摘要
在大尺寸直拉硅单晶生长过程中,针对水平磁场单方向磁力线分布引起的熔体温度分布非轴对称特征,提出了一种双磁力线结构的磁场——四极磁场。为准确描述非轴对称磁场作用下晶体生长过程,采用三维数值模拟方法,建立了四极磁场下二维/三维混合热场模型的边界条件,并将三维数值模拟结果与水平磁场作以对比。结果表明,四极磁场降低了熔体内部温度的非轴对称性;增加磁感应强度有利于增加熔体自由表面附近温度分布的均匀性,但对固液界面形状调节作用不明显;强磁场环境下,提高晶体旋转速度有利于改变固液界面凹凸程度,改善固液界面形态的非轴对称性。
In large diameter Czochralski silicon crystal growth process, for the non axial symmetric features in melt temperature caused by the unidirectional magnetic flux distribution, a magnetic field with dual flux line structure is proposed the quad-pole magnetic field. A three dimensional numerical simulation method is used to describe the growth process of the crystal growth process under the non axial symmetric magnetic field. The boundary conditions of 2D/3D hybrid hot zone model with quad-pole magnetic field are established and the 3D numerical results are compared with the bi-pole horizontal magnetic field hot zone. The results shows that in quad-pole magnetic fieht, the non-axial symmetry of the internal temperature of the melt is reduced; Increasing the magnetic flux density helps to improve the temperature distribution uniformity near the free surface of the melt, but improvements on the shape of solid-liquid interface is not obvious ; Under strong magnetic flux density, a higher crystal rotation rate will helps improve the deflection of the solid-liquid interface, and improve the non-axial symmetry of the solid-liquid interface shape.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2015年第9期238-243,共6页
Transactions of Materials and Heat Treatment
基金
国家重点基础研究发展计划(2014CB360508)
博士点基金优先发展领域(20136118130001)
关键词
直拉硅单晶
非轴对称性
四极磁场
数值模拟
Czochralski silicon
non-axial symmetry
quad-pole magnetic field
numerical simulation
作者简介
张晶（1986-），女，博士，从事直拉硅单晶多场耦合建模、热系统设计与控制参数研究，发表论文4篇，E-mail：zj18467@163．com.
通讯作者：刘丁（1957-），男，教授，从事晶体生长核心工艺参数优化与控制系统研究，发表论文篇150余篇，电话：029-82312088，E—mail：liud@xaut．edu．cn。
