holding container made of quartz having a bottomed cylindrical shape (hereinafter, simply referred to as “quartz crucible 35a”), and also has a bottomed structure adapted to hold the outside of the quartz crucible 35a. It consists of a cylindrical graphite outer holding container (“graphite crucible 35b”).

  These crucibles are fixed to the upper end portion of the support shaft 36 so as to be able to rotate and move up and down, and a resistance heating heater 38 is arranged substantially concentrically outside the crucible. Further, a heat insulating material 39 is disposed concentrically around the outside of the heater 38. Then, a predetermined weight of the silicon raw material charged into the crucible is melted by the heater 38 to form a silicon raw material melt 32.

  The central axis of the crucible filled with the silicon raw material melt 32 is the pulling wire (or pulling shaft, hereinafter referred to as both) rotating on the same axis as the support shaft 36 in the reverse direction or in the same direction at a predetermined speed. (Referred to as “pull-up shaft 37”), and a seed crystal 34 is held at the lower end of the pull-up shaft 37.

  In such a manufacturing apparatus, a silicon raw material was charged into a quartz crucible, and was formed after melting the silicon raw material in a heater 38 disposed around the crucible in an inert gas atmosphere under reduced pressure. The seed crystal 34 held at the lower end of the pull-up shaft 37 is immersed in the surface of the molten liquid, and the pull-up shaft 37 is pulled upward while rotating the crucible and the pull-up shaft 37, and silicon is formed on the lower end surface of the seed crystal 34. A single crystal 33 is grown. When the silicon single crystal 33 is grown, a horizontal magnetic field is applied to the silicon raw material melt 32 by the magnetic field application device 40 disposed coaxially facing the quartz crucible 35a.

  As described above, when pulling up a single crystal from the silicon raw material melt in the quartz crucible, the HMCZ method suppresses the thermal convection of the melt, and the temperature near the melt surface (solid-liquid interface temperature of the pulled single crystal). Therefore, there is an advantage that uniform and low oxygen concentration silicon single crystal can be easily obtained. In addition, as a result of suppressing the occurrence of dislocations and defects, even a single crystal having a large diameter can be easily manufactured. Furthermore, as a result of suppressing convection, there is an advantage that the crucible wall is hardly deteriorated.

  In a conventional apparatus for producing a single crystal by the HMCZ method, the convection near the melt surface is suppressed by aligning the central axis of the coil with the melt surface in the quartz crucible and lower than the melt surface. A thermal convection was formed on the surface (for example, see Patent Document 1). In this device, heat transfer to the boundary layer between the single crystal being pulled and the melt is enhanced, the temperature difference between the crucible and the boundary layer can be reduced, and the portion below the melt surface is sufficient. Since the melt stirred in this way is supplied to the boundary layer, it is possible to obtain a single crystal with uniform characteristics compared to the apparatus used in the normal CZ method, and also to prevent crucible cracks due to thermal stress. It is said that there is.

  However, with the recent increase in diameter of single crystals, there is a demand for large silicon single crystals having a diameter of 300 mm or more. Accordingly, it is necessary to grow a silicon single crystal by melting a silicon raw material having a weight of 300 kg or more into a large quartz crucible having a diameter of 800 mm or more. An HMCZ method for convection control of the melt in the growth of a silicon single crystal from such a large-capacity silicon raw material melt has been proposed (for example, see Patent Document 2). In addition, regarding the control of the interstitial oxygen concentration of the silicon single crystal grown by the HMCZ method, the vertical direction between the device (see, for example, Patent Document 3) and the magnetic field applying device and the crucible defined for the radius of curvature of the magnetic field to be applied. A method for setting the relative position is disclosed (for example, see Patent Documents 4 and 5).

  However, when a silicon single crystal is grown using the method and apparatus described above, it becomes difficult to control the interstitial oxygen concentration in the single crystal in the growth direction, and a rapid change in the oxygen concentration occurs in the latter half of the single crystal growth. As a result, the silicon single crystal cannot be manufactured within the required quality standard, and the yield of the silicon single crystal is reduced. In addition, there is a problem that the interstitial oxygen concentration of the single crystal varies greatly between manufacturing apparatuses, and the cause of such variation is not clear.

US Pat. No. 4,565,671 JP-A-8-239292 JP 62-256791 A JP-A-8-333191 JP-A-9-188590

  An object of the present invention is to provide a method for manufacturing a high-quality silicon single crystal having no variation by controlling the interstitial oxygen concentration of a silicon single crystal grown by the HMCZ method with high accuracy, and a manufacturing apparatus therefor. .

In order to solve the above problems, the present invention manufactures a single crystal by a horizontal magnetic field application CZ method in which a single crystal is pulled up while applying a horizontal magnetic field to a silicon raw material melt accommodated in a quartz crucible by a magnetic field application device. In the method, the center position of the magnetic field generated by the magnetic field application device is measured, and the center position of the measured magnetic field is aligned with the pulling-up axis serving as the rotation axis of the single crystal, and the initial magnetic field distribution is designed. possible to produce a single crystal after eliminating the offset between that provides a method for manufacturing a silicon single crystal according to claim.

  In this way, by aligning the measured magnetic field center position with the pull-up axis, which is the rotation axis of the single crystal, the magnetic field distribution is optimized and the rapid convection that occurs in the silicon raw material melt in the quartz crucible. It is possible to manufacture a high-quality silicon single crystal by controlling the interstitial oxygen concentration in the manufactured single crystal with high accuracy. Further, variation in the interstitial oxygen concentration of the single crystal between the manufacturing apparatuses is suppressed, and the yield of the silicon single crystal can be improved.

In the manufacturing method of the present invention, it is not preferable is intended to adjust the distance between the center position and the pulling axis of the magnetic field so as to be within 2 mm.
As a result, the magnetic field distribution can be more accurately optimized, so that rapid convection generated in the silicon raw material melt can be further prevented, and the interstitial oxygen concentration in the produced single crystal can be further accurately determined. A higher quality silicon single crystal can be manufactured by controlling. In addition, if the distance between the center position of the magnetic field and the pull-up axis is adjusted within 2 mm, the variation in the interstitial oxygen concentration of the single crystal between the manufacturing apparatuses can be made to a level that hardly causes a problem. The yield can be further improved.

In the manufacturing method of the present invention, the measurement of the center position of the magnetic field is carried out by measuring the intensity of the magnetic field at the measurement pitch 50mm or less, it is not preferable to determine the center position of the magnetic field.
By determining the center position of the magnetic field by such measurement, it is possible to accurately measure the magnetic field distribution and align the center position of the magnetic field more accurately in the alignment, which occurs in the silicon raw material melt. Rapid convection can be further prevented, and the interstitial oxygen concentration in the produced single crystal can be controlled with higher accuracy, and a higher quality silicon single crystal can be produced.

In the manufacturing method of the present invention, the alignment, it is not preferable to carry out by moving the magnetic field applying device.
Thereby, it can align easily and can optimize magnetic field distribution, without moving the quartz crucible and supporting shaft etc. which were enlarged and increased in weight.

Further, in an apparatus for producing a single crystal by a horizontal magnetic field application CZ method in which a single crystal is pulled while applying a horizontal magnetic field to a silicon raw material melt contained in a quartz crucible by a magnetic field application apparatus, at least the silicon raw material fusion A quartz crucible for holding the liquid, a support shaft for supporting the quartz crucible, and a pulling shaft for rotating and pulling up a seed crystal that is immersed in the silicon raw material melt and growing a single crystal on its lower end surface; A magnetic field application device installed coaxially and oppositely across a quartz crucible so as to apply a horizontal magnetic field to the silicon raw material melt, and the center position of the magnetic field generated by the magnetic field application device and the attraction that provides an apparatus for manufacturing a silicon single crystal, characterized in that it is intended to be the alignment with the upper shaft.

  Thus, by aligning the center position of the magnetic field with the pulling-up axis, the magnetic field distribution is optimized, and rapid convection that occurs in the silicon raw material melt in the quartz crucible is prevented, and the manufactured single crystal It becomes an apparatus capable of producing a high-quality silicon single crystal by controlling the interstitial oxygen concentration with high accuracy. In addition, it is possible to eliminate individual differences between devices, suppress variation in interstitial oxygen concentration in the single crystal, and improve the yield of the silicon single crystal.

Moreover, it is not preferable distance between the center positions of the magnetic field and the pulling member is intended to be incorporated tailored to be within 2 mm.
As a result, the magnetic field distribution can be more accurately optimized, so that rapid convection generated in the silicon raw material melt can be further prevented, and the interstitial oxygen concentration in the produced single crystal can be further accurately determined. It becomes an apparatus that can be controlled to produce a higher quality silicon single crystal. In addition, since the distance between the center position of the magnetic field and the pull-up axis is adjusted to within 2 mm, the variation in the interstitial oxygen concentration of the single crystal between the manufacturing apparatuses can be brought to a level that hardly poses a problem, and the yield of the silicon single crystal Can be further improved.

Further, the magnetic field applying device has a moving mechanism, it is not preferable in which positions of the pulling member and the center position of the magnetic field by the moving mechanism is incorporated combined.
As a result, the magnetic field distribution can be easily optimized without moving a large and heavy quartz crucible, support shaft, etc., which prevents the rapid convection that occurs in the silicon raw material melt. In addition, the interstitial oxygen concentration in the single crystal can be controlled with high accuracy to produce a high-quality silicon single crystal.

  As described above, in the present invention, when a single crystal is manufactured by the HMCZ method, the single crystal is grown after aligning the center position of the magnetic field with the pulling axis. This makes it possible to optimize the magnetic field distribution, prevent rapid convection generated in the silicon raw material melt in the quartz crucible, and control the interstitial oxygen concentration of the grown silicon single crystal with high accuracy to achieve high accuracy. Quality silicon single crystals can be manufactured. Further, since the alignment is performed in each device, there is no variation in interstitial oxygen concentration in the single crystal between devices, and the yield of the silicon single crystal can be improved.

Hereinafter, the present invention will be described more specifically.
As described above, in order to control the oxygen concentration in a large-diameter single crystal, the vertical direction between the magnetic field application device and the crucible is increased so as to enhance the effect of suppressing convection of the melt in the crucible and the device specified for the radius of curvature of the magnetic field. Although the method of setting the relative position in the direction has been disclosed, when the critical value of the restraining force by the magnetic field is exceeded, rapid convection occurs in the melt in the crucible, and the melt with a high oxygen concentration on the quartz crucible surface is single. We approached the crystal growth and found that oxygen was taken into the single crystal.

  In this case, the manufacturing apparatus is originally designed so that the center position of the magnetic field coincides with the pulling-up axis. However, since cryogenic liquid helium is used for the magnetic field application apparatus, the material for fixing the internal coil is used. It was found that when the manufacturing equipment was actually installed, a large deviation from the initial magnetic field distribution occurred due to the expansion and contraction due to cooling. Furthermore, as the diameter of the single crystal increases, the entire manufacturing equipment becomes larger, so it is necessary to strengthen the structure of the building where the manufacturing equipment is installed, and when iron equipment is used on the floor or in the manufacturing equipment itself. There are cases where many magnetic materials such as iron parts are used. For this reason, it has been found that when a manufacturing apparatus is actually installed due to the influence of a frequently used magnetic material, a deviation occurs from the initial magnetic field distribution.

  In addition, when a silicon single crystal is grown with a manufacturing device that has a deviation from the initial magnetic field distribution, it becomes difficult to control the growth direction of the interstitial oxygen concentration in the single crystal. It was found that there was a problem that the oxygen concentration suddenly fluctuated in the second half.

  Therefore, the present inventors measure the center position of the magnetic field generated by the magnetic field application device, align the measured magnetic field center position with the pull-up axis serving as the rotation axis of the single crystal, and produce the manufacturing apparatus. The single crystal was grown after eliminating the deviation from the initial magnetic field distribution and optimizing the magnetic field distribution.

  As a result, rapid fluctuations in oxygen concentration in the latter half of single crystal growth can be prevented, interstitial oxygen concentration in the single crystal can be controlled, and variations in equipment can be suppressed to produce a high-quality silicon single crystal. It has been discovered that it can be manufactured and that this can also improve the yield of silicon single crystals.

The present invention has been completed based on the above findings, and the present invention will be described in more detail below with reference to the drawings. However, the present invention is not limited to these.
FIG. 1 is a diagram schematically showing a cross-sectional configuration example of a silicon single crystal manufacturing apparatus of the present invention. Moreover, FIG. 2 is a figure which shows typically the upper surface structural example of the manufacturing apparatus of the silicon single crystal of this invention. The manufacturing apparatus used for the method for manufacturing a silicon single crystal of the present invention is as follows.

  This manufacturing apparatus is composed of a silicon single crystal pulling device 11 and a magnetic field applying device 10 disposed on the outer side of the silicon crucible so as to be coaxially opposed so as to apply a horizontal magnetic field to the silicon raw material melt. Is done.

  The pulling device 11 includes a hollow cylindrical chamber 1, and a crucible is disposed at the center thereof. This crucible has a double structure, and is an inner holding container made of quartz having a bottomed cylindrical shape (hereinafter simply referred to as “quartz crucible 5a”) and a similarly bottomed fitting adapted to hold the outside of the quartz crucible 5a. It is composed of a cylindrical graphite outer holding container (“graphite crucible 5b”).

  These crucibles are fixed to the upper end portion of the support shaft 6 so as to be able to rotate and move up and down, and a resistance heating heater 8 is arranged substantially concentrically outside the crucible. Further, a heat insulating material 9 is concentrically arranged around the outside of the heater 8. Then, a predetermined weight of silicon raw material charged into the crucible is melted by the heater 8 to form a silicon raw material melt 2.

  The central axis of the crucible filled with the silicon raw material melt 2 is a pulling wire (or pulling shaft, which is the same as the support shaft 6) that rotates at a predetermined speed in the opposite direction or in the same direction. The seed crystal 4 is held at the lower end of the pull-up shaft 7. A silicon single crystal 3 is formed on the lower end surface of the seed crystal 4.

  Furthermore, a moving mechanism 12 that moves the magnetic field application device 10 in the lateral direction and the front-rear direction is provided on the gantry of the magnetic field application device 10 provided outside the pulling device 11. Then, by moving the magnetic field application device 10 by the moving mechanism 12, the center position 13 of the magnetic field generated by the magnetic field application device 10 can be moved, and the center position 13 can be aligned with the pulling shaft 7.

  As described above, the manufacturing apparatus moves the magnetic field application device in the lateral direction and the front-rear direction by the moving mechanism arranged on the mount of the magnetic field application device, so that the center position 13 of the generated magnetic field and the pull-up axis are By aligning, it is possible to eliminate the deviation from the initial magnetic field distribution and to align the center position of the magnetic field. Therefore, by pulling up the single crystal using this apparatus, the rapid convection generated in the silicon raw material melt in the quartz crucible is prevented, and the interstitial oxygen concentration of the grown silicon single crystal is controlled with high accuracy. A high quality silicon single crystal can be manufactured.

In this case, the manufacturing apparatus can be adjusted so that the distance between the center position of the magnetic field and the pulling-up shaft is within 2 mm.
By adjusting the distance between the center position of the magnetic field and the pull-up axis within such a range, the magnetic field distribution can be adjusted more accurately, so that rapid convection generated in the silicon raw material melt in the quartz crucible Can be further prevented, and the interstitial oxygen concentration in the single crystal can be controlled with higher accuracy to produce a higher quality silicon single crystal. Further, if the distance between the center position of the magnetic field and the pulling-up axis is adjusted to be within 2 mm, the influence of the interstitial oxygen concentration of the single crystal due to the variation between apparatuses can be extremely reduced.

Further, as described above, the magnetic field application device has a moving mechanism, and the moving mechanism can align the position of the center of the magnetic field with the position of the pull-up shaft, more preferably, A push bolt type magnetic field position fine adjustment mechanism is provided on the mount of the magnetic field application device.
By moving the magnetic field application device by such a moving mechanism and aligning the center position of the magnetic field generated by the magnetic field application device, there is no need to move the quartz crucible and the support shaft etc. that have become larger and heavier, The magnetic field distribution can be easily adjusted. In addition, it prevents the rapid convection that occurs in the silicon raw material melt in the quartz crucible, controls the interstitial oxygen concentration in the single crystal, and makes the magnetic field distribution appropriate for producing high-quality silicon single crystal. This can be easily achieved by using a push bolt type magnetic field position fine adjustment mechanism. Furthermore, the center position of the magnetic field can be easily adjusted by the push bolt type magnetic field position fine adjustment mechanism, so that a high-quality silicon single crystal can be manufactured even when the production equipment is expanded or changed. it can. Of course, the moving mechanism is not limited to this, and any mechanism can be used as long as the magnetic field applying device can be moved and the center position of the magnetic field can be moved so that alignment can be performed.

Next, although an example of the method for producing the silicon single crystal of the present invention is shown below, the present invention is not limited to these.
In the present invention, in a method for producing a single crystal by the HMCZ method in which a single crystal is pulled while applying a horizontal magnetic field to a silicon raw material melt accommodated in a quartz crucible by a magnetic field application device, a magnetic field generated by the magnetic field application device After measuring the center position of the film and aligning the measured center position of the magnetic field with the pull-up axis serving as the rotation axis of the single crystal, a silicon single crystal is manufactured.
Such a method of the present invention can be carried out using, for example, the apparatus as described above.

  As described above, after measuring the center position of the magnetic field generated by the magnetic field application device, the alignment between the measured center position of the magnetic field and the pull-up axis is aligned and aligned, so that the magnetic field with respect to the initial design of the device is adjusted. The deviation of distribution can be eliminated. Since the silicon single crystal can be manufactured after the magnetic field distribution is optimized, the rapid convection that occurs in the silicon raw material melt in the quartz crucible is prevented, and the interstitial oxygen concentration of the grown silicon single crystal is reduced. A high-quality silicon single crystal can be manufactured with high accuracy.

In this case, the distance between the center position of the magnetic field and the pull-up axis can be adjusted to be within 2 mm.
By matching the distance between the center position of the magnetic field and the pulling axis within such a range, the magnetic field distribution can be more accurately matched to the initial magnetic field distribution of the device design. Rapid convection generated in the silicon raw material melt during production can be further prevented, and the interstitial oxygen concentration in the single crystal can be controlled with higher accuracy to produce a higher quality silicon single crystal. it can. In addition, if the distance between the center position of the magnetic field and the pulling axis is adjusted to be within 2 mm, the influence of the interstitial oxygen concentration of the single crystal due to the variation between the devices can be greatly reduced. The yield of silicon single crystals can also be improved.

The measurement of the center position of the magnetic field may be performed by any measurement method as long as the center position is known, but the center position of the magnetic field can be determined by measuring the strength of the magnetic field at a measurement pitch of 50 mm or less. it can.
By determining the center position of the magnetic field by such measurement, the center position of the magnetic field can be derived by accurately grasping the magnetic field distribution. Therefore, by aligning the obtained center position of the magnetic field and the pulling-up axis, it is possible to more reliably eliminate the deviation of the magnetic field distribution from the initial design of the apparatus. In addition, the rapid convection generated in the silicon raw material melt during the production of the silicon single crystal can be further prevented, and the interstitial oxygen concentration in the produced single crystal can be controlled with higher accuracy, resulting in higher quality. The silicon single crystal can be manufactured.

Further, the alignment can be performed by moving the magnetic field application device as described above.
More preferably, it is performed by a structure in which a push bolt type magnetic field position fine adjustment mechanism is provided on the mount of the magnetic field application device.
By moving the magnetic field application device in the lateral direction and the front-rear direction in this manner, the center position of the magnetic field can be easily adjusted without moving a large and heavy quartz crucible or support shaft. Can be adjusted to the pulling shaft. And by aligning, the deviation between the distribution of the magnetic field applied from the magnetic field application device and the initial magnetic field distribution of the device can be eliminated, and the rapid convection generated in the silicon raw material melt is prevented and manufactured. A high-quality silicon single crystal can be manufactured by controlling the interstitial oxygen concentration in the single crystal with high accuracy.

Next, the present invention will be described more specifically with reference to Examples and Comparative Examples of the present invention, but the present invention is not limited to these.
(Example)
Using the manufacturing apparatus shown in FIG. 1, after filling a quartz crucible having an inner diameter of 812 mm with a silicon raw material of 360 kg and forming a melt, Ar is flowed as an inert gas into the single crystal growth furnace from above 170 L / min. was maintained at the conditions of 75torr (9999Pa), the crucible rotation 0.5～1.5Rpm, single crystal rotation rate conversely rotated at 8rpm to the rotation direction of the crucible, pulling up the silicon single crystal having a diameter of 300 mm, and grown It was. At that time, the center position of the magnetic field generated by the magnetic field application device was measured, and the center position of the measured magnetic field was aligned with the pulling axis serving as the rotation axis of the single crystal, and then the single crystal was grown.

FIG. 3 is a view showing a flow of alignment of the center position of the magnetic field of the present invention. First, the magnetic field strength is measured, and the center position of the magnetic field is calculated from the measurement result. Then, the magnetic field applying device is moved, the center position of the magnetic field is adjusted to the pulling up axis, and after the magnetic field applying device is fixed, the production of the silicon single crystal is started. In this case, the process until the magnetic field application device is fixed is performed at least once at the time of installation of the manufacturing apparatus, but is performed again when the apparatus is added, changed, modified, or at a predetermined cycle. It is preferable to do this.
Here, FIG. 9 is a diagram schematically showing an example of a top surface configuration of a manufacturing apparatus suitable for carrying out a conventional method for manufacturing a silicon single crystal by the HMCZ method. The center position 42 of the magnetic field calculated from the measurement result of the strength of the magnetic field is displaced from the pull-up axis as shown in FIG.

According to the flow shown in FIG. 3, the magnetic field application device is moved to align the magnetic field center position with the pull-up axis. As a result, the deviation from the initial design of the magnetic field distribution is 8 mm in the horizontal direction and 4 mm in the front-rear direction. Was able to be adjusted to 2 mm in the horizontal direction and 0.5 mm in the front-rear direction.
Here, a method for measuring the center position of the magnetic field is described below. FIG. 4 is a diagram schematically showing the method for measuring the center position of the magnetic field of the present invention. First, a magnetic field measuring jig 23 with a measuring pitch of 50 mm (with a 90 cm square jig with holes formed so that magnetic field measuring elements can be set at equal intervals of 50 mm) is installed on the pulling shaft 21, and a magnetic field is applied. A magnetic field is applied from the device 22, and the strength of the magnetic field at each point is measured with a gauss meter with the horizontal direction from the pull-up shaft 21 as the X axis and the front and rear direction as the Y axis. Then, using the fact that the parabola with the lowest X-axis center and the highest Y-axis center is drawn in the magnetic field distribution, a quadratic curve is calculated from the measurement result to derive the center position of the magnetic field. FIG. 5 is a schematic diagram of the magnetic field distribution of the X-axis and the Y-axis of the example. Compared to the initial magnetic field distributions X and Y, which are ideal magnetic field distributions, the measured magnetic field distributions X ′ and Y ′ are shifted by ΔX and ΔY.

  Next, the center position of the magnetic field is measured as described above, and as shown in FIG. 9, the center position of the magnetic field where the deviation occurs is aligned with the pull-up axis, and the alignment is performed as shown in FIG. The silicon single crystal grown after the above was cylindrically polished, and the interstitial oxygen concentration in the single crystal was measured with an infrared absorption oxygen measuring device.

(Comparative example)
In the method for producing a silicon single crystal of the above example, the same evaluation as in the example was performed for a silicon single crystal grown under the condition where the center position of the magnetic field was not measured and the alignment of the magnetic field application device was not performed. The center position of the magnetic field at this time is 8 mm in the lateral direction and 4 mm in the front-rear direction with respect to the pulling-up axis as shown in FIG.

6 and 8 are diagrams showing the results of measuring the interstitial oxygen concentration in the single crystals of Examples and Comparative Examples, respectively.
In the examples, the interstitial oxygen concentration in the silicon single crystal was flat, and was within the quality standards required over almost the entire length of the grown silicon single crystal. However, in the comparative example, the oxygen concentration rapidly increased in the latter half of the grown silicon single crystal, exceeding the required standard.

  In the examples, the yield of the single crystal was improved because the oxygen concentration was within the required quality standards over the entire length of the grown silicon single crystal. However, in the comparative example, since the oxygen concentration exceeded the required standard, the quality was poor and the yield of the grown silicon single crystal was reduced.

  From the above, according to the method and apparatus for manufacturing a silicon single crystal of the present invention, the magnetic field distribution that has been shifted from the initial design of the apparatus is aligned with the pulling axis by measuring the center position of the magnetic field. Can be optimized. Then, by manufacturing a silicon single crystal after that, it is possible to prevent rapid convection generated in the silicon raw material melt in the quartz crucible, and to accurately control the interstitial oxygen concentration in the manufactured single crystal. .

  Thereby, since the interstitial oxygen concentration in the silicon single crystal having a large diameter can be controlled, a high quality silicon single crystal can be manufactured, and the required quality standard can be satisfied. Therefore, since the yield of the silicon single crystal can be improved, it can be widely used in the field of manufacturing a silicon single crystal. In addition, since the center position of the magnetic field is adjusted for each manufacturing apparatus, there is no variation between apparatuses.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

It is a figure which shows typically the example of a cross-sectional structure of the manufacturing apparatus of the silicon single crystal of this invention. It is a figure which shows typically the upper surface structural example of the manufacturing apparatus of the silicon single crystal of this invention. It is the figure which showed the flow of alignment of the center position of the magnetic field of this invention. It is a figure which shows typically the measuring method of the center position of the magnetic field of this invention. It is the schematic of the magnetic field distribution of the X-axis and Y-axis of an Example. It is a figure which shows the result of having measured the interstitial oxygen concentration in the single crystal of an Example. It is a figure which shows typically the principal part structure of the manufacturing apparatus suitable for enforcing the manufacturing method of the silicon single crystal by the conventional HMCZ method. It is a figure which shows the result of having measured the interstitial oxygen concentration in the single crystal of a comparative example. It is a figure which shows typically the upper surface structural example of the manufacturing apparatus suitable for implementing the manufacturing method of the silicon single crystal by the conventional HMCZ method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Chamber, 2 ... Silicon raw material melt, 3 ... Silicon single crystal, 4 ... Seed crystal, 5a ... Quartz crucible, 5b ... Graphite crucible, 6 ... Support shaft, 7 ... Pull-up shaft, 8 ... Heater, 9 ... Heat insulation 10: Magnetic field applying device, 11: Lifting device, 12: Moving mechanism, 13: Center position of magnetic field, 21: Pulling up axis, 22: Magnetic field applying device, 23: Jig for magnetic field measurement,
31 ... Chamber, 32 ... Silicon raw material melt, 33 ... Silicon single crystal, 34 ... Seed crystal, 35a ... Quartz crucible, 35b ... Graphite crucible, 36 ... Support shaft, 37 ... Pull-up shaft, 38 ... Heater, 39 ... Heat insulation 40: Magnetic field application device, 41: Lifting device, 42: Center position of magnetic field.

Claims (2)

In a method for producing a single crystal by a horizontal magnetic field application CZ method in which a single crystal is pulled up while applying a horizontal magnetic field by a magnetic field application device to a silicon raw material melt accommodated in a quartz crucible, the magnetic field generated by the magnetic field application device The center position of the magnetic field is measured by measuring the strength of the magnetic field at a measurement pitch of 50 mm or less, determining the center position of the magnetic field, and determining the center position of the measured magnetic field and the single position of the magnetic field. A single crystal is manufactured after aligning the distance with the pulling-up axis, which is the rotation axis of the crystal, to be within 2 mm and eliminating the deviation from the initial magnetic field distribution. A method for producing a silicon single crystal. The method for producing a silicon single crystal according to claim 1 , wherein the alignment is performed by moving the magnetic field application device.

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