电子束诱导定向凝固对硅中Fe杂质分凝的影响  

Influence of Directional Solidification Induced by Electron Beam onSegregation of Fe in Silicon

作　　者：蒋健博 黄以平[3] 李少林[3] 刘海浪[3] 彭治国[3] 谭毅[4] JIANG Jianbo;HUANG Yiping;LI Shaolin;LIU Hailang;PENG Zhiguo;TAN Yi(State Key Laboratory of Metal Materials for Marine Equipment and Applications,Anshan 114000,China;Ansteel Beijing Research Institute,Beijing 102209,China;Institute of Electrical and Mechanical Engineering,Guilin University of Electronic Technology,Guilin 541004,China;School of Materials Science and Engineering,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]海洋装备用金属材料及其应用国家重点实验室,鞍山114000 [2]鞍钢集团北京研究院,北京102209 [3]桂林电子科技大学机电工程学院,桂林541004 [4]大连理工大学材料科学与工程学院,大连116024

出　　处：《材料导报》2020年第S02期173-176,共4页Materials Reports

基　　金：海洋设备与应用金属材料国家重点实验室基础项目(SKLMEA-K201801)。

摘　　要：定向凝固是去除硅中金属杂质的主要技术,利用杂质在硅中的分凝效应将其富集到最后凝固区域,杂质分凝效果取决于其在固液界面前沿传输的驱动力。然而,在传统的定向凝固技术中,由热梯度提供的驱动力有限,只能通过降低凝固速率或增加凝固次数实现杂质的深度去除。本研究利用电子束降束诱导的方式实现了硅的定向凝固,并考察了Fe杂质的提纯效果及影响机制。结果表明,在电子束诱导凝固条件下,Fe含量被降低到0.2×10-6(质量分数,下同)以下,其扩散层厚度为4.13×10-4 m,比传统定向凝固的扩散层厚度小一个数量级,可以在较大的凝固速率下获得较好的提纯效果。电子束作用形成的大温度梯度强化了熔体对流,并且电子的定向迁移与杂质元素具有交互作用,增加了界面前沿杂质传输的驱动力。Directional solidification is a main technology to remove metal impurities in silicon.These impurities can be enriched to the final solidification region by segregation effect.The effect of segregation depends on the driving force of impurities transport at the front of solid-liquid interface.However,during traditional directional solidification technology,the driving force provided by thermal gradient is limited,so that the deep removal of impurities can only be achieved by reducing the solidification rate or increasing the solidification times.In this study,the directional solidification of silicon is achieved by the induction of electron beam,the purification effect of Fe and its influence mechanism are investigated.The results show that Fe content is reduced to less than 0.2×10-6 by the induction of electron beam.The diffusion layer thickness of Fe is 4.13×10-4 m,which is one order of magnitude smaller than that during traditional directional solidification.The large temperature gradient formed by electron beam enhances the convection of melt,and the directional migration of electrons interacts with impurity elements,which increase the driving force of impurity transport at the front of solid-liquid interface.

关 键 词：电子束 定向凝固 多晶硅 Fe杂质 分凝 

分 类 号：TF134[冶金工程—冶金物理化学]