工业硅中杂质铁去除的理论分析

Theoretical Considerations of Removal of Iron Impurity in Commercial Silicon

分析了硅中杂质的分凝特性,计算、讨论了在定向凝固条件下硅中铁的有效分凝系数 K_(fef)和凝固速度 f的关系,并用生产实践中铁在硅锭中的分布,验证了理论分析的可靠性。提出了用组合结晶器定向凝固技术去除工业硅中杂质铁的工艺方法。

Based on an analysis made theoretically to the segregation behavior of some impurities in commercial silicon,the relationship between the useful segrega- tion coefficient of iron impurity Kfef and its solidifying rate f is discussed and calculated under conditions of oriented solidification. Reliability of the theoretical considerations has been verified in industrial practice as shown by the iorn distribution in silicon ingots.An effective process is thus suggested to remove iron impurity in commercial silicon by way of a new solidification technique utilizing a combination mould.