Numerical study of the influence of forced melt convection on the impurities transport in a silicon directional solidification process

Time dependent three-dimensional numerical simulations were carried out in order to understand the effects of forced convection induced by electromagnetic stirring of the melt, on the crucible dissolution rate and on the impurity distribution in multicrystalline silicon (mc-Si) melt for different values of the diffusion coefficient and electric and magnetic field parameters. Once the electromagnetic stirring is switched on, in a relative short period of time approx. 400 s the impurities are almost homogenized in the whole melt. The dissolution rate was estimated from the total mass of impurities that was found in the silicon melt after a certain period of time. The obtained results show that enhanced convection produced by the electromagnetic stirring leads to a moderate increase of the dissolution rate and also to a uniform distribution of impurities in the melt.