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A traveling wave magnetic field control method suitable for crystal growth process

A traveling wave magnetic field and crystal growth technology, applied in crystal growth, single crystal growth, single crystal growth, etc., can solve the problems of not changing high-quality crystals, achieve optimized temperature distribution, wide modulation range, and improve crystal quality Effect

Active Publication Date: 2022-04-22
XI AN JIAOTONG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, in the existing studies on crystal growth controlled by traveling-wave magnetic fields, the magnetic field parameters no longer change with crystal growth after being determined, and there is no systematic research on changing the traveling-wave magnetic field parameters for different crystal growth stages to obtain high-quality crystals

Method used

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  • A traveling wave magnetic field control method suitable for crystal growth process
  • A traveling wave magnetic field control method suitable for crystal growth process
  • A traveling wave magnetic field control method suitable for crystal growth process

Examples

Experimental program
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Embodiment 1

[0022] The present embodiment is to control the crystallization interface shape of different longcrystalline stages by adjusting the traveling wave magnetic field parameters.

[0023] See Figure 1 The traveling-wave magnetic field is generated by six sets of coils with sinusoidal alternating current. Figure 2 The Lorentz force distribution in the conductive melt at different stages of crystal growth process is given, at this time, the inner diameter of the six sets of coils generating the traveling wave magnetic field is 230mm, the outer diameter is 330mm, the coil height is 40mm, the number of turns of each set of coils is 38 turns, the inflow current of each turn is 5A frequency 50Hz, the phase difference between adjacent coils is 60°, the spacing is 100mm, and the diameter and height of the silicon melt are 100mm when the full melt state is 100mm. Figure 3 The deformation of the median ordinate interface is defined as the difference between the interface position at the centra...

Embodiment 2

[0025] The present embodiment is to control the concentration and distribution of oxygen impurities by adjusting the traveling wave magnetic field parameters of different longcrystalline stages.

[0026] See Figure 4 The distribution of oxygen impurities in the silicon crystal when the 5A current is passed into the coil, the direction of the traveling wave magnetic field is downward, and the magnetic field frequency is 0, 50, 150, and 500Hz, respectively. It can be found that with the increase of frequency, the concentration of oxygen impurities in the lower part of the crystal first increases and then decreases, while the concentration of oxygen impurities in the upper part of the crystal is not much different. Therefore, in order to reduce the content of oxygen impurities in the crystal and so that the oxygen impurities are evenly distributed in the crystal, a larger frequency (e.g., 500Hz) may be used in the early stage of the longcrystalline, a frequency may be reduced in the ...

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Abstract

The invention discloses a traveling-wave magnetic field control method suitable for crystal growth process. The method is to apply a traveling-wave magnetic field generated by a sinusoidal alternating power supply on the periphery of the conductive melt. The traveling-wave magnetic field generating device consists of multiple groups Coil composition, coil structure parameters and current parameters can be easily adjusted. The induced current generated by the traveling wave magnetic field in the conductive melt interacts with the magnetic field to generate a Lorentz force. For a certain kind of conductive melt, the change of the parameters of the traveling wave magnetic field will affect the size of the Lorentz force, Orientation and its distribution in the melt. The present invention controls crystal growth parameters such as melt flow, temperature distribution, crystal interface shape, and impurity distribution by changing the traveling wave magnetic field parameters in different crystal growth stages, so as to improve the crystal quality, for example, modulating the traveling wave magnetic field parameters during the crystal growth process so that The shape of the crystallization interface has been kept straight or slightly convex, and the impurities are evenly distributed in the axial and radial directions.

Description

Technical field [0001] The present invention belongs to the field of crystal growth control technology, specifically relates to a traveling-wave magnetic field control method suitable for the crystal growth process. Background [0002] In recent years, the research on magnetic field control technology during crystal growth has gradually received attention. Magnetic fields can generally be divided into dynamic magnetic fields and static magnetic fields. Because the dynamic magnetic field requires much less magnetic field strength to control crystal growth than the static magnetic field, and the dynamic magnetic field has more adjustable parameters and can be designed as needed, this makes the dynamic magnetic field have a wide range of application prospects. The traveling-wave magnetic field is a kind of dynamic magnetic field, which generates an induced current in the conductive melt based on the law of electromagnetic induction, and the induced current interacts with the magnet...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C30B30/04C30B29/06
CPCC30B30/04C30B29/06
Inventor 李早阳刘文超邵玥刘立军孙聂枫
Owner XI AN JIAOTONG UNIV