横向磁场下坩埚转速对半导体级直拉单晶硅熔体中流场与氧浓度的影响机制  

Influence Mechanism of Crucible Rotation Rates on the Flow Field and Oxygen Concentration of the Semiconductor-Grade Czochralski Monocrystalline Silicon Melt under Transverse Magnetic Field

作　　者：王黎光 芮阳 盛旺 马吟霜 马成 陈炜南 邹啟鹏 杜朋轩 黄柳青 罗学涛[2,3] WANG Liguang;RUI Yang;SHENG Wang;MA Yinshuang;MA Cheng;CHEN Weinan;ZOU Qipeng;DU Pengxuan;HUANG Liuqing;LUO Xuetao(Ningxia Research Center of Semiconductor-grade Silicon Wafer Materials Engineering Technology,Ferrotec(Ningxia)Semiconductor Co.,Ltd.,Yinchuan 750021,China;Xiamen Key Laboratory of Electronic Ceramic Materials and Devices,College of Materials,Xiamen University,Xiamen 361005,China;Shenzhen Research Institute of Xiamen University,Shenzhen 518063,China;Ningxia Polytechnic,Yinchuan 750021,China)

机构地区：[1]宁夏中欣晶圆半导体科技有限公司,宁夏半导体级硅晶圆材料工程技术研究中心,银川750021 [2]厦门大学材料学院,厦门市电子陶瓷材料与元器件重点实验室,厦门361005 [3]厦门大学深圳研究院,深圳518063 [4]宁夏职业技术学院,银川750021

出　　处：《人工晶体学报》2023年第9期1641-1650,共10页Journal of Synthetic Crystals

基　　金：宁夏回族自治区重点研发计划(2022BFE02007);深圳市基础研究面上项目(JCYJ20210324121813037)。

摘　　要：利用ANSYS有限元软件分析了横向磁场下不同坩埚转速对200 mm半导体级直拉单晶硅的流场及氧浓度的影响。研究结果表明:在横向磁场下,硅熔体的流场和氧浓度分布呈三维非对称性,熔体对流形式主要包括泰勒-普劳德曼漩涡、浮力-热毛细漩涡及次漩涡,其中前两者有助于氧挥发,而次漩涡则起到抑制作用。当坩埚转速较低(0.5~1.0 r/min)时,较弱的熔体对流强度导致坩埚壁与固液界面间的热传导效率低,氧主要以扩散机制迁移至固液界面,熔硅中氧浓度高;当坩埚转速较高(2~2.5 r/min)时,氧通过强对流形式迁移至固液界面。随着坩埚转速增加,次漩涡和浮力-热毛细漩涡的作用强度提高,浮力-热毛细漩涡影响区域远离自由表面,使硅熔体中的氧浓度呈先下降后上升的趋势。数值模拟结果与实验结果均表明,在横向磁场条件下优选1.5 r/min的坩埚转速可获得平均氧浓度较低的单晶硅。上述分析结果可以为横向磁场下半导体级单晶硅拉晶参数优化提供参考依据。In this study,the influence mechanism of crucible rotation rates on the flow field and oxygen concentration of 200 mm semiconductor-grade Czochralski monocrystalline silicon under transverse magnetic field was investigated using ANSYS finite element software.The results show that flow field and oxygen concentration distribution of the silicon melt exhibit three-dimensional asymmetry under transverse magnetic field.The convective forms of the melt mainly include Taylor-Proundman vertices,buoyance-thermocapillary vortices,and secondary vortices.The former two contributed to the volatilization of oxygen,while the latter one had a suppressing effect.When the crucible rotation rate is low(0.5~1.0 r/min),the weaker convective strength of the melt results in low thermal conductivity efficiency between the crucible wall and the solid-liquid interface,and oxygen mainly migrates to the solid-liquid interface through a diffusion mechanism,resulting in high oxygen concentration in silicon melt.When the crucible rotation rate is high(2~2.5 r/min),oxygen migrates to the solid-liquid interface through strong convective forms.As the crucible rotation rate increases,the strength of the secondary vortices and buoyancy-thermocapillary vortices increases,and the region affected by the latter moved away from the free surface,resulting in a trend of first decreasing and then increasing oxygen concentration in the silicon melt.Both the numerical simulation results and experimental results indicate that a crucible rotation rate of 1.5 r/min is optimal for obtaining monocrystalline silicon with lower average oxygen concentration.The results of comparative analysis between experiments and numerical simulations can provide a reference basis for optimizing the parameters of the crystal growth process under transverse magnetic field.

关 键 词：ANSYS有限元分析 200 mm半导体级单晶硅 直拉法 坩埚转速 流场 氧浓度 

分 类 号：TQ127.2[化学工程—无机化工] TN304.1[电子电信—物理电子学]