Global Simulation and Experiments on Oxygen Transport In Silicon CZ furnace

硅直拉炉氧传输的全局模拟与实验

• 批准号: 13450321
• 负责人: IMAISHI Nobuyuki
• 金额: $ 10.75万
• 依托单位: Kyushu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13450321/
• 关键词: Silicon single crystal; Czochralski furnace; oxygen mass transfer; Numerical simulation; Global analysis of flow, heat and mass transfer; Secondary flows; Concective instability; シリコン単結晶; チヨクラルスキー炉; 酸素不純物; シミュレーション

In this Research project, we have developed a numerical simulation code for a global analysis of silicon Czochralski furnace based on a mathematical mode, in which we assumed axisymmetric, pseudo steady state of flow, temperature and concentration fields in the furnace. These codes were effectively runned to elucidate the role of gas phase diffusion and the Marangoni effect acting on the melt surface in the mass transfer of oxygen impurity. We have investigated the effects of axial magnetic field on the oxygen mass transfer. Further numerical Investigations have been done so as to evaluate the effect of thermophysical properties on the mass transfer.These numerical results revealed that mass transfer of SiO in the gas phase is the largest mass transfer resistance in a small silicon Cz furnace. However, oxygen mass transfer rate is a complex function of velocity and temperature fields in the gas and melt. By installing a gas guide between the crucible and crystal, whole volume of gas fl … More ows along the melt surface and the gas phase mass transfer coefficient is significantly increased. This type of gas flow give rise of large share stress in the melt and changes the melt flow pattern and decrease the mass transfer rate in the melt. Numerical results indicated that temperature coefficient of surface tension is one of the important factor of determining the melt flow pattern. Detailed measurement of surface tension of silicon melt is necessary to understand the transport phenomena in silicon Cz furnace including the effect of oxygen partial pressure in gas phase.These numerical results had been scheduled to be compared with new experimental results using a small Cz furnace which was moved from NEC company. The time of the moving was originary scheduled on 2001 but it was delayed to 2002 and further moved again to the Institute of Applied Mechanics, Kyushu University on late 2002. Since then the furnace was mostly used for oxide crystal pulling. Thus, we could not conduct detailed experiments of oxygen transport using the furnace. The numerical results were compared with few experimental results. We get confidence on our numerical results of global simulations since both results showed reasonable agreement with each other.The results of these global simulation were reported in 5 papers on International Journals. In addition to these global analyses, we have reported 3 papers on three dimensional simulation of pattern formation in annular pools of silicon melt. We published one review article on the convective instability of melt flow in Cz furnace. Less

在本研究项目中，我们已经开发了一个数值模拟程序的基础上的数学模型，其中我们假设轴对称，假稳态的流场，温度场和浓度场的直拉硅炉的整体分析。这些程序有效地解释了气相扩散和熔体表面Marangoni效应在氧杂质传质中的作用。研究了轴向磁场对氧传质的影响。数值模拟结果表明，在小型硅质Cz炉中，SiO在气相中的传质是最大的传质阻力。然而，氧气传质速率是气体和熔体中的速度场和温度场的复杂函数。通过在坩埚和晶体之间安装气体导管， ...更多信息 沿着熔体表面流动，气相传质系数显著增加。这种气体流动在熔体中产生了较大的剪切应力，改变了熔体的流动形态，降低了熔体中的传质速率。结果表明，表面张力温度系数是决定熔体流动形态的重要因素之一。为了了解硅熔体在Cz炉中的输运现象，包括气相中氧分压的影响，需要详细测量硅熔体的表面张力，这些数值计算结果已被安排与从NEC公司引进的小型Cz炉的新实验结果进行比较。搬迁时间原定于2001年，但推迟到2002年，并于2002年底再次搬迁到九州大学应用力学研究所。从那时起，该炉主要用于氧化物晶体提拉。因此，我们无法使用该炉进行详细的氧输送实验。数值计算结果与少量实验结果进行了比较。我们对我们的全球模拟的数值结果有信心，因为这两个结果显示出合理的协议彼此。这些全球模拟的结果在国际期刊上发表了5篇论文。除了这些全面的分析，我们已经报道了3篇论文的三维模拟图形形成的环形池的硅熔体。我们发表了一篇关于直拉炉内熔体流动对流不稳定性的综述文章。少

项目成果

N.Imaishi, K.Kakimoto: "Convective in stability in crystal growth system"Annual Review of Heat Transfer(Begel House). vol.12. 187-221 (2002)

N.Imaishi、K.Kakimoto：“晶体生长系统中的稳定对流”传热年度评论（Begel House）。

Y.R.Li et al.: "Effects of temperature coefficient of surface tension on oxygen transport in a small silicon Cz furnace"Journal of Crystal Growth. (印刷中). (2004)

Y.R.Li 等人：“表面张力温度系数对小型硅直晶炉中氧传输的影响”《晶体生长》杂志（2004 年出版）。

M.W.Li et al.: "Global Simulation of Silicon Czochralski Furnace"Journal of Crystal Growth. 234. 32-46 (2002)

M.W.Li 等人：“硅直拉炉的全局模拟”晶体生长杂志。

Y.R.Li, N.Imaishi, T.Azami, T.Hibiya: "Thermocapillary flow in a thin annular pool of silicon melt"Proceedings of SPIE, Material Processing in Microgravity 3. 4813. 12-23 (2002)

Y.R.Li、N.Imaishi、T.Azami、T.Hibiya：“硅熔体薄环形池中的热毛细管流动”SPIE 论文集，微重力材料加工 3. 4813. 12-23 (2002)

Y.R.Li et al.: "Three dimensional numerical simulation of thermocapillary flow of moderate Prandtl number fluid in an annular pool"Journal of Crystal Growth. 259. 374-387 (2003)

Y.R.Li 等人：“环形池中中等普朗特数流体热毛细管流动的三维数值模拟”晶体生长杂志。