A magnetron coil and crystal manufacturing apparatus

Abstract

The application discloses a magnetic control coil, which comprises a coil support body and N pairs of coil groups, the coil groups are arranged in a plane of the coil support body, and N is an integer not less than 1. The application adopts a plurality of surface type coil groups to replace traditional rectangular cross-section circular, runway-shaped or saddle-shaped coil groups, so that the generation efficiency of a transverse magnetic field can be improved, and the introduction of impurities and the generation of defects in a crystal manufacturing process can be effectively inhibited, and the efficiency and quality of the crystal manufacturing can be improved.

Description

Technical Field

[0001] This invention relates to the field of crystal manufacturing technology, and in particular to a magnetic control coil and crystal manufacturing equipment. Background Technology

[0002] In the field of crystal manufacturing, methods such as the Czochralski method and zone melting are commonly used for crystal preparation. The prepared crystals are then subjected to post-processing such as cutting and polishing to obtain components with specific functions. For example, in the Czochralski process for single-crystal silicon, molten crystal raw materials are gradually solidified from a liquid phase into a solid phase according to a specific process, forming a crystal with a specific atomic arrangement structure. The crystal can be either polycrystalline or single-crystal. During the crystal pulling growth process, due to the thermal convection of the melt, various defects often occur at the solid-liquid interface of the crystal during growth, such as point defects or the introduction of impurity elements.

[0003] Therefore, how to effectively suppress the influence of melt thermal convection on crystal growth (especially large-size crystals) is an urgent problem to be solved in the field of crystal manufacturing. Summary of the Invention

[0004] To reduce the impact of thermal convection on crystal quality during crystal growth, this application proposes a magnetron coil and a crystal manufacturing device. Based on the magnetron coil laid flat along the surface of the coil support, the strength of the transverse magnetic field can be increased, thereby effectively suppressing the generation of defects and the introduction of impurities during crystal manufacturing, and improving the efficiency and quality of crystal manufacturing.

[0005] According to a first aspect of this application, a magnetically controlled coil is proposed, comprising a coil support and N pairs of coil groups, the coil groups being laid flat along the surface of the coil support; N is an integer not less than 1.

[0006] In one embodiment, the coil support is arranged around a central axis; the i-th pair of coils in N pairs of coils is symmetrically distributed based on the central axis; i is an integer not less than 1 and not greater than N.

[0007] In one embodiment, the coil support is cylindrical and made of stainless steel or aluminum alloy.

[0008] In one embodiment, the cylindrical side of the coil support includes a coil region and a non-coil region; the coil region is used to arrange coil groups, and the non-coil region is set as a hollow structure.

[0009] In one implementation, each coil group contains M layers of coils, where M is an integer not less than 1; when M is not less than 2, the (j+1)th layer of coils is located above the surface of the i-th layer of coils away from the central axis, where j is an integer not less than 1 and not greater than M.

[0010] In one embodiment, each coil group unfolds in a concentric rectangle along the cylindrical side of the coil support; the concentric rectangle includes a first direction line segment, which is a line segment parallel to the central axis.

[0011] In one embodiment, the concentric rectangle includes a second direction line segment; the second direction line segment is a line segment perpendicular to the direction of the central axis.

[0012] In one embodiment, a transition arc is provided between the first direction line segment and the second direction line segment, and the radius of curvature of the arc is not less than a preset threshold.

[0013] In one embodiment, N pairs of coil groups are wound from the same set of wires; the same set of wires is made of multiple wires arranged side by side, twisted or braided.

[0014] In one embodiment, the coil assembly is made of a superconducting material.

[0015] In one embodiment, the magnetron has current leads for connecting the magnetron to a power source.

[0016] In one embodiment, the surface of the coil support is provided with a groove for fixing the coil assembly.

[0017] In one embodiment, a heat-conducting layer is applied to the surface of the coil support; the heat-conducting layer includes at least one of the following: a pure copper plate, a pure aluminum plate, or a pipeline through which a low-temperature fluid flows.

[0018] According to a second aspect of this application, a crystal manufacturing apparatus is provided, comprising a crystal growth furnace and any of the aforementioned magnetron coils; the crystal growth furnace is equipped with a heating device and a crucible for containing crystal raw materials, the crucible being placed inside the cavity of the crystal growth furnace; the magnetron coils are arranged around the crystal growth furnace and symmetrically distributed along the central axis of the crystal growth furnace.

[0019] In one embodiment, the crystal manufacturing equipment further includes: a heat-insulated vacuum chamber, with a magnetron coil disposed inside the heat-insulated vacuum chamber.

[0020] In one embodiment, the crystal manufacturing equipment further includes a cooling device for reducing the temperature inside the heat-insulating cavity.

[0021] In one embodiment, the interior of the heat-insulating vacuum cavity where the magnetron coil is located is a vacuum environment, and the magnetron coil is suspended in the vacuum environment of the heat-insulating vacuum cavity by a hanger. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0023] Figure 1 A schematic diagram of a magnetically controlled coil structure according to this application is shown;

[0024] Figure 2 A schematic diagram of a coil assembly structure according to this application is shown;

[0025] Figure 3 A schematic diagram of a crystal manufacturing equipment is shown.

[0026] In the diagram: 1. Coil support, 2. Coil assembly, 3. Insulated vacuum chamber, 4. Radiant cooling shield, 5. Refrigeration unit, 6. Current leads Detailed Implementation

[0027] Embodiments of the present invention are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0028] To better understand the technical solution of this application, the application scenarios of the magnetron coil and crystal manufacturing equipment involved in this application are further described below. It should be understood that the scenario description here is only for better understanding of the technical solution of this application and should not be used to limit the application scenarios of this application. The magnetron coil involved in this application can be applied to the field of single crystal silicon manufacturing. In the process of single crystal silicon manufacturing, the crystal grown by Czochralski is often very susceptible to the influence of melt thermal convection. Especially with the rapid development of semiconductor microelectronic devices, large-scale integrated circuits, solar panels and other device manufacturing technologies, the requirements for the quality and size of single crystal silicon are becoming increasingly higher. In the preparation process of such large-size single crystal silicon, the thermal convection of the melt is further enhanced, and the influence of impurity elements (such as oxygen) and melt uniformity is further increased, often leading to a reduction in crystal quality and making it difficult to prepare large-size, high-quality single crystal silicon crystals.

[0029] To better reduce the impact of thermal convection on crystal quality, the magnetic control coil proposed in this application can effectively solve this problem. In addition, the magnetic control coil of this application has the characteristics of high magnetic field utilization efficiency, concentrated magnetic force, uniform magnetic field, simple setup and maintenance, and low cost.

[0030] This application proposes a magnetically controlled coil, comprising: a coil support and N pairs of coil groups, the coil groups being laid out flat along the surface of the coil support; N is an integer not less than 1.

[0031] Reference Figure 1 In this application, the coil support can be a coil support frame, used for fixing the coil group and providing electromagnetic force support. The number of coil groups can be set according to the required magnetic field strength. For example, the number of N pairs of coil groups can be 1 pair, 2 pairs, or 3 pairs, and there is no limitation here.

[0032] The coil assembly is composed of multiple coils wound in a spiral. The spacing between each coil can be set as needed, for example, the spacing can be 2mm, 3mm, 4mm, etc., and there is no limitation here. The coils can be wound spirally from the inside to the outside along the surface of the coil support, or spirally wound from the outside to the inside, and there is no limitation here.

[0033] In this application, multiple coils are formed by winding a set of wires on the surface of a coil support, and these coils are arranged in a two-dimensional flat distribution on the surface of the coil support. The surface of the coil support can be flat or curved, and is not limited here. The two ends of the set of wires extend to form the current leads of the multiple coils. Compared with the prior art's process of layer-by-layer tightly wound circular coils or saddle-shaped coils based on a single rectangular cross-section superconducting wire, the magnetic control coil of this application has a higher magnetic field utilization efficiency.

[0034] The advantages of the magnetic control coil of this application will be further explained below in conjunction with traditional magnetron coils and winding processes. Existing technologies use circular or saddle-shaped magnetron coils wound with rectangular cross-sections. During use, as the coil thickens radially, according to Biot-Savart's law, the efficiency of magnetic field generation decreases with increasing radial thickness. More magnetron force is concentrated on the coil, resulting in a high internal magnetic field. Such coils often struggle to generate larger external magnetic fields to meet the high magnetic field requirements of industries such as crystal manufacturing. Furthermore, the high internal magnetic field further weakens the current-carrying capacity of the coil conductors, reducing conductor utilization. Simultaneously, the concentration of magnetic force on the coil itself exerts a significant magnetic influence, negatively impacting coil fixation and the stability of the internal structure of the coil conductors. With the development of superconducting technology in recent years, the disadvantages of such magnetron coils have become even more pronounced in superconducting magnetic coils.

[0035] The magnetic control coil in this application is wound in a two-dimensional flat pattern along the surface of the support. The radial thickness of the coil can be the thickness of a corresponding number of layers of wire / wire group, specifically, it can be the thickness of one or two layers of wire / wire group. The radial thickness of the coil is greatly reduced, which effectively avoids the concentration of magnetic flux inside the coil, reduces the influence of magnetic flux on the coil wire, improves the magnetic field utilization efficiency, and is conducive to generating a higher intensity external magnetic field.

[0036] In some optional embodiments, the magnetic control coil wire of this application is composed of multiple sets of wires. For example, in some scenarios, 19 wires can be used to form the coil cable of this application, and the diameter of each wire can be 0.6mm.

[0037] In some embodiments, the coil support is arranged around the central axis; the i-th pair of coils in the N pairs of coils is symmetrically distributed based on the central axis; i is an integer not less than 1 and not greater than N.

[0038] Specifically, the coil support can be a one-piece structure or a split structure, without limitation here. The one-piece coil support can be cylindrical; the split coil support can be a portion of an arc cut from any two non-parallel planes parallel to the central axis of the cylinder. That is, the cross-section of the coil support can be an arc or a ring. The coil support is arranged around the central axis, or its surface can be uniformly distributed around the central axis. Based on the arrangement of the coil support, the i-th pair of coils is symmetrically distributed around the central axis, thus generating a transverse magnetic field perpendicular to the central axis from the symmetrically distributed i-th pair of coils, where i can be 1, 2, 3, etc., without limitation here.

[0039] In some embodiments, the coil support is cylindrical and made of stainless steel or aluminum alloy. The cylindrical shape can be circular or polygonal. Furthermore, the cross-section of the variable cylindrical shape can be polygonal, including quadrilaterals, pentagons, hexagons, etc., without limitation.

[0040] A thermally conductive layer with a high thermal conductivity can be applied to the surface of the coil support. For example, the thermally conductive layer can be at least one of a pure copper plate, a pure aluminum plate, or a conduit containing a low-temperature fluid, to enhance thermal conductivity.

[0041] In some embodiments, the cylindrical side of the coil support includes a coil region and a non-coil region; the coil region is used to wind and arrange coil groups, and the non-coil region is configured as a hollow structure. Specifically, the non-coil region may be located at the gap between two adjacent coil regions, or it may be located at the center of a coil group, without limitation. This hollow structure further reduces the weight and volume of the coil support, a feature significant in some superconducting magnetron coils. For example, in the cryogenic environment required for superconducting wire operation, reducing the weight and volume of the coil support can effectively increase the cooling rate of the coil, thereby improving the operating efficiency of the equipment.

[0042] In some embodiments, each coil group contains M layers of coils, where M is an integer not less than 1; when M is not less than 2, the (j+1)th layer of coils is located above the surface of the i-th layer of coils away from the central axis, where j is an integer not less than 1 and not greater than M.

[0043] Reference Figure 2 The number of coil layers M can be set according to the required magnetic field strength. For example, M can be 1, 2, 3, etc. The selection of the number of layers is related to the number and thickness of the wires used to wind the coil. In specific implementation, the optimal magnetic control coil parameters can be obtained through limited experiments based on the actual situation. Specifically, in the optimal embodiment of this application, when the wire is a superconducting wire, the wire group consists of 19 wires, and the single wire is 0.6mm, then the optimal magnetic control coil of the optimal embodiment of this application is constructed using 2 layers of coils.

[0044] When M is not less than 2, the (j+1)th layer coil and the i-th layer coil are arranged in a two-dimensional, flat, two-layer configuration, with j being 1, 2, 3, etc., without limitation here. Coil groups corresponding to different layers can be coils with the same winding pattern. That is, when the j-th layer coil is wound as a flat rectangle, the (j+1)-th layer coil can be wound above the j-th layer coil according to the same winding rules. Thus, the two layers of coils have the same planar structure, forming two layers of coils perpendicular to the central axis of the coil. This two-layer magnetically controlled coil has a stronger magnetic field generating capability.

[0045] In some embodiments, each coil group has a concentric rectangle as the planar shape unfolded along the surface of the coil support; the concentric rectangle includes a first direction line segment, which is a line segment parallel to the direction of the central axis.

[0046] The surface of the support can be either flat or curved. For example, when the support is a polygonal cylinder, the sides are flat. In this case, a coil group can be located on one support surface or on multiple adjacent and continuous support surfaces; there is no limitation here. When the support is cylindrical, the surface is curved.

[0047] After the coil assembly is unfolded along the surface of the coil support, the planar shape of the coil assembly is a concentric rectangle. Specifically, the concentric rectangle contains a first direction line segment, which is a line segment parallel to the central axis.

[0048] In some embodiments, the concentric rectangle includes a second direction line segment; the second direction line segment is a line segment perpendicular to the direction of the central axis.

[0049] In some embodiments, to reduce the degradation of insulation and conductivity caused by excessive bending of the coil conductor, a transition arc or spline curve is provided between adjacent first-direction line segments and second-direction line segments in the coil group. The minimum radius of curvature of the transition arc or spline curve is not less than a preset threshold. The preset threshold can be determined based on the overall size of the coils in the actual coil group. When the minimum radius of curvature of the transition curve is greater than the preset threshold, excessive bending strain in the superconducting wire can lead to degradation of current-carrying capacity, potentially affecting the generation of the magnetic field in the magnetically controlled coil.

[0050] In some embodiments, N pairs of coil groups are wound from the same set of wires; the same set of wires is formed by multiple wires wound, twisted, or braided together. The use of multiple wires wound, twisted, or braided together in the same set of wires can effectively increase the engineering current density and is also more conducive to the implementation of precise wiring magnet manufacturing processes with slotted wires.

[0051] In some embodiments, the coil assembly is made of a superconducting material, such as NbTi, Nb3Sn, or Mg2B superconducting wire. When the coil in this application is a superconducting coil, the magnetron coil of this application can generate a stronger magnetic flux, thereby meeting the crystal manufacturing industry's demand for high-strength transverse magnetic fields.

[0052] In some embodiments, the magnetically controlled coil has a current lead for connecting the magnetically controlled coil to a power source. That is, the coils in the N pairs of coil groups have the same current lead, with current fed in from one end of the wire and flowing out from the other end, forming a closed loop of the magnetically controlled coil through connection with the power source, and generating a magnetic field through the charged current in the coil.

[0053] In some embodiments, the surface of the coil support is provided with grooves for fixing the coil assembly. The grooves can be configured according to the arrangement shape of the coil assembly. For example, when the magnetically controlled coil needs to be wound along a concentric rectangle, a U-shaped groove can be machined according to the concentric rectangle of the coil assembly in the magnetically controlled coil during the processing of the coil support. Then, the wires in the magnetically controlled coil are arranged in the groove according to the shape of the groove to form the magnetically controlled coil. Preferably, grooves corresponding to the first direction line segment and the second direction line segment are machined only on the surface of the coil support, so that the coil assembly is laid flat on the surface of the coil support according to the first direction line segment and the second direction line segment. At the same time, based on the limiting effect of the grooves, a transition arc is naturally formed between adjacent first direction line segments and second direction line segments in the coil assembly. That is, there is no need to machine grooves at the corresponding positions of the transition arc of the coil assembly. It should be understood that the depth of the groove can be determined according to the number of coil assembly layers to be arranged. For example, when two coil assemblies need to be arranged, it can be determined according to the diameter of the wires in the coil assembly. It should also be understood that fixing the coil assembly of the magnetron coil through grooves is only one method provided in this application. In addition, there are many other methods that can be implemented, such as using ultrasonic-assisted bonding or photocurable resin rapid bonding methods to arrange and form the coil assembly of the magnetron coil. This application does not limit the specific methods.

[0054] Figure 3 This application illustrates a crystal manufacturing apparatus that can be used for the manufacture of silicon crystals.

[0055] In some embodiments, the crystal manufacturing equipment includes a crystal growth furnace and any of the above-mentioned magnetron coils; the crystal growth furnace is equipped with a heating device and a crucible for containing crystal raw materials, and the crucible is placed inside the cavity of the crystal growth furnace; the magnetron coils are arranged around the crystal growth furnace and symmetrically distributed along the central axis of the crystal growth furnace.

[0056] The aforementioned coil groups can be symmetrically arranged on both sides of the crystal manufacturing equipment, with the coil groups laid flat along the surface of the coil support. See also Figure 3 The magnetron coil includes a coil support 1 and a coil assembly 2. The coil support 1 is cylindrical, and the coil assembly 2 is disposed on both sides of the crystal manufacturing equipment. Specifically, the coil assembly 2 can exist in pairs, for example, one pair, two pairs, etc., without limitation here.

[0057] like Figure 3As shown, in some embodiments, the crystal manufacturing equipment of this application further includes a thermally insulated vacuum cavity 3, with the magnetron coil disposed inside the thermally insulated vacuum cavity 3 to ensure that the magnetron coil operates within a suitable temperature range. For example, when the magnetron coil is made of superconducting wire material, it often needs to operate at extremely low temperatures, and the thermally insulated vacuum cavity 3 can provide a powerful working space for the ultra-low temperature environment. In some optional embodiments, the thermally insulated vacuum cavity 3 can be configured as a hollow cavity, and a liquid inert gas (such as liquid helium) can be injected into the cavity to ensure extremely low temperatures within the cavity, thereby providing an ultra-low temperature environment for the operation of the superconducting coil. In some scenarios, such a container with an insulated space can be called a Dewar container, and a crystal growth furnace is set inside the Dewar container for crystal pulling.

[0058] The inner wall of the insulated vacuum chamber in this application can be the same component as the furnace wall of the crystal growth furnace (not shown), further reducing the complexity of the crystal manufacturing equipment and saving manufacturing costs. Of course, in some embodiments, the insulated vacuum chamber and the magnetron coil can be independent components, with the inner wall of the insulated vacuum chamber maintaining a certain distance from the furnace wall of the crystal growth furnace. In some optional embodiments, the coil support 1 can be configured as a hollow structure; that is, a support structure is provided in the coil area, and a hollow structure can be provided in the non-coil area. This can significantly reduce the mass of the support, while reducing the cooling load in the low-temperature environment and improving cooling efficiency.

[0059] In crystal fabrication apparatuses, Czochralski-grown crystals are highly susceptible to the effects of melt thermal convection, which can negatively impact crystal quality, introduce impurities, or cause various defects at the solid-liquid interface. Symmetrically arranging magnetrons around the crystal growth furnace, the transverse magnetic field generated by these magnetrons can effectively mitigate the influence of thermal convection on the solid-liquid interface during crystal growth, resulting in high-quality crystals. The magnetron coils provided in this application can generate a stronger transverse magnetic field, providing excellent mitigation of thermal convection in the fabrication of large-size single-crystal silicon. It should be understood that... Figure 3 The magnetic control coil shown in this application is merely a simple example of a principle, and in actual use it can take many forms, which are not limited here.

[0060] In one embodiment, the interior of the heat-insulating vacuum cavity 3 containing the magnetron coil is a vacuum environment, and the magnetron coil is suspended in the vacuum environment of the heat-insulating vacuum cavity 3 by a hanger rod. The hanger rod can be made of a material with high strength and poor thermal conductivity.

[0061] In some embodiments, the crystal manufacturing equipment proposed in this application further includes a cooling device for reducing the temperature inside the heat-insulating vacuum chamber 3. The cooling device 4 may include a radiative cooling screen 4 and a cooling unit 5. The radiative cooling screen 4 completely encloses the magnetron coil. A certain gap may exist between the inner wall of the radiative cooling screen 4 and the magnetron coil to prevent solid-state heat conduction. The surface is coated with multiple layers of aluminum-plated thin film. The radiative cooling screen is maintained at a temperature range of 60K to 100K by the primary cooling head of the cooling unit 5, thereby blocking heat radiation from the outer wall of the heat-insulating vacuum chamber 3 at room temperature and ensuring a low-temperature operating environment for the internal magnetron coil assembly. For example, when the coil group 2 in the magnetron coil is a superconducting coil, the ultra-low temperature of the magnetron coil assembly can be maintained by liquid inert gas and the cooling device, thereby providing a suitable operating temperature for the superconducting coil.

[0062] The crystal manufacturing equipment of this application is described in detail below. See also... Figure 3 A crystal manufacturing device, comprising a coil support 1, a coil assembly 2, a heat-insulating vacuum chamber 3, a radiation cooling screen 4, a refrigerator 5, and current leads 6, etc.

[0063] The coil support 1 and the coil group 2 together form a magnetically controlled coil. In this embodiment, the magnetically controlled coils are distributed in pairs on the surface of the coil support. It should be understood that... Figure 3 On the visible side of the back, there is another coil group. These two coil groups can be wound with the same set of superconducting wires. When the superconducting wires are in working condition, the magnetron coils composed of symmetrically arranged coil groups generate a strong transverse magnetic field. This transverse magnetic field can be applied to the molten raw material inside the container, thereby suppressing the thermal convection of the raw material, making the crystal growth environment more stable, and which is conducive to obtaining high-quality crystal materials.

[0064] In this embodiment, to efficiently generate a horizontal transverse magnetic field, each coil in each coil group 2 typically has a concentric rectangle with rounded corners when unfolded in planar form. The coil group 2 can be preloaded with aluminum alloy or brass wire to control any displacement that may occur when subjected to electromagnetic force. The coil support 1 and coil group 2 are treated with a low-temperature resistant insulating material between themselves and the external preload structure. For example, polyimide is used for insulation to ensure that no discharge breakdown occurs during magnetron operation and after quench failure. In some alternatives, the coil support 1 can be fabricated with U-shaped grooves through machining, 3D printing, or injection molding. These U-shaped grooves can accommodate the superconducting magnetron coils, and two layers of coil groups can be embedded in them, fixing the magnetron coils in the groove form. In other alternatives, the magnetron coils can be fixed to the surface of the coil support 1 using low-temperature resistant resin to ensure that the magnetron coils are arranged in a two-dimensional planar layout. It should be understood that on the surface of a coil support with multiple coil groups, different fixing methods can be combined based on the above-mentioned methods. For example, one coil group can be fixed using a groove-shaped method, and another coil group can be fixed using ultra-low temperature resin.

[0065] The heat-insulating vacuum chamber 3 is cylindrical, and the chamber formed by the inner wall of the cylinder can accommodate the crystal growth furnace crucible. The crystal raw material is placed inside the crucible in the crystal growth furnace, and the outer periphery of the crucible is equipped with heat-insulating material and a heating element, which can heat and melt the crystal raw material inside the crucible. In this embodiment, the heat-insulating vacuum chamber 3 can also serve as the furnace wall of the crystal growth furnace. In some scenarios, this type of sealed furnace wall can be called a vacuum external Dewar container. The sealed space inside the container can be kept in a vacuum state by evacuation, thereby better insulating it from the outside world, protecting the components inside the sealed chamber, and providing a suitable temperature environment for the operation of the internal components.

[0066] A radiative cooling screen 4 is installed inside the insulated vacuum chamber 3, completely covering the internal magnetron coil assembly, and maintaining a certain gap between itself and the inner wall of the external insulated vacuum chamber and the outer surface of the internal magnetron coil to prevent solid-to-solid heat transfer. The magnetron coil, consisting of the coil support 1 and the coil assembly 2, and the radiative cooling screen 4 are suspended inside the insulated vacuum chamber 3 by a tie rod or support assembly made of a high-strength, low-thermal-conductivity material. This creates a first temperature zone between the radiative cooling screen 4 and the magnetron coil, and a second temperature zone between the radiative cooling screen 4 and the wall of the insulated vacuum chamber 3. The first and second temperature zones are relatively independent. In actual operation, a cooling device can maintain the temperature of the second temperature zone at 60-100K and the temperature of the first temperature zone below 10K, thus providing a suitable temperature environment for the superconducting coil. The radiative cooling screen 4 can be made of a high-thermal-conductivity material; no specific material is limited. A cooling unit 5 is located on the outer wall of the insulated vacuum chamber 3 and is used for conductive cooling of the magnetron coil and the radiative cooling screen 4. The cooling capacity is transferred from the cold head of the refrigeration unit to the interior through the cooling conduction structure within the insulated vacuum chamber 3. The number of refrigeration units 5 can be 1, 2, 3, etc., which can be set according to needs.

[0067] The current lead 6 is used to connect the magnetron coil to the power supply. Current is delivered to the magnetron coil through the current lead, energizing it and generating a magnetic field. The current lead has the characteristics of high current carrying capacity and low thermal load, and can deliver a large current from room temperature to the extremely low temperature coil. When the current reaches the set value, it remains stable, and the magnetic field generated by the magnetron coil also achieves a stable field strength and uniformity.

[0068] It should be understood that in the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0069] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0070] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A magnetically controlled coil, characterized in that, include: A coil support and N pairs of coil groups, the coil groups being arranged flat along the surface of the coil support; N is an integer not less than 1; characterized in that each coil group, unfolded along the surface of the coil support, has a concentric rectangular shape; the coil support is arranged around a central axis; the concentric rectangle includes a first direction line segment, which is a line segment parallel to the direction of the central axis; the concentric rectangle includes a second direction line segment, which is a line segment perpendicular to the direction of the central axis; a transition arc is provided between the first direction line segment and the second direction line segment, the radius of curvature of the arc being not less than a preset threshold; the surface of the coil support is provided with a groove, the groove being used to allow the coil groups to be arranged flat on the surface of the coil support according to the first direction line segment and the second direction line segment, while allowing a natural transition arc to be formed between adjacent first direction line segments and second direction line segments in the coil group; wherein, the groove is processed according to a preset processing method; wherein, the preset processing method includes processing only at the corresponding positions of the first direction line segment and the second direction line segment on the surface of the coil support, and not processing the groove at the corresponding positions of the transition arc of the coil group.

2. The magnetically controlled coil according to claim 1, characterized in that, The i-th pair of coils in the N pairs of coil groups are symmetrically distributed based on the central axis; i is an integer not less than 1 and not greater than N.

3. The magnetically controlled coil according to claim 2, characterized in that, The coil support is cylindrical and made of stainless steel or aluminum alloy.

4. The magnetically controlled coil according to claim 3, characterized in that, The cylindrical side surface of the coil support includes a coil region and a non-coil region; The coil area is used to arrange the coil group, and the non-coil area is set as a hollow structure.

5. The magnetically controlled coil according to claim 2, characterized in that, Each coil group comprises M layers of coils, where M is an integer not less than 1; when M is not less than 2, the (j+1)th layer of coil is located above the surface of the i-th layer of coil away from the central axis, where j is an integer not less than 1 and not greater than M.

6. The magnetically controlled coil according to claim 1, characterized in that, The N pairs of coil groups are wound from the same set of wires; the same set of wires is made of multiple wires arranged side by side, twisted or braided.

7. The magnetically controlled coil according to claim 1, characterized in that, The coil assembly is made of superconducting material.

8. The magnetically controlled coil according to claim 1, characterized in that, The magnetron has a current lead for connecting the magnetron to a power source.

9. The magnetically controlled coil according to claim 1, characterized in that, The surface of the coil support is covered with a heat-conducting layer; the heat-conducting layer includes at least one of the following: a pure copper plate, a pure aluminum plate, or a pipeline through which a low-temperature fluid flows.

10. A crystal manufacturing apparatus, comprising a crystal growth furnace and a magnetron coil as described in any one of claims 1-8; the crystal growth furnace is equipped with a heating device and a crucible for containing crystal raw materials, the crucible being placed inside the cavity of the crystal growth furnace; the magnetron coil is disposed around the crystal growth furnace and symmetrically distributed along the central axis of the crystal growth furnace.

11. The crystal manufacturing equipment according to claim 10, characterized in that, The crystal manufacturing equipment further includes a heat-insulated vacuum chamber, and the magnetron coil is disposed inside the heat-insulated vacuum chamber.

12. The crystal manufacturing equipment according to claim 11, characterized in that, The crystal manufacturing equipment further includes a refrigeration device for reducing the temperature inside the heat-insulated vacuum chamber.

13. The crystal manufacturing equipment according to claim 12, characterized in that, The heat-insulating vacuum cavity is a vacuum environment, and the magnetron coil is suspended in the vacuum environment of the heat-insulating vacuum cavity by a hanger.

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