摘要
利用FEAMG-CZ软件,模拟研究了cusp磁场对称面(定义为0高斯面)与熔体自由表面距离对直拉硅固液界面氧浓度分布的影响。结果表明:随着0高斯面的下移,熔体中的最小氧浓度降低,而固液界面的氧浓度升高,且径向均匀性变差。分析表明,这与熔体自由表面处的Marangoni流有关,抑制该流动有利于熔体中氧的蒸发,从而在自由表面下获得更低氧浓度的熔体,但会阻碍自由表面下方低氧熔体往固液界面的输运。因此,推断当0高斯面位于熔体自由表面下某一位置时,固液界面氧浓度将达到最低。模拟中,该位置位于Hm=0～-0.01m之间。
Numerical simulations were performed with FEMAG-CZ software to investigate effects of distance between the symmetric plane of cusp magnetic field（defined as 0-plane） and the free surface of melt on oxygen concentration of the solid-liquid（S-L） interface.It has been shown that the shift-down of 0-plane resulted in a decrease of minimum oxygen concentration in the melt,an increase of oxygen concentration of the S-L interface,and a reduction of the oxygen-radial uniformity,which is relevant to Marangoni convection exiting on the free surface of the melt.Suppression of the convection was favorable for evaporation of oxygen in the melt,which helped to obtain lower-oxygen concentration melt under the free surface of melt,but hindered transportation of the lower-oxygen melt to the solid-liquid interface.So it was inferred that oxygen concentration at the solid-liquid interface reached minimum when 0-plane was located under the free surface（the distance is between 0 and-0.01 m in simulation）.
出处
《微电子学》
CAS
CSCD
北大核心
2012年第5期729-732,共4页
Microelectronics
基金
国家科技重大专项(2008zx02401
2009zx02011)
关键词
cusp磁场
直拉硅
氧浓度
数值模拟
Cusp magnetic field
CZ-Si
Oxygen concentration
Numerical simulation
