Numerical study of the influence of different types of magnetic fields on the interface shape in directional solidification of multi-crystalline silicon ingots

Numerical simulations were carried out in order to study the effect of various types of magnetic fields (steady vertical and horizontal magnetic fields and a combination of a steady field and DC electric current) on melt convection and interface shape during directional solidification of multi-crystalline silicon ingots. It is shown that steady magnetic fields can decrease the interface deflection. The electromagnetic field produced by the combination of DC current through the melt and a steady magnetic field can produce a stirring effect in the melt for a relatively small value of magnetic field and electrical current. Consequently, a more uniform distribution of dopants and impurities can be obtained in the silicon crystals. The melt rotation rate can be easily controlled by the intensity of the electrical current.