采用基于有限元方法的Comsol 4.3a软件,对有、无稳恒磁场作用时多晶硅定向凝固晶体生长过程进行了模拟分析。根据模拟结果,阐明了稳恒磁场对硅熔体的流场、热场以及固液界面形状的影响。数值计算表明与未添加磁场相比,施加稳恒磁场后,硅熔体的流动区域变小,最大流速从70.793μm/s下降到了60.623μm/s,减少了14.37%,硅熔体上表面的紊波受到了抑制;硅熔体的轴向温差下降了1/3,径向温差增大了1/3;硅熔体的固液界面趋于平坦,有利于多晶硅晶体生长。
The process of crystal growth with and without steady magnetic field during direction solidification of polysilicon was numerical simulated by COMSOL Multiphysics version 4.3, which was based on finite element method. The influences of steady magnetic field on velocity field, temperature field and solid-liquid interface shape in the polysilicon melt were illuminated according to the simulated results. The results of numerical calculation shows that: when the steady magnetic field is applied, the flow region of polysilicon melt has became small and the largest flow rate of melt decreases from 70.793 μm/s to 60.623 μm/s which has fallen by 14.37%. The turbulent waves on the surface of polysilicon melt were subdued. The axial temperature difference has decreased by a third and the radial temperature difference has increased by third. The solid-liquid interface shape in polysilicon melt has became smooth ,which is help for polysilicon columnar crystal growth.