Numerical analysis of dopant concentration in 200 mm (8 inch) floating zone silicon

In this paper, the calculation of dopant concentration for 200 mm floating zone silicon was carried out. The numerical model includes natural convection, thermocapillary convection, electromagnetic force, and rotation of the melt. The dopant concentration was obtained using steady-state calculation of dopant convection and diffusion. Through the comparison between the melt flow and normalized resistivity distribution, we investigated that, besides the well-known separation point, there was a secondary minimum resistivity near external triple point. This phenomenon was also indicated in previous experimental result, and thus was confirmed that the phenomenon was caused by strong electromagnetic force at external triple point.