Monocrystalline silicon, manufacturing method thereof and silicon wafer

Abstract

The present disclosure provides a single crystal silicon, a method for manufacturing the same, and a silicon wafer, the method comprising: when applying a magnetic field to a raw material melt and pulling up the single crystal silicon by a Czochralski method, growing the single crystal silicon in such a manner that the magnetic field intensity is controlled to 2000-3000 gauss. The silicon single crystal thus grown has an oxygen concentration of 5.6 ppma or more and 8.5 ppma or less, an RRG in a crystal cross-section orthogonal to the growth direction of the silicon single crystal of 1% or less, a low oxygen concentration, and high uniformity of radial resistance distribution.

Description

Technical Field

[0001] The present disclosure relates to the field of semiconductor manufacturing technology, and in particular to a single crystal silicon and a manufacturing method thereof, and a silicon wafer. Background Art

[0002] In the chip manufacturing process, in order to ensure that high-end process chips, especially storage-related chips, have a high yield, the silicon wafer used as the substrate must not only have a low oxygen concentration, but also a high uniformity in radial resistance distribution. For example, during the heat treatment stage of the chip manufacturing process, a high concentration of oxygen atoms will gather to form oxygen precipitation. During the plasma etching stage, local stress concentration or inconsistent electrical characteristics will occur between the locations where oxygen precipitation is formed in the silicon wafer and other locations where oxygen precipitation is not formed, resulting in device failure. In addition, the low uniformity of the radial resistance distribution of the silicon wafer will lead to significant differences in electrical performance among semiconductor devices of the same batch, such as significant differences in cutoff voltage among semiconductor devices of the same batch.

[0003] In the growth process of single crystal silicon, oxygen is one of the most common impurities. It will form a silicon-oxygen complex in the silicon crystal, affecting the electrical properties and mechanical stability of the material. At present, in order to reduce the oxygen concentration of single crystal silicon and improve mass productivity, the magnetic Czochralski (MCZ) method is usually used to pull the single crystal silicon while applying a magnetic field. According to the MCZ method, it is possible to suppress the convection of the melt and the melting of oxygen atoms into the raw material melt caused by the melting loss of the quartz crucible, thereby reducing the oxygen concentration in the single crystal silicon.

[0004] However, in actual use of the currently used MCZ method, the melt flow under the action of the magnetic field has a high degree of three-dimensional complexity, which will cause the radial resistance distribution of the single crystal silicon in the crystal cross section orthogonal to its growth direction to become uneven. Summary of the invention

[0005] The present invention provides a single crystal silicon and a manufacturing method thereof, as well as a silicon wafer. In the process of pulling a single crystal silicon rod by the Czochralski method, the magnetic field strength is controlled to obtain a single crystal silicon and a silicon wafer with low oxygen concentration and high uniformity of radial resistance distribution.

[0006] The technical solution of the present disclosure is achieved as follows: In a first aspect, the present disclosure provides a method for manufacturing single crystal silicon, the method comprising: When a magnetic field is applied to the raw material melt and a single crystal silicon is pulled by the Czochralski method, the growth of the single crystal silicon is carried out in a manner that controls the magnetic field strength to be between 2000 gauss and 3000 gauss, so as to obtain a single crystal silicon having an oxygen concentration of greater than 5.6 ppma and less than 8.5 ppma, and a radial resistivity gradient RRG within a crystal cross section orthogonal to the growth direction of the single crystal silicon of less than 1%.

[0007] In a second aspect, the present disclosure provides a single crystal silicon having an oxygen concentration of 5.6 ppma to 8.5 ppma, and a resistivity gradient RRG within a crystal cross section orthogonal to a growth direction of the single crystal silicon of less than 1%.

[0008] The single crystal silicon provided according to the second aspect has a low oxygen concentration and a uniform radial resistance distribution, and can be used as a suitable material for silicon wafers for high-end process chips, especially storage-related chips.

[0009] In a third aspect, the present disclosure provides a silicon wafer having an oxygen concentration of greater than 5.6 ppma and less than 8 ppma and an RRG of less than 1%.

[0010] The silicon wafer provided according to the third aspect has a low oxygen concentration and a uniform radial resistance distribution, and can be used as a suitable material for silicon wafers for high-end process chips, especially storage-related chips.

[0011] The present disclosure provides a single crystal silicon and a manufacturing method thereof, as well as a silicon wafer; in the process of pulling a single crystal silicon rod by the CZ method, the magnetic field strength is controlled to be between 2000G (Gauss) and 3000 (Gauss), thereby obtaining a single crystal silicon and a silicon wafer with low oxygen concentration and high uniformity of radial resistance distribution. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The present invention is a schematic side cross-sectional view of the structure of a crystal pulling furnace applicable to a method for manufacturing single crystal silicon.

[0013] Figure 2 This is a flowchart for explaining the method for producing single crystal silicon based on the present disclosure.

[0014] Figure 3 A simplified cross-sectional view of the shape of a single crystal silicon ingot provided in the present disclosure.

[0015] Figure 4 A schematic diagram of the 3D simulation of the solid-liquid interface during the growth of single crystal silicon provided in the present invention.

[0016] Figure 5 (A) is a schematic diagram of the doping substance concentration at the solid-liquid interface during the 3D simulation of single crystal silicon growth provided by the present invention.

[0017] Figure 5(B) is a schematic diagram of the horizontal flow velocity of the melt at the solid-liquid interface in the 3D simulation of the single crystal silicon growth process provided by the present invention.

[0018] Figure 6 A schematic diagram of radial resistance distribution of single crystal silicon grown when the horizontal magnetic field strength provided in the present disclosure is set to 3500G.

[0019] Figure 7 A schematic diagram of the simulation results of the concentration of doping substances at the solid-liquid interface obtained by simulation when the horizontal magnetic field strength provided in the present disclosure is set to 4000G, 3000G and 2000G respectively.

[0020] Figure 8 The present disclosure provides a schematic diagram of radial resistance distribution of single crystal silicon grown when the horizontal magnetic field strength is set to 1500G, 2000G, 2200G, 2500G, 2700G, 3000G and 3500G respectively.

[0021] Fig. 9 A schematic diagram of oxygen concentration obtained by simulation when the horizontal magnetic field strength provided in the present disclosure is set to 1000G, 2000G, 2500G, 3000G and 4000G respectively.

[0022] Fig.10 A schematic diagram of the oxygen concentration of single crystal silicon grown when the horizontal magnetic field strength provided in the present disclosure is set to 2000G, 2200G, 2500G, 2700G, 3000G and 3500G respectively. DETAILED DESCRIPTION

[0023] The technical solutions in the present disclosure will be described clearly and completely below in conjunction with the accompanying drawings in the present disclosure.

[0024] See also Figure 1 , which shows a side cross-sectional view of a structure example of a crystal pulling furnace that can be applied to the single crystal silicon manufacturing method proposed in the present disclosure. Figure 1 As shown, the crystal pulling furnace 1 includes a chamber 10, a quartz crucible 11 carrying a raw material melt 2 in the chamber 10, a graphite base 12 for holding the quartz crucible 11, a rotating shaft 13 supporting the base 12, an axis driving mechanism 14 for driving the rotating shaft 13 to rotate and rise and fall, a heater 15 arranged around the base 12, a heat insulating material 16 arranged along the inner surface of the chamber 10 on the outer side of the heater 15, a guide tube 17 arranged above the quartz crucible 11, a single crystal pulling wire 18 arranged above the quartz crucible 11 and coaxially with the rotating shaft 13, and a wire winding mechanism 19 arranged above the chamber 10.

[0025] Continue to see Figure 1The crystal pulling furnace 1 also includes a magnetic field applying device 21 arranged outside the chamber 10, a CCD camera 22 for photographing the inside of the chamber 10, an image processing unit 23 for processing the image photographed by the CCD camera 22, and a control unit 24 for controlling the shaft driving mechanism 14, the heater 15 and the wire winding mechanism 19 according to the output of the image processing unit 23.

[0026] In detail, the chamber 10 is composed of a main chamber 10a and a slender cylindrical crystal pulling chamber 10b connected to the upper opening of the main chamber 10a, and a quartz crucible 11, a susceptor 12, a heater 15 and a guide tube 17 are arranged in the main chamber 10a. A gas inlet 10c for introducing an inert gas such as argon, i.e., a purge gas, into the chamber 10 is provided at the upper part of the crystal pulling chamber 10b, and a gas outlet 10d for discharging the inert gas is provided at the bottom of the main chamber 10a. The inert gas is introduced into the chamber 10 from the gas inlet 10c, and the introduction amount can be controlled by a valve. In addition, the inert gas in the closed chamber 10 is discharged from the gas outlet 10d to the outside of the chamber 10, so that the SiO gas or CO gas generated in the chamber 10 can be recovered and the chamber 10 can be kept clean. In some examples, although not shown, a vacuum pump is connected to the gas outlet 10 d via a pipe, and the vacuum pump sucks the inert gas in the chamber 10 while controlling its flow rate through a valve, so that the chamber 10 is kept in a constant reduced pressure state.

[0027] An observation window 10 e is provided at the upper portion of the main chamber 10 a , and the growth condition of the silicon single crystal 3 , that is, the solid-liquid interface can be observed through the observation window 10 e .

[0028] The susceptor 12 is fixed to the upper end of a rotating shaft 13 extending in the vertical direction. In addition, the lower end of the rotating shaft 13 passes through the center of the bottom of the chamber 10 and is connected to a shaft driving mechanism 14 provided outside the chamber 10. The susceptor 12, the rotating shaft 13, and the shaft driving mechanism 14 constitute a rotating mechanism and a lifting mechanism of the quartz crucible 11.

[0029] The heater 15 melts the silicon raw material and the dopant filled in the quartz crucible 11 to form the raw material melt 2, and maintains the raw material melt 2 in a molten state. In some examples, the heater 15 is a carbon resistance heating heater, and is a substantially cylindrical member provided so as to surround the entire circumference of the quartz crucible 11 in the susceptor 12. In addition, the outer side of the heater 15 is surrounded by a heat insulating material 16, thereby improving the heat preservation in the chamber 10.

[0030] The magnetic field applying device 21 applies a magnetic field to the raw material melt 2 to suppress convection of the raw material melt 2 , thereby suppressing the dissolution of oxygen from the quartz crucible 11 and reducing the oxygen concentration in the silicon single crystal 3 .

[0031] Figure 2This is a flow chart for explaining the method for producing single crystal silicon based on the present disclosure. Figure 3 2 is a simplified cross-sectional view showing the shape of a single crystal silicon ingot. Figure 2 as well as Figure 3 As shown, the method for manufacturing single crystal silicon includes steps S11 to S16.

[0032] In step S11, the raw material in the quartz crucible 11 is heated to form a raw material melt 2; In the present disclosure, the raw materials in the quartz crucible 11 include dopants such as boron, phosphorus, arsenic or antimony in addition to silicon raw materials; accordingly, the raw material melt 2 includes other doping elements in addition to most of the silicon elements. In some examples, these dopants can be placed in the quartz crucible 11 at the same time as the silicon raw materials, and the silicon raw materials and dopants are heated and melted to form the raw material melt 2. In some examples, the silicon raw materials can be first placed in the quartz crucible 11 and heated and melted to form a silicon melt, and then the dopants are loaded into the doping cap and lowered above the silicon melt. The high temperature causes the dopants to be converted into liquid or gaseous state and mixed into the silicon melt to form the raw material melt 2.

[0033] In step S12 , the seed crystal attached to the front end of the wire 18 is dropped to allow the seed crystal to touch the raw material melt 2 .

[0034] It should be noted that after completing the above two steps, a pulling process is then performed to grow a single crystal by slowly pulling up the seed crystal while maintaining contact with the raw material melt 2. The pulling process includes steps S13 to S16 in sequence. Specifically, step S13 is a diameter reduction process for forming a neck 3a in which the crystal diameter is reduced to be very thin in order to eliminate dislocations. Step S14 is a shoulder growth process for forming a shoulder 3b in which the crystal diameter slowly increases in order to obtain a specified diameter. Step S15 is a body growth process for forming a body 3c in which the crystal diameter is maintained constant. Step S16 is a tail growth process for forming a tail 3d in which the crystal diameter slowly decreases, and the tail growth process ends when the single crystal finally leaves the melt surface. Through the above pulling processes, a single crystal is produced. Figure 3 The single crystal silicon ingot 3 shown has a neck portion 3a, a shoulder portion 3b, a body portion 3c, and a tail portion 3d in order from the upper end (top) toward the lower end (bottom) of the single crystal.

[0035] It should be noted that in the pulling process described in the above steps S13 to S16, in order to control the diameter of the single crystal silicon 3 and the liquid level position of the raw material melt 2, the CCD camera 22 takes an image of the boundary between the single crystal silicon 3 and the raw material melt 2, and the diameter of the single crystal at the solid-liquid interface and the distance (gap) between the melt surface and the insulator 17 are calculated from the photographed image. The control unit 24 controls the pulling conditions such as the pulling speed of the wire 18 and the power of the heater 15 so that the diameter of the single crystal silicon 3 becomes the target diameter. In addition, the control unit 24 controls the height position of the quartz crucible 11 so that the distance between the melt surface and the insulator 17 becomes constant.

[0036] In some examples, when implementing the above Figure 2 During the manufacturing method of single crystal silicon shown in the figure, the rotation speed of the single crystal silicon 3 is 8 to 11 rpm, the rotation speed of the quartz crucible 11 carrying the raw material melt 2 is 0.1 to 3 rpm, the pressure in the crystal pulling furnace 1 for growing the single crystal silicon is 20 to 70 Torr, the inert gas flow rate in the crystal pulling furnace 1 is 90 to 180 slm, and the maximum Gaussian plane is -200 to 200 mm, wherein the maximum Gaussian plane is the horizontal plane with the highest magnetic field intensity. Optionally, the maximum Gaussian plane can be the plane where the center point of the magnetic field coil is located.

[0037] In the present disclosure, the magnetic field applying device 21 applies a horizontal magnetic field to the raw material melt 2, and the magnetic field strength is controlled between 2000 Gauss (G, Gauss) and 3000G. This is because, through simulation and actual production of finished products, it can be found that: under the action of the horizontal magnetic field, the radial concentration distribution of the doping substance in the single crystal silicon at the solid-liquid interface is correlated with the melt flow at the solid-liquid interface, and the magnetic field strength of the horizontal magnetic field has the greatest influence on the melt flow, that is, the magnetic field strength of the horizontal magnetic field has the greatest influence on the concentration distribution of the doping substance at the solid-liquid interface. If the magnetic field strength is too high, the convection inside the melt will be excessively suppressed, affecting the growth rate and quality of the silicon crystal. If the magnetic field strength is too low, the melt convection cannot be effectively suppressed, resulting in inaccurate control of the oxygen content, affecting the resistivity uniformity of the silicon wafer. At the same time, if the magnetic field strength is too low, it may also cause the oxygen content in the silicon crystal to be too high, increasing crystal defects.

[0038] In detail, first of all, for Figure 1 The crystal pulling furnace structure shown and Figure 2 The manufacturing method of single crystal silicon shown in the figure is simulated in 3D, and the correlation between the radial concentration distribution of the doping material in the single crystal silicon at the solid-liquid interface and the melt flow at the solid-liquid interface under the action of the magnetic field can be obtained. Taking the dopant boron as an example, specifically, see Figure 4 The 3D simulation results for the solid-liquid interface are shown in the figure. At the solid-liquid interface selected by the box, Figure 5As shown in (A), the concentration of the doping substance, that is, the dopant boron, is the highest in the two regions indicated by A and B at the solid-liquid interface, and combined with Figure 5 As shown in (B), at the solid-liquid interface, the horizontal flow velocity of the melt in the two regions indicated by A and B is the smallest. Figure 5 (A) and Figure 5 (B) It can be seen that the two areas indicated by A and B are at the convergence of the melt flow in the horizontal direction, and the concentration of the dopant is the highest in these two areas. The reason is that the dopant is enriched at the solid-liquid interface, and the smaller the horizontal velocity, the thicker the boundary layer concentration of the dopant, resulting in the highest concentration of the dopant at the enriched area of ​​the solid-liquid interface, such as in the areas indicated by A and B. In addition, since the higher the concentration of the dopant, the lower the resistivity, therefore, according to Figure 5 (A) and Figure 5 From the simulation results presented in (B), it can be seen that the resistivity of the areas indicated by A and B will be significantly lower than the resistivity of other areas in the radial direction of the solid-liquid interface, and the radial resistance distribution at the solid-liquid interface is uneven.

[0039] Next, Figure 2 Taking the manufacturing method shown in the figure as an example, the horizontal magnetic field strength is set to 3500G to grow single crystal silicon, and then the resistivity of the silicon wafer obtained by processing the single crystal silicon is measured, and the following can be obtained: Figure 6 The radial resistance distribution diagram is shown in Figure 1. Figure 6 It can be found that there are low resistivity areas A' and B' in the silicon wafer along the radial direction, that is, the areas with the highest doping concentration. Although the positions of the low resistivity areas A' and B' are Figure 1 There is a gap between the positions of the areas indicated by A and B shown in the figure, but the phenomenon obtained in the 3D simulation is still reproduced from the actual process, that is, there will be enriched areas of doping substances in the radial direction of the silicon wafer, such as the low resistivity areas A' and B'. These two low resistivity areas make the radial resistance distribution of the silicon wafer uneven. In the present disclosure, the radial resistivity of the silicon wafer can be measured by the four-probe method.

[0040] Combined with the above Figure 5 (A) and Figure 5 (B) shows the 3D simulation results and Figure 6 The radial resistance distribution under the actual process conditions shown in the figure is still taking the dopant boron as an example. The present disclosure sets the horizontal magnetic field strength from high to low to 4000G, 3000G and 2000G respectively for 3D simulation to obtain the simulation results of the doping substance concentration at the solid-liquid interface, such as Figure 7 As shown. Figure 7It can be seen that as the horizontal magnetic field strength continues to decrease, the location of the area with the maximum dopant concentration at the solid-liquid interface (i.e., the red ring part in the simulation figure) gradually moves toward the edge of the single crystal silicon, until the horizontal magnetic field strength drops to 2000G, the area with the maximum dopant concentration moves out of the solid-liquid interface, that is, when the horizontal magnetic field is set at 2000G, the radial resistance distribution is more uniform than that at 3000G and 4000G. Figure 7 From the simulation results shown, it can be seen that the horizontal magnetic field intensity has a great influence on the distribution of the dopant concentration at the solid-liquid interface. This influence can be expressed as follows: the lower the horizontal magnetic field intensity, the more uniform the distribution of the dopant concentration at the solid-liquid interface, and thus the more uniform the radial resistance distribution of the silicon wafer.

[0041] The influence of magnetic field intensity and resistivity distribution is described below through a plurality of embodiments and comparative examples.

[0042] Embodiment 1: In this embodiment, the horizontal magnetic field strength is set to 2000G for single crystal silicon growth, and the resistivity is measured after sampling the silicon wafer obtained by processing the single crystal silicon. For example, the in-plane distribution of the resistivity of the silicon wafer can be measured. For example, the radial resistivity can be measured radially from the center of the wafer by a four-probe method, and the following can be obtained: Figure 8 The scatter plot of the radial resistivity distribution corresponding to 2000G (diamond block) is then used to calculate the radial resistivity gradient of the radial resistance distribution uniformity. Specifically, the maximum resistivity within the radial measurement range of the silicon wafer can be set to ρ Max , the minimum value is set to ρ Min When , the radial resistivity gradient (RRG) used to characterize the uniformity of radial resistance distribution is calculated by the following formula.

[0043] RRG(%)={(ρMax-ρMin) / ρMin}×100% Through the above method, it can be calculated that when the horizontal magnetic field strength is 2000G, the corresponding RRG is 0.61%.

[0044] Embodiment 2: In this embodiment, the horizontal magnetic field strength is set to 2200 G for single crystal silicon growth, and the radial resistivity is measured after sampling the silicon wafer obtained by processing the single crystal silicon, and the following can be obtained: Figure 8 The scatter plot of the radial resistivity distribution corresponding to 2200G (circle) is then used to calculate the radial resistivity gradient of the radial resistance distribution uniformity. It can be obtained that when the horizontal magnetic field strength is 2200G, the corresponding RRG is 0.41%.

[0045] Embodiment 3: In this embodiment, the horizontal magnetic field strength is set to 2500G for single crystal silicon growth, and the radial resistivity is measured after sampling the silicon wafer obtained by single crystal silicon processing, and the following can be obtained: Figure 8 The scatter plot of the radial resistivity distribution corresponding to 2500G ("cross" shape) is then used to calculate the radial resistivity gradient of the radial resistance distribution uniformity. It can be obtained that when the horizontal magnetic field strength is 2500G, the corresponding RRG is 0.88%.

[0046] Embodiment 4: In this embodiment, the horizontal magnetic field strength is set to 2700G for single crystal silicon growth, and the radial resistivity is measured after sampling the silicon wafer obtained by processing the single crystal silicon, and the following can be obtained: Figure 8 The scatter plot of the radial resistivity distribution corresponding to 2700G (triangle) is shown in the figure. Then the radial resistivity gradient of the radial resistance distribution uniformity is calculated from the scatter plot of the radial resistivity distribution. It can be obtained that when the horizontal magnetic field strength is 2700G, the corresponding RRG is 0.9%.

[0047] Embodiment 5: In this embodiment, the horizontal magnetic field strength is set to 3000G for single crystal silicon growth, and the radial resistivity is measured after sampling the silicon wafer obtained by single crystal silicon processing, and the following can be obtained: Figure 8 The scatter plot of the radial resistivity distribution corresponding to 3000G ("X" shape) is then used to calculate the radial resistivity gradient of the radial resistance distribution uniformity. It can be obtained that when the horizontal magnetic field strength is 3000G, the corresponding RRG is 0.99%.

[0048] It should be noted that the calculation methods of the resistivity gradient in Examples 2 to 5 can all refer to Example 1, and will not be elaborated here.

[0049] It can be obtained from the above-mentioned Examples 1 to 5 that when the horizontal magnetic field strength is between 2000G and 3000G, the resistivity gradient is less than 1%.

[0050] Comparative Example 1: In this embodiment, the horizontal magnetic field strength is set to 1500G for single crystal silicon growth, and the radial resistivity is measured after sampling the silicon wafer obtained by single crystal silicon processing, and the following can be obtained: Figure 8The scatter plot of the radial resistivity distribution corresponding to 1500G ("rice" shape) is then used to calculate the radial resistivity gradient of the radial resistance distribution uniformity. It can be obtained that when the horizontal magnetic field strength is 1500G, the corresponding RRG is 1.24%.

[0051] Comparative Example 2: In this embodiment, the horizontal magnetic field strength is set to 3500G for single crystal silicon growth, and the radial resistivity is measured after sampling the silicon wafer obtained by single crystal silicon processing, and the following can be obtained: Figure 8 The scatter plot of the radial resistivity distribution corresponding to 3500G (square) in the figure is used to calculate the radial resistivity gradient of the radial resistance distribution uniformity. It can be obtained that when the horizontal magnetic field strength is 3500G, the corresponding RRG is 1.11%.

[0052] According to the above-mentioned embodiments 1 to 5, as well as comparative examples 1 and 2, it can be obtained that when the horizontal magnetic field strength is set to 1500G, 2000G, 2200G, 2500G, 2700G, 3000G and 3500G in sequence, the corresponding RRGs are 1.24%, 0.61%, 0.41%, 0.88%, 0.9%, 0.99% and 1.11% respectively. From the above RRG, it can be seen that when the horizontal magnetic field is 2200G, the radial resistance distribution is the most uniform (limited to the current simulation results), and when the horizontal magnetic field strength is 2000G to 3000G, the RRG is below 1%, and when the horizontal magnetic field strength is outside 2000G to 3000G, the RRG is above 1%, that is, the present disclosure sets the horizontal magnetic field strength to 2000G to 3000G, which can improve the uniformity of the resistivity of the obtained silicon wafer.

[0053] In addition, the present disclosure sets the horizontal magnetic field strength from low to high to 1000G, 2000G, 2500G, 3000G and 4000G respectively for 3D simulation to obtain the simulation results of oxygen concentration, such as Fig. 9 As shown. Fig. 9 It can be seen that the oxygen concentration will gradually decrease and then increase with the increase of horizontal magnetic field strength.

[0054] The effect of magnetic field strength on oxygen concentration is described below through a number of embodiments and comparative examples.

[0055] Embodiment 6: The horizontal magnetic field strength can be set to 2000G for single crystal silicon growth and the oxygen concentration can be measured after sampling the silicon wafer obtained by the single crystal silicon processing. In the present disclosure, the oxygen concentration can be measured by Fourier Transform Infrared Spectroscopy (FTIR) in accordance with ASTM F-121 (1979) standard to obtain an oxygen concentration of about 8 ppma.

[0056] Embodiment 7: The horizontal magnetic field strength can be set to 2200G for single crystal silicon growth and the oxygen concentration of the silicon wafer obtained by the single crystal silicon processing is measured after sampling. The measured oxygen concentration is about 7.5ppma.

[0057] Embodiment 8: The horizontal magnetic field strength can be set to 2500G for single crystal silicon growth and the oxygen concentration of the silicon wafer obtained by the single crystal silicon processing is measured after sampling. The measured oxygen concentration is about 5.6ppma.

[0058] Embodiment 9: The horizontal magnetic field strength can be set to 3000G for single crystal silicon growth and the oxygen concentration of the silicon wafer obtained by the single crystal silicon processing is measured after sampling. The measured oxygen concentration is about 8.1ppma.

[0059] According to the above-mentioned Examples 6 to 9, when the horizontal magnetic field strength is between 200G and 3000G, the oxygen concentration of the silicon wafer in the manufactured single crystal silicon is greater than 5.6ppma and less than 8.5ppma.

[0060] Comparative Example 3: The horizontal magnetic field strength can be set to 1000G for single crystal silicon growth and the oxygen concentration of the silicon wafer obtained by the single crystal silicon processing is measured after sampling. The measured oxygen concentration is about 12.5ppma.

[0061] Comparative Example 4: The horizontal magnetic field strength can be set to 3500G to grow single crystal silicon and the oxygen concentration of the silicon wafer obtained by the single crystal silicon processing is measured after sampling. The measured oxygen concentration is about 9.5ppma.

[0062] Comparative Example 5: The horizontal magnetic field strength can be set to 4000G for single crystal silicon growth and the oxygen concentration of the silicon wafer obtained by the single crystal silicon processing is measured after sampling. The measured oxygen concentration is about 11.2ppma.

[0063] Reference Fig. 9 and Fig.10 , when the horizontal magnetic field is 2500G, the oxygen concentration is the lowest, which is 5.6ppma.

[0064] comprehensive Figure 8 , Fig. 9 and Fig.10 The measurement results shown show that when the magnetic field strength of the horizontal magnetic field is controlled between 2000G and 3000G, the oxygen concentration of the manufactured single crystal silicon is 5.6ppma or more and 8.5ppma or less, and the radial resistivity gradient RRG in the crystal cross section orthogonal to the growth direction of the single crystal silicon is 1% or less. Moreover, the oxygen concentration of the silicon wafer obtained by processing the single crystal silicon is 5.6ppma or more and 8.5ppma or less, and the RRG is 1% or less.

[0065] Specifically, when the magnetic field strength of the horizontal magnetic field is controlled between 2200G and 2500G, the oxygen concentration of the manufactured crystalline silicon is greater than or equal to 5.6ppma and less than or equal to 7.5ppma, and the RRG in the crystal cross section perpendicular to the growth direction of the single crystal silicon is less than or equal to 0.9%. Moreover, the oxygen concentration of the silicon wafer obtained by processing the single crystal silicon is greater than or equal to 5.6ppma and less than or equal to 7.5ppma, and the RRG is less than or equal to 0.9%.

[0066] As described above, in the method for manufacturing single crystal silicon based on the present disclosure, when a magnetic field is applied to the raw material melt and single crystal silicon is pulled up using the Czochralski method, the growth of the single crystal silicon is carried out in a manner that controls the magnetic field strength to be between 2000 gauss and 3000 gauss, thereby being able to manufacture single crystal silicon with a low oxygen concentration and a radial resistance distribution that is as uniform as possible.

[0067] It should be noted that the technical solutions described in the present disclosure can be combined arbitrarily without conflict.

[0068] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for producing single crystal silicon, characterized in that: The method for manufacturing single crystal silicon comprises: When a magnetic field is applied to the raw material melt and single crystal silicon is pulled by the Czochralski method, the growth of the single crystal silicon is carried out in a manner that controls the magnetic field strength to be between 2000 gauss and 3000 gauss, so as to obtain single crystal silicon having an oxygen concentration of greater than 5.6 ppma and less than 8.5 ppma, and a radial resistivity gradient RRG of less than 1% in a crystal cross section orthogonal to the growth direction of the single crystal silicon.

2. The method for producing single crystal silicon according to claim 1, wherein: The applied magnetic field is a horizontal magnetic field.

3. The method for producing single crystal silicon according to claim 1, wherein: The applied magnetic field strength is 2200 Gauss to 2500 Gauss.

4. The method for producing single crystal silicon according to claim 1, wherein: The raw material melt is formed by melting silicon raw material and dopant by heating.

5. The method for producing single crystal silicon according to any one of claims 1 to 3, characterized in that: When a magnetic field is applied to the raw material melt and single crystal silicon is pulled using the Czochralski method, the rotation speed of the single crystal silicon is 8 to 11 rpm, the rotation speed of the quartz crucible carrying the raw material melt is 0.1 to 3 rpm, the pressure in the crystal pulling furnace for growing the single crystal silicon is 20 to 70 Tor, the inert gas flow rate in the crystal pulling furnace is 90 to 180 slm, and the maximum Gaussian plane is -200 to 200 mm.

6. A single crystal silicon, characterized in that: The single crystal silicon is grown by controlling the magnetic field strength to be between 2000 gauss and 3000 gauss when a magnetic field is applied to a raw material melt and the single crystal silicon is pulled by the Czochralski method; and the oxygen concentration of the single crystal silicon is greater than 5.6 ppma and less than 8.5 ppma, and the radial resistivity gradient RRG in a crystal cross section orthogonal to the growth direction of the single crystal silicon is less than 1%.

7. The silicon single crystal according to claim 6, characterized in that: The oxygen concentration is 5.6 ppma or more and 8 ppma or less, The RRG of the crystal cross section is less than 0.9%.

8. A silicon wafer, characterized in that: The silicon wafer is obtained by processing the single crystal silicon according to claim 6 or 7, and the oxygen concentration of the silicon wafer is greater than 5.6 ppma and less than 8.5 ppma, and the RRG of the silicon wafer is less than 1%.

9. The silicon wafer according to claim 8, characterized in that: The oxygen concentration is 5.6 ppma or more and 8 ppma or less, RRG is less than 0.9%.

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