Three-dimensional modelling of melt flow and segregation during Czochralski growth of GexSi1−x single crystals
Three-dimensional modelling of melt flow and segregation during Czochralski growth of GexSi1−x single crystals
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DOI：
10.1016/j.ijthermalsci.2006.07.010
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发表时间：
2007-06
影响因子：
4.5
通讯作者：
S. Abbasoğlu;I. Sezai
中科院分区：
文献类型：
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作者：
S. Abbasoğlu;I. Sezai
对直拉法（Cz）过程中GexSi 1 − x熔体中的流场和硅的径向偏析进行了一系列非稳态三维数值模拟。除了重力驱动的自然对流（浮力对流），对流的影响，由表面张力驱动的熔体的自由表面上被包括在模型中，通过考虑热，以及溶质Marangoni对流。在晶体生长过程中的浓度和流场的几个温差（ΔT），驱动浮力和Marangoni对流。结果发现，在生长界面处的最大硅浓度差随着温度差的增加而减小，这是由于界面附近的较高流速。然而，在界面处的Si浓度的时间波动增加在较高的温度差。模型中还考虑了长径比（Ar）的影响。结果发现，硅在晶体-熔体界面处的径向偏析随着坩埚中熔体的长径比的减小而改善。
A series of unsteady three-dimensional (3-D) numerical simulations were carried out to examine the flow field and the radial segregation of silicon (Si) in a GexSi1−xmelt during Czochralski (Cz) process. In addition to the gravity driven natural convection (buoyant convection), the effect of convection driven by surface tension on the free surface of the melt was included in the model, by considering thermal, as well as solutal Marangoni convection. The concentration and flow fields during crystal growth are presented for several temperature differences (ΔT), driving buoyant and Marangoni convection. It was found that the maximum silicon concentration difference at the growth interface decreases as temperature difference increases due to higher flow velocities in the vicinity of the interface. However, temporal fluctuations of Si concentration at the interface increase at higher temperature differences. The effects of aspect ratio (Ar) were also considered in the model. It was found that the radial segregation of Si at the crystal-melt interface improves as the aspect ratio of the melt in the crucible decreases.