多晶硅真空定向凝固系统的结构特性优化研究

摘要

Influence of heating time was calculated for polysilicon increased charge along the axial and radial during directional solidification process by unsteady lumped parameter method.The temperature field,melt flow,solid-liquid interface shape and stress size and distribution of the polycrystalline silicon crystal growth in the process of directional solidification were analyzed by the numerical simulation.The results show that adding the upper heater for increased charge along the radial of silicon can not only significantly shorten the heating time,also reduce the radial temperature gradient of the silicon and adjust solid-liquid interface shape.These works would provide theoretical basis for design and utilization of large-scale polysilicon vacuum directional solidification equipment modified.%采用非稳态集中参数法分别计算了沿轴向和径向增加装料量对多晶硅定向凝固过程中加热时间的影响,并通过数值模拟对比分析了多晶硅定向凝固过程中晶体生长时的温度场、熔体流动、固-液界面形状和应力大小及分布等情况.并对装料沿径向增加以提高单炉生产率的方案提出了添加硅料表面上加热器的优化措施,不仅可以显著缩短加热时间,还能减小硅料的径向温度梯度,调节固-液界面形状.这将为大型化多晶硅真空定向凝固设备的优化设计与开发利用提供理论基础.