Defects in the Oxidation-Induced Stacking Fault Ring Region in Czochralski Silicon Crystal

Abstract

We have examined the defects in the oxidation-induced stacking fault (OSF) ring region in the as-grown Czochralski silicon crystals subjected to in situ annealing by the halt of pulling during crystal growth using secondary ion mass spectrometry (SIMS) and transmission electron microscopy (TEM) in order to investigate the nature of OSF nuclei. Oxygen aggregates were observed in the ring region in the crystals held for 4 h and 16 h using SIMS. The aggregate density in the crystal held for 16 h corresponded to the density of the grown-in defects without a flow pattern revealed by non-agitated Secco etching. TEM observation indicated that one of the grown-in defects in the ring region in the crystal held for 4 h was oxygen precipitate with a dislocation loop. OSF density decreased with holding time and density of another defect which was not an OSF increased with holding time in the ring region held at temperatures below about 1060°C. We believe that the OSF nuclei were oxygen precipitates and the dislocation loop was appeared around the precipitate during the halt of pulling process, so that OSF nuclear density was decreased.