A saddle-shaped permanent magnetic field device for silicon single crystal growth

Abstract

This utility model discloses a saddle-shaped permanent magnetic field device for silicon single crystal growth, belonging to the field of semiconductor manufacturing technology. It includes a saddle-shaped single crystal permanent magnet, a walking mechanism, a lifting mechanism, and a support. The saddle-shaped single crystal permanent magnet consists of left and right yoke plates, left and right saddle-shaped magnetic poles, left and right top wires, and a magnetic guide plate. The saddle-shaped structure of the single crystal permanent magnet significantly improves the uniformity of the magnetic field strength within the circumference, which is more conducive to improving the resistivity and impurity uniformity of the single crystal. The lifting mechanism can move the magnetic field up and down as a whole, serving as a preliminary position adjustment. The internal design of the left and right saddle-shaped magnetic poles allows for slight up and down movement. The center of the magnetic poles can be adjusted according to the actual height of the molten silicon surface. The magnetic poles are produced using a vacuum infusion process, isolating the magnetic material from the air, providing heat insulation, and increasing service life. The left and right top wire structure allows for adjustment of the magnetic pole spacing, thereby making the magnetic field strength adjustable and improving applicability.

Description

Technical Field

[0001] This utility model relates to a saddle-shaped permanent magnetic field device for silicon single crystal growth, and particularly to the field of semiconductor manufacturing technology. Background Technology

[0002] Currently, semiconductor silicon wafers are categorized by size into 4-6 inch, 8-inch, and 12-inch wafers. 4-6 inch wafers are primarily used in the manufacture of diodes, transistors, and power devices; 8-inch wafers are mainly used in power devices, automotive chips, power managers, display drivers, and fingerprint recognition chips; and 12-inch wafers are primarily used in high-end fields such as integrated circuits or processing chips. Domestic 4-6 inch single-crystal growth technology is mature. However, with the continuous upgrading of chip products and the improvement of process technology, the quality requirements for single crystals are also increasing, as are the requirements for single-crystal growth equipment. Currently, the main magnetic fields used in 4-6 inch single-crystal growth are single-crystal electromagnetic fields and single-crystal permanent magnetic fields. Single-crystal electromagnetic fields have high energy consumption, high maintenance costs, and short lifespans, and are gradually being replaced by permanent magnets. Conventional single-crystal permanent magnetic fields have unadjustable magnetic field strength, making them unable to flexibly adapt to process requirements. Furthermore, the permanent magnetic field cannot be turned off, increasing the difficulty of maintenance during single-crystal furnace operations and posing significant safety hazards. In addition, the conventional single-crystal permanent magnetic field has a two-pole structure, which results in poor magnetic field uniformity. The magnetic field strength is stronger near the poles and weaker on the sides. The silicon solution is subjected to uneven magnetic field forces within the circumference, affecting the resistivity uniformity. Furthermore, the height of the central magnetic field of the single-crystal permanent magnetic field is not adjustable, making it impossible to accommodate various thermal field sizes and limiting its application. Utility Model Content

[0003] This invention provides a saddle-shaped permanent magnetic field device for silicon single crystal growth to overcome the shortcomings of conventional single crystal permanent magnetic fields in the prior art, such as the inability to adjust the magnetic field strength, the inability to flexibly meet process requirements, the inability to shut down the permanent magnetic field, the increased difficulty of maintenance of the single crystal furnace, and the significant safety hazards.

[0004] To solve the above-mentioned technical problems, this utility model provides the following technical solution: This utility model discloses a saddle-shaped permanent magnetic field device for silicon single crystal growth, including a saddle-shaped single crystal permanent magnet, a traveling mechanism, a support assembly, and a lifting mechanism; the saddle-shaped single crystal permanent magnet is fixed on a bearing seat with a connecting plate and a fixed pulley of the traveling mechanism, the bearing seat including a driving bearing seat and a driven bearing seat; the two guide rails of the traveling mechanism are fixed on the support, forming a C-shaped integral structure installed on both sides of the single crystal furnace.

[0005] Furthermore, the saddle-shaped single-crystal permanent magnet includes a left magnetic pole and a right magnetic pole, and the center of the magnetic field formed by the left and right magnetic poles is located 20 mm below the surface of the molten silicon inside the single-crystal furnace.

[0006] Furthermore, the saddle-shaped single-crystal permanent magnet includes a left yoke plate, a left magnetic pole, a right magnetic pole, a right yoke plate, a right top wire, a magnetic guide plate, and a left top wire; the left yoke plate, the left magnetic pole, the right magnetic pole, the right yoke plate, and the magnetic guide plate are made of high-permeability DT4 electrical pure iron; the left yoke plate is connected to the left magnetic pole, the right magnetic pole is connected to the right yoke plate, the left yoke plate is connected to the magnetic guide plate, and the right yoke plate is connected to the magnetic guide plate, forming a C-shaped whole.

[0007] Furthermore, the left and right magnetic poles of the saddle-shaped single-crystal permanent magnet are N and S poles, respectively, with opposite polarities.

[0008] Furthermore, the magnetic induction lines of the saddle-shaped single-crystal permanent magnet are directed from the N pole of the left magnetic pole through the single crystal furnace to the S pole of the right magnetic pole, then to the right yoke plate, through the magnetic guide plate, back to the left yoke plate, and then to the left magnetic pole, forming a loop. The magnetic field strength at the center point of the horizontal distance between the centers of the left and right magnetic poles is what affects crystal pulling. The magnetic field strength is any value between 800GS and 1500GS.

[0009] Furthermore, the right and left top wires of the saddle-shaped single-crystal permanent magnet are respectively installed on both sides of the magnetic guide plate at the connection points with the left and right yoke plates. The right and left top wires open or reduce the connection points between the left and right yoke plates and the magnetic guide plate. Then, pads made of DT4 electrical pure iron are added or removed between the left and right yoke plates and the magnetic guide plate. When a circuit is formed, the distance between the left and right magnetic poles is changed, thereby increasing or decreasing the central magnetic field strength.

[0010] Furthermore, the left and right magnetic poles of the saddle-shaped single-crystal permanent magnet are composed of rare-earth alloy magnetic blocks, upper set screws, magnetic pole guide rails, lower set screws, magnetic pole sliders, and magnetic pole cavities. The magnetic pole cavities are made of stainless steel and are stepped in shape. The magnetic pole sliders are made of DT4 electrical pure iron. The rare-earth alloy magnetic blocks are stacked in rows in the magnetic pole cavities. The magnetic pole cavities are connected to the magnetic pole sliders. The magnetic pole guide rails are connected to the left and right yoke plates. The magnetic pole cavities and magnetic pole sliders are mounted on the magnetic pole guide rails and their positions are fixed by the upper and lower set screws.

[0011] Furthermore, the left and right magnetic poles of the saddle-shaped single-crystal permanent magnet have a saddle-shaped structure, which improves the circumferential uniformity of the magnetic field.

[0012] Furthermore, the left and right magnetic poles of the saddle-shaped single-crystal permanent magnet are adjusted in vertical position by upper and lower top wires, thereby adjusting the position of the magnetic field center.

[0013] Furthermore, the drive shaft of the walking mechanism is fixed at both ends on the active bearing seat and the driven bearing seat, and there are active pulleys and driven pulleys fixed on the drive shaft on the outside. The active pulleys and driven pulleys are mounted on the guide rail, and one end of the drive shaft is connected to the drive motor.

[0014] The beneficial effects achieved by this utility model are: 1. The saddle-shaped magnetic pole structure increases the uniformity of the circumferential magnetic field strength within the single crystal furnace area. The single crystal magnet can move back and forth and move up and down through the walking and lifting mechanisms, which facilitates maintenance. The magnetic pole slide rails enable slight up and down movement of the magnetic poles, which can be matched with different sizes of hot fields and crucibles. The left and right yoke plate top wire structure enables the magnetic pole spacing to be adjusted, thereby changing the magnetic field strength. It can be matched with different crystal pulling processes to achieve a multifunctional, energy-saving, and uniform single crystal magnet.

[0015] 2. The saddle-shaped permanent magnetic field device for silicon single crystal growth has an adjustable magnetic field strength, which can be flexibly matched with process requirements. The permanent magnetic field can be turned off and has a high safety factor.

[0016] 3. By adding a walking mechanism and a lifting mechanism to the bottom of the magnetic field, the magnetic field can move back and forth and rise and fall, which is convenient for maintenance. The magnetic poles can be finely adjusted up and down through the set wires and slide rails, which can better match different sizes of hot fields and crucible heights. By adding a set wire mechanism between the two yoke plates and the magnetic guide plate, the distance between the two magnetic poles can be adjusted, and the magnetic field strength can be adjusted to meet more crystal pulling needs. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the structural composition of the saddle-shaped single-crystal permanent magnet of this utility model; Figure 2a This is a schematic diagram of the working position of the saddle-shaped single-crystal permanent magnet of this utility model; Figure 2b This is a schematic diagram of the maintenance position of the saddle-shaped single-crystal permanent magnet of this utility model; Figure 3 This is a schematic diagram of the walking mechanism of this utility model; Figure 4 This is a schematic diagram of the structure of the saddle-shaped permanent magnet of this utility model; Figure 5 This is a schematic diagram of the structure of the magnetic pole of the saddle-shaped permanent magnet of this utility model; Figure 6a This is a top view of the lifting mechanism of this utility model; Figure 6b This is a front view schematic diagram of the lifting mechanism of this utility model.

[0018] In the diagram: 1-1, Single crystal furnace; 1-2, Saddle-shaped single crystal permanent magnet; 1-3, Walking mechanism; 1-4, Support assembly; 1-5, Lifting mechanism; 3-1, Drive motor; 3-2, Driving pulley; 3-3, Guide rail; 3-4, Driving bearing housing; 3-5, Transmission shaft; 3-6, Rack; 3-7, Driven pulley; 3-8, Driven bearing housing; 3-9, Fixed pulley; 4-1, Left yoke plate; 4-2, ... 4-3 Left magnetic pole; 4-4 Right magnetic pole; 4-5 Right yoke plate; 4-6 Right set screw; 4-7 Magnetic guide plate; 4-8 Left set screw; 5-1 Rare earth alloy magnetic block; 5-2 Upper set screw; 5-3 Magnetic pole guide rail; 5-4 Lower set screw; 5-5 Magnetic pole slider; 5-6 Magnetic pole cavity; 6-1 Gear motor; 6-2 Coupling; 6-3 Drive shaft; 6-4 Gear reducer; 6-5 Screw jack. Detailed Implementation

[0019] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0020] Example 1

[0021] like Figures 1-6b As shown, a saddle-shaped permanent magnetic field device for silicon single crystal growth includes a saddle-shaped single crystal permanent magnet 1-2, a walking mechanism 1-3, a support assembly 1-4, and a lifting mechanism 1-5.

[0022] Saddle-shaped single-crystal permanent magnets 1-2 are installed on both sides of the single-crystal furnace 1-1. The saddle-shaped single-crystal permanent magnets 1-2 form a magnetic field for processing silicon single crystals. Molten silicon single crystal melt is placed inside the single-crystal furnace 1-1. The center point of the magnetic field is located below the surface of the silicon single crystal melt. Preferably, the center point of the magnetic field is at any height of 8mm-22mm from the surface of the silicon single crystal melt; or preferably, the center point of the magnetic field is at any position of 0mm-20mm from the surface of the silicon single crystal melt, that is, the center point of the magnetic field is located at any position within 20mm of the surface of the silicon single crystal melt.

[0023] The saddle-shaped single-crystal permanent magnet uses rare-earth alloy as the magnetic source to provide a stable and uniform magnetic field for single crystal growth. The magnetic field can effectively suppress melt fluctuations and reduce the scouring of the crucible caused by melt fluctuations. The saddle-shaped structure can make the silicon melt more uniformly stressed, further reducing fluctuations. It can also improve the resistance uniformity of silicon single crystals and improve the consistency of single crystal products.

[0024] In the prior art, oxygen formed by the melt scouring the crucible leads to the formation of defects in the single crystal silicon rod. However, the magnetic field provided by the saddle-shaped single crystal permanent magnet 1-2 in this application does not have the structure of the melt scouring the crucible. Therefore, it can effectively improve the quality of the single crystal, reduce single crystal defects, and improve the resistance uniformity. Moreover, the saddle-shaped single crystal permanent magnet does not require any power consumption, which reduces the cost of crystal pulling.

[0025] The saddle-shaped single-crystal permanent magnet 1-2 mainly consists of two saddle-shaped magnetic poles, two yoke plates, and a magnetic guide plate. The saddle-shaped magnetic poles are mounted on the yoke plates, which are rectangular thick iron plates welded together. The magnetic guide plate is also a rectangular thick iron plate joint structure. There are connecting plates at both ends of the magnetic guide plate, which are connected to the yoke plates to form a C-shaped structure. One of the two magnetic poles is the N pole, and the other is the S pole. The magnetic poles are saddle-shaped. Inside the saddle-shaped structure, the magnetic poles are formed by rectangular alloy magnetic blocks arranged in a stepped manner. The rectangular alloy magnetic blocks are installed in a stepped stainless steel cavity. The stepped stainless steel cavity is a symmetrical structure with a lower middle and higher sides, forming a saddle-shaped magnetic pole structure. The magnetic field flows from the N pole to the S pole, then through the yoke plate to the magnetic guide plate, and then back to the magnetic pole, forming a magnetic loop that concentrates the magnetic field in the single-crystal furnace area. At the connection between the yoke plate and the magnetic guide plate of the saddle-shaped single-crystal permanent magnet 1-2, a setter wire structure is provided. The purpose is to change the distance between the magnetic guide plate and the yoke plate by adjusting the setter wire structure, thereby changing the distance between the two magnetic poles. Increasing the distance between the magnetic poles reduces the central magnetic field strength, which can be matched to the crystal pulling process to select a suitable magnetic field strength, making the magnetic field application more flexible. The connection between the magnetic poles and the yoke plate adopts the form of a guide rail, with setter wires added at the top and bottom. This allows for fine-tuning of the magnetic poles vertically, better matching the melt surface position, and obtaining a better crystal pulling effect.

[0026] The traveling mechanism 1-3 allows the saddle-shaped permanent magnetic field 1-2 to move flexibly back and forth. This improves the safety and reduces the difficulty of single-crystal furnace maintenance. Because working in a magnetic field environment poses certain safety hazards, maintenance tools must be non-magnetic, and maintenance personnel must not wear any iron parts. Furthermore, a magnetic field is not needed during the melting process; in fact, it would increase melting time. Increasing the heating power would increase melting time and energy consumption. Therefore, during the melting stage, the saddle-shaped permanent magnet can be moved to the maintenance position without affecting melting efficiency.

[0027] The drive motor 3-1 of the traveling mechanism 1-3 is a geared motor with a brake function, which can brake in time during operation. The driven pulley 3-7 has a gear structure on the outside, which can mesh with the rack and pinion, driving the pulley to make the saddle-shaped permanent magnetic field move smoothly on the slide rail.

[0028] The support components 1-4 provide support for all parts and are fixed to the ground with expansion bolts. They adopt a 4-square steel column structure and are connected as a whole by tie rods. The upper part is connected to the lifting mechanism.

[0029] The lifting mechanism 1-5 allows the saddle-shaped magnet to move vertically up and down in the single crystal furnace. When using different thermal fields and crucibles in the single crystal furnace, the liquid level of the melt needs to be adjusted, and sometimes the adjustment distance is large. With the lifting mechanism, the height of the magnetic pole center can be quickly adjusted to match the liquid level of the melt, which is convenient and quick to use and improves work efficiency.

[0030] The lifting mechanism 1-5 has a C-shaped structure, which matches the shape of the saddle-shaped permanent magnetic field, facilitating installation. The geared motor 6-1 has a two-sided output shaft structure, and the reducer 6-4 has a right-angle structure, which rotates the transmission direction by 90 degrees. The four screw jacks 6-5 have a worm gear screw structure, with the upper ends of the four screw jacks 6-5 connected by a connecting plate, and the lower ends directly connected to the load.

[0031] The saddle-shaped single-crystal permanent magnet 1-2 is fixed on the bearing seat with connecting plate and the fixed pulley 3-9 of the traveling mechanism 1-3. The bearing seat includes a driving bearing seat 3-4 and a driven bearing seat 3-7. The two guide rails 3-3 of the traveling mechanism 1-3 are fixed on the bracket 1-4, forming a C-shaped integral structure installed on both sides of the single crystal furnace 1-1. The saddle-shaped single-crystal permanent magnet 1-2 is installed on both sides of the single crystal furnace 1-1. The saddle-shaped single-crystal permanent magnet 1-2 forms a magnetic field for processing silicon single crystals. Molten silicon single crystal melt is placed inside the single crystal furnace 1-1. The center point of the magnetic field is located below the surface of the silicon single crystal melt, preferably at any height of 8mm-22mm from the surface of the silicon single crystal melt; or preferably at any position of 0mm-20mm from the surface of the silicon single crystal melt, with the center point of the magnetic field located at any position within 20mm of the surface of the silicon single crystal melt. The left magnetic pole 4-2 of the saddle-shaped single-crystal permanent magnet 1-2 is the N pole, and the right magnetic pole 4-3 of the saddle-shaped single-crystal permanent magnet 1-2 is the S pole, with opposite polarities. The left magnetic pole 4-2 and the right magnetic pole 4-3 of the saddle-shaped single-crystal permanent magnet 1-2 are composed of a rare-earth alloy magnetic block 5-1, an upper setter 5-2, a magnetic pole guide rail 5-3, a lower setter 5-4, a magnetic pole slider 5-5, and a magnetic pole cavity 5-6. The magnetic pole cavity 5-6 is made of stainless steel and has a stepped shape. The magnetic pole slider 5-5 is made of DT4 electrical pure iron. Rare earth alloy magnetic blocks 5-1 are stacked in rows inside the magnetic pole cavity 5-6. The magnetic pole cavity 5-6 is connected to the magnetic pole slider 5-5. The magnetic pole guide rail 5-3 is connected to the left and right yoke plates. The magnetic pole cavity 5-6 and the magnetic pole slider 5-5 are mounted on the magnetic pole guide rail 5-3. The magnetic pole cavity 5-6 and the magnetic pole slider 5-5 are fixed in position by the upper set screw 5-2 and the lower set screw 5-4. The left magnetic pole 4-2 and the right magnetic pole 4-3 are produced using a vacuum infusion process. After assembling the rare earth alloy magnetic blocks 5-1, the entire magnetic pole is placed in a curing oven, a vacuum is drawn, and then epoxy resin (HY750) is infused. After infusion, the magnetic pole is transferred to a curing oven at a temperature of 40 degrees Celsius for 4 hours of curing and integral molding. The left magnetic pole 4-2 and right magnetic pole 4-3 of the saddle-shaped single-crystal permanent magnet 1-2 have a saddle-shaped structure, which improves the circumferential uniformity of the magnetic field. The left magnetic pole 4-2 and right magnetic pole 4-3 of the saddle-shaped single-crystal permanent magnet 1-2 can be adjusted vertically by using the upper set screw 5-2 and the lower set screw 5-4, thereby adjusting the position of the magnetic field center.

[0032] The magnetic field lines of the saddle-shaped single-crystal permanent magnet 1-2 run from the N pole of the left magnetic pole 4-2 through the single-crystal furnace to the S pole of the right magnetic pole 4-3, then to the right yoke plate 4-4, through the magnetic guide plate 4-6, back to the left yoke plate 4-1, and then to the left magnetic pole 4-2, forming a loop. The magnetic field strength at the center point of the horizontal distance between the centers of the left magnetic pole 4-2 and the right magnetic pole 4-3 is the primary factor affecting crystal pulling; the magnetic field strength is any value between 800GS and 1500GS. The right top screw 4-5 and left top screw 4-7 of the saddle-shaped single crystal permanent magnet 1-2 are installed on both sides of the magnetic plate 4-6 at the connection points with the left yoke plate 4-1 and the right yoke plate 4-4. The right top screw 4-5 and left top screw 4-7 can open or reduce the connection points between the left yoke plate 4-1 and the right yoke plate 4-4 and the magnetic plate 4-6. Then, pads are added or removed between the left yoke plate 4-1 and the right yoke plate 4-4 and the magnetic plate 4-6. The pads are made of DT4 electrical pure iron. When a circuit is formed, the distance between the left magnetic pole 4-2 and the right magnetic pole 4-3 can be changed, thereby increasing or decreasing the central magnetic field strength.

[0033] The walking mechanism 1-3 is mounted on the lifting mechanism 1-5, which is mounted on the support assembly 1-4. The saddle-shaped single-crystal permanent magnet 1-2 is mounted on the walking mechanism 1-3, forming a C-shaped integral installation on both sides of the single crystal furnace 1-1. The center point of the magnetic field formed by the single-crystal permanent magnet 1-2 is located 20mm below the surface of the silicon melt. The drive motor 3-1 of the walking mechanism 1-3 drives the transmission shaft 3-5, and both ends of the transmission shaft 3-5 are fixed to the active bearing seat 3-4 and the driven bearing seat 3-5. On the outer side of the moving bearing housing 3-8, there are driving pulleys 3-2 and driven pulleys 3-7 fixed to the drive shaft 3-5. The driving pulleys 3-2 and driven pulleys 3-7 are mounted on the guide rail 3-3. The drive shaft 3-5 drives the driving pulleys 3-2 and driven pulleys 3-7 to roll. A gear is fixed on the outer side of the driven pulley 3-7. The gear and rack 3-6 move. The traveling mechanism 1-3 drives the integral saddle-shaped single crystal permanent magnet 1-2 to move freely back and forth, freely switching between the working position and the maintenance position. The two ends of the drive shaft 3-5 of the traveling mechanism 1-3 are fixed to the driving bearing housing 3-4 and driven bearing housing 3-8. The outer side of the driving pulleys 3-2 and driven pulleys 3-7 are fixed to the drive shaft 3-5. The driving pulleys 3-2 and driven pulleys 3-7 are mounted on the guide rail 3-3. One end of the drive shaft 3-5 is connected to the drive motor 3-1.

[0034] The lifting mechanism 1-5 is connected to the support below. The geared motor 6-1 drives the coupling 6-2. Through the transmission shaft and the geared motor 6-1, the four screw jacks can lift and lower simultaneously, making the saddle-shaped single crystal permanent magnet adjustable up and down.

[0035] like Figure 1As shown, the bottom of the saddle-shaped single-crystal permanent magnet is connected to the driving pulley and driven pulley of the traveling mechanism via bolts. The guide rail below the traveling mechanism is connected to the lifting mechanism via bolts, and the lifting mechanism is connected to the bracket via bolts, forming a C-shaped whole, which is installed on both sides of the single crystal furnace. The saddle-shaped permanent magnetic field can provide a stable, energy-free horizontal magnetic field for single crystal growth. The traveling mechanism 1-3 allows the saddle-shaped permanent magnetic field 1-2 to move flexibly back and forth. On the one hand, this can improve the safety of single crystal furnace maintenance and reduce the difficulty of maintenance, because there are certain safety hazards in working in a magnetic field environment. Maintenance tools must be non-magnetic, and maintenance personnel cannot wear any iron parts. On the other hand, the magnetic field is not needed during the melting process. The presence of a magnetic field will increase the melting time. Only by increasing the heating power can the melting time be increased, which increases energy consumption. Therefore, during the melting stage, the saddle-shaped permanent magnet can be moved to the maintenance position, so as not to affect the melting efficiency. The lifting mechanism 1-5 allows the saddle-shaped magnet to move vertically up and down within the single crystal furnace. When using different thermal fields and crucibles in the single crystal furnace, the molten metal level needs adjustment, sometimes by a significant distance. The lifting mechanism allows for quick adjustment of the magnetic pole center height to match the molten metal level, making it convenient and efficient. The support assembly 1-4 provides support for all components. It is fixed to the ground with expansion bolts and uses a 4-square steel column structure connected by tie rods to form a stable support.

[0036] like Figure 2a and Figure 2b As shown, the traveling mechanism 1-3 allows the saddle-shaped permanent magnetic field 1-2 to move flexibly back and forth. Figure 2b As shown, the magnetic field is moved to an area outside the single crystal furnace via a walking mechanism. This improves the safety and reduces the difficulty of single crystal furnace maintenance, as working in a magnetic field environment poses certain safety hazards. Maintenance tools must be non-magnetic, and maintenance personnel must not wear any iron parts. On the other hand, the magnetic field is not needed during the melting process. In fact, the magnetic field would increase the melting time. Only by increasing the heating power can the melting time be increased, which would increase energy consumption. Therefore, during the melting stage, the saddle-shaped permanent magnet can be moved to the maintenance position without affecting the melting efficiency.

[0037] like Figure 3As shown, the drive motor 3-1 of the walking mechanism 1-3 drives the transmission shaft 3-5. The two ends of the transmission shaft 3-5 are fixed on the active bearing seat 3-4 and the driven bearing seat 3-8. The active pulley 3-2 and the driven pulley 3-7 are fixed on the outer side of the transmission shaft 3-5. The active pulley 3-2 and the driven pulley 3-7 are mounted on the guide rail 3-3. The transmission shaft 3-5 drives the active pulley 3-2 and the driven pulley 3-7 to roll. A gear is fixed on the outer side of the driven pulley 3-7. The gear and the rack 3-6 move. Through the above structure, the walking mechanism 1-3 can smoothly drive the integral saddle-shaped single crystal permanent magnet 1-2 to move freely back and forth, and freely switch between the working position and the maintenance position.

[0038] like Figure 4 As shown, the saddle-shaped single-crystal permanent magnet 1-2 includes a left yoke plate 4-1, a left magnetic pole 4-2, a right magnetic pole 4-3, a right yoke plate 4-4, a right top wire 4-5, a magnetic guide plate 4-6, and a left top wire 4-7; the left yoke plate 4-1, the left magnetic pole 4-2, the right magnetic pole 4-3, the right yoke plate 4-4, and the magnetic guide plate 4-6 are made of high-permeability DT4 electrical pure iron; the left yoke plate 4-1 is connected to the left magnetic pole 4-2, the right magnetic pole 4-3 is connected to the right yoke plate 4-4, the left yoke plate 4-1 is connected to the magnetic guide plate 4-6, and the right yoke plate 4-4 is connected to the magnetic guide plate 4-6, forming a C-shaped whole.

[0039] The left magnetic pole 4-2 is mounted on the left yoke plate 4-1 via the magnetic pole guide rail 5-3, and the right magnetic pole 4-3 is mounted on the right yoke plate 4-4 via the magnetic pole guide rail 5-3. The left yoke plate 4-1 and the right yoke plate 4-4 are mounted on both sides of the magnetic guide plate 4-6. The right set screw 4-5 and the left set screw 4-7 are respectively mounted on both sides of the magnetic guide plate 4-6 at the connection points with the left yoke plate 4-1 and the right yoke plate 4-4. The right set screw 4-5 and the left set screw 4-7 can be used to open or reduce the connection points between the left yoke plate 4-1 and the right yoke plate 4-4 and the magnetic guide plate 4-6. Then, pads made of DT4 electrical pure iron are added or removed between the left yoke plate 4-1 and the right yoke plate 4-4 and the magnetic guide plate 4-6. When a circuit is formed, the distance between the left magnetic pole 4-2 and the right magnetic pole 4-3 is changed, thereby increasing or decreasing the central magnetic field strength. In this embodiment, the left magnetic pole 4-2 and the right magnetic pole 4-3 are made using a vacuum-infused epoxy process, which reduces the oxidation of the magnetic material in contact with air, increases heat insulation, and improves the service life of the equipment.

[0040] like Figure 5As shown, the left magnetic pole 4-2 and the right magnetic pole 4-3 are composed of rare earth alloy magnetic blocks 5-1, upper set screws 5-2, magnetic pole guide rails 5-3, lower set screws 5-4, magnetic pole sliders 5-5, and magnetic pole cavities 5-6. The rare earth alloy magnetic blocks 5-1 are stacked in rows and installed in the stainless steel magnetic pole cavities 5-6. The stainless steel magnetic pole cavities 5-6 are designed in a saddle-shaped stepped shape. The magnetic pole arrangement improves the uniformity of the magnetic field around the circumference. The upper set screws 5-2 and lower set screws 5-4 are fixed on the yoke plate. The magnetic pole sliders 5-5 can be moved on the magnetic pole guide rails 5-3 by the upper set screws 5-2 and lower set screws 5-4, thereby adjusting the vertical position of the magnetic pole cavities, changing the position of the magnetic pole center, and allowing the central magnetic field surface to move up and down to match the position of the thermal field.

[0041] like Figure 6a and Figure 6b As shown, the lifting mechanism 1-5 is connected to the support frame at the bottom. The geared motor 6-1 drives the coupling 6-2, and through the transmission shaft 3-5 and the reducer, enables the four screw jacks to lift simultaneously, allowing the saddle-shaped single-crystal permanent magnet to be adjusted vertically. The lifting mechanism 1-5 has a C-shaped structure, matching the shape of the saddle-shaped permanent magnet for easy installation. The geared motor 6-1 has a two-sided output shaft structure, and the reducer 6-4 has a right-angle structure, allowing the transmission direction to rotate 90 degrees. The four screw jacks 6-5 are worm gear screw structures, with their upper ends connected via connecting plates and their lower ends directly connected to the load. The worm gear screw structure is compact, small in size, operates smoothly and quietly, and can flexibly and reliably lift the single-crystal permanent magnet. The transmission shaft 6-3 is connected to the coupling 6-2 at both ends. The output of the geared motor 6-1 drives the rotation, and the torque is transmitted from the transmission shaft 6-3 to the reducer 6-4, and finally to the screw jacks 6-5, ultimately achieving vertical movement and serving the function of connection and torque transmission.

[0042] It should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The terminology used in the description of this application is only for describing specific embodiments and is not intended to limit the exemplary embodiments according to this application. For ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings indicate similar items, and therefore, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0043] It should be noted that the terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and are not limited in number; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0044] It should be noted that in the description of this application, the directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

Claims

1. A saddle-shaped permanent magnetic field device for silicon single crystal growth, characterized in that, It includes a saddle-shaped single-crystal permanent magnet (1-2), a walking mechanism (1-3), a support assembly (1-4), and a lifting mechanism (1-5); The saddle-shaped single-crystal permanent magnet (1-2) is fixed on the bearing seat with connecting plate and the fixed pulley (3-9) of the walking mechanism (1-3). The bearing seat includes an active bearing seat (3-4) and a driven bearing seat (3-8). The two guide rails (3-3) of the walking mechanism (1-3) are fixed on the support assembly (1-4) to form a C-shaped integral structure installed on both sides of the single crystal furnace (1-1).

2. The saddle-shaped permanent magnetic field device for silicon single crystal growth according to claim 1, characterized in that, The saddle-shaped single-crystal permanent magnet (1-2) includes a left magnetic pole (4-2) and a right magnetic pole (4-3). The center of the magnetic field formed by the left magnetic pole (4-2) and the right magnetic pole (4-3) is located 20 mm below the surface of the molten silicon inside the single crystal furnace (1-1).

3. The saddle-shaped permanent magnetic field device for silicon single crystal growth according to claim 1, characterized in that, The saddle-shaped single-crystal permanent magnet (1-2) includes a left yoke plate (4-1), a left magnetic pole (4-2), a right magnetic pole (4-3), a right yoke plate (4-4), a right top wire (4-5), a magnetic guide plate (4-6), and a left top wire (4-7); The left yoke plate (4-1), left magnetic pole (4-2), right magnetic pole (4-3), right yoke plate (4-4), and magnetic guide plate (4-6) are made of high permeability DT4 electrical pure iron. The left yoke plate (4-1) is connected to the left magnetic pole (4-2), the right magnetic pole (4-3) is connected to the right yoke plate (4-4), the left yoke plate (4-1) is connected to the magnetic guide plate (4-6), and the right yoke plate (4-4) is connected to the magnetic guide plate (4-6), forming a C-shaped whole.

4. The saddle-shaped permanent magnetic field device for silicon single crystal growth according to claim 3, characterized in that, The left magnetic pole (4-2) and right magnetic pole (4-3) of the saddle-shaped single crystal permanent magnet (1-2) are N pole and S pole, respectively, with opposite polarities.

5. The saddle-shaped permanent magnetic field device for silicon single crystal growth according to claim 3, characterized in that, The magnetic field lines of the saddle-shaped single-crystal permanent magnet (1-2) are directed from the N pole of the left magnetic pole (4-2), through the single crystal furnace, to the S pole of the right magnetic pole (4-3), then to the right yoke plate (4-4), through the magnetic guide plate (4-6), back to the left yoke plate (4-1), and then to the left magnetic pole (4-2), forming a loop. The magnetic field strength at the center point of the horizontal distance between the centers of the left magnetic pole (4-2) and the right magnetic pole (4-3) is what affects the crystal pulling. The magnetic field strength is any value between 800GS and 1500GS.

6. The saddle-shaped permanent magnetic field device for silicon single crystal growth according to claim 5, characterized in that, The right top wire (4-5) and left top wire (4-7) of the saddle-shaped single crystal permanent magnet (1-2) are respectively installed on both sides of the magnetic plate (4-6) at the connection points with the left yoke plate (4-1) and the right yoke plate (4-4). The right top wire (4-5) and left top wire (4-7) are used to push open or reduce the connection points between the left yoke plate (4-1) and the right yoke plate (4-4) and the magnetic plate (4-6). Then, pads made of DT4 electrical pure iron are added or removed between the left yoke plate (4-1) and the right yoke plate (4-4) and the magnetic plate (4-6). When a circuit is formed, the distance between the left magnetic pole (4-2) and the right magnetic pole (4-3) is changed, thereby increasing or decreasing the central magnetic field strength.

7. The saddle-shaped permanent magnetic field device for silicon single crystal growth according to claim 6, characterized in that, The left magnetic pole (4-2) and right magnetic pole (4-3) of the saddle-shaped single crystal permanent magnet (1-2) are composed of a rare earth alloy magnetic block (5-1), an upper top wire (5-2), a magnetic pole guide rail (5-3), a lower top wire (5-4), a magnetic pole slider (5-5), and a magnetic pole cavity (5-6). The magnetic pole cavity (5-6) is made of stainless steel and has a stepped shape. The magnetic pole slider (5-5) is made of DT4 electrical pure iron. Rare earth alloy magnetic blocks (5-1) are stacked in rows in the magnetic pole cavity (5-6). The magnetic pole cavity (5-6) is connected to the magnetic pole slider (5-5). The magnetic pole guide rail (5-3) is connected to the left and right yoke plates. The magnetic pole cavity (5-6) and the magnetic pole slider (5-5) are installed on the magnetic pole guide rail (5-3) and fixed in position by the upper set screw (5-2) and the lower set screw (5-4).

8. The saddle-shaped permanent magnetic field device for silicon single crystal growth according to claim 7, characterized in that, The left magnetic pole (4-2) and right magnetic pole (4-3) of the saddle-shaped single crystal permanent magnet (1-2) have a saddle-shaped structure, which improves the circumferential uniformity of the magnetic field.

9. The saddle-shaped permanent magnetic field device for silicon single crystal growth according to any one of claims 3-8, characterized in that, The left magnetic pole (4-2) and right magnetic pole (4-3) of the saddle-shaped single crystal permanent magnet (1-2) are adjusted up and down by the upper set wire (5-2) and the lower set wire (5-4), thereby adjusting the position of the magnetic field center.

10. The saddle-shaped permanent magnetic field device for silicon single crystal growth according to claim 1, characterized in that, The drive shaft (3-5) of the walking mechanism (1-3) is fixed at both ends on the active bearing seat (3-4) and the driven bearing seat (3-8). The active pulley (3-2) and the driven pulley (3-7) are fixed on the drive shaft (3-5) on the outside. The active pulley (3-2) and the driven pulley (3-7) are mounted on the guide rail (3-3). One end of the drive shaft (3-5) is connected to the drive motor (3-1).

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