流态化多晶硅化学气相沉积过程的数值模拟

利用基于欧拉-欧拉两相流模型,建立硅烷热分解的均相和非均相反应模型,模拟了二维流态化的多晶硅化学气相沉积过程,以及硅烷、硅烯和硅沉积速率在反应器中的分布规律.模拟结果表明多晶硅的沉积主要发生在流化床中的密相区及气泡的周围,浓度相对较小的硅烯非均相反应对多晶硅沉积的贡献约为硅烷的10;.分析了硅烷入口浓度和反应温度对硅沉积速率及转化率的影响,模拟的硅沉积速率与文献中的实验数据做了比较.

Simulation of Polycrystalline Silicon Chemical Vapor Deposition in Fluidized Bed

The fluidized bed Chemical Vapor Deposition(CVD) process constitutes today one of the most efficient techniques for modification and control of the surface state of powders.In this paper,the polycrystalline silicon fluidized bed CVD process from silane(SiH4) has been modeled.The multi-fluid Eulerian code MFIX coupled homogenous and heterogeneous reaction models was utilized to simulate the distribution of the silane,silylene,silicon deposition rates from them and the influence of the concentration of silane and reaction temperature on the growth rate of the polycrystalline silicon and the silane conversion.The results show that the polycrystalline silicon deposition mainly occurred at the dense zone and the periphery of the bubbles.The contribution of rather low concentration silylene to deposition rate is about 10% of the one of the silane.The numerical growth rates of polysilicon are nearly consistent with the experimental results.