Considerations on the effect of interstitial and precipitated Fe in intentionally Fe-doped mc-silicon

In this work laboratory scale multicrystalline silicon ingots were grown which have been intentionally contaminated with iron by adding FeSi2 to the silicon feedstock. It is shown that an iron contamination at these high levels does not result in a structural breakdown of the columnar grain growth regime because constitutional supercooling could be avoided by strong mixing of the melt in the present crystal growth experiments. The minority carrier lifetime mappings are dominated by the iron contamination and show the distribution of the impurity over the grown ingots. Specific resistivity was measured over the ingot height. The measured values show an interaction of iron with oxygen which leads to the suppression of thermal donor generation.