Monocrystalline silicon ingot product, monocrystalline growth device and monocrystalline growth method

Abstract

A monocrystalline silicon ingot product, a monocrystalline growth device and a monocrystalline growth method. The monocrystalline growth device comprises a furnace, a crucible, a heater, an insulating support, a support rod, a short-circuit connecting block and a first driving apparatus, wherein the heater is divided into a heating region and a short-circuit region by the short-circuit connecting block. During crystal growth, the insulating support is driven by means of the first driving apparatus as the crucible moves upwards, such that the short-circuit connecting block slowly rises, so as to control the length of the heating region of the heater, thereby enhancing the ability to regulate and control the temperature gradient distribution of a growth interface, improving the uniformity of V / G at the growth interface, and promoting the growth of a high-quality monocrystalline silicon ingot product. In addition, the heating area of the heater is adjusted by means of regulating the length of the heating region of the heater, and thus an application process window of the heater is expanded, one heater can be applied to the production of a plurality of monocrystalline silicon ingot products having different oxygen contents; moreover, by means of the monocrystalline silicon growth method, the production of a monocrystalline silicon ingot product having a low oxygen content of 3 nppma to 20 nppma is realized.

Description

A single-crystal silicon rod product, single-crystal growth equipment and single-crystal growth method

[0001] This application claims priority to Chinese Patent Application No. 202411954380.2, filed on December 26, 2024, entitled "A Single Crystal Silicon Rod Product, Single Crystal Growth Equipment and Single Crystal Growth Method", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This invention belongs to the field of monocrystalline silicon production technology, and specifically relates to a monocrystalline silicon rod product, monocrystalline growth equipment, and monocrystalline growth method. Background Technology

[0003] The Czochralski method, also known as the Czochralski process, is a commonly used single crystal growth method. It involves melting polycrystalline silicon in a high-purity quartz crucible within a cylindrical furnace using graphite resistance heating. A seed crystal is then inserted into the surface of the melt for fusion, while the seed crystal is rotated and the crucible is reversed, causing the seed crystal to slowly rise. Through processes such as crystal introduction, shoulder formation, shoulder rotation, constant diameter growth, and tailing, a crystal rod of the desired diameter and length is finally grown.

[0004] In the process of Czochralski single-crystal silicon growth, the heater, as one of the most important components of the Czochralski single-crystal silicon thermal field system, primarily converts electrical energy into heat energy to maintain the thermodynamic conditions required for single-crystal growth. The formation and growth of micro-defects during Czochralski single-crystal silicon growth follow the V / G theory proposed by Voronkov. This theory posits that the ratio of the pulling speed V to the temperature gradient G at the growth interface front is a crucial indicator determining the defect distribution in single-crystal silicon. By controlling the pulling speed V and the temperature gradient G at the growth interface front, defect-free perfect single crystals can be grown. However, during the Czochralski single-crystal silicon growth process, the pulling speed V at the growth interface is generally approximately fixed. Therefore, controlling the temperature gradient G at the growth interface front becomes particularly important. The heater and thermal field structure are the main factors affecting the temperature gradient G near the solid-liquid interface of the crystal growth process. This gradient G continuously changes throughout the single-crystal silicon growth process with variations in growth conditions such as crucible position and melt depth, thus affecting the magnitude of V / G and ultimately determining whether perfect single-crystal silicon can be grown.

[0005] In existing Czochralski single-crystal silicon thermal field systems, the heating zone of the heater is generally fixed and cannot change with the growth conditions of single-crystal silicon. Furthermore, during the growth process of single-crystal silicon, the crucible position generally rises and the depth of the molten silicon liquid surface decreases, causing the growth interface of single-crystal silicon to deviate further and further from the center of the heater heating zone. This leads to an increase in the non-uniformity of the temperature gradient G at the growth interface, which is more detrimental to the control of the temperature gradient G and V / G at the growth interface, and is not conducive to the growth of high-quality single-crystal silicon.

[0006] Based on the above, it is necessary to provide a single-crystal silicon rod product, a single-crystal growth equipment, and a single-crystal growth method to achieve the growth of defect-free single-crystal silicon rod products.

[0007] It should be noted that the above introduction to the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of this application and facilitating understanding by those skilled in the art. It should not be assumed that these technical solutions are known to those skilled in the art simply because they have been described in the background section of this application. Summary of the Invention

[0008] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a single crystal silicon rod product, a single crystal growth device, and a single crystal growth method to solve the problem that in the process of growing single crystal silicon using the Czochralski method, the temperature gradient G and V / G at the growth interface are difficult to control due to the fixed heating zone of the heater, which makes it difficult to achieve the growth of defect-free single crystal silicon rod products.

[0009] To achieve the above and other related objectives, the present invention provides a single crystal growth apparatus, the single crystal growth apparatus comprising:

[0010] The furnace body has a seed crystal lifting mechanism at its top, which includes a seed crystal rope and a seed crystal clamp. The seed crystal rope passes through a hole at the top of the furnace body and the seed crystal clamp is installed at the bottom end of the seed crystal rope. The seed crystal clamp is used to install the seed crystal. The furnace body has a base at its bottom and a through hole on the base.

[0011] The insulation cavity is located inside the furnace body, and the bottom and side walls of the insulation cavity are provided with insulation layers;

[0012] A crucible, fixed to the base and placed inside the insulation cavity, is used to hold molten silicon;

[0013] A heater is disposed inside the insulation cavity, located around the crucible, and is used to heat the crucible;

[0014] An insulating support is disposed inside the heater. The insulating support has multiple protrusions that pass through the heater and are exposed on the outside of the heater. A short-circuit connection block is provided on the protrusion that divides the heater into a heating zone and a short-circuit zone.

[0015] A first driving device is connected to the insulating support in a transmission manner. The first driving device is used to drive the insulating support to move up and down to change the area of ​​the heating zone of the heater.

[0016] Optionally, the heater includes multiple blades, each blade having a strip groove, and the number of short-circuit connecting blocks is equal to or less than the number of blades. When the number of short-circuit connecting blocks is equal to the number of blades, the multiple heating zones of the heater arranged circumferentially have the same length in the axial direction. When the number of short-circuit connecting blocks is less than the number of blades, at least two heating zones of the heater arranged circumferentially have different lengths in the axial direction.

[0017] Optionally, both the heater and the insulating support are annular structures, and the insulating support is slidably connected to the strip groove.

[0018] Optionally, the single crystal growth equipment further includes a support rod, one end of which is fixedly connected to the insulating support, and the other end of which is connected to a first driving device, so that the insulating support moves up and down under the control of the first driving device to change the area of ​​the heating zone of the heater.

[0019] Optionally, the top of the insulation cavity is provided with an insulation cover plate. The single crystal growth equipment further includes a flow guide tube, which is disposed inside the insulation cavity and connected to the insulation cover plate. The flow guide tube extends from the outside of the crucible to above the molten silicon. Optionally, the height of the short-circuit connection block is 10mm to 200mm.

[0020] Optionally, the short-circuit connection block is made of a low resistivity material, and the resistance of the material forming the short-circuit connection block is less than the resistance of the heater.

[0021] Optionally, the insulating support includes at least a silicon nitride insulating support, a silicon carbide insulating support, or an aluminum nitride insulating support.

[0022] Optionally, the single crystal growth equipment further includes a crucible driving device, wherein the support shaft of the crucible driving device passes through the insulation layer and the through hole on the base and is fixedly connected to the crucible, for driving the crucible to move upward at a preset rate during the single crystal growth process.

[0023] The present invention also provides a single crystal growth method, wherein during the single crystal growth process, the length of the heating zone of the heater is changed by moving the short-circuit connecting block up and down, thereby adjusting the heating area of ​​the heating zone of the heater during the single crystal growth process.

[0024] Optionally, during the silicon melting stage of the single crystal growth process, the short-circuit connection block is moved to the bottom of the heater to maximize the length of the heating zone of the heater.

[0025] Optionally, the short-circuit connection block is moved up to a height of 30% to 60% of the heater and then kept in a fixed position, thereby making the length of the heating zone 40% to 70% of the length of the initial heating zone.

[0026] Optionally, during single crystal growth, the crucible is moved upward at a preset rate and the rising rate of the short-circuit connection block is 0.1 to 0.9 times the rising rate of the crucible.

[0027] Optionally, the single crystal growth method is performed based on the aforementioned single crystal growth equipment.

[0028] The present invention also provides a single-crystal silicon rod product, which is obtained by the single-crystal growth method described above, and the oxygen content of the single-crystal silicon rod product is 3nppma to 20nppma.

[0029] As described above, the monocrystalline silicon rod product, monocrystalline growth equipment, and monocrystalline growth method of the present invention have the following beneficial effects: The monocrystalline growth equipment of the present invention, by adding a short-circuit connecting block on the insulating support, allows the insulating support and the short-circuit connecting block to rise slowly when needed via a first driving device, thereby controlling the length of the heating zone of the heater, thereby enhancing the ability to regulate the temperature gradient distribution at the growth interface, improving the uniformity of V / G at the growth interface, and promoting the growth of high-quality monocrystalline silicon rod products. In addition, by adjusting the length of the heating zone of the heater, the heating area of ​​the heater can be adjusted, expanding the application process window of the heater, enabling the same heater to meet the needs of producing monocrystalline silicon products with different oxygen contents such as logic devices, memory devices, and power devices. Furthermore, the monocrystalline growth method achieves the production of monocrystalline silicon rod products with low oxygen content of 3nppma to 20nppma. Attached Figure Description

[0030] Figure 1 shows a schematic diagram of the single crystal growth apparatus of the present invention.

[0031] Figure 2 shows a schematic diagram of the heater in the single crystal growth equipment of the present invention.

[0032] Figure 3 shows a schematic diagram of the insulating support and short-circuit connection block in the single crystal growth equipment of the present invention.

[0033] Component labeling descriptions: 10. Furnace body; 11. Seed crystal rope; 12. Seed crystal chuck; 13. Seed crystal; 14. Insulation cavity; 15. Crucible; 151. Inner crucible; 152. Outer crucible; 16. Heater; 161. Strip groove; 17. Insulating bracket; 171. Protrusion; 18. Short-circuit connection block; 19. Support rod; 20. First drive device; 21. Insulation cover plate; 22. Guide tube; 23. Molten silicon; 24. Single crystal silicon rod; 25. Support shaft; 26. Base. Detailed Implementation

[0034] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0035] In the detailed description of embodiments of the present invention, for ease of explanation, the schematic diagrams illustrating the device structure may be partially enlarged without adhering to the general scale, and the schematic diagrams are merely examples and should not limit the scope of protection of the present invention. Furthermore, in actual manufacturing, the three-dimensional spatial dimensions of length, width, and depth should be included.

[0036] For ease of description, spatial relation terms such as “below,” “under,” “lower than,” “below,” “above,” and “upper” may be used herein to describe the relationship between one element or feature shown in the accompanying drawings and other elements or features. It will be understood that these spatial relation terms are intended to include directions other than those depicted in the accompanying drawings for devices in use or operation.

[0037] Please refer to Figures 1 to 3. It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0038] Example 1

[0039] As shown in Figure 1, the present invention provides a single crystal growth device, including a furnace body 10. A seed crystal lifting mechanism is provided on the top of the furnace body 10. The seed crystal lifting mechanism includes a seed crystal rope 11 and a seed crystal chuck 12. The seed crystal rope 11 passes through a perforation in the top of the furnace body 10 and the seed crystal chuck 12 is installed at the bottom end of the seed crystal rope 11. The seed crystal chuck 12 is used to install a seed crystal 13. A base 26 is provided at the bottom of the furnace body 10 and a through hole is provided on the base 26.

[0040] The single crystal growth equipment also includes a heat preservation cavity 14, which is located inside the furnace body 10. The bottom and side walls of the heat preservation cavity 14 are provided with heat preservation layers, and the top of the heat preservation cavity 14 is provided with a heat preservation cover plate 21.

[0041] Furthermore, the single crystal growth equipment also includes a crucible 15, which is fixed on the base 26 and placed inside the insulation cavity 14 to support molten silicon 23.

[0042] Furthermore, the single crystal growth equipment also includes a heater 16, which is disposed inside the insulation cavity 14 and located around the crucible 15 for heating the crucible 15; the single crystal growth equipment also includes an insulating support 17, which is disposed inside the heater 16 and has multiple protrusions 171 that pass through the heater 16 and are exposed on the outside of the heater 16. A short-circuit connection block 18 is provided on the protrusion 171 that divides the heater 16 into a heating zone and a short-circuit zone.

[0043] Furthermore, the single crystal growth equipment also includes a first driving device 20, which is connected to the insulating support 17 via a transmission. The first driving device 20 is used to drive the insulating support 17 to move up and down to change the area of ​​the heating zone of the heater.

[0044] In one example, the single crystal growth apparatus also includes a support rod 19, one end of which is fixedly connected to an insulating support 17, and the other end of which is connected to a first driving device 20, so that the insulating support 17 moves up and down under the control of the first driving device 20 to change the area of ​​the heating zone of the heater 16.

[0045] In one example, the single crystal growth apparatus also includes a flow guide tube 22, which is disposed within the insulation cavity 14 and connected to the insulation cover plate 21. The flow guide tube 22 extends from the outside of the crucible 15 to above the molten silicon 23. The single crystal growth apparatus of the present invention enhances the ability to control the temperature gradient distribution at the growth interface by adding a short-circuit connecting block 18 to the heater 16, thereby changing the length of the heating zone on the heater 16 when needed by adjusting the height of the short-circuit connecting block 18. This improves the uniformity of the V / G ratio at the growth interface and is more conducive to ensuring the stable and consistent quality of single crystal silicon production.

[0046] Specifically, referring to Figure 1, after the polycrystalline silicon raw material is placed into the crucible 15, the polycrystalline silicon raw material, which is initially in a solid state, is melted in the single crystal furnace using a heater 16 to form molten silicon 23. Then, a seed crystal 13 fixed on the seed crystal chuck 12 is inserted into the surface of the molten silicon 23. After the seed crystal 13 and the molten silicon 23 are fully fused, the seed crystal lifting mechanism is used to lift the seed crystal 13 up and down, so that the single crystal silicon rod 24 grows at the lower end of the seed crystal 13. This is a commonly used existing technology and will not be described in detail here.

[0047] Specifically, referring to Figure 1, the top of the insulation cavity 14 is open and facing upwards. Insulation layers are provided on the bottom and side walls of the insulation cavity 14. An insulation cover plate 21, such as a graphite insulation cover plate 21, is provided on the top of the insulation cavity 14. The side of the insulation cover plate 21 facing the insulation cavity 14 is connected to the insulation layer on the side wall of the insulation cavity. Furthermore, the single crystal growth equipment, such as a single crystal furnace, also includes a flow guide tube 22. The flow guide tube 22 extends from the outside of the crucible 15 to above the molten silicon 23 (that is, the flow guide tube 22 extends generally downward from above the opening of the crucible 15 toward the side where the opening of the crucible 15 is located, so that it is located above the molten silicon 23). The flow guide tube 22 is located at the top of the heat preservation cavity 14 and is connected to the heat preservation cover plate 21. For example, the flow guide tube 22 includes a cylinder body and an extension protruding outward from the end of the cylinder body away from the crucible 15 toward the circumferential surface of the cylinder body. The side of the extension facing the heat preservation cover plate is connected to the heat preservation cover plate 21. Optionally, the cylinder body of the flow guide tube 22 can be a conical cylinder. The smaller opening of the conical cylinder is located near the crucible 15, and the larger opening of the conical cylinder is located away from the crucible 15. The insulation layer can be made of one or more materials such as graphite felt or carbon-carbon composite material. For example, the insulation layer can be made of graphite felt. Through the combined action of the insulation layer and the insulation cover plate 21, the influence of the temperature generated by the heater 16 on the furnace body 10 can be reduced, thereby stabilizing the thermal field and reducing heat loss, so as to ensure the quality and shape of the single crystal silicon rod 24 inside the furnace body 10.

[0048] Referring to Figure 1, in this embodiment, the crucible 15 generally includes an inner crucible 151 and an outer crucible 152. The inner crucible 151 is used to hold molten silicon 23, and the outer crucible 152 is wrapped around the outside of the inner crucible 151. The inner crucible 151 and / or the outer crucible 152 can be made of one or more of graphite, quartz, or carbon-carbon composite materials. For example, the inner crucible 151 can be made of quartz, and the outer crucible 152 can be made of graphite.

[0049] Referring to Figure 1, the heater 16 is disposed within the insulation cavity 14, and is positioned between the insulation layer and the outer periphery of the crucible 15. Specifically, a side heater 16 can be disposed around the graphite crucible 15 to comprehensively heat the polycrystalline silicon raw material placed inside the quartz crucible 15, causing it to melt rapidly and form molten silicon 23. In other embodiments, a bottom heater 16 can also be disposed at the bottom of the graphite crucible 15. The side heater 16 and the bottom heater 16 are independent of each other and can individually heat the polycrystalline silicon raw material to melt it.

[0050] As an example, referring to Figure 2, the heater 16 has an annular structure and includes multiple blades. The blades are provided with strip grooves 161. Optionally, each blade can correspond to a heating zone.

[0051] Specifically, referring to Figure 2, the blade has a strip groove 161. The strip groove 161 has two forms: opening upward and opening downward. Two adjacent strip grooves 161 with the same opening direction constitute a blade. The heater 16 includes multiple blades. An insulating support 17 is also provided inside the heater 16 so that the current path generated by the heater 16 is distributed in an S-shape in a single blade.

[0052] As an example, referring to Figure 3, the number of short-circuit connection blocks 18 is equal to or less than the number of blades. When the number of short-circuit connection blocks 18 is equal to the number of blades, the heating areas of the heater 16 have the same height in the circumferential direction. That is, the multiple heating areas of the heater 16 arranged in the circumferential direction have the same length in the axial direction. When the number of short-circuit connection blocks 18 is less than the number of blades, the heating areas of the heater 16 have different heights in the circumferential direction. That is, at least two heating areas of the heater 16 arranged in the circumferential direction have different lengths in the axial direction. For example, the length of the heating area corresponding to a blade between two adjacent short-circuit connection blocks 18 is less than the length of the heating area corresponding to a blade in the strip groove that is not provided with a short-circuit connection block 18.

[0053] Specifically, as shown in Figures 1 and 3, the insulating support 17 has multiple protrusions 171, which pass through the strip groove of the heater 16. The insulating support 17 and the strip groove 161 are slidably connected so that the insulating support 17 can move up and down along the strip groove 161. A short-circuit connection block 18 is provided on the protrusions 171 exposed on the outside of the heater 16 (e.g., on the outside of the outer peripheral surface of the annular structure heater 16). The current path generated by the heater 16 flows through the short-circuit connection block 18, thereby dividing the heater 16 into a heating zone and a short-circuit zone. The area above the short-circuit connection block 18 is the area through which the current flows, i.e., the heating zone. According to the "skin effect" of the current, the current in the heater 16 will preferentially pass through the short-circuit connection block 18. The area below the short-circuit connection block 18 will be short-circuited and lose its resistive heating efficiency, forming a short-circuit zone. As shown in Figures 1 and 3, a support rod 19 is also fixedly connected to the insulating support 17. One end of the support rod 19 is connected to the insulating support 17, and the other end of the support rod 19 is connected to the first driving device 20. The first driving device 20 is located below the furnace body 10 and outside the furnace body 10. The first driving device 20 drives the support rod 19 so that the insulating support 17 and the short-circuit connection block 18 rise slowly, causing the isothermal zone in the center of the heating zone of the heater 16 to move upward and closer to the growth interface of the single crystal silicon rod 24. This is beneficial to improve the consistency of the temperature gradient of the growth interface and improve the uniformity of V / G of the growth interface, thereby obtaining a flatter growth interface morphology.

[0054] As shown in Figure 2, the insulating support 17 is also a ring structure and nested inside the heater 16. Multiple protrusions 171 protrude from the outer circumferential surface of the insulating support 17. When the number of short-circuit connecting blocks 18 is equal to the number of blades, the heating area of ​​the heater 16 has the same height along the circumference (that is, the multiple heating areas arranged along the circumference of the heater have the same length in the axial direction of the heater), so as to form a uniform thermal field environment and meet the requirements of specific products for uniform circumferential thermal field conditions. When the number of short-circuit connecting blocks 18 is less than the number of blades, the heating area of ​​the heater 16 has different heights along the circumference, so as to form a non-uniform thermal field environment around the crucible 15. On the one hand, by locally adjusting the heating area area of ​​the heater 16, the ability to adjust the oxygen content in the single crystal silicon rod 24 is enhanced. On the other hand, it can compensate for problems such as the asymmetric distribution of the molten silicon 23 liquid surface temperature caused by horizontal magnetic fields, non-circumferentially symmetrical thermal field components, etc., and improve the stability of the growth process of the single crystal silicon rod 24.

[0055] As an example, the height of the short-circuit connection block 18 is 10mm to 200mm, and the height of the short-circuit connection block 18 is also the dimension of the short-circuit connection block 18 in the axial direction of the heater 16.

[0056] As an example, the material of the short-circuit connection block 18 includes a low resistivity material, and the resistance of the material forming the short-circuit connection block 18 is less than the resistance of the heater 16.

[0057] Specifically, the height of the short-circuit connection block 18 is 10mm to 200mm. For example, the height of the short-circuit connection block 18 can be 10mm, 30mm, 90mm, 150mm, or 200mm. By setting short-circuit connection blocks 18 of different heights, the length of the heating zone of the heater 16 (i.e., the axial dimension of the heating zone) at the beginning of crystal growth can be controlled. During the growth of the single crystal silicon rod 24, the length of the heating zone of the heater 16 has a significant impact on the oxygen content in the molten silicon 23 and the single crystal silicon rod 24. Furthermore, according to the "skin effect" of current, the current in the heater 16 will preferentially pass through the low resistivity material. Therefore, the material forming the short-circuit connection block 18 includes a low resistivity material, and the resistance of the material forming the short-circuit connection block 18 is less than the resistance of the heater 16. This causes a short circuit to occur in the area below the short-circuit connection block 18, resulting in the loss of resistive heating efficiency and the formation of a short-circuit region.

[0058] As an example, the insulating support 17 includes at least one of silicon nitride insulating support, silicon carbide insulating support, or aluminum nitride insulating support.

[0059] Specifically, in this embodiment, an insulating contact is formed between the insulating support 17 and the heater 16. The insulating support 17 includes at least one of silicon nitride insulating support, silicon carbide insulating support, or aluminum nitride insulating support. For example, the insulating support 17 can be a silicon nitride insulating support.

[0060] As an example, the single crystal growth equipment also includes a crucible driving device, wherein the support shaft 25 of the crucible driving device passes through the insulation layer and the through hole on the base 26 and is fixedly connected to the crucible 15, for driving the crucible 15 to move upward at a preset rate during the single crystal growth process.

[0061] Specifically, as shown in Figure 1, a crucible driving device is also provided below the furnace body 10. The support shaft 25 of the crucible driving device passes through the through holes in the insulation layer and the base 26 and is fixedly connected to the bottom of the crucible 15. It is used to drive the crucible 15 to move upward at a preset constant speed during the single crystal growth process. After the growth of the single crystal silicon rod 24 of the required length is completed, the crucible 15 can also be driven to descend so that the single crystal silicon rod 24 is separated from the upper surface of the molten silicon 23. In order to accurately control the lifting speed of the crucible 15 and the short-circuit connecting block 18, the crucible driving device and the first driving device 20 of the support rod 19 used above need to have good control accuracy.

[0062] Example 2

[0063] This invention also provides a single crystal growth method, which can be based on the single crystal growth equipment described in Embodiment 1 above. Therefore, please refer to the foregoing description of the single crystal growth equipment; for the sake of brevity, it will not be repeated here. Furthermore, during the growth of the single crystal silicon rod 24, the length of the heating zone of the heater 16 has a significant impact on the oxygen content in the molten silicon 23 and the single crystal silicon rod 24. Generally, the shorter the length of the heating zone of the heater 16, the shorter the high-temperature zone on the inner wall of the inner crucible 151. During the growth of the single crystal silicon rod 24, the oxygen concentration entering the molten silicon 23 is also lower, resulting in a lower oxygen content in the grown single crystal silicon rod 24.

[0064] When using the aforementioned single crystal growth equipment for single crystal growth, the length of the heating zone of the heater 16 is changed by continuously moving the short-circuit connecting block 18, thereby achieving high-quality growth of the single crystal silicon rod 24. Specifically, during the single crystal growth process, in the silicon melting stage, the short-circuit connecting block 18 is first moved to the bottom of the heater 16 to maximize the area of ​​the heating zone of the heater 16. Then, the first driving device 20 is activated to drive the support rod 19, which further drives the insulating support 17 and causes the short-circuit connecting block 18 to move upward, thereby changing the length of the heating zone of the heater 16. This adjusts the area of ​​the heating zone of the heater 16 during the single crystal growth process, which is beneficial for growing high-quality single crystal silicon rod products.

[0065] As an example, crucible 15 moves upward at a preset rate, and the rising rate of short-circuit connection block 18 is 0.1 to 0.9 times the rising rate of crucible 15. It should be noted that, depending on the growth requirements of single-crystal silicon rod products with different oxygen contents, the rising rate of short-circuit connection block 18 is 0.1 to 0.9 times the rising rate of crucible 15. Furthermore, as an example, during single-crystal growth, crucible 15 moves upward at a preset constant speed. Compared to the related art where the heating zone of heater 16 remains unchanged during single-crystal silicon rod product growth, the ratio of the growth interface height difference to the diameter is less than 5%, meaning that the single-crystal silicon rod 24 can maintain an approximately flat growth interface from beginning to end, thus further contributing to the growth of high-quality single-crystal silicon rod products.

[0066] As an example, the short-circuit connection block 18 is moved up to a height position of 30% to 60% of the heater and then kept in a fixed position, thereby making the length of the heating zone 40% to 70% of the length of the initial heating zone.

[0067] Specifically, during the single crystal growth process, the static operating mode of the single crystal growth equipment can be utilized, whereby the position of the short-circuit connection block 18 is moved upward once and then kept fixed, to achieve the growth of single crystal silicon rod products with low oxygen content. During the silicon melting stage, the short-circuit connection block 18 is first moved to the bottom of the heater 16 to maximize the area of ​​the heating zone of the heater 16. Then, the short-circuit connection block 18 is moved upward to a position of 30%–60% of the initial height of the heater 16 and kept fixed, thereby adjusting the area of ​​the heating zone of the heater 16 during single crystal growth to 40%–70% of the initial area. According to the present invention, a single crystal growth device and a single crystal growth method with adjustable heating zone length of heater 16 can be selected according to the needs of product category to grow single crystal silicon rod products with oxygen content of 3nppma to 20nppma. When the required product oxygen content is determined, the method of adjusting the heating zone length by using a moving short-circuit connecting block during the growth of single crystal silicon rod 24 can make the oxygen content at the head and tail of single crystal silicon rod 24 uniform and consistent, with a difference of less than 1nppma.

[0068] In summary, this invention provides a single-crystal silicon rod product, a single-crystal growth equipment, and a single-crystal growth method. The single-crystal growth equipment includes a furnace body, a crucible, a heater, an insulating support, a support rod, a short-circuit connection block, and a first driving device. The heater is divided into a heating zone and a short-circuit zone by the short-circuit connection block. During crystal growth, as the crucible moves upward, the first driving device drives the support rod, causing the insulating support and short-circuit connection block to rise slowly. This controls the length of the heating zone of the heater, thereby enhancing the ability to regulate the temperature gradient distribution at the growth interface, improving the uniformity of the V / G ratio at the growth interface, and promoting the growth of high-quality single-crystal silicon rod products. Furthermore, by adjusting the length of the heating zone, the heating area of ​​the heater can be adjusted, expanding the application process window of the heater. This allows the same heater to meet the production needs of single-crystal silicon rod products with different oxygen contents for applications such as logic devices, memory devices, and power devices. Moreover, this single-crystal growth method enables the production of low-oxygen single-crystal silicon rod products with oxygen contents ranging from 3 nppma to 20 nppma.

[0069] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A single crystal growth apparatus, characterized by, include: The furnace body has a seed crystal lifting mechanism at its top, which includes a seed crystal rope and a seed crystal chuck. The seed crystal rope passes through a hole at the top of the furnace body and the seed crystal chuck is installed at the bottom end of the seed crystal rope. The seed crystal chuck is used to install the seed crystal. The furnace body has a base at its bottom and a through hole on the base. The insulation cavity is located inside the furnace body, and the bottom and side walls of the insulation cavity are provided with insulation layers; A crucible, fixed to the base and placed inside the insulation cavity, is used to hold molten silicon; A heater is disposed inside the insulation cavity, located around the crucible, and is used to heat the crucible; An insulating support is disposed inside the heater. The insulating support has multiple protrusions that pass through the heater and are exposed on the outside of the heater. A short-circuit connection block is provided on the protrusion that divides the heater into a heating zone and a short-circuit zone. A first driving device is connected to the insulating support in a transmission manner. The first driving device is used to drive the insulating support to move up and down to change the area of ​​the heating zone of the heater.

2. The single crystal growth apparatus of claim 1, wherein The heater includes multiple blades, each blade having a slotted groove. The number of short-circuit connecting blocks is equal to or less than the number of blades. When the number of short-circuit connecting blocks is equal to the number of blades, the multiple heating zones arranged circumferentially in the heater have the same length in the axial direction. When the number of short-circuit connecting blocks is less than the number of blades, at least two heating zones arranged circumferentially in the heater have different lengths in the axial direction.

3. The single crystal growth apparatus of claim 2, wherein Both the heater and the insulating support are annular structures, and the insulating support is slidably connected to the strip groove.

4. The single crystal growth apparatus according to any one of claims 1 to 3, characterized by, The single crystal growth equipment also includes: A support rod is provided, one end of which is fixedly connected to the insulating bracket, and the other end of which is connected to the first driving device, so that the insulating bracket moves up and down under the control of the first driving device to change the area of ​​the heating zone of the heater.

5. The single crystal growth apparatus according to any one of claims 1 to 4, characterized by, The top of the insulation cavity is provided with an insulation cover plate, and the single crystal growth equipment further includes: A flow guide tube is disposed inside the heat preservation cavity and connected to the heat preservation cover plate. The flow guide tube extends from the outside of the crucible to above the molten silicon.

6. The single crystal growth apparatus according to any one of claims 1 to 5, characterized by, The height of the short-circuit connection block is 10mm to 200mm.

7. The single crystal growth apparatus according to any one of claims 1 to 6, characterized in that, The short-circuit connection block is made of a low resistivity material, and the resistance of the material forming the short-circuit connection block is less than the resistance of the heater.

8. The single crystal growth apparatus according to any one of claims 1 to 7, characterized in that, The insulating support includes at least a silicon nitride insulating support, a silicon carbide insulating support, or an aluminum nitride insulating support.

9. The single crystal growth apparatus according to any one of claims 1 to 8, characterized in that, The single crystal growth equipment further includes a crucible driving device, wherein the support shaft of the crucible driving device passes through the insulation layer and the through hole on the base and is fixedly connected to the crucible, for driving the crucible to move upward at a preset rate during the single crystal growth process.

10. A method for growing a single crystal, characterized in that, In the single crystal growth method, the length of the heating zone of the heater is changed by moving the short-circuit connecting block up and down during the single crystal growth process, thereby adjusting the heating area of ​​the heating zone of the heater during the single crystal growth process.

11. The single crystal growth method according to claim 10, characterized in that, During the silicon melting stage of the single crystal growth process, the short-circuit connection block is moved to the bottom of the heater to maximize the length of the heating zone of the heater.

12. The single crystal growth method according to claim 11, characterized in that, After the short-circuit connection block is moved up to a height of 30% to 60% of the heater, it is kept in a fixed position, thereby making the length of the heating zone 40% to 70% of the length of the initial heating zone.

13. The single crystal growth method according to any one of claims 10 to 12, characterized in that, During single crystal growth, the crucible is moved upward at a preset rate, and the rising rate of the short-circuit connection block is 0.1 to 0.9 times the rising rate of the crucible.

14. The single crystal growth method according to any one of claims 10 to 13, characterized in that, The single crystal growth method is performed using the single crystal growth apparatus as described in any one of claims 1 to 9.

15. A single-crystal silicon rod product, characterized in that, The single-crystal silicon rod product is obtained by the single-crystal growth method as described in any one of claims 10 to 14, and the oxygen content of the single-crystal silicon rod product is 3 nppma to 20 nppma.

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