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CN-121983407-A - Superconducting magnet for monocrystalline silicon drawing process and adjusting method of process magnetic field

CN121983407ACN 121983407 ACN121983407 ACN 121983407ACN-121983407-A

Abstract

The application discloses a superconducting magnet for a monocrystalline silicon drawing process and a process magnetic field adjusting method, wherein the superconducting magnet comprises a body, a coil carrier, a first coil assembly, a second coil assembly and a magnetic control sliding sleeve; the magnetic control sliding sleeve comprises a third coil component used for changing the fluid state of magnetic fluid, when the third coil component is powered off, the magnetic fluid is in a low-viscosity fluid state, the magnetic control sliding sleeve is in an unlocked first state, when the third coil component is powered on, the magnetic fluid is in a high-viscosity fluid state, and the magnetic control sliding sleeve is in a positioned second state. By combining electromagnetic drive and magnetic fluid positioning, the magnetic field can be quickly, flexibly and accurately adjusted, and the problems of poor universality and difficult adjustment of the superconducting magnet can be solved.

Inventors

  • ZHU LIANG
  • ZHANG YING
  • NIU JIAZHEN
  • ZHANG FENG
  • WU ZHIBIN

Assignees

  • 浙江晶盛机电股份有限公司
  • 杭州慧翔电液技术开发有限公司

Dates

Publication Date
20260505
Application Date
20260122

Claims (10)

  1. 1. A superconducting magnet for a single crystal silicon drawing process, comprising: A body (10); -at least one pair of coil carriers (20), said coil carriers (20) being movably mounted to said body (10); a first coil assembly (30) mounted to each of said coil carriers (20) for generating a process magnetic field; a second coil block (40) mounted to each of the coil carriers (20) for driving a pair of the coil carriers (20) to move by generating electromagnetic force; The magnetic control sliding sleeve (12) is used for positioning or unlocking the coil carrier (20) on the body (10), the magnetic control sliding sleeve (12) comprises a third coil assembly (124) used for changing the fluid state of magnetic fluid, when the third coil assembly (124) is powered off, the magnetic fluid is in a low-viscosity fluid state, the magnetic control sliding sleeve (12) is in an unlocked first state, when the third coil assembly (124) is powered on, the magnetic fluid is in a high-viscosity fluid state, and the magnetic control sliding sleeve (12) is in a positioned second state.
  2. 2. The superconducting magnet according to claim 1, wherein, The body (10) is of an annular structure and is provided with at least one section of sliding rail (11), and the coil carrier (20) is installed on the sliding rail (11) through the magnetic control sliding sleeve (12) and can move along the sliding rail (11).
  3. 3. The superconducting magnet according to claim 2, wherein, An adjustable angle is formed between the axes of a pair of said first coil assemblies (30).
  4. 4. The superconducting magnet of claim 3, wherein the superconducting magnet comprises a plurality of magnets, The second coil assembly (40) is arranged between a pair of coil carriers (20), and electromagnetic forces which are attracted or repelled are generated by passing currents in different directions into the second coil assembly (40) so as to drive the pair of coil carriers (20) to be close to or far away from each other along the sliding rail (11).
  5. 5. The superconducting magnet of claim 3, wherein the superconducting magnet comprises a plurality of magnets, The second coil assemblies (40) are arranged on the opposite end surfaces of the pair of coil carriers (20), when currents in different directions are introduced into the pair of second coil assemblies (40), attractive or repulsive electromagnetic forces are generated, and the second coil assemblies (40) are mutually close to or far away from each other along the sliding rail (11) along with the coil carriers (20); Or, a pair of second coil assemblies (40) are arranged between the opposite end surfaces of the pair of coil carriers (20), the pair of second coil assemblies (40) are fixed on the body (10), and when currents in different directions are introduced into the pair of second coil assemblies (40), electromagnetic forces which attract or repel each other are generated, and the coil carriers (20) are mutually close to or far away from each other along the sliding rail (11).
  6. 6. The superconducting magnet according to claim 2, wherein, And a slide rail positioning groove (111) is formed in the slide rail (11), and when the magnetic control sliding sleeve (12) is in the second state, the magnetic fluid is matched with the slide rail positioning groove (111) to position the coil carrier (20).
  7. 7. A method for adjusting a magnetic field of a single crystal silicon drawing process, applied to the superconducting magnet as claimed in any one of claims 1 to 6, characterized in that the adjusting method comprises: de-energizing the third coil assembly (124) to place the magnetically controlled sliding sleeve (12) in an unlocked first state to allow movement of the coil carrier (20); energizing the second coil assembly (40) to generate an electromagnetic force to drive the coil carrier (20) to move along the body (10) to a target position; Energizing the third coil assembly (124) after the coil carrier (20) reaches the target position, switching the magnetically controlled sliding sleeve (12) to a second state of positioning to secure the coil carrier (20); energizing the first coil assembly (30) to produce a process magnetic field.
  8. 8. The method for adjusting a magnetic field in a single crystal silicon pulling process according to claim 7, Said energizing said second coil assembly (40) to generate an electromagnetic force to drive said coil carrier (20) to move along said body (10) to a target position, comprising: By controlling the direction of the current flowing into the second coil assembly (40), attractive or repulsive electromagnetic forces are selectively generated to drive the coil carriers (20) toward or away from each other.
  9. 9. The method for adjusting a magnetic field in a single crystal silicon pulling process according to claim 7, The superconducting magnet includes a pair of first coil assemblies (30), and the adjustment method adjusts an included angle between axes of the pair of first coil assemblies (30) by moving a position of the coil carrier (20).
  10. 10. A method for adjusting a magnetic field in a single crystal silicon pulling process according to any one of claims 7 to 9, The powering down the third coil assembly (124) to place the magnetically controlled sliding sleeve (12) in an unlocked first state to allow movement of the coil carrier (20) further comprises: -de-energizing and demagnetizing the first coil assembly (30) and the second coil assembly (40).

Description

Superconducting magnet for monocrystalline silicon drawing process and adjusting method of process magnetic field Technical Field The application relates to the technical field of single crystal preparation, in particular to a superconducting magnet for a single crystal silicon drawing process and a regulating method of a process magnetic field. Background In the crystal pulling preparation process of semiconductor materials such as monocrystalline silicon, a magnetic control Czochralski Method (MCZ) is generally adopted to carry out in a monocrystalline furnace. The magnetic control Czochralski method suppresses heat convection in the magnetic fluid by applying a specific magnetic field outside the magnetic fluid of the single crystal furnace, thereby precisely controlling the growth process and the final crystal quality of the single crystal. The magnetic field is typically generated by a superconducting magnet disposed outside the single crystal furnace. However, the existing mainstream four-coil superconducting magnet is generally of a fixed structure. The coil of this fixed structure can only produce a fixed magnetic field distribution, and the process window of the fixed magnetic field is very small, resulting in insufficient versatility of magnetic field adjustment. In particular, when it is desired to cope with different sizes of crucibles (e.g. specifications of 24 inches, 28 inches, 32 inches, 36 inches, etc. of the main stream) or different crystal pulling process requirements, a fixed magnetic field distribution is difficult to provide a process window meeting the requirements, manual adjustments which can be time and labor consuming may be repeated, and even the magnets may need to be thoroughly replaced. While there are solutions to utilize six coil superconducting magnets and adjusting the current to the corresponding superconducting magnet coils to adjust the magnetic field, this technique requires additional coils and corresponding cryogenic cooling systems, which is cost prohibitive. Therefore, how to effectively improve the versatility and/or the process adaptation range of the superconducting magnet at low cost is a problem to be solved by those skilled in the art. Disclosure of Invention The application aims to solve the technical problems of poor universality and difficult magnetic field adjustment of a superconducting magnet in the prior art, and provides a superconducting magnet for a monocrystalline silicon drawing process and a process magnetic field adjustment method so as to realize quick, flexible and accurate adjustment of a crystal pulling magnetic field. The application provides a superconducting magnet for a monocrystalline silicon drawing process, which comprises a body, at least one pair of coil carriers, a first coil assembly mounted on each coil carrier, a second coil assembly mounted on each coil carrier and a magnetic control sliding sleeve, wherein the coil carriers are movably mounted on the body, the first coil assembly is used for generating a process magnetic field, the second coil assembly is used for driving the pair of coil carriers to move through electromagnetic force, the magnetic control sliding sleeve is used for positioning or unlocking the coil carriers on the body, the magnetic control sliding sleeve comprises a third coil assembly used for changing the fluid state of magnetic fluid, when the third coil assembly is powered off, the magnetic fluid is in a low-viscosity fluid state, the magnetic control sliding sleeve is in an unlocked first state, and when the third coil assembly is powered on, the magnetic fluid is in a high-viscosity fluid state, and the magnetic control sliding sleeve is in a positioned second state. In some embodiments, the body is of annular structure and is provided with at least one section of slide rail, and the coil carrier is mounted on the slide rail through the magnetic control slide sleeve and can move along the slide rail. In some embodiments, the axes of the pair of first coil assemblies form an adjustable included angle therebetween. In some embodiments, the second coil assembly is mounted between a pair of coil carriers, and by passing currents in different directions through the second coil assembly, attractive or repulsive electromagnetic forces are generated to drive the pair of coil carriers toward or away from each other along the sliding rail. In some embodiments, the opposite end surfaces of the pair of coil carriers are respectively provided with a second coil component, when currents in different directions are introduced into the pair of second coil components, attractive or repulsive electromagnetic forces are generated, and the second coil components are mutually close to or far away from each other along the sliding rail along with the coil carriers; or a pair of second coil assemblies are arranged between the opposite end surfaces of the pair of coil carriers, the pair of second coil assemblies are fixed on