Effect of crucible rotation on the distribution of carbon, oxygen and nitrogen impurities in multi-crystalline silicon grown by directional solidification process – a numerical simulation analysis

Abstract

Simulation analysis is done to understand the effect of crucible rotation on the distribution of carbon, nitrogen and oxygen impurities in directionally solidified mc-silicon ingot. Based on their segregation coefficient and solubility, these non-metallic impurities get incorporated into mc-silicon ingot from feedstock and different parts of the furnace. The temperature gradient in silicon melt causes irregular melt convection and that is minimized by applying rotation on the crucible. In the present work, we have applied spin up crucible rotation with different rotation rates such as 3, 6, 9, 12 and 15 rpm from beginning to the end of the growth and distribution of impurities was analyzed. Also, the segregation, axial and radial distribution of non-metallic impurities in silicon ingot for different rpm was investigated.