DEFECTS IN THE OXIDATION-INDUCED STACKING-FAULT RING REGION IN CZOCHRALSKI SILICON CRYSTAL

We have examined the defects in the oxidation-induced stacking fault ( OSF) ring region in the as-grown Czochralski silicon crystals subjecte d to bl situ annealing by the halt of pulling during crystal growth us ing secondary ion mass spectrometry (SIMS) and transmission electron m icroscopy (TEM) in order to investigate the nature of OSF nuclei. Oxyg en aggregates were observed in the ring region in the crystals held fo r 4h and 16h using SIMS. The aggregate density in the crystal held for 16 h corresponded to the density of the grown-in defects without a Ro w pattern revealed by non-agitated Sccco etching, TEM observation indi cated that one of the grown-in defects in the ring legion in the cryst al held for 4 h was oxygen precipitate with a dislocation loop. OSF de nsity 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 degrees C. We believe that the OSF nucle i were oxygen precipitates and the dislocation loop was appeared aroun d the precipitate during the halt of pulling process, so that OSF nucl ear density was decreased.