Internal gettering of iron in multicrystalline silicon at low temperature

Abstract

The interstitial iron concentration in multicrystalline silicon wafers, determined from recombination lifetime measurements, is effectively reduced by annealing the wafers at very low temperature (300–500 °C). During annealing, the iron concentration decreases by more than one order of magnitude. The observed disappearance of interstitial iron is explained by internal gettering of the iron by crystallographic defects.