The influence of thermal point defects on the precipitation of oxygen in dislocation-free silicon crystals

Abstract

The precipitation of oxygen in regularly grown and in situ-quenched dislocation-free Czochralski silicon crystals has been investigated by means of infrared absorption spectroscopy, preferential etching, and x-ray transmission topography. In addition, the effect of doping with acceptor or donor impurities on oxygen precipitation has been studied. The experimental results indicate that at oxygen supersaturation ratios smaller than 20 the formation of nuclei for precipitation predominantly occurs via a heterogeneous in which thermal point defects, in particular silicon interstitials, play an important role.