Single-crystal silicon and manufacturing method therefor, and silicon wafer

Abstract

A single-crystal silicon and a manufacturing method therefor, and a silicon wafer. The manufacturing method comprises: when a magnetic field is applied to a raw material melt and a single-crystal silicon is pulled by using the Czochralski method, growing the single-crystal silicon in a manner of controlling the magnetic field strength to be between 2000 Gauss and 3000 Gauss. In this way, the oxygen concentration of the grown single-crystal silicon is 5.6 ppma or more and 8.5 ppma or less, and the RRG in the crystal cross section orthogonal to the growth direction of the single-crystal silicon is 1% or less.

Description

A single-crystal silicon, its manufacturing method, and a silicon wafer

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411682128.0, filed in China on November 22, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of semiconductor manufacturing technology, and in particular to a single-crystal silicon, a method for manufacturing the same, and a silicon wafer. Background Technology

[0004] In chip manufacturing processes, to ensure high yields for high-end chips, especially memory-related chips, it is essential that the silicon wafer used as the substrate has not only a low oxygen concentration but also high uniformity in its radial resistance distribution. For example, during the thermal processing stage of chip manufacturing, high concentrations of oxygen atoms can accumulate to form oxygen precipitation. During the plasma etching stage, the locations where oxygen precipitation forms on the silicon wafer can create localized stress concentrations or inconsistent electrical properties compared to other areas, leading to device failure. Furthermore, low uniformity in the radial resistance distribution of the silicon wafer can result in significant differences in electrical performance within the same batch of semiconductor devices; for instance, there may be noticeable differences in the cutoff voltage between devices from the same batch.

[0005] Oxygen is one of the most common impurities in the growth of monocrystalline silicon. It forms silicon-oxygen complexes in the silicon crystal, affecting the electrical properties and mechanical stability of the material. Currently, to reduce the oxygen concentration in monocrystalline silicon and improve mass production, the magnetic czochralski (MCZ) method, which involves pulling monocrystalline silicon while applying a magnetic field, is commonly used. According to the MCZ method, melt convection can be suppressed, and the incorporation of oxygen atoms into the raw material melt caused by melting loss in the quartz crucible can be suppressed, thereby reducing the oxygen concentration in the monocrystalline silicon.

[0006] However, in practical applications of the MCZ method currently used, the melt flow under the influence of a magnetic field has a high degree of three-dimensional complexity, which leads to uneven radial resistance distribution in the crystal cross section orthogonal to the growth direction of single-crystal silicon. Summary of the Invention

[0007] This disclosure provides a single-crystal silicon, a method for manufacturing the same, and a silicon wafer; in the process of Czochralski pulling a single-crystal silicon rod, the magnetic field strength is controlled to obtain single-crystal silicon and silicon wafers with low oxygen concentration and high uniformity of radial resistance distribution.

[0008] The technical solution disclosed herein is implemented as follows:

[0009] In a first aspect, this disclosure provides a method for manufacturing single-crystal silicon, the method comprising:

[0010] When applying a magnetic field to the raw material molten liquid and pulling single-crystal silicon using the Czeklaussky method, the single-crystal silicon is grown in such a way that the magnetic field strength is controlled at 2000 Gauss to 3000 Gauss, so as to obtain single-crystal silicon with an oxygen concentration of 5.6 ppma or higher and 8.5 ppma or lower, and a radial resistivity gradient (RRG) of less than 1% in the crystal cross section orthogonal to the growth direction of the single-crystal silicon.

[0011] Secondly, this disclosure provides a monocrystalline silicon with an oxygen concentration of 5.6 ppma or higher and 8.5 ppma or lower, and a resistivity gradient RRG of less than 1% in a crystal cross section orthogonal to the growth direction of the monocrystalline silicon.

[0012] The monocrystalline silicon provided in the second aspect has a low oxygen concentration and a uniform radial resistance distribution, making it a suitable material for silicon wafers for high-end process chips, especially memory-related chips.

[0013] Thirdly, this disclosure provides a silicon wafer with an oxygen concentration of 5.6 ppma or more and 8 ppma or less, and an RRG of 1% or less.

[0014] The silicon wafer provided by the third party has a low oxygen concentration and a uniform radial resistance distribution, making it a suitable material for silicon wafers for high-end process chips, especially memory-related chips.

[0015] This disclosure provides a single-crystal silicon, a method for manufacturing the same, and a silicon wafer. During the Czochralski process of producing a single-crystal silicon rod, the magnetic field strength is controlled between 2000 G (Gauss) and 3000 G (Gauss) to obtain single-crystal silicon and silicon wafers with low oxygen concentration and high uniformity of radial resistance distribution. Attached Figure Description

[0016] Figure 1 is a side cross-sectional view of the structure of a crystal pulling furnace applicable to monocrystalline silicon manufacturing methods.

[0017] Figure 2 is a flowchart illustrating the method for manufacturing monocrystalline silicon based on the present disclosure.

[0018] Figure 3 is a simplified cross-sectional view of the shape of the single-crystal silicon ingot provided in this disclosure.

[0019] Figure 4 is a schematic diagram of the solid-liquid interface during the 3D simulated single-crystal silicon growth process provided in this disclosure.

[0020] Figure 5(A) is a schematic diagram of the dopant concentration at the solid-liquid interface during the 3D simulated single-crystal silicon growth process provided in this disclosure.

[0021] Figure 5(B) is a schematic diagram of the horizontal flow velocity of the melt at the solid-liquid interface during the 3D simulated single-crystal silicon growth process provided in this disclosure.

[0022] Figure 6 is a schematic diagram of the radial resistance distribution of single-crystal silicon grown when the horizontal magnetic field strength is set to 3500G, as provided in this disclosure.

[0023] Figure 7 is a schematic diagram of the simulation results of the dopant concentration at the solid-liquid interface when the horizontal magnetic field strength is set to 4000G, 3000G and 2000G respectively.

[0024] Figure 8 is a schematic diagram of the radial resistance distribution of single-crystal silicon grown when the horizontal magnetic field strength provided in this disclosure is set to 1500G, 2000G, 2200G, 2500G, 2700G, 3000G and 3500G respectively.

[0025] Figure 9 is a schematic diagram of the simulated oxygen concentration when the horizontal magnetic field strength provided in this disclosure is set to 1000G, 2000G, 2500G, 3000G and 4000G respectively.

[0026] Figure 10 is a schematic diagram of the oxygen concentration of single-crystal silicon grown when the horizontal magnetic field strength provided in this disclosure is set to 2000G, 2200G, 2500G, 2700G, 3000G and 3500G respectively. Detailed Implementation

[0027] The technical solutions in this disclosure will now be clearly and completely described with reference to the accompanying drawings.

[0028] Referring to Figure 1, a side cross-sectional view of a structural example of a crystal pulling furnace applicable to the single-crystal silicon manufacturing method proposed in this disclosure is shown. As shown in Figure 1, the crystal pulling furnace 1 includes a chamber 10, a quartz crucible 11 carrying molten raw material 2 within the chamber 10, a graphite base 12 for holding the quartz crucible 11, a rotating shaft 13 supporting the base 12, a shaft drive mechanism 14 for driving the rotating shaft 13 to rotate and move, a heater 15 disposed around the base 12, a heat insulation material 16 disposed on the outer side of the heater 15 along the inner surface of the chamber 10, a guide tube 17 disposed above the quartz crucible 11, a single-crystal pulling wire 18 disposed above the quartz crucible 11 and coaxially with the rotating shaft 13, and a wire winding mechanism 19 disposed above the chamber 10.

[0029] Referring again to Figure 1, the crystal pulling furnace 1 also includes a magnetic field application device 21 disposed outside the chamber 10, a CCD camera 22 for capturing images inside the chamber 10, an image processing unit 23 for processing images captured by the CCD camera 22, and a control unit 24 for controlling the shaft drive mechanism 14, the heater 15 and the wire winding mechanism 19 according to the output of the image processing unit 23.

[0030] In detail, chamber 10 consists of a main chamber 10a and a slender cylindrical crystal pulling chamber 10b connected to the upper opening of the main chamber 10a. A quartz crucible 11, a base 12, a heater 15, and a guide tube 17 are disposed within the main chamber 10a. A gas inlet 10c for introducing inert gases such as argon into chamber 10 (i.e., purging gas) is provided at the upper part of the crystal pulling chamber 10b, and an outlet 10d for discharging inert gases is provided at the bottom of the main chamber 10a. Inert gases are introduced into chamber 10 through the gas inlet 10c, and the introduction rate can be controlled by a valve. Furthermore, the inert gases within the sealed chamber 10 are discharged to the outside of chamber 10 through the outlet 10d, thereby enabling the recovery of SiO or CO gases generated within chamber 10 and maintaining the cleanliness of chamber 10. In some examples, although not shown, a vacuum pump is connected to the outlet 10d via piping. The vacuum pump draws inert gas from the chamber 10 while the flow rate is controlled by a valve, so that the chamber 10 is kept in a constant depressurized state.

[0031] An observation window 10e is provided at the upper part of the main chamber 10a, through which the growth status of the single crystal silicon 3, i.e. the solid-liquid interface, can be observed.

[0032] The base 12 is fixed to the upper end of the rotating shaft 13, which extends vertically. The lower end of the rotating shaft 13 passes through the center of the bottom of the chamber 10 and is connected to the shaft drive mechanism 14 located outside the chamber 10. The base 12, the rotating shaft 13, and the shaft drive mechanism 14 constitute the rotating and lifting mechanism of the quartz crucible 11.

[0033] Heater 15 melts the silicon raw material and dopant filled into the quartz crucible 11 to form raw material melt 2, and maintains the raw material melt 2 in a molten state. In some examples, heater 15 is a carbon resistance heater and is a generally cylindrical component arranged to surround the quartz crucible 11 within the base 12. Moreover, the outside of heater 15 is surrounded by heat-insulating material 16, thereby improving the thermal insulation of the chamber 10.

[0034] The magnetic field applying device 21 suppresses the convection of the raw material melt 2 by applying a magnetic field to the raw material melt 2, thereby suppressing the melting of oxygen from the quartz crucible 11 and reducing the oxygen concentration in the single crystal silicon 3.

[0035] Figure 2 is a flowchart illustrating the method for manufacturing monocrystalline silicon based on the present disclosure. Figure 3 is a simplified cross-sectional view showing the shape of a monocrystalline silicon ingot. As shown in Figures 2 and 3, the method for manufacturing monocrystalline silicon includes steps S11 to S16.

[0036] In step S11, the raw material in the quartz crucible 11 is heated to form raw material melt 2;

[0037] In this disclosure, the raw materials in the quartz crucible 11 include, in addition to silicon, dopants such as boron, phosphorus, arsenic, or antimony; correspondingly, the raw material melt 2 includes, in addition to most of the silicon, other doping elements. In some examples, these dopants can be placed in the quartz crucible 11 simultaneously with the silicon raw material, and the silicon raw material and dopants melt upon heating to form the raw material melt 2. In some examples, the silicon raw material can be first placed in the quartz crucible 11 and heated to melt to form a silicon melt, then the dopants can be placed in a doping chamber and lowered above the silicon melt, where the high temperature causes the dopants to transform into a liquid or gaseous state and incorporate into the silicon melt to form the raw material melt 2.

[0038] In step S12, the seed crystal installed at the front end of the wire 18 is dropped so that the seed crystal is immersed in the raw material melt 2.

[0039] It should be noted that after completing the above two steps, a pulling process is then performed to cultivate a single crystal by slowly pulling the seed crystal while maintaining contact with the raw material molten liquid 2. The pulling process includes steps S13 to S16 sequentially. Specifically, step S13 is a necking process to form a very thin neck 3a to prevent dislocation. Step S14 is a shoulder cultivation process to form a shoulder 3b with a slowly increasing crystal diameter to obtain a specified diameter. Step S15 is a body cultivation process to form a body 3c with a constant crystal diameter. Step S16 is a tail cultivation process to form a tail 3d with a slowly decreasing crystal diameter, and this tail cultivation process ends when the single crystal finally leaves the molten liquid surface. Through the above pulling process, a single crystal silicon ingot 3, as shown in Figure 3, is produced, having a neck 3a, shoulder 3b, body 3c, and tail 3d sequentially from the upper end (top) to the lower end (bottom) of the single crystal.

[0040] It should be noted that in the pulling process described in steps S13 to S16 above, in order to control the diameter of the monocrystalline silicon 3 and the liquid surface position of the raw material molten 2, an image of the boundary between the monocrystalline silicon 3 and the raw material molten 2 is captured by a CCD camera 22. The diameter of the monocrystalline silicon at the solid-liquid interface and the gap between the molten surface and the guide tube 17 are calculated from the photographic image. The control unit 24 controls the pulling speed of the wire 18, the power of the heater 15, and other pulling conditions in a way that makes the diameter of the monocrystalline silicon 3 the target diameter. Furthermore, the control unit 24 controls the height position of the quartz crucible 11 in a way that keeps the gap between the molten surface and the guide tube 17 constant.

[0041] In some examples, during the manufacturing process of the single crystal silicon shown in Figure 2 above, 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 molten liquid 2 is 0.1 to 3 rpm, the pressure inside the crystal pulling furnace 1 for growing the single crystal silicon is 20 to 70 Tor, the flow rate of the inert gas inside the crystal pulling furnace 1 is 90 to 180 slm, and the maximum Gaussian plane is -200 to 200 mm. The maximum Gaussian plane is the horizontal plane with the highest magnetic field strength. Optionally, the maximum Gaussian plane can be the plane where the center point of the magnetic field coil is located.

[0042] In this disclosure, the magnetic field applying device 21 applies a horizontal magnetic field to the raw material molten liquid 2, and the magnetic field strength is controlled between 2000 Gauss (G) and 3000 G. This is because, through simulation and actual production, it has been found that under the action of a horizontal magnetic field, the radial concentration distribution of dopants in 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 impact on the melt flow. In other words, the magnetic field strength of the horizontal magnetic field has the greatest impact on the concentration distribution of dopants at the solid-liquid interface. Excessive magnetic field strength will lead to excessive suppression of convection within the melt, affecting the growth rate and quality of the silicon crystal. Insufficient magnetic field strength will fail to effectively suppress melt convection, resulting in inaccurate oxygen content control, affecting the resistivity uniformity of the silicon wafer. Simultaneously, insufficient magnetic field strength may also lead to excessive oxygen content in the silicon crystal, increasing crystal defects.

[0043] In detail, firstly, a 3D simulation of the crystal pulling furnace structure shown in Figure 1 and the single-crystal silicon manufacturing method shown in Figure 2 is performed to obtain the correlation between the radial concentration distribution of dopants at the solid-liquid interface and the melt flow at the solid-liquid interface under the action of a magnetic field. Taking boron as an example, specifically referring to the 3D simulation results of the solid-liquid interface shown in Figure 4, at the solid-liquid interface selected by the box, as shown in Figure 5(A), the concentration of dopants, i.e., boron, is the highest in the two regions indicated by A and B at the solid-liquid interface. Furthermore, as shown in Figure 5(B), the horizontal flow velocity of the melt is the lowest in the two regions indicated by A and B at the solid-liquid interface. Based on Figures 5(A) and 5(B), it can be seen that the two regions indicated by A and B are at the convergence points of the horizontal melt flow, and the concentration of dopants is the highest in these two regions. The reason for this is that the dopant accumulates at the solid-liquid interface, and the lower the horizontal velocity, the thicker the boundary layer concentration of the dopant. This results in the highest concentration of the dopant at the solid-liquid interface, such as in the regions indicated by A and B. Furthermore, since the higher the dopant concentration, the lower the resistivity, the simulation results shown in Figures 5(A) and 5(B) indicate that the resistivity of the regions indicated by A and B will be significantly lower than that of other radial regions at the solid-liquid interface, indicating a non-uniform radial resistance distribution at the solid-liquid interface.

[0044] Next, taking the manufacturing method shown in Figure 2 as an example, the horizontal magnetic field strength is set to 3500G for single-crystal silicon growth. The resistivity of the silicon wafer obtained from the single-crystal silicon processing is then measured, resulting in the radial resistance distribution diagram shown in Figure 6. Figure 6 shows low resistivity regions A' and B' along the radial direction within the silicon wafer, representing the regions with the highest dopant concentration. Although the positions of the low resistivity regions A' and B' differ from those indicated by A and B in Figure 1, the phenomenon described in the 3D simulation is still reproduced in the actual process. That is, areas of dopant enrichment, such as the low resistivity regions A' and B', appear in the radial direction of the silicon wafer. These two low resistivity regions result in an uneven radial resistance distribution on the silicon wafer. In this disclosure, the radial resistivity of the silicon wafer can be measured using the four-probe method.

[0045] Combining the 3D simulation results shown in Figures 5(A) and 5(B) and the radial resistance distribution under actual process conditions shown in Figure 6, still taking boron dopant as an example, this 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 dopant concentration at the solid-liquid interface, as shown in Figure 7. As can be seen from Figure 7, as the horizontal magnetic field strength decreases, the region with the highest dopant concentration at the solid-liquid interface (i.e., the red ring in the simulation figure) gradually moves towards the edge of the single-crystal silicon until the horizontal magnetic field strength drops to 2000G, at which point the region with the highest dopant concentration moves out of the solid-liquid interface. That is, when the horizontal magnetic field is set to 2000G, the radial resistance distribution is more uniform compared to 3000G and 4000G. As shown in Figure 7, the simulation results indicate that the horizontal magnetic field strength has a significant impact on the distribution of dopant concentration at the solid-liquid interface. This impact can be described as follows: the lower the horizontal magnetic field strength, the more uniform the distribution of dopant concentration at the solid-liquid interface, which in turn results in a more uniform radial resistance distribution on the silicon wafer.

[0046] The influence of magnetic field strength on resistivity distribution will be illustrated below through several examples and comparative examples.

[0047] Example 1:

[0048] In this embodiment, a horizontal magnetic field strength of 2000G is set for single-crystal silicon growth, and the resistivity is measured after sampling the silicon wafer obtained from the processed single-crystal silicon. For example, the in-plane distribution of resistivity of the silicon wafer can be measured. For instance, the radial resistivity can be measured radially from the center of the wafer using a four-probe method, resulting in a scatter plot of the radial resistivity distribution corresponding to 2000G (diamond-shaped blocks) as shown in Figure 8. The radial resistivity gradient, which characterizes the uniformity of the radial resistance distribution, is then calculated from the scatter plot. Specifically, the radial resistivity gradient (RRG), which characterizes the uniformity of the radial resistance distribution, can be calculated based on the following formula when the maximum value of the resistivity within the radial measurement range of the silicon wafer is set as ρMax and the minimum value as ρMin: RRG(%) = {(ρMax-ρMin) / ρMin} × 100%;

[0049] The above method can be used to calculate that the corresponding RRG is 0.61% when the horizontal magnetic field strength is 2000G.

[0050] Example 2:

[0051] In this embodiment, a horizontal magnetic field strength of 2200G is set for single-crystal silicon growth. After sampling the silicon wafer obtained from the single-crystal silicon processing, the radial resistivity is measured. A scatter plot of the radial resistivity distribution corresponding to 2200G (circle) is obtained as shown in Figure 8. Then, the radial resistivity gradient of the radial resistivity distribution uniformity is calculated from the scatter plot of the radial resistivity distribution. It can be found that when the horizontal magnetic field strength is 2200G, the corresponding RRG is 0.41%.

[0052] Example 3:

[0053] In this embodiment, a horizontal magnetic field strength of 2500G is set for single-crystal silicon growth. After sampling the silicon wafer obtained from the single-crystal silicon processing, the radial resistivity is measured. A scatter plot of the radial resistivity distribution corresponding to 2500G ("+" shape) is obtained as shown in Figure 8. Then, the radial resistivity gradient of the radial resistivity distribution uniformity is calculated from the scatter plot of the radial resistivity distribution. It can be found that the corresponding RRG is 0.88% when the horizontal magnetic field strength is 2500G.

[0054] Example 4:

[0055] In this embodiment, a horizontal magnetic field strength of 2700G is set for single-crystal silicon growth. After sampling the silicon wafer obtained from the single-crystal silicon processing, the radial resistivity is measured. A scatter plot of the radial resistivity distribution corresponding to 2700G (triangle) is obtained as shown in Figure 8. Then, the radial resistivity gradient of the radial resistivity distribution uniformity is calculated from the scatter plot of the radial resistivity distribution. It can be found that the corresponding RRG is 0.9% when the horizontal magnetic field strength is 2700G.

[0056] Example 5:

[0057] In this embodiment, a horizontal magnetic field strength of 3000G is set for single-crystal silicon growth. After sampling the silicon wafer obtained from the single-crystal silicon processing, the radial resistivity is measured. A scatter plot of the radial resistivity distribution corresponding to 3000G ("X" shape) is obtained as shown in Figure 8. Then, the radial resistivity gradient of the radial resistivity distribution uniformity is calculated from the scatter plot of the radial resistivity distribution. It can be found that the corresponding RRG is 0.99% when the horizontal magnetic field strength is 3000G.

[0058] It should be noted that the calculation method of resistivity gradient in Examples 2 to 5 can all refer to Example 1, and will not be repeated here.

[0059] As can be seen from Examples 1 to 5 above, when the horizontal magnetic field strength is between 2000G and 3000G, the resistivity gradient is less than 1%.

[0060] Comparative Example 1:

[0061] In this embodiment, a horizontal magnetic field strength of 1500G is set for single-crystal silicon growth. After sampling the silicon wafer obtained from the single-crystal silicon processing, the radial resistivity is measured. A scatter plot of the radial resistivity distribution corresponding to 1500G ("rice" shape) is obtained as shown in Figure 8. Then, the radial resistivity gradient of the radial resistivity distribution uniformity is calculated from the scatter plot of the radial resistivity distribution. It can be found that the corresponding RRG is 1.24% when the horizontal magnetic field strength is 1500G.

[0062] Comparative Example 2:

[0063] In this embodiment, a horizontal magnetic field strength of 3500G is set for single-crystal silicon growth. After sampling the silicon wafer obtained from the single-crystal silicon processing, the radial resistivity is measured. A scatter plot of the radial resistivity distribution corresponding to 3500G (square) is obtained as shown in Figure 8. Then, the radial resistivity gradient of the radial resistivity distribution uniformity is calculated from the scatter plot of the radial resistivity distribution. It can be found that the corresponding RRG is 1.11% when the horizontal magnetic field strength is 3500G.

[0064] Based on Examples 1 to 5 and Comparative Examples 1 and 2, it can be seen that when the horizontal magnetic field strength is set sequentially to 1500G, 2000G, 2200G, 2500G, 2700G, 3000G, and 3500G, the corresponding Resistive Resistivity (RRG) is 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). Furthermore, when the horizontal magnetic field strength is between 2000G and 3000G, the RRG is below 1%, and when the horizontal magnetic field strength is outside the range of 2000G to 3000G, the RRG is above 1%. That is, by setting the horizontal magnetic field strength to between 2000G and 3000G, this disclosure can improve the uniformity of the resistivity of the obtained silicon wafer.

[0065] Furthermore, this disclosure uses 3D simulations with horizontal magnetic field strengths ranging from low to high, set to 1000G, 2000G, 2500G, 3000G, and 4000G, to obtain simulation results of oxygen concentration, as shown in Figure 9. Figure 9 shows that the oxygen concentration gradually decreases and then increases with increasing horizontal magnetic field strength.

[0066] The effect of magnetic field strength on oxygen concentration will be illustrated below through several examples and comparative examples.

[0067] Example 6:

[0068] A horizontal magnetic field strength of 2000G can be used to grow single-crystal silicon, and the oxygen concentration can be measured after sampling the silicon wafer obtained from the processing of the single-crystal silicon. In this disclosure, the oxygen concentration is approximately 8 ppma, which can be obtained by Fourier Transform Infrared Spectroscopy (FTIR) conforming to ASTM F-121 (1979).

[0069] Example 7:

[0070] The horizontal magnetic field strength can be set to 2200G for single-crystal silicon growth, and the oxygen concentration can be measured after sampling the silicon wafer obtained from the single-crystal silicon processing. The measured oxygen concentration is approximately 7.5 ppma.

[0071] Example 8:

[0072] The horizontal magnetic field strength can be set to 2500G for single-crystal silicon growth, and the oxygen concentration of the silicon wafer obtained after processing the single-crystal silicon can be measured. The measured oxygen concentration is approximately 5.6 ppma.

[0073] Example 9:

[0074] The horizontal magnetic field strength can be set to 3000G for single-crystal silicon growth, and the oxygen concentration can be measured after sampling the silicon wafer obtained from the single-crystal silicon processing. The measured oxygen concentration is approximately 8.1 ppma.

[0075] Through Examples 6 to 9 above, it can be obtained that when the horizontal magnetic field strength is between 200G and 3000G, the oxygen concentration of the silicon wafer is 5.6ppma or more and 8.5ppma or less in the manufactured single crystal silicon.

[0076] Comparative Example 3:

[0077] The horizontal magnetic field strength can be set to 1000G for single-crystal silicon growth, and the oxygen concentration can be measured after sampling the silicon wafer obtained from the single-crystal silicon processing. The measured oxygen concentration is approximately 12.5 ppma.

[0078] Comparative Example 4:

[0079] The horizontal magnetic field strength can be set to 3500G for single-crystal silicon growth, and the oxygen concentration of the silicon wafer obtained after processing the single-crystal silicon can be measured. The measured oxygen concentration is approximately 9.5 ppma.

[0080] Comparative Example 5:

[0081] The horizontal magnetic field strength can be set to 4000G for single-crystal silicon growth, and the oxygen concentration can be measured after sampling the silicon wafer obtained from the single-crystal silicon processing. The measured oxygen concentration is approximately 11.2 ppma.

[0082] Referring to Figures 9 and 10, the oxygen concentration is lowest at 5.6 ppma when the horizontal magnetic field is 2500 G.

[0083] Combining the measurement results shown in Figures 8, 9, and 10, it can be seen 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 5.6 ppma or higher and 8.5 ppma or lower, and the radial resistivity gradient (RRG) within the crystal cross-section orthogonal to the growth direction of the single-crystal silicon is 1% or lower. Furthermore, the silicon wafer obtained from processing this single-crystal silicon has an oxygen concentration of 5.6 ppma or higher and 8.5 ppma or lower, and an RRG of 1% or lower.

[0084] Furthermore, 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 5.6ppma or higher and 7.5ppma or lower, and the RRG (Reduced Rate of Gain) in the crystal cross-section orthogonal to the growth direction of the single crystal silicon is 0.9% or lower. Moreover, the silicon wafer obtained from processing this single crystal silicon has an oxygen concentration of 5.6ppma or higher and 7.5ppma or lower, and an RRG of 0.9% or lower.

[0085] As explained above, the method for manufacturing single-crystal silicon based on this disclosure, by applying a magnetic field to the raw material melt and using the Czeklaussky method to pull single-crystal silicon, can produce single-crystal silicon with low oxygen concentration and as uniform a radial resistance distribution as possible by controlling the magnetic field strength at 2000 Gauss to 3000 Gauss.

[0086] It should be noted that the technical solutions described in this disclosure can be combined arbitrarily as long as they do not conflict.

[0087] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A method for manufacturing monocrystalline silicon, the method comprising: When applying a magnetic field to the raw material molten liquid and using the Czeklaussky method to pull single crystal silicon, 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 with an oxygen concentration of 5.6 ppma or higher and 8.5 ppma or lower, and a radial resistivity gradient (RRG) of less than 1% in the crystal cross section orthogonal to the growth direction of the single crystal silicon.

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

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

4. The method for manufacturing single-crystal silicon according to claim 1, wherein, The raw material melt is formed by heating silicon raw material and dopants to melt.

5. The method for manufacturing single-crystal silicon according to any one of claims 1 to 3, wherein, When applying a magnetic field to the molten raw material and pulling single-crystal silicon using the Czeklaussky method, the rotational speed of the single-crystal silicon is 8 to 11 rpm, the rotational speed of the quartz crucible carrying the molten raw material is 0.1 to 3 rpm, the pressure inside the crystal pulling furnace for growing the single-crystal silicon is 20 to 70 Tor, the flow rate of the inert gas inside the crystal pulling furnace is 90 to 180 slm, and the maximum Gaussian plane is -200 to 200 mm.

6. A monocrystalline silicon, wherein the monocrystalline silicon is grown by applying a magnetic field to a raw material melt and pulling the monocrystalline silicon using the Czeklaussky method, wherein the magnetic field strength is controlled to be between 2000 Gauss and 3000 Gauss; and wherein the oxygen concentration of the monocrystalline silicon is 5.6 ppma or more and 8.5 ppma or less, and the radial resistivity gradient (RRG) in a crystal cross section orthogonal to the growth direction of the monocrystalline silicon is 1% or less.

7. The monocrystalline silicon according to claim 6, wherein, Oxygen concentration is above 5.6 ppma and below 8 ppma. The RRG of the crystal cross section is less than 0.9%.

8. A silicon wafer, wherein, The silicon wafer is obtained by processing monocrystalline silicon as described in claim 6 or 7, and the oxygen concentration of the silicon wafer is 5.6 ppma or more and 8.5 ppma or less, and the RRG of the silicon wafer is 1% or less.

9. The silicon wafer according to claim 8, wherein, Oxygen concentration is above 5.6 ppma and below 8 ppma. RRG is below 0.9%.

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