Mechanism of internal gettering of interstitial impurities in Czochralski-grown silicon

Abstract

Results of the low-temperature precipitation of interstitial Fe (\ensuremath{\approxeq}250 \ifmmode^\circ\else\textdegree\fi{}C) in Czochralski-grown Si after different annealing treatments for the precipitation of oxygen are presented. It is concluded that the Fe solubility is not affected by the oxygen-precipitation process. The Fe-precipitation kinetics are found to be strongly accelerated by oxygen-precipitation--induced defects. Based on the results the mechanism of internal gettering is derived. For the first time the contribution of oxygen precipitates and dislocations to the internal-gettering process have been determined quantitatively.