Removal of phosphorus in molten silicon by electron beam candle melting

In the current study, a new method for the removal of phosphorus in molten silicon, electron beam candle melting (EBCM), is proposed and discussed. The proposed method combines the characteristics of electron beam melting (EBM) and the high saturated vapor pressure of P in molten Si. Simulation results show the existence of three typical temperature distributions and morphologies of the molten pool that correspond to the different radii of the electron beam circular pattern at constant power. The critical molten pool with the maximum surface area and the minimum depth was determined. EBCM resulting in the critical molten pool was proven to be more effective in the removal of P in molten Si compared with EBM. In addition, the energy utilization ratio was enhanced.

► As a new method, EBCM is proposed and discussed.
► It combines the feature of EBM and the saturated vapor pressure of P in molten Si.
► A molten pool with maximum surface area and minimum depth exists during EBCM.
► Compared with EBM, EBCM is more effective in the removal of P in molten Si.
► Compared with EBM, EBCM has a higher energy utilization ratio.