| dc.description.abstract | The Continuous Czochralski crystal growth (CCz) method is an improvement based on the traditional Czochralski crystal growth (Cz) technique, aimed at enhancing production efficiency. The CCz method continuously adds polycrystalline silicon to the crucible, maintaining a consistent melt level and stable chemical composition. However, to prevent incompletely melted polycrystalline silicon from affecting crystal growth, a partition is added in the study to separate the feed area from the crystal growth area. But this also results in an increase in oxygen concentration and altered melt flow and heat transfer.
Therefore, this study addresses the issues of rising oxygen concentration and unstable melt flow in continuous Czochralski double-crucible growth through numerical simulations to analyzes the effects of various factors on flow patterns, temperature distribution, oxygen concentration, and the height of the crystal-melt interface, including the presence or absence of a cusp magnetic field, different magnetic field densities, different crystal and crucible rotation directions, balanced versus unbalanced magnetic field conditions, and different magnetic ratios (MR). The differences between Cz and CCz methods are also compared.
Research results show that when a magnetic field is applied during the counter-rotation of the crucible and crystal, the Lorentz force generated by the magnetic field alters the size of secondary vortices. Thereby influencing the flow structure within the melt. This has a critical impact on the oxygen concentration at the crystal-melt interface. In addition, an unbalanced magnetic field can increase the temperature of the melt, allowing the silicon to melt more thoroughly. Compared to the balanced magnetic field, it reduces the oxygen concentration. However, in the case of co-rotation, the vortex below the solid-liquid interface is enhanced. While this can reduce the oxygen impurity concentration, it also leads to an increase in the interface height. | en_US |