多晶硅真空定向凝固过程Marangoni对流对铸锭质量的影响研究  

Effect of Marangoni Convection on Ingot Quality During Vacuum Directional Solidification of Polycrystalline Silicon

作　　者：多文超 杨玺 何云飞 李秋菊[4] 魏奎先[1,2] 吕国强[1,2] 马文会[1,2] DUO Wenchao;YANG Xi;HE Yunfei;LI Qiuju;WEI Kuixian;LV Guoqiang;MA Wenhui(State Key Laboratory of Clean Utilization of Complex Nonferrous Metal Resources Jointly Constructed by the Ministry and the Province of Kunming University of Science and Technology,Kunming 650093,China;Faculty of Metallurgical and Energy Engineering,Kunming University of Science and Technology,Kunming 650093,China;Yunnan Energy Investment Research Institute Co.,Ltd,Kunming 650093,China;State Key Laboratory of Metallurgy and Preparation of High Quality Special Steel Jointly Built by Shanghai University,Shanghai 200444,China)

机构地区：[1]昆明理工大学复杂有色金属资源清洁利用省部共建国家重点实验室,昆明650093 [2]昆明理工大学冶金与能源工程学院真空冶金国家工程实验室,昆明650093 [3]云南省能投研究院有限公司,昆明650093 [4]上海大学省部共建高品质特殊钢冶金与制备国家重点实验室,上海200444

出　　处：《真空科学与技术学报》2021年第6期515-523,共9页Chinese Journal of Vacuum Science and Technology

基　　金：国家自然科学基金项目资助(No.51864031);省部共建高品质特殊钢冶金与制备国家重点实验室;上海市钢铁冶金新技术开发应用重点实验室开放课题(SKLASS 2019-18);上海市科学技术委员会(No.19DZ2270200)基金资助。

摘　　要：对于多晶硅垂直布里奇曼真空定向凝固过程,熔体自由表面张力引起的Marangoni对流对晶体生长质量有着明显的影响。本文通过建立多晶硅真空定向凝固过程的热场-流场-应力场多场耦合数学物理模型,采用数值模拟和实验研究了Marangoni对流作用下熔体传热特性、熔体流动行为、铸锭热应力等因素对硅晶体生长质量的影响。结果表明:Marangoni对流会增强硅熔体流场的流动强度,使得硅熔体平均流速增大3倍左右,进而影响硅熔体内部的对流换热能力,使硅熔体和硅固体温度分布更加均匀,硅熔体温度梯度降低4.8%-9.9%,硅固体温度梯度降低2.1%-2.6%,使多晶硅铸锭过程产生更小的热应力和更少缺陷。Marangoni convection caused by the gradient of melt free surface tension has a significant effect on the growth quality of polycrystalline silicon during vertical Bridgman vacuum directional solidification.In this paper,a multi-field coupled mathematical and physical model of thermal field,flow field,and stress field in the vacuum directional solidification process of polycrystalline silicon was established.Numerical simulations and experiments are used to study the influence of factors such as melt heat transfer characteristics,melt flow behavior,and ingot thermal stress on the growth quality of silicon crystals under Marangoni convection.The results show that Marangoni convection can enhance the flow intensity of silicon melt flow field,make the average velocity of silicon melt increase about three times,and then affect the convective heat transfer capacity of silicon melt,make the temperature distribution of silicon melt and silicon solid more uniform,the temperature gradient of the silicon melt is reduced by 4.8%-9.9%,and the temperature gradient of the silicon solid is reduced by 2.1%-2.6%,which makes the polysilicon ingot process produce smaller thermal stress and fewer defects.

关 键 词：真空定向凝固 Marangoni对流 温度梯度 熔体流动 热应力 

分 类 号：TF136[冶金工程—冶金物理化学]