Abstract In Czochralski silicon (CZ-Si) crystal growth, packed Si chunks experience collapse and volume shrinkage during the melting process. The axial movements of the crucible and the melting of the Si feedstock lead to dynamic thermal and flow fields and affect mass transport. To study the effect of crucible movement on the melting process and carbon (C) contamination, the cases of fixed and lifting crucible were investigated by the transient global simulation with dynamic mesh deformation. The gap width between the gas-guide and the top surface of Si feedstock was kept constant during the crucible lifting process. Impurity and species transport in Si feedstock and argon gas was investigated for the cases with the fixed and lifting crucibles. The comparison of C accumulation processes indicated that the lifting crucible case resulted in higher C contamination than that found in the fixed crucible case. Furthermore, lifting crucible cases with different gap widths were investigated to elaborate strategies for controlling the crucible movement for its effect on the melting process and C contamination in CZ-Si crystal growth. It was observed that the optimum gap width for C reduction results from the trade-off between the back diffusion and gas convection.

中文翻译：

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可控坩埚运动对直拉硅晶体生长中熔化过程和碳污染的影响

摘要 在直拉硅 (CZ-Si) 晶体生长过程中，堆积的硅块在熔化过程中会发生坍塌和体积收缩。坩埚的轴向运动和硅原料的熔化导致动态热场和流场并影响质量传输。为了研究坩埚运动对熔化过程和碳（C）污染的影响，通过具有动态网格变形的瞬态全局模拟研究了固定坩埚和提升坩埚的情况。在坩埚提升过程中，气体导向器和硅原料顶面之间的间隙宽度保持恒定。在固定坩埚和升降坩埚的情况下，研究了硅原料和氩气中的杂质和物质传输。C 积累过程的比较表明，提升坩埚外壳比固定坩埚外壳导致更高的 C 污染。此外，研究了具有不同间隙宽度的提升坩埚外壳，以制定控制坩埚运动的策略，因为它对 CZ-Si 晶体生长中的熔化过程和 C 污染的影响。据观察，C 还原的最佳间隙宽度来自反向扩散和气体对流之间的权衡。