TWI730878B - Production method of single crystal silicon - Google Patents

Abstract

Provided is a method of producing a silicon single crystal capable of reducing an oxygen concentration, implementing uniformity of the oxygen concentration in a direction of a crystal growth axis, and the uniformity of the oxygen concentration in a substrate plane perpendicular to the axis. The method of producing a silicon single crystal includes a growing step of the silicon single crystal with applying a horizontal magnetic field when pulling the silicon single crystal from silicon melt in a quartz glass crucible, wherein a center of the magnetic field is positioned in the melt below a free surface in a central portion of the crystal, a magnetic field strength is at least 2,000 gauss while pulling, a flow of the melt flowing from the crystal to a sidewall of the crucible exists on a surface of the melt, and a flow velocity of the melt is 0.16 m/s or less.

Description

Method for manufacturing single crystal silicon

The present invention relates to a method of manufacturing single crystal silicon, and in particular to a method of manufacturing single crystal silicon, which can reduce the oxygen concentration and increase the uniformity of the oxygen concentration in the direction of the crystal growth axis, and further The uniformity of the oxygen concentration in the substrate surface where the crystal growth axis is vertical is improved.

The oxygen concentration of the silicon substrate used in the conventional CZ method (Czochralski process; Czochralski method) is to pursue the gettering effect, although the silicon substrate ^{with a relatively high concentration (≧1.0×10 18} atoms/cm ³⁾ Mainstream, but in recent years, in CMOS (Complementary Metal Oxide Semiconductor) imaging sensors, etc., low-oxygen plates (<1.0×10 ¹⁸ atoms) have been sought in order to reduce white defects. /cm ³ ).

Although the silicon substrate is made of single crystal silicon, as a method of manufacturing single crystal silicon, CZ is widely used to pull the single crystal silicon while growing the single crystal from the silicon melt in the quartz glass crucible. law.

Among the aforementioned methods for manufacturing single crystal silicon, as a method for adjusting the oxygen concentration of single crystal silicon, there are known such as those described in Japanese Patent Publication No. 58-50953, Japanese Patent Application Publication No. 2000-264784, and Japanese Patent Application Publication No. 4-31386. The method of applying a magnetic field to control convection, as shown in Japanese Patent Laid-open No. 9-142990, shows the control of the flow rate of inert gas or the internal pressure of the furnace, or the rotation control of the quartz glass crucible, as shown in the Japanese Patent Laid-Open No. 2005-145724 The method of controlling the rotation of single crystal silicon.

However, even if the above-mentioned method of adjusting the oxygen concentration of single crystal silicon is used, the oxygen concentration in the second half of the straight body portion of the single crystal silicon (the second half of the lift) will increase and the direction of the crystal growth axis cannot be achieved. The issue of the uniformity of oxygen concentration.

Specifically, the oxygen concentration of single crystal silicon depends on the reaction of the silicon melt with the quartz components of the quartz glass crucible, the dissolution of the side walls of the quartz glass crucible, and the absorption of oxygen by the silicon melt. Therefore, once the oxygen absorbed in the silicon melt diffuses in the melt or is released from the melt to the outside, the oxygen is absorbed by the single crystal silicon, the oxygen concentration of the single crystal silicon increases.

Therefore, it is necessary to control the flow (convection) in the silicon melt in such a way that the oxygen absorbed in the silicon melt diffuses in the melt or is released to the outside before the oxygen is absorbed into the single crystal silicon.

Regarding the aforementioned control of the flow in the silicon melt, when the amount of silicon melt in the quartz glass crucible is large, the aforementioned method of adjusting the oxygen concentration of the single crystal silicon can control the flow in the silicon melt. (convection).

However, in a state where the amount of silicon melt in the quartz glass crucible is small (the second half of the straight body part of the single crystal silicon (the latter half of the pulling part)), the flow of the silicon melt cannot be controlled. The oxygen concentration in the second half of the straight body portion (the second half of the lift) becomes high, and there is a problem that the uniformity of the oxygen concentration in the direction of the crystal growth axis of the single crystal silicon cannot be achieved.

In order to solve this problem, the following method is proposed in Japanese Patent Application Laid-Open No. 4-31386: With the pulling (with the decrease of the amount of silicon melt contained in the quartz glass crucible), the magnetic field strength is changed from 3000 Gauss (Gauss) drops to 2000 Gauss, 1000 Gauss and 500 Gauss.

However, when the magnetic field strength is reduced to 3000 Gauss, 2000 Gauss, 1000 Gauss, 500 Gauss, and the magnetic field is set to a low magnetic field, the dispersion of the oxygen concentration in the substrate surface perpendicular to the crystal growth axis increases, which hinders the substrate surface. The technical issue of the uniformity of the oxygen concentration.

In order to solve the above-mentioned problems, the inventors of the present invention have made efforts and studies to reduce the oxygen concentration, the uniformity of the oxygen concentration in the substrate plane perpendicular to the crystal growth axis, and the improvement of the uniformity of the oxygen concentration in the direction of the crystal growth axis. .

In the aforementioned research, the inventors of the present case focused on the flow of the silicon melt surface, and learned that the flow rate of the silicon melt flowing from the side of the single crystal silicon to the side wall of the vitreous silica crucible is below a specific flow rate. The present invention can be achieved by reducing the oxygen concentration and achieving the uniformity of the oxygen concentration in the direction of the crystal growth axis.

The object of the present invention is to provide a method for manufacturing single crystal silicon that can reduce the oxygen concentration and achieve the uniformity of the oxygen concentration in the direction of the crystal growth axis and achieve the uniformity of the oxygen concentration in the substrate plane perpendicular to the crystal growth axis.

In order to achieve the above purpose, the single crystal silicon manufacturing method considered is to pull the single crystal silicon from the silicon melt in the quartz glass crucible, while applying a horizontal magnetic field to grow the single crystal silicon; on the surface of the silicon melt There is a flow of silicon melt from the single crystal silicon side to the side wall of the quartz glass crucible, and the flow velocity of the silicon melt flowing from the single crystal silicon side to the side wall of the quartz glass crucible is less than 0.16 m/s.

In the present invention, in the pulling of single crystal silicon, the flow velocity of the silicon melt flowing from the single crystal silicon side to the side wall of the quartz glass crucible is set to 0.16 m/s or less, thereby reducing the oxygen concentration of the single crystal silicon, thereby The uniformity of the oxygen concentration in the direction of the crystal growth axis and the uniformity of the oxygen concentration in the substrate plane perpendicular to the crystal growth axis can be achieved.

As the flow of the silicon melt on the surface of the silicon melt, for example, it flows from the single crystal silicon side to the side wall of the quartz glass crucible, then contacts (along) the side wall of the quartz glass crucible, flows downward and rises from the bottom surface of the quartz glass crucible.的流。 The flow. When the silicon melt flows in contact with the side wall of the quartz glass crucible, due to the chemical activity of the silicon in the melting point, the silicon melt will react with the quartz component of the quartz glass to dissolve the side wall of the quartz glass crucible and absorb oxygen .

Furthermore, when oxygen is absorbed by the single crystal silicon before being released from the aforementioned silicon melt and diffused, the oxygen concentration of the single crystal silicon increases. That is, when the flow from the single crystal silicon side to the side wall of the vitreous silica crucible becomes faster, the flow rising from the bottom surface of the vitreous silica crucible also becomes faster, and oxygen is absorbed into the single crystal before it is released from the silicon melt and diffuses. The degree of crystalline silicon becomes larger.

In particular, when the flow velocity of the silicon melt from the single crystal silicon side to the side wall of the quartz glass crucible exceeds 0.16 m/s, the flow of the silicon melt rising from the bottom surface of the quartz glass crucible also becomes faster. There is a risk of oxygen being released from the silicon melt and being absorbed by the single crystal silicon before it diffuses. Therefore, the flow velocity of the silicon melt exceeding 0.16 m/s is not good.

Here, it is preferable that the center of the horizontal magnetic field is located in the silicon melt within a range of 60 mm from the surface of the melt to the lower part, and the magnetic field strength during pulling of the single crystal silicon is at least 2000 Gauss. In the case where the aforementioned magnetic field intensity is less than 2000 Gauss, it becomes difficult to control the flow of the silicon melt. In particular, when the magnetic field is changed to a low magnetic field, the dispersion of the oxygen concentration in the substrate surface perpendicular to the crystal growth axis becomes large, and the uniformity of the oxygen concentration in the substrate surface cannot be achieved, which is not preferable. Furthermore, when the magnetic field strength exceeds 4000 Gauss, the flow velocity of the silicon melt flowing from the single crystal silicon side to the side wall of the quartz glass crucible becomes 0.16 m/s or more, which causes the melt with high oxygen concentration to reach the crystal. , So it is less good. Therefore, the magnetic field strength is preferably between 2000 Gauss and 4000 Gauss. In addition, the position of the center of the magnetic field is preferably within a range of 60 mm below the surface of the melt, and the position of the center of the magnetic field is more preferably within a range of 20 mm below the surface of the melt.

In addition, it is preferable that the center of the magnetic field in the horizontal direction is located below the center of the single crystal silicon, and in the pulling of the straight body of the single crystal silicon with a solidification rate of 0.4 or less, the magnetic field strength is at least 3000 Gauss, which exceeds the solidification rate. The above-mentioned magnetic field strength is gradually reduced from a rate of 0.4 to a curing rate of 0.6, and the magnetic field strength is set to 2000 Gauss after a curing rate of 0.6. In the pulling of the straight body of single crystal silicon with a solidification rate of 0.4 or less, since the magnetic field strength is at least 3000 Gauss, the flow in the silicon melt can be controlled, and the oxygen concentration can be reduced and the single crystal silicon can be reduced. The uniformity of the oxygen concentration in the direction of the crystal growth axis and the dispersion of the oxygen concentration in the substrate plane perpendicular to the crystal growth axis can be controlled, so that the uniformity of the oxygen concentration in the substrate plane can be achieved.

When the curing rate exceeds 0.4 to the curing rate 0.6, the aforementioned magnetic field strength is gradually reduced. In particular, the magnetic field strength is set to 2000 Gauss after the curing rate 0.6. Therefore, in addition to reducing the oxygen concentration and the uniformity of the oxygen concentration in the direction of the crystal growth axis of the single crystal silicon, it is also possible to control the dispersion of the oxygen concentration in the substrate surface perpendicular to the crystal growth axis, thereby making it possible to achieve more in-plane oxygen concentration. The uniformity of oxygen concentration.

In addition, it is preferable that the value calculated according to the following calculation formula is 190 or less; the aforementioned calculation formula is defined as follows: radius of single crystal silicon [mm] ÷ radius of crucible [mm] × rotation number of single crystal silicon [rpm] ( revolution per minute) x magnetic field intensity [Gauss] ÷ (distance from the surface of the silicon melt to the lower end of the shielding plate) [mm]. The value calculated based on the aforementioned formula of single crystal silicon radius ÷ crucible radius × single crystal silicon revolutions × magnetic field strength ÷ (distance from the surface of the molten silicon to the lower end of the shielding plate) is 190 or less In this case, the flow velocity of the flow of the silicon melt from the single crystal silicon side to the side wall of the crucible can be set to 0.16 m/s or less.

As a result, as described above, the oxygen concentration of the single crystal silicon can be reduced, the uniformity of the oxygen concentration in the direction of the crystal growth axis, and the uniformity of the oxygen concentration in the substrate plane perpendicular to the crystal growth axis can be achieved.

In addition, the single crystal silicon manufacturing method considered to achieve the above purpose is to pull the single crystal silicon from the silicon melt in the quartz glass crucible, while applying a horizontal magnetic field to grow the single crystal silicon; In the single crystal silicon step, adjust the radius of the single crystal silicon, the radius of the crucible, the number of revolutions of the single crystal silicon, the strength of the magnetic field, and the distance from the surface of the silicon melt to the lower end of the shielding plate to pull the single crystal silicon so that The value calculated according to the following calculation formula becomes less than 190; the aforementioned calculation formula is defined as follows: the radius of the single crystal silicon [mm] ÷ the radius of the crucible [mm] × the number of revolutions of the single crystal silicon [rpm] × the magnetic field intensity [Gauss] ÷ (The distance from the surface of the silicon melt to the lower end of the shielding plate) [mm].

According to the radius of single crystal silicon [mm] ÷ radius of crucible [mm] × single crystal silicon revolutions [rpm] × magnetic field strength [Gauss] ÷ (distance from the surface of the molten silicon to the lower end of the shielding plate) [mm ] The calculated value is 190 or less, so that the flow rate of the silicon melt flowing from the single crystal silicon side to the side wall of the vitreous silica crucible can be set to 0.16 m/ during the pulling of the single crystal silicon. s or less, the oxygen concentration of the single crystal silicon can be reduced, the uniformity of the oxygen concentration in the direction of the crystal growth axis, and the uniformity of the oxygen concentration in the substrate plane perpendicular to the crystal growth axis can be achieved.

In addition, there is no need to measure the flow rate of the silicon melt, and the calculation is based on the radius of the single crystal silicon ÷ the radius of the crucible × the number of revolutions of the single crystal × the magnetic field strength ÷ (the distance from the surface of the silicon melt to the lower end of the shielding plate) The value calculated by the formula can determine whether the flow velocity of the silicon melt from the single crystal silicon side to the side wall of the crucible becomes 0.16 m/s or less. According to the present invention, it is possible to obtain a method for manufacturing single crystal silicon that reduces the oxygen concentration and the uniformity of the oxygen concentration in the direction of the crystal growth axis and the uniformity of the oxygen concentration in the substrate plane perpendicular to the crystal growth axis.

In the single crystal silicon manufacturing method of the present invention, when pulling the single crystal silicon from the silicon melt in the quartz glass crucible, it is one of the manufacturing methods of the single crystal silicon that grows the single crystal silicon while applying a horizontal magnetic field. In the surface of the silicon melt, there is a flow of silicon melt from the aforementioned single crystal silicon side to the side wall of the quartz glass crucible, and the flow rate of the silicon melt flowing from the aforementioned single crystal silicon side to the side wall of the quartz glass crucible is set It is 0.16m/s or less. In particular, in the pulling of single crystal silicon, it is characterized in that the flow velocity of the silicon melt flowing from the side of the single crystal silicon to the side wall of the crucible is set to 0.16 m/s or less.

The silicon melt in the quartz glass crucible is affected by the strength of the magnetic field, the center position of the magnetic field, the flow rate of the inert gas or the furnace pressure, the number of revolutions of the quartz glass crucible, and the number of revolutions of single crystal silicon. The flow (convection) of the silicon melt in the pot changes.

Fig. 1 is a diagram showing an example of the flow of the silicon melt M in the quartz glass crucible. Based on Fig. 1, the flow velocity of the silicon melt M from the single crystal silicon side to the side wall of the crucible is set to 0.16 m/s or less The reasons are explained. Furthermore, Figure 1 shows the simulation results of the flow of the silicon melt under the condition of pulling up in the curing rate of 0.25 in the experiment 1 described later. A magnetic field of 3000 Gauss is applied in the horizontal direction and shows the horizontal direction. The flow of silicon melt in a state where the center of the magnetic field is located in the silicon melt 20 mm below the free surface in the center of the single crystal silicon. In addition, the B system in the figure shows that the direction of the magnetic flux is from the far side of the paper surface to the near side of the paper surface.

The silicon melt M in the quartz glass crucible 1 has various flows. For example, as shown by arrow X1 in Figure 1 (the flow of silicon melt flowing from above to below while contacting the side wall of the vitreous silica crucible, hereinafter also referred to as flow X1), the silicon melt has one side in contact (along ) The side wall 1a of the vitreous silica crucible flows from the upper side to the lower side. Moreover, when the aforementioned silicon melt contacts (along) the side wall 1a of the quartz glass crucible, the silicon melt M will react with the quartz component of the quartz glass crucible 1 due to the chemical activity of the silicon in the melting point, thereby reducing The side wall 1a of the vitreous silica crucible dissolves and further absorbs O (oxygen).

As indicated by the arrow X2 (the flow of silicon melt rising from the bottom surface of the quartz glass crucible below the single crystal silicon C, hereinafter also referred to as flow X2), the silicon melt M containing the aforementioned oxygen flows from below the single crystal silicon C The bottom surface of the crucible (the bottom surface of the center portion of the crucible) rises. Then, as indicated by arrow X3 (the flow of silicon melt flowing to the radial outside of the crucible, hereinafter also referred to as flow X3), after flowing (orbiting) to the radial outside of the crucible, as shown by arrow X4 (flowing to The flow of the silicon melt inside the crucible radially inside and returning to the bottom of the single crystal silicon, hereinafter also referred to as flow X4), returns to the bottom of the single crystal silicon C, as shown by the arrow X5 (from the single crystal on the surface of the silicon melt) The flow of the silicon melt flowing from the side of the crystalline silicon to the side wall of the crucible, hereinafter also referred to as flow X5), flows from the side of the single crystal silicon to the side of the crucible side wall.

In this way, when the side wall 1a of the quartz glass crucible is dissolved, the silicon melt M that has absorbed O (oxygen), that is, the oxygen-enriched silicon melt M, moves around when rising from the bottom surface of the quartz glass crucible 1 below the single crystal silicon C. After reaching the radial outside, it reaches the free surface. As a result, the oxygen absorbed by the silicon melt M diffuses, and the oxygen concentration of the silicon melt M can be reduced, and the single crystal silicon C can be prevented from absorbing oxygen, and the oxygen concentration of the single crystal silicon C can be reduced.

Next, the single crystal silicon C is pulled from the state shown in FIG. 1, and the flow of the silicon melt M in the vitreous silica crucible 1 in the state where the molten silicon M in the vitreous silica crucible 1 is reduced is shown in the figure. 2. Furthermore, FIG. 2 shows the simulation result of the flow of the silicon melt under the pulling condition with a curing rate of 0.6 in Experiment 1 described later. As shown in Figure 2, when the single crystal silicon C is pulled, the silicon melt in the quartz glass crucible 1 is reduced, and the occurrence of the flow after the large detour to the radially outer side as shown in Figure 1 is suppressed. As a result, the flow X2 rising from the bottom surface of the crucible below the single crystal silicon C (the bottom surface of the center of the crucible) becomes stronger (the flow velocity becomes faster).

In this way, the silicon melt no longer detours, and when the silicon melt rises from the bottom surface of the crucible toward the lower end of the single crystal silicon C, the oxygen has been absorbed by the single crystal silicon before the oxygen diffuses or is released from the silicon melt that has absorbed oxygen. C absorption. That is, the silicon melt that rises from the bottom of the crucible below the single crystal silicon is rich in oxygen. If the oxygen is absorbed by the single crystal silicon, the oxygen concentration cannot be reduced, and the oxygen concentration in the direction of the crystal growth axis is uniform. Sex is a hindrance.

Here, when the flow rate of the flow X2 rising from the bottom surface of the crucible below the single crystal silicon is small, the flow rate of the flow X5 of the silicon melt flowing from the side of the single crystal silicon C to the side wall 1a of the vitreous silica crucible also changes. small. In other words, when the flow rate of the flow X5 of the silicon melt flowing from the single crystal silicon side to the side wall 1a of the vitreous silica crucible is small, the flow rate of the flow X2 rising from the crucible bottom surface 1b below the single crystal silicon C is also Become smaller.

Furthermore, as shown in FIG. 1, in the case where the flow X2 rising from the bottom surface 1b of the crucible below the single crystal silicon C is small, it is because the side wall 1a of the vitreous silica crucible passes through the bottom surface of the crucible to reach the single crystal silicon C. It takes time, or after rising from the bottom of the crucible, it goes around to the radially outer side of the crucible and passes directly under the surface of the liquid to be absorbed by the silicon crystals. Therefore, the diffusion of oxygen from the silicon melt and the reduction of oxygen concentration can be achieved. The uniformity of the oxygen concentration in the direction of the crystal growth axis and the uniformity of the oxygen concentration in the surface of the substrate perpendicular to the crystal growth axis. In particular, when the flow rate of the silicon melt X5 flowing from the side of the single crystal silicon C to the side wall 1a of the quartz glass crucible is 0.16 m/s or less, the oxygen concentration can be lowered, and the crystal growth axis can be suppressed. The unevenness of the oxygen concentration in the direction.

In addition, as shown in FIG. 3, for example, as the flow of the silicon melt in the vitreous silica crucible 1, there is a flow Y1 (hereinafter also referred to as flow Y1) that flows from below to above in contact with (along) the side wall 1a of the vitreous silica crucible. In this case, the silicon melt will also react with the quartz component of the quartz glass crucible, thereby dissolving the side wall 1a of the quartz glass crucible, thereby absorbing oxygen.

The aforementioned silicon melt flows along the side wall of the quartz glass crucible 1 to reach the free surface. After that, a flow Y2 (hereinafter also referred to as flow Y2) flowing from the side wall of the quartz glass crucible 1 to the single crystal silicon side is formed. The aforementioned flow of silicon melt Y2 is due to the diffusion of oxygen absorbed into the silicon melt and the degree of oxygen release from the melt becomes higher, so that the silicon melt with low oxygen concentration flows to the single crystal silicon side, so that only single crystals The silicon has a low concentration in the outer periphery, which causes poor in-plane distribution, which is not preferable.

In addition, in the case shown in FIG. 3, a flow X2 that rises from the bottom surface 1b of the crucible below the single crystal silicon C is also formed. That is, the silicon melt flowing from the side wall of the quartz glass crucible to the single crystal silicon side has a low oxygen concentration, and the silicon melt rising from the bottom surface of the crucible below the single crystal silicon C does not diffuse oxygen and Since it is released from the melt, it has a high oxygen concentration.

As a result, the oxygen concentration in the center of the single crystal silicon becomes high. On the other hand, because the oxygen concentration in the outer periphery of the single crystal silicon becomes low, the in-plane distribution deteriorates, so that the concentration of oxygen perpendicular to the growth axis of the crystal becomes poor. The uniformity of the oxygen concentration in the surface of the substrate hinders it. Therefore, in the flow of the silicon melt M on the surface, it is preferable that the flow Y2 from the side wall of the crucible to the single crystal silicon side does not reach the single crystal silicon.

In addition, the flow of the silicon melt in the quartz glass crucible is affected by the strength of the magnetic field. In particular, when the single crystal silicon is pulled to reduce the silicon melt in the vitreous silica crucible, it is strongly affected by the intensity of the magnetic field, and the silicon melt flowing from the side of the single crystal silicon to the side wall of the crucible is caused to flow. Make a change. In other words, even if the flow rate of the inert gas or the furnace pressure, the number of revolutions of the quartz glass crucible, and the number of revolutions of single crystal silicon are the same, the flow of the silicon melt in the quartz glass crucible will occur due to the intensity of the magnetic field. Variety.

For example, FIG. 4 shows the flow of silicon melt in a state where a magnetic field of 1000 Gauss is applied to the horizontal direction. The aforementioned Figure 4 shows the simulation results of the flow of the silicon melt under the pulling condition of the curing rate 0.6 in the experiment 1 described later. The magnetic field of 1000 Gauss is applied in the horizontal direction, and the center of the magnetic field in the horizontal direction is in the single crystal. The flow of the silicon melt in the silicon melt 20mm below the free surface in the silicon center. In addition, the symbol B in the figure ☉ indicates that the direction of the magnetic flux is from the far side of the paper to the near side of the paper. In addition, the arrow mark of B indicates the direction of the magnetic flux. In addition, (b) in FIG. 4 is the same diagram as FIG. 3.

As shown in Fig. 4(a) and Fig. 4(b), in the case of 1000 Gauss, since the flow Y2 of silicon melt flowing from the side wall of the crucible to the single crystal silicon side is generated, it is less good. In addition, since the ascending flow X2 from the bottom of the crucible below the single crystal silicon C becomes stronger, the silicon melt that has absorbed oxygen flows to the lower end of the single crystal silicon, and because the single crystal silicon absorbs too much oxygen, it is relatively Bad.

In addition, in the state shown in FIG. 4, the state of changing the magnetic field intensity from 1000 Gauss to 2000 Gauss is shown in FIG. 5(a) and FIG. 5(b). As shown in FIG. 5, the silicon melt containing oxygen largely detours (flows X3) to the radially outer side and rises. As a result, oxygen in the silicon melt diffuses, and the oxygen concentration can be reduced.

In addition, in the state shown in FIG. 4, the state after changing the magnetic field intensity from 1000 Gauss to 3000 Gauss is shown in FIG. 6(a) and FIG. 6(b). As shown in FIG. 6, the silicon melt containing oxygen largely detours (flows X3) to the radially outer side and rises. As a result, oxygen in the silicon melt diffuses, and the oxygen concentration can be reduced.

Therefore, the pulling of single crystal silicon is preferably controlled in the following manner: the magnetic field strength is at least 2000 Gauss, and as the flow of the silicon melt surface, there is silicon flowing from the side of the single crystal silicon to the side wall of the crucible. The flow of melt. In addition, when there is a flow from the side wall of the crucible toward the single crystal silicon side as the flow of the silicon melt surface, it is preferable that the flow from the side wall of the crucible toward the single crystal silicon side does not reach the single crystal silicon. Take control.

In particular, there is sufficient silicon melt in the quartz glass crucible, and in the pulling of the straight body of single crystal silicon with a solidification rate of 0.4 or less, it is preferable that the magnetic field strength is at least 3000 Gauss. In order to ensure that there is sufficient silicon melt in the vitreous silica crucible, a flow that detours to the radially outer side as shown in Fig. 1 occurs. As a result, since oxygen in the silicon melt is diffused and released, the oxygen concentration of the single crystal silicon can be reduced.

In addition, it is preferable that the aforementioned magnetic field strength is gradually reduced from a curing rate of 0.4 to a curing rate of 0.6, and the magnetic field strength is set to 2000 Gauss after a curing rate of 0.6. With the decrease of the silicon melt in the quartz glass crucible, the aforementioned magnetic field strength is gradually reduced. After the curing rate is 0.6, the magnetic field strength is set to 2000 Gauss, as shown in Figure 5 (a) and Figure 5 As shown in (b), the silicon melt containing oxygen largely circulates to the outside in the radial direction, so that the silicon melt rises from the bottom surface of the crucible below the single crystal silicon. As a result, the oxygen of the silicon melt diffuses to reduce the oxygen concentration, and since FIGS. 1 and 5 (b) become the same environment, the oxygen concentration in the direction of the crystal growth axis becomes uniform.

In addition, there is a flow of silicon melt from the side of the single crystal silicon to the side wall of the crucible, and the condition that the flow rate of the silicon melt from the side of the single crystal silicon to the side wall of the crucible is under 0.16 m/s is subject to a magnetic field. The influence of intensity, flow rate of inert gas or furnace pressure control, rotation control of quartz glass crucible, and rotation control of single crystal silicon. Although the flow rate of the silicon melt can be measured using a tracer or the like, the crystals in the pulling process cannot be used as a product when the measurement is performed, and the preparations for the measurement operation of the tracer are complicated. Therefore, although the flow velocity of the silicon melt can be estimated by simulation, under conditions that require analysis of three-dimensional convection such as a transverse magnetic field, the calculation time becomes huge.

Therefore, the present inventors reviewed a relational expression to easily find the following conditions: the flow velocity of the silicon melt flowing from the single crystal silicon side to the side wall of the crucible is set to 0.16 m/s or less. Specifically, through three-dimensional simulation, it became clear that the radius of the single crystal silicon ÷ the radius of the crucible × the number of revolutions of the single crystal × the magnetic field strength ÷ (the distance from the surface of the molten silicon to the lower end of the shielding plate) When the value calculated by the calculation formula is 190 or less, the flow velocity of the silicon melt from the single crystal silicon side to the side wall of the crucible can be set to 0.16 m/s or less.

Here, the reason for setting the radius of the single crystal silicon ÷ the radius of the crucible × the number of revolutions of the single crystal silicon × the magnetic field strength ÷ (the distance from the surface of the silicon melt to the lower end of the shielding plate) is based on the following. The driving force of the flow from the silicon crystal to the side wall of the crucible depends on the radius of the single crystal silicon and the radius of the crucible, the number of rotations of the single crystal silicon and the strength of the magnetic field. Here, when the radius of the crucible is large, since the driving force of the flow from the silicon crystal to the side wall of the crucible is reduced, it is set to divide (divide) the radius of the single crystal silicon by the crucible The radius of the pot.

In addition, normally, although only the driving force should be considered, the distance from the surface of the silicon melt to the lower end of the shielding plate changes the difficulty of controlling the oxygen concentration of the melt. Therefore, the aforementioned distance must also be considered. For example, when the aforementioned distance is too narrow, the influence of the atmosphere (argon (Ar) gas flow rate or furnace pressure) in the furnace is large, and therefore the control of the magnetic field strength becomes difficult. In the case of a wide distance, it is caused by the molten metal. The influence of convection is strong and the aforementioned driving force control becomes effective. Furthermore, since it is considered that the speed of the crucible has a small influence on the flow rate, it is not included in the aforementioned relational expression. However, since the lower the rotation speed of the crucible, the more low-oxygen crystals can be obtained, so it is preferable to set the rotation speed of the crucible to 1.0 rpm or less.

[Experiment 1 to Experiment 4] The general pulling device shown in Figure 7 is used to pull the single crystal silicon under the conditions shown in Table 1 and Figure 8, and the silicon melt in the pulling is from the single crystal silicon side to the side wall of the crucible The flow rate, the oxygen concentration and the dispersion of the oxygen concentration in the direction of the crystal growth axis of the single crystal silicon, and the dispersion of the oxygen concentration in the substrate plane perpendicular to the crystal growth axis were measured.

First, the lifting device shown in FIG. 7 will be described. The lifting device 10 has: a cylindrical chamber (cavity) 11, a crucible 12 installed in the chamber 11, and a crucible The raw material silicon of the pot 12 is melted by a carbon heater 13. The inner side of the crucible 12 is composed of a quartz glass crucible 12a, and the outer side of the crucible 12 is composed of a graphite crucible 12b. In addition, in the chamber 11, a heat preservation tube 14 is provided around the outer periphery of the carbon heater 13. The thermal insulation cylinder 14 is formed in a cylindrical shape, and a thermal insulation board 15 extending inward is provided at the upper end of the thermal insulation cylinder 14. In addition, a radiation shield (shielding plate) 16 is provided to prevent excess radiant heat from the carbon heater 13 and the like from being given to the single crystal silicon C during growing (during pulling).

In the aforementioned radiation shield (shielding plate) 16, openings are formed in the upper part of the aforementioned radiation shield (shielding plate) 16 so as to surround the periphery of the single crystal silicon C, which is tied to the upper portion of the crucible 12 and in the vicinity of the crucible 12 16b. An opening 16a is formed in the lower part of the radiation shield (shielding plate) 16, and a tapered surface 16c is formed so that the area of the opening gradually decreases from the upper part to the lower part. By providing the aforementioned radiation shield 16, the purifying inert gas (Ar gas) G supplied into the crucible 12 from above flows to the crucible through the gap between the radiation shield 16 and the surface of the silicon melt M At last, the inert gas G for purification is finally discharged to the outside of the chamber 11 (outside the chamber). Furthermore, the gap between the lower end of the radiation shield 16 and the surface of the silicon melt M is called a gap (Gap).

In addition, the outer side of the chamber 11 is provided with a magnetic field generating device 17 for applying a magnetic field in the horizontal direction. The magnetic field from the aforementioned magnetic field generating device 17 is arranged in such a manner that the center of the horizontal magnetic field is located in the silicon melt below the free surface in the center portion of the single crystal silicon. In addition, in the pulling of the single crystal silicon, the magnetic field generating device 17 is controlled such that the magnetic field strength generates at least 2000 Gauss. Furthermore, although not shown in the figure, the pulling mechanism for pulling the single crystal silicon C is arranged above the chamber 11. The aforementioned pulling mechanism is composed of a winding mechanism driven by a motor and a pulling cable 18 that can be wound up by the aforementioned winding mechanism. In addition, a seed crystal P is installed at the front end of the pulling cable 18, and the pulling cable 18 is pulled while being grown into a single crystal silicon C.

In addition, although not shown, the single crystal silicon pulling device 10 is provided with: a motor, which rotates the crucible 12; a lifting device, which controls the height of the crucible 12; and a control device, which controls the aforementioned motor and the aforementioned lifting device; The aforementioned single crystal silicon pulling device 10 is constructed by rotating the crucible 12 and raising the height position of the crucible 12 while growing the single crystal silicon C. In addition, although not shown, the upper part of the chamber 11 is provided with a gas supply port 11a, and the inert gas (Ar gas) for purification is configured to be supplied into the chamber 11. In addition, a plurality of exhaust ports 11b are provided on the bottom surface of the chamber 11, and an exhaust pump (not shown) as an exhaust mechanism is connected to the exhaust port. Therefore, the inert gas (Ar gas) G for purification that has been supplied from the gas supply port into the chamber 11 can flow to the crucible by the exhaust pump through the gap between the radiation shield 16 and the surface of the silicon melt M In addition, the inert gas G for purification is finally discharged to the outside of the chamber 11 (outside the chamber).

Here, Gap in Table 1 is the gap size between the radiation shield 16 and the surface of the silicon melt M, SR is the number of crystallization revolutions, CR is the number of crucible revolutions, and the flow rate of Ar is the purification supplied to the chamber 11 With the flow rate of inert gas (Ar gas), the pressure in the furnace is the pressure in the chamber 11. In addition, the intensity of the magnetic field is changed under the conditions shown in FIG. 8, and the center position of the magnetic field is set to 20 mm below the surface of the silicon melt M. That is, in Experiment 1, the magnetic field strength was set to 3000 Gauss, and the single crystal silicon was pulled.

In Experiment 2, the magnetic field strength was set to 3000 Gauss, and the single crystal silicon was pulled until the curing rate was 0.4. The magnetic field strength was gradually decreased until the curing rate was 0.7. Then, the magnetic field strength was set to 1500 Gauss and the single crystal silicon was processed. Lift up. In Experiment 3, the magnetic field strength was set to 3000 Gauss, and the single crystal silicon was pulled until the curing rate was 0.4. The magnetic field strength was gradually decreased until the curing rate was 0.6. Then, the magnetic field strength was set to 2000 Gauss and the single crystal silicon was performed. Of lifting. In Experiment 4, the magnetic field strength was set to 3000 Gauss, the magnetic field strength was gradually decreased until the curing rate was 0.2, and then the magnetic field strength was set to 2000 Gauss, and the single crystal silicon was pulled.

[Table 1] parameter Experiment 1 Experiment 2 Experiment 3 Experiment 4 Gap(mm) 40 40 40 40 SR(rpm) 9 9 9 9 CR(rpm) 0.5 0.5 0.1 0.1 Ar flow (L/min) 100 100 100 100 Furnace pressure (Torr) 50 50 50 50 Magnetic field strength (G) 3000 3000⇒1500 3000⇒2000 3000⇒2000 Magnetic field position (mm) -20 -20 -20 -20

Fig. 9 shows the flow direction and flow rate of the silicon melt during the pulling in the above experiment 1 to experiment 4. (A) in Fig. 9 shows the direction and flow rate of the flow of the silicon melt during the pulling at a curing rate of 0.25 (3000 Gauss: refer to Fig. 8) in Experiment 1. (B) in Fig. 9 shows the direction and flow rate of the flow of the silicon melt during the pulling at a curing rate of 0.6 in Experiment 1 (3000 Gauss: refer to Fig. 8). (C) in Fig. 9 shows the direction and flow rate of the flow of the silicon melt during the pulling at a curing rate of 0.6 in Experiment 3 (2000 Gauss: refer to Fig. 8).

As shown in (a) in Figure 9, the maximum value of the flow velocity during pulling (3000 Gauss) at a curing rate of 0.25 is in the range of 0.20m/s to 0.24m/s. In addition, as shown in (b) of Fig. 9, the maximum value of the flow velocity during pulling (3000 Gauss) at a curing rate of 0.6 is in the range of 0.20m/s to 0.24m/s. In contrast, as shown in (c) in Fig. 9, the maximum value of the flow velocity during pulling (2000 Gauss) at a curing rate of 0.6 is in the range of 0.12 m/s to 0.16 m/s. Therefore, when the single crystal silicon is pulled to reduce the silicon melt in the quartz glass crucible, the flow rate of the silicon melt flowing from the single crystal silicon side to the side wall of the quartz glass crucible can be reduced by reducing the magnetic field strength. The maximum value is set to 0.16m/s or less.

In addition, the oxygen concentration of the single crystal silicon after pulling was measured. The measurement system was measured using Fourier transform infrared spectroscopy (FT-IR). The results of the measurement are shown in FIG. 10. In Experiment 1, the oxygen concentration after the curing rate 0.6 increased. In contrast, in Experiments 2, 3, and 4, there was no increase in the oxygen concentration after the curing rate 0.6, or even if the oxygen concentration increased, it was less than 1.0× 10 ¹⁸ atoms/cm ³ .

That is, according to B in FIG. 9, it can be seen that the flow rate of the silicon melt surface is fast as a result of the magnetic field of 3000 Gauss after the curing rate is 0.6. Therefore, the flow after a large detour to the radially outer side as shown in Fig. 1 does not occur, and the flow rises from the bottom surface of the crucible below the single crystal silicon, so that oxygen is absorbed by the single crystal silicon. As a result, it is considered that the oxygen concentration after the curing rate 0.6 has risen.

In addition, the dispersion ΔOi of the oxygen concentration in the crystal growth axis direction of the single crystal silicon after the pulling was measured. The measurement system used Fourier Transform Infrared Spectroscopy (FT-IR), and measured at a pitch of 5 mm in the radial direction. The results of the aforementioned measurement are shown in FIG. 11. The dispersion ΔOi of the oxygen concentration is obtained from the following calculation formula. ΔOi=(Maximum value-minimum value of measuring point)/Minimum value×100[%] In Experiment 2, the oxygen concentration after the curing rate 0.7 was dispersion. In contrast, the large in-plane dispersion of the oxygen concentration in Experiments 1, 3, and 4 was not found. It is considered that this is a result of the generation of a magnetic field (1500 gauss) below 2000 Gauss after the curing rate is 0.7, and the convection of the silicon melt becomes unstable, thereby increasing the dispersion of the oxygen concentration.

Furthermore, the dispersion of the oxygen concentration in the surface of the substrate in the magnetic field intensity in (a) of FIG. 12 in Experiment 2 is shown in (b) of FIG. 12. That is, from Experiment 2 with a curing rate of 0.52 (test material No. 1), a curing rate of 0.59 (test material No. 2), a curing rate of 0.67 (test material No. 3), and a curing rate of 0.75 (test material No. 4) after growth The dispersion of oxygen concentration in the plane of the cut-out substrate was measured. The measurement system used Fourier Transform Infrared Spectroscopy (FT-IR), and the measurement was performed in the radial direction under the condition of a pitch of 5 mm. The result of the aforementioned measurement is shown in (b) of FIG. 12. According to (b) in FIG. 12, it can be seen that by setting the magnetic field strength to 2000 Gauss, the dispersion of the oxygen concentration in the plane can be reduced.

[Experiment 5 and Experiment 6] In Experiment 5 and Experiment 6, the single crystal silicon was pulled by changing the magnetic field intensity in the manner shown in FIG. 13. The lifting conditions are as follows. In Experiment 5, the magnetic field strength was set to 3000 Gauss, and the magnetic field strength was gradually decreased from a curing rate of 0.4, and then the magnetic field strength was set to 2000 Gauss from a curing rate of 0.6. The other conditions were set to be the same as Experiment 1. In Experiment 6, the magnetic field strength was set to 2000 Gauss, and the magnetic field strength was gradually increased until the curing rate was 0.2, and then the magnetic field strength was slowly decreased from the curing rate of 0.4, and the magnetic field strength was set to 2000 gauss from the curing rate of 0.6. The other conditions were set to be the same as Experiment 1.

In addition, the dispersion of the resistivity in the plane of the substrate cut out from the single crystal silicon after the pulling was measured. The measurement was performed using a four-probe method with a pitch of 5 mm in the radial direction of the silicon substrate. The results of the aforementioned measurement are shown in FIG. 14. It can be clearly seen from FIG. 14 that when the magnetic field strength is set to 2000 Gauss, the dispersion of the resistivity in the plane is small.

[Experiment 7 to Experiment 15] There is a flow of silicon melt from the side of the single crystal silicon to the side wall of the crucible, and the relational expression used to easily find the following conditions has been reviewed: the flow of the silicon melt from the side of the aforementioned single crystal silicon to the side wall of the crucible has been reviewed. The flow velocity becomes 0.16 m/s or less. Furthermore, the flow velocity in Table 2 is a value obtained by simulation. That is, using the conditions shown in Table 2, in the calculation based on the radius of the single crystal silicon ÷ the radius of the crucible × the number of revolutions of the single crystal × the magnetic field strength ÷ (the distance from the surface of the molten silicon to the lower end of the shielding plate) When the calculated value of the formula is less than 190, there is a flow of silicon melt from the single crystal silicon side to the side wall of the crucible, and the flow of silicon melt from the aforementioned single crystal silicon side to the side wall of the crucible is confirmed The flow velocity can be 0.16m/s or less. In addition, there are cases where the magnetic field intensity can be set to 0.16 m/s or less even under the conditions of 1000 Gauss and 1500 Gauss. However, since good in-plane uniformity of oxygen concentration cannot be obtained, it is not preferable.

[Table 2] Crystal radius cry [mm] Crucible radius cru [mm] Crystal revolutions SR [rpm] Magnetic field [G: Gauss] The distance from the surface of the silicon melt to the lower end of the shielding plate Gap [mm] The result calculated according to the aforementioned formula Velocity [m/s] Judgment (＜190) Experiment 7 155 394 9 3000 55 193.1 0.195 X Experiment 8 155 394 9 2000 55 128.7 0.142 〇 Experiment 9 105 296 20 3000 30 709.5 0.188 X Experiment 10 105 296 12 2000 50 170.3 0.141 〇 Experiment 11 155 394 8 3000 20 472.1 0.251 X Experiment 12 155 394 8 2000 20 314.7 0.249 X Experiment 13 155 394 9 3000 40 265.5 0.233 X Experiment 14 155 394 9 2000 40 177.0 0.152 〇 Experiment 15 155 394 9 1500 40 132.8 0.148 △

In this way, the value calculated based on the calculation formula of the radius of the single crystal silicon ÷ the radius of the crucible × the number of revolutions of the single crystal × the magnetic field strength ÷ (the distance from the surface of the molten silicon to the lower end of the shielding plate) is 190 or less Under the condition of, the flow velocity of the flow of the silicon melt from the single crystal silicon side to the side wall of the crucible becomes 0.16 m/s or less. Therefore, there is no need to measure the flow rate of the silicon melt, and the calculation is based on the radius of the single crystal silicon ÷ the radius of the crucible × the number of revolutions of the single crystal × the magnetic field strength ÷ (the distance from the surface of the silicon melt to the lower end of the shielding plate) The value calculated by the formula can determine whether the flow velocity of the silicon melt from the single crystal silicon side to the side wall of the crucible becomes 0.16 m/s or less.

[Experiment 1, Experiment 16 to Experiment 20] As shown in Table 3, in Experiment 1 (positioning the center of the magnetic field to be 20 mm from the surface of the melt to the bottom), the oxygen concentration in the pulling single crystal silicon and the solidification rate of 0.25 was measured. The measurement system was measured using Fourier Transform Infrared Spectroscopy (FT-IR). The results of the measurement are shown in FIG. 15. As shown in Table 3, except for changing the position relative to the center of the magnetic field in Experiment 1, under the same conditions as Experiment 1, the oxygen concentration in pulling single crystal silicon and the curing rate of 0.25 was measured. The results of the measurement are shown in FIG. 15.

[table 3] Experiment 1 Experiment 16 Experiment 17 Experiment 18 Experiment 19 Experiment 20 Gap(mm) 40 40 40 40 40 40 SR(rpm) 9 9 9 9 9 9 CR(rpm) 0.5 0.5 0.5 0.5 0.5 0.5 Ar flow (L/min) 100 100 100 100 100 100 Furnace pressure (Torr) 50 50 50 50 50 50 Magnetic field strength (Gauss) 3000 3000 3000 3000 3000 3000 Magnetic field position (mm) -20 +50 0 -60 -70 -100 Oxygen concentration (×10 ¹⁸ atomos/cm ³ ) 0.78 1.01 0.80 0.89 1.03 1.18

As can be understood from Fig. 15, under the condition that the center of the magnetic field is in the silicon melt within a range of 60 mm from the surface of the melt to the bottom (Experiments 17 and 18), it has been found that the oxygen concentration is less than 1.0×10 ¹⁸ The low oxygen concentration of atoms/cm ^3.

1,12a: Quartz glass crucible 1a: side wall of quartz glass crucible 1b: bottom of the crucible 10: Lifting device 11: Chamber 11a: Gas supply port 11b: Exhaust port 12: Crucible 12b: Graphite crucible 13: Carbon heater 14: Insulation tube 15: Insulation board 16: Radiation shield (shielding plate) 16a, 16b: opening 16c: Cone 17: Magnetic field generator 18: Tirasu C: Monocrystalline silicon G: Inert gas for purification M: Silicon melt P: seed crystal X1: Flow of silicon melt (flowing from above to below while contacting the side wall of the quartz glass crucible) X2: Flow of silicon melt (rising from the bottom of the crucible below the single crystal silicon C) X3: Flow of silicon melt (flow to the radial outside of the crucible) X4: Flow of silicon melt (flows to the radial inner side of the crucible and returns to the bottom of the single crystal silicon) X5: Flow of silicon melt (flow from the single crystal silicon side to the side wall of the crucible in the surface of the silicon melt) Y1: Flow of silicon melt (flowing from below to above along the side wall of the quartz glass crucible) Y2: Flow of silicon melt (from the side wall of the quartz glass crucible to the single crystal silicon side)

[Figure 1] A schematic diagram showing the flow of silicon melt. [FIG. 2] A schematic diagram showing the flow of silicon melt from the state of FIG. 1 to the state after the silicon melt in the vitreous silica crucible is reduced. [Fig. 3] is a schematic diagram showing other flows of silicon melt. [Fig. 4] is a schematic diagram showing the flow of the silicon melt under the condition that the magnetic field intensity is set to 1000 Gauss. Fig. 4(a) is a plan view, and Fig. 4(b) is a cross-sectional view. [Fig. 5] is a schematic diagram showing the flow of the silicon melt under the condition that the magnetic field strength has been set to 2000 Gauss. (a) in Fig. 5 is a plan view, and (b) in Fig. 5 is a cross-sectional view. [Fig. 6] is a schematic diagram showing the flow of the silicon melt under the condition that the magnetic field strength has been set to 3000 Gauss. (a) in Fig. 6 is a plan view, and (b) in Fig. 6 is a cross-sectional view. [Fig. 7] A schematic configuration diagram of a single crystal silicon pulling device. [Figure 8] is a graph showing the change of the magnetic field intensity in Experiment 1 to Experiment 4. [Figure 9] is a graph showing the flow direction and flow rate of the silicon melt on the surface. (a) in Figure 9 is a graph showing the time point of the solidification rate of 0.25 (magnetic field strength of 3000 Gauss) in Experiment 1, in Figure 9 (b) is a graph showing the time point of the curing rate of 0.6 (magnetic field intensity of 3000 Gauss) in Experiment 1, and (c) in FIG. 9 is a graph showing the time point of the curing rate of 0.6 (magnetic field strength of 2000 Gauss) in Experiment 2. [Figure 10] is a graph showing the relationship between the curing rate and the oxygen concentration in Experiment 1 to Experiment 4. [Figure 11] is a graph showing the dispersion relationship between the curing rate and the oxygen concentration in the direction of the crystal growth axis of single crystal silicon in Experiments 1 to 4. [Fig. 12] is a graph showing the relationship between the magnetic field strength in Experiment 2 and the dispersion of oxygen concentration in the substrate plane perpendicular to the crystal growth axis. Fig. 12(a) is a graph showing the measurement points, Fig. 12 (B) is a graph showing the dispersion of oxygen concentration in the surface of the substrate at each measurement point. [Figure 13] is a graph showing the changes in magnetic field strength in Experiment 5 and Experiment 6. [Fig. 14] A graph showing the relationship between the solidification rate in Experiment 5 and Experiment 6 and the dispersion of resistivity in the direction of the crystal growth axis of single crystal silicon. [Figure 15] is a graph showing the relationship between the position of the magnetic field center and the oxygen concentration in Experiment 1, Experiment 16 to Experiment 20.

1: Quartz glass crucible

1a: side wall of quartz glass crucible

1b: bottom of the crucible

C: Monocrystalline silicon

M: Silicon melt

X1: Flow of silicon melt (flowing from above to below while contacting the side wall of the quartz glass crucible)

X2: Flow of silicon melt (rising from the bottom of the crucible below the single crystal silicon C)

X3: Flow of silicon melt (flow to the radial outside of the crucible)

X4: The flow of silicon melt (flows to the radial inside of the crucible and returns to the bottom of the single crystal silicon)

X5: Flow of silicon melt (flow from the single crystal silicon side to the side wall of the crucible in the surface of the silicon melt)

Claims (4)

A method for manufacturing single crystal silicon is to pull the single crystal silicon from the silicon melt in the quartz glass crucible while applying a horizontal magnetic field to grow the single crystal silicon; there are some on the surface of the silicon melt The flow of the silicon melt from the single crystal silicon side to the side wall of the quartz glass crucible, and the flow rate of the silicon melt from the single crystal silicon side to the side wall of the quartz glass crucible is 0.16 m/s or less; The center of the horizontal magnetic field is located below the center of the single crystal silicon, and the magnetic field strength during the pulling of the straight body part of the single crystal silicon with a solidification rate of 0.4 or less is at least 3000 Gauss, which exceeds the solidification rate The intensity of the magnetic field is gradually decreased from 0.4 to 0.6 of the curing rate, and the intensity of the magnetic field is set to 2000 Gauss after the curing rate of 0.6. The method for manufacturing single crystal silicon according to claim 1, wherein the center of the magnetic field in the horizontal direction is in the silicon melt within a range of 60 mm from the surface of the melt to the bottom, and the pulling of the single crystal silicon The magnetic field strength in is at least 2000 Gauss. For the method of manufacturing single crystal silicon described in claim 1, the value calculated according to the following calculation formula is less than 190; the aforementioned calculation formula is defined as follows: radius of single crystal silicon [mm] ÷ radius of crucible [mm]× Single crystal silicon rotation speed [rpm] × magnetic field strength [Gauss] ÷ (distance from the surface of the molten silicon to the lower end of the shielding plate) [mm]. A method for manufacturing single crystal silicon is to pull the single crystal silicon from the silicon melt in the quartz glass crucible, while applying a horizontal magnetic field to grow the single crystal silicon; in the step of pulling the single crystal silicon In the above-mentioned single crystal silicon radius, crucible radius, single crystal silicon rotation speed, magnetic field strength, and the distance from the surface of the silicon melt to the lower end of the shielding plate are adjusted to pull the single crystal silicon so as to be based on the following The value calculated by the calculation formula becomes less than 190; the aforementioned calculation formula is defined as follows: the radius of the single crystal silicon [mm] ÷ the radius of the crucible [mm] × the number of revolutions of the single crystal silicon [rpm] × the magnetic field intensity [Gauss] ÷ (from The distance from the surface of the silicon melt to the lower end of the shielding plate Away) [mm].

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