Simulation of the superconducting magnet for a silicon single crystal growth

Abstract

The magnetic Czochralsky (MCz) technique is the most common and widely used approach to producing single crystal silicon. The magnetic field is applied to control the temperature fluctuations and suppress silicon melt convection. However, the magnetic field quality and manufacturing costs were mainly determined by the shape of the coils. In order to generate the transverse magnetic field, two pairs of coils are arranged around the crucible and face each other in opposite directions to construct the superconducting magnets system, which has an inner diameter of 1600 mm and an outer diameter of 2400 mm. The simulating results indicate the magnetic flux density (B) in the center of molten silicon is 0.4 T, and the magnetic field inhomogeneity in the X-Y plane is about 20%. The electrical power consumption and cooling capacity will be reduced. Furthermore, a smaller cryostat is required to hold the curve shape coils, which results in lower cost and lower weight of the superconducting magnet.