JP5454625B2 - Silicon single crystal wafer obtained from ingot pulled by silicon single crystal pulling method - Google Patents

Description

The present invention relates to a method for pulling a large-diameter silicon single crystal, and more specifically, a magnetic field applied CZ method (Magnetic field applied Czochralski) for pulling a single crystal from a melt while applying a magnetic field to a raw material melt in a quartz crucible. method;. hereinafter, the called MCZ method), relates to a silicon single crystal wafer sliced from more obtained silicon single crystal ingot to how to pull a silicon single crystal having a large diameter.

  In recent years, with an increase in the diameter of a single crystal to be manufactured, the size of a quartz crucible used for pulling the single crystal has also increased, and the volume of the melt in the quartz crucible has increased. The challenge is how to control the thermal convection of this increased volume of melt.

  As one of the measures, the MCZ method in which a magnetic field is applied to the raw material melt in the crucible is known. The MCZ method suppresses melt convection in a direction perpendicular to the magnetic field lines by applying a magnetic field to the raw material melt. Although there are various types of magnetic field application methods in the MCZ method, the practical application of the HMCZ method (Horizontal Magnetic field applied CZ method) that applies a magnetic field in the horizontal direction to control the oxygen concentration and improve the single crystallization rate. Is progressing.

  However, when a horizontal magnetic field is applied to the raw material melt by the HMCZ method, it is possible to reduce the oxygen concentration, but there is a problem that micro variation in the oxygen concentration occurs. Various studies have been conducted in the past to solve this problem.

  For example, a method of controlling the vertical position of the coil central axis of the electromagnet at the start of crystal pulling to an appropriate value including the vertical position of the lower surface of the melt in the crucible is disclosed (see, for example, Patent Document 1). ). In Patent Document 1, the strength of the magnetic field applied to the melt near the crystal growth interface in the crucible is weakened to increase the degree of freedom of melt convection, and the melt near the bottom of the crucible is applied to this. Since it is configured to increase the strength of the magnetic field and suppress the convection, it is possible to pull up a single crystal with a small variation in micro oxygen concentration. Further, since the convection of the melt is effectively suppressed at the bottom of the crucible where oxygen mainly dissolves in the melt, a large-diameter single crystal having a low oxygen concentration and few defects can be stably produced. In addition, since the melt hardly erodes the crucible, the life of the crucible can be extended, and the number of crucibles required for the amount of single crystal to be pulled can be reduced.

  In addition, the relative position in the vertical direction between the electromagnet and the crucible is set so that the coil central axis of the electromagnet passes through the center in the depth direction of the melt in the crucible or the lower portion thereof, and the melt depth direction. That the magnetic field strength of the electromagnet is controlled within the range of 0.8 to 1.2 of the average value, and the coil diameter of the electromagnet is set to be not less than three times the melt depth in the crucible at the start of pulling of the single crystal. (For example, refer to Patent Document 2).

  Further, a manufacturing method is disclosed in which the crucible is raised so that the position of the melt surface becomes substantially constant as the amount of single crystal pulled increases, and the magnetic field application device is raised following the crucible (for example, , See Patent Document 3). In Patent Document 3, the magnetic field can always be held at the optimum position for convection suppression, and as a result, a uniform single crystal with a low oxygen concentration can be easily obtained.

  In addition, the magnetic field strength of the surface of the raw material melt in the crucible on the crucible shaft is controlled to 0.8 to 0.95 times the magnetic field strength of the bottom surface of the crucible on the crucible shaft, or opposed to the left and right around the crucible shaft. A manufacturing method of a silicon single crystal is disclosed in which an opening angle is formed on the coil surface of the electromagnet and the opening angle is controlled within a range of 0 to 30 degrees (see, for example, Patent Document 4). According to Patent Document 4, it is possible to grow a silicon single crystal having high local oxygen concentration uniformity in the growth direction of the grown single crystal with high productivity and high yield. Furthermore, the inclination of the magnetic flux vector on the inner wall of the crucible on the surface of the raw material melt in the crucible is controlled within a range of 14 to 20 degrees, or the ratio B / B between the left and right electromagnet coils and the inner diameter A of the crucible, A / B is set to 0. The effect is achieved by setting the ratio within the range of 3 to 0.6 or the ratio of the diameter R of the electromagnetic coil to the melt depth D in the crucible at the start of pulling, and D / R being 0.5 or less. Can be increased.

  Also disclosed is a single crystal growth method in which the vertical position of the coil is changed in order to control the oxygen concentration in the single crystal while applying a horizontal magnetic field to the raw material melt using a saddle-shaped coil. (For example, refer to Patent Document 5). According to this Patent Document 5, the oxygen concentration can be controlled without manipulating the crucible rotation speed, thereby suppressing the crucible rotation speed to a low level.

  Furthermore, in the entire region from the melt surface of the raw material melt toward the bottom of the crucible, a magnetic field can be applied so that the magnetic field strength is gradually increased or decreased monotonously, and the maximum strength of the applied magnetic field is 0.6 times to A silicon single crystal pulling apparatus set in a range of 0.9 times is disclosed (for example, see Patent Document 6). According to this Patent Document 6, the oxygen concentration of the pulled silicon single crystal ingot decreases at a constant rate over the entire length in the growth direction of the ingot, so that an unstable region does not occur, so that the impurity concentration is low. Uniform distribution can be suppressed, oxygen concentration and dopant concentration are prevented from varying in a minute range, resistivity variation due to variation in dopant concentration is prevented, and device characteristics and yield are kept good in the device process. It becomes possible.

JP-A-9-188590 (Claim 1, paragraph [0035], FIG. 1) JP-A-8-333919 (Claims 1, 3, 5 and FIG. 1) WO 02/10485 pamphlet (page 3, lines 20-24, page 4, lines 10-14) JP 2000-119095 (Claims 1-6, paragraph [0005], FIG. 1) JP 2004-189559 A (Claim 1, paragraph [0018]) JP 2007-210865 (Claims 2, 3, paragraph [0014])

  However, various problems have arisen as the crystal diameter is increased to 300 mm wafers and 450 mm wafers. Specifically, the pulling furnace itself must be enlarged in order to pull up the large-diameter silicon single crystal. Then, a Helmholtz type magnetic field application device has been conventionally used for applying a horizontal magnetic field, but the Helmholtz type magnetic field application device must also be enlarged. However, even the Helmholtz-type magnetic field application device that has been used for applying a horizontal magnetic field in pulling up a conventional single-crystal single crystal has a large device itself and a large magnetic field leakage. In the meantime, a larger installation area is required, and there is a concern about an increase in production cost due to magnetic field leakage. In particular, when a single crystal for a 450 mm wafer is pulled up, the installation area becomes very large, making it difficult to adopt the Helmholtz type.

  Therefore, when applying a horizontal magnetic field, it is possible to generate a magnetic field of the same strength with a smaller magnetomotive force than that of the Helmholtz type, and it is possible to reduce the size of the coil so that a small installation area is required. Although it is conceivable to employ an apparatus, it has been difficult to obtain a parallel horizontal magnetic field equivalent to the case of using a Helmholtz type large coil. Specifically, as the distance from the magnetic field center increases, the change in magnetic field strength tends to increase and the ratio of the longitudinal magnetic field component tends to increase.

  As described above, when a region having a large longitudinal magnetic field component ratio or a small region occurs in the raw material melt, the effect of suppressing the melt convection becomes non-uniform in the quartz crucible and easily leads to fluctuations in oxygen concentration. Inferred. Furthermore, since the amount of the raw material melt changes with the pulling of the single crystal, convection control is considered to be extremely difficult.

The object of the present invention is to control the local oxygen concentration variation of the single crystal to be pulled up by controlling the ratio of the transverse magnetic field component and the longitudinal magnetic field component in the horizontal magnetic field applied using the saddle-shaped coil. can suppress, cut from more lifted ingot pulling how the silicon single crystal is to provide a silicon single crystal wafer used in the large-diameter wafer of 450mm or 675mm outer peripheral grinding and chamfering were subjected .

The invention according to claim 1 is arranged in a horizontal direction to the silicon raw material melt stored in the quartz crucible by a pair of saddle-shaped coils which are arranged opposite to each other with the quartz crucible sandwiched and curved along the outer diameter of the chamber. A silicon single crystal wafer obtained by peripheral grinding, slicing and chamfering the silicon single crystal ingot pulled by the method of pulling up the silicon single crystal ingot from the raw material melt while applying a magnetic field. The diameter of the silicon single crystal ingot is 450 mm or more, and the oxygen concentration variation (surface) of the silicon single crystal wafer is excluded except for a region of 10% from the outer periphery of the diameter of the silicon single crystal wafer after the chamfering process. (Internal oxygen concentration difference / in-plane oxygen concentration average value) is 5% or less.

The invention according to claim 2 is the invention according to claim 1, wherein the silicon single crystal ingot has a diameter of 458 mm or more and 683 mm or less.

The silicon single crystal wafer of the present invention has a local oxygen concentration of a single crystal to be pulled up by controlling a ratio of a transverse magnetic field component and a longitudinal magnetic field component in a horizontal magnetic field applied using a saddle-shaped coil. using the pulling method for a silicon single crystal that can suppress variations in, and the outer peripheral ground pulling the silicon single crystal ingot by the method, slicing, Ru obtained by chamfering. This silicon single crystal wafer has a variation in oxygen concentration (in-plane oxygen concentration difference / in-plane oxygen concentration average) of the silicon single crystal wafer except for a region of 10% from the outer periphery of the diameter of the silicon single crystal wafer after chamfering. Value) can be 5% or less.

It is the schematic of the pulling apparatus of the silicon single crystal which applied the magnetic field to the horizontal direction using the saddle-shaped coil. It is a perspective view which shows a pair of saddle-shaped exciting coil used for the apparatus. It is a figure explaining the relationship between the longitudinal magnetic field component BZ and the transverse magnetic field component BY of the magnetic field applied in a specific position. It is a figure which shows [Oi] in-plane distribution in the silicon single crystal wafer cut out in the position of the straight body length of 305 mm of the silicon single crystal ingot pulled up in Example 1. FIG. It is a figure which shows [Oi] in-plane distribution in the silicon single crystal wafer cut out in the position of the straight body length of 300 mm of the silicon single crystal ingot pulled up in the comparative example 1.

  Next, the best mode for carrying out the present invention will be described with reference to the drawings.

  In order to obtain a high-quality silicon single crystal by suppressing variations in local oxygen concentration when using a saddle-shaped coil in pulling up a large-diameter silicon single crystal, the present inventors It has been found that it is necessary to control the ratio of the transverse magnetic field component and the longitudinal magnetic field component in the horizontal magnetic field to be applied, and the present invention has been completed.

That is, the present invention applies a magnetic field in a horizontal direction to a raw material melt stored in a quartz crucible by a pair of saddle-shaped coils that are arranged opposite to each other with a quartz crucible interposed and curved along the outer diameter of the chamber. On the other hand, it is a silicon single crystal wafer cut out from an ingot pulled by a silicon single crystal pulling method for pulling a single crystal from a raw material melt.
A characteristic configuration of this pulling method is that when the radius at the inner wall surface of the quartz crucible is R, the radius of the single crystal to be pulled is r, and the magnetic field center position (X, Y, Z) is (0, 0, 0), The relationship between the longitudinal magnetic field component BZ and the transverse magnetic field component BY of the applied magnetic field is expressed as follows: | longitudinal magnetic field component BZ / transverse magnetic field component BY | ≦ 1.1, (0, ±) at the position (0, ± R, −R). At the position of R / 2, −R / 2) | vertical magnetic field component BZ / transverse magnetic field component BY | ≦ 0.25 and at the position of (0, ± r, −r) | vertical magnetic field component BZ / transverse magnetic field component Each of BY | ≦ 0.25 is satisfied. When pulling up a silicon single crystal in a state controlled so as to satisfy the above ranges, the ratio of the longitudinal magnetic field component that affects the variation in local oxygen concentration of the single crystal to be pulled is increased in the raw material melt. As a result, the convection of the raw material melt becomes almost uniform without generating large or small regions, and as a result, variation in local oxygen concentration of the pulled single crystal is suppressed, and in-plane distribution of oxygen concentration is achieved. Is stable.

  In the pulling method of the present invention, the Z-axis is the pulling direction, the Y-axis is perpendicular to the Z-axis, the horizontal magnetic field application direction, and the X-axis is perpendicular to the Y-axis and Z-axis. Say.

FIG. 1 shows a magnetic field application type silicon single crystal pulling apparatus 10 for performing the above method. A quartz crucible 13 for storing the raw material melt 12 is provided in the chamber 11 of the apparatus 10, and the outer peripheral surface of the quartz crucible 13 is covered with a graphite susceptor (not shown). The lower surface of the quartz crucible 13 is fixed to the upper end of the support shaft 14 via the graphite susceptor, and the lower portion of the support shaft 14 is connected to a crucible driving means (not shown). Although the crucible driving means is not shown, it has a first rotating motor for rotating the quartz crucible 13 and an elevating motor for moving the quartz crucible 13 up and down, and the quartz crucible 13 can be rotated in a predetermined direction by these motors. It can move up and down.

  The outer peripheral surface of the quartz crucible 13 is surrounded by a heater 16 at a predetermined interval from the quartz crucible 13, and the heater 16 is surrounded by a heat insulating cylinder 15. The heater 16 heats and melts the high-purity silicon polycrystal charged in the quartz crucible 13 to form the raw material melt 12.

  A cylindrical casing (not shown) is connected to the upper end of the chamber 11. This casing is provided with a rotating pulling means (not shown). The rotary pulling means includes a pulling head (not shown) provided at the upper end of the casing so as to be turnable in a horizontal state, a second rotating motor (not shown) for rotating the head, and the quartz crucible 13 from the head. It has a wire cable 17 that hangs down toward the center of rotation, and a pulling motor (not shown) that is provided in the head and winds or feeds the wire bull 17. A seed crystal 18 is attached to the lower end of the wire cable 17 for pulling up the silicon single crystal 19 by dipping in the raw material melt 12.

  The pulling device 10 is provided with a pair of saddle-shaped exciting coils 21 and 21 so as to sandwich the chamber 11. A pair of saddle-shaped excitation coils 21 and 21 are the same shape and size, and their general shape will be described on behalf of one excitation coil 21. As shown in FIG. A semi-circular upper semi-annular portion 21a extending horizontally along the outer surface of the chamber 11, and a semi-circular portion extending downward along the outer surface of the chamber 11 that is positioned below the upper annular portion with a predetermined distance therebetween. A circular lower semicircular portion 21b, and a pair of linear portions 21c and 21d extending in the vertical direction and interconnecting the ends of the upper semicircular portion 21a and the lower semicircular portion 21b are provided. A pair of exciting coils 21 and 21 are connected in series by a power lead wire 22, and when energized to each exciting coil 21 and 21 from a power source (not shown), a horizontal line connecting the centers of both coils 21 and 21 as shown in FIG. It is configured to generate magnetic flux in the direction. The pair of exciting coils 21 and 21 are arranged outside the chamber 11 so as to be movable up and down.

Next, the above pulling method using this silicon single crystal pulling apparatus will be described.

  As shown in FIG. 1, a high-purity silicon polycrystal and a dopant impurity are put into a quartz crucible 13, and the high-purity silicon polycrystal is heated and melted by a heater 16 to obtain a raw material melt 12. The liquid surface position of the raw material melt 12 at the start of pulling of the silicon single crystal 19 and the vertical centers of the exciting coils 21 and 21, that is, the magnetic field center position are the same as the melt surface position. The vertical position of the pair of exciting coils 21 and 21 is determined so that the range is r × 0.5 from the top to r × 1.5 from the bottom.

  Next, the exciting coils 21 and 21 are energized from a power source (not shown) to generate a magnetic flux in the horizontal direction connecting the coils 21 and 21 as shown in FIG.

  Here, the magnetic field generated by the saddle-shaped excitation coils 21 and 21 is composed of only the transverse magnetic field component for the magnetic field indicated by the solid line generated at the center in the vertical direction of the excitation coils 21 and 21, but is indicated by the solid line. In the magnetic field indicated by the alternate long and short dash line generated at a position away from the magnetic field in the vertical direction, the longitudinal magnetic field component increases with distance from the magnetic field center except for the crystal central axis (in the middle of the coils 21 and 21). This tendency becomes remarkable because the size of the quartz crucible increases as the diameter of the single crystal ingot to be pulled up increases.

  Therefore, in this embodiment, as shown in FIG. 3, the relationship between the longitudinal magnetic field component BZ and the transverse magnetic field component BY of the magnetic field to be applied at a specific position is controlled so as to satisfy the following expressions, respectively. Pull up the silicon single crystal ingot.

  Specifically, the radius of the quartz crucible inner wall surface is R, the radius of the single crystal to be pulled is r, and the magnetic field center position (X, Y, Z) is (0, 0, 0). When the relationship between the longitudinal magnetic field component BZ and the transverse magnetic field component BY is at the position of (0, ± R, −R), the | longitudinal magnetic field component BZ / transverse magnetic field component BY | ≦ 1.1, (0, ± R / 2, −R / 2) at the position | vertical magnetic field component BZ / transverse magnetic field component BY | ≦ 0.25 and at the position (0, ± r, −r) | vertical magnetic field component BZ / transverse magnetic field component BY | ≦ 0. .25 is controlled so as to satisfy each of .25.

  Of these, at the position of (0, ± R, −R), the | vertical magnetic field component BZ / transverse magnetic field component BY | ≦ 1.0, and at the position of (0, ± R / 2, −R / 2) | vertical magnetic field It is possible to perform control so as to satisfy | longitudinal magnetic field component BZ / transverse magnetic field component BY | ≦ 0.2 at the position of component BZ / transverse magnetic field component BY | ≦ 0.2 and (0, ± r, −r). Particularly preferred.

  Thereby, in the raw material melt 12, there is no region where the ratio of the longitudinal magnetic field component is large or small enough to affect the variation in local oxygen concentration of the single crystal to be pulled up, and the convection of the raw material melt is not caused. Is almost uniform. As a result, variation in local oxygen concentration of the pulled single crystal is suppressed, and the in-plane distribution of oxygen concentration is stabilized.

  The above control can be adjusted according to the size and shape of the exciting coil 21.

  Subsequently, in a state in which the horizontal magnetic field to be applied is controlled as described above, the quartz crucible 13 is rotated counterclockwise at a predetermined speed by the crucible driving means via the support shaft 14. The speed of this crucible rotation varies depending on the crystal quality such as the desired oxygen concentration of the silicon single crystal ingot 19. Then, the wire cable 17 is fed out by a pulling motor (not shown) of the rotary pulling means to lower the seed crystal 18, and the tip of the seed crystal 18 is brought into contact with the raw material melt 12. Thereafter, the seed crystal 18 is gradually pulled to form a seed constriction portion, and a silicon single crystal ingot 19 is grown below the seed crystal 18. When pulling up the silicon single crystal ingot 19, the wire cable 17 is rotated so that the seed crystal 18 rotates clockwise at a predetermined speed.

In the above method, the diameter of the silicon single crystal ingot to be pulled is 450 mm or more, preferably 458 mm or more and 683 mm or less. That is, it is a size that can be used for a 450 mm wafer and a 675 mm wafer having a large diameter. Here, the size of the silicon single crystal ingot is slightly larger than the size used as a wafer. Machining such as peripheral grinding and chamfering is performed before the wafer is shipped as a product from the ingot. This is because it is considered that the diameter becomes smaller.

  For example, when pulling up a single crystal of a wafer having a diameter of 450 mm, the quartz crucible 13 is rotated counterclockwise, for example, at a speed of 0.1 to 1 rotation / minute, and the wire cable 17 is rotated 5 to 6 rotations / minute. It is preferred to rotate clockwise at speed.

  The silicon single crystal ingot pulled up in this way has a suppressed variation in local oxygen concentration.

  The silicon single crystal wafer of the present invention is a silicon single crystal wafer obtained by grinding, slicing, and chamfering a silicon single crystal ingot pulled up by the above method. The wafer cut out from the ingot in which the variation in local oxygen concentration is suppressed, except for the region of 10% from the outer periphery of the diameter of the silicon single crystal wafer after chamfering, the oxygen concentration of the silicon single crystal wafer The variation (in-plane oxygen concentration difference / in-plane oxygen concentration average value) can be 5% or less.

Next, examples of the present invention will be described in detail together with comparative examples.
<Example 1>
As shown in FIG. 1, a pair of saddle-shaped exciting coils 21 and 21 are arranged so as to sandwich a chamber 11 of a silicon single crystal pulling apparatus 10 for a 450 mm wafer. That is, the quartz crucible 13 provided in the chamber 11 had an outside diameter of 36 inches (about 900 mm) including the thickness of the straight body portion of the quartz crucible. The radius R of the inner wall surface of the quartz crucible is about 450 mm, and the radius r of the silicon single crystal ingot to be pulled up is about 230 mm.

  The vertical positions of the exciting coils 21 and 21 were arranged so as to coincide with the liquid surface position of the raw material melt 12. At the start of pulling, as shown in FIG. 3, at the position (0, ± R, −R), that is, (0, ± 450, −450), | vertical magnetic field component BZ / transverse magnetic field component BY | = 0.9, at the position of (0, ± R / 2, −R / 2), that is, (0, ± 225, −225), | vertical magnetic field component BZ / transverse magnetic field component BY | = 0.2, (0 , ± r, -r), ie, (vertical magnetic field component BZ / transverse magnetic field component BY) = 0.2 at (0, ± 230, -230).

  In such a horizontal magnetic field application type single crystal pulling apparatus, the silicon single crystal rod 19 having a diameter of the straight body portion of 458 mm is rotated at a rotational speed of 5-6 times / min and a pulling speed of 0.4-0. Pulled up at 5 mm / min.

  Further, FIG. 4 shows the [Oi] in-plane distribution in a silicon single crystal wafer obtained by subjecting the pulled silicon single crystal ingot to peripheral grinding, slicing at a position of a straight body length of 305 mm, and chamfering.

<Comparative Example 1>
As shown in FIG. 1, a pair of saddle-shaped exciting coils 21 and 21 are arranged so as to sandwich a chamber 11 of a silicon single crystal pulling apparatus 10 for a 450 mm wafer. That is, the quartz crucible 13 provided in the chamber 11 had an outside diameter of 36 inches (about 900 mm) including the thickness of the straight body portion of the quartz crucible. The radius R of the inner wall surface of the quartz crucible is about 450 mm, and the radius r of the silicon single crystal ingot to be pulled up is about 230 mm.

  The vertical positions of the exciting coils 21 and 21 were arranged so as to coincide with the liquid surface position of the raw material melt 12. At the start of pulling, as shown in FIG. 3, at the position (0, ± R, −R), that is, (0, ± 450, −450), | vertical magnetic field component BZ / transverse magnetic field component BY | = 1.5, at the position of (0, ± R / 2, −R / 2), that is, (0, ± 225, −225), | vertical magnetic field component BZ / transverse magnetic field component BY | = 0.26, (0 , ± r, −r), that is, | longitudinal magnetic field component BZ / transverse magnetic field component BY | = 0.26 at (0, ± 230, −230).

  Then, similarly to Example 1, the silicon single crystal rod 19 having a diameter of the straight body portion of 458 mm in the horizontal magnetic field application type single crystal pulling apparatus was rotated at a speed of 5-6 times / min and the pulling speed was It pulled up at 0.4-0.5 mm / min.

  FIG. 5 shows the [Oi] in-plane distribution of a silicon single crystal wafer obtained by subjecting the pulled silicon single crystal ingot to peripheral grinding, slicing at a position of a straight body length of 300 mm, and chamfering.

<Comparison evaluation>
As is clear from FIG. 4, in the silicon single crystal wafer cut out from the ingot pulled up in Example 1, the oxygen concentration is substantially constant from the crystal center to the vicinity of the outer periphery, and satisfies the range defined in the present invention. It was confirmed that the silicon single crystal wafer cut out from the silicon single crystal ingot pulled up by controlling in this way has a good [Oi] in-plane distribution in a region necessary for device manufacture. [Oi] For measurement, FT-IR was used, and the beam size was 4 mmφ.

The in-plane oxygen concentration difference in the region excluding 10% region from the outer periphery of the silicon single crystal wafer (region indicated by “r × 90%” in FIG. 4) is 0.20 atoms / cc, The average value of the in-plane oxygen concentration was 12.8 atoms / cc. When the oxygen concentration variation (in-plane oxygen concentration difference / in-plane oxygen concentration average value) was determined from these values, the oxygen concentration variation was 5% or less .

  On the other hand, as shown in FIG. 5, it was confirmed that the oxygen concentration of the silicon single crystal wafer cut out from the ingot pulled up in Comparative Example 1 greatly fluctuated from the center of the crystal to the outer periphery, and no particular effort was made. It has been found that simply adopting a saddle-shaped coil cannot solve the problem of variation in oxygen concentration when pulling up a large-diameter silicon single crystal ingot.

DESCRIPTION OF SYMBOLS 10 Pulling-up apparatus 11 Chamber 12 Raw material melt 13 Quartz crucible 14 Support shaft 15 Heat insulation cylinder 16 Heater 17 Wire cable 18 Seed crystal 19 Silicon single crystal 21 Vertical coil-shaped exciting coil

Claims (2)

The raw material is applied while applying a magnetic field in a horizontal direction to the silicon raw material melt stored in the quartz crucible by a pair of saddle-shaped coils that are arranged opposite to each other with a quartz crucible sandwiched along the outer diameter of the chamber. the silicon single crystal ingot from the melt and the outer circumference grinding the silicon single crystal ingot was pulled up by the pulling method was sliced, and a silicon single crystal wafer obtained by chamfering,
The diameter of the silicon single crystal ingot is 450 mm or more, and the oxygen concentration variation (in-plane) of the silicon single crystal wafer is excluded except for a region of 10% from the outer periphery of the diameter of the silicon single crystal wafer after the chamfering process. (Oxygen concentration difference / in-plane oxygen concentration average value) is 5% or less. 2. The silicon single crystal wafer according to claim 1, wherein a diameter of the silicon single crystal ingot is 458 mm or more and 683 mm or less.