Study of the characteristics of defects in the Oxidation-induced Stacking Fault-Ring area in Czochralski Silicon crystals by multi-chroic infrared light scattering tomography and transmission electron microscopy

A new defect morphology of dark stripes was observed in both as-grown and annealed Czochralski silicon (CZ-Si) crystals by photoluminescence (PL) mapping of a multi-chroic infrared light scattering tomography (MC-IR-LST) system. The dark stripes in the as-grown CZ-Si crystal are believed to be highly decorated striations, where grown-in defects have inhomogeneously segregated during the crystal growth. When this crystal was annealed at 1150°C for 16 h in an O2 atmosphere, defects such as stacking faults, oxygen-precipitate-related polyhedral defects, impurities and dislocation loops were observed around the dark stripes in the oxidation-induced stacking fault (OSF)-ring region using transmission electron microscopy (TEM) and the MC-IR-LST system. Investigation results suggested that the main grown-in defects around dark stripes were oxygen precipitate nuclei and vacancy-related nuclei, which resulted in the formation of such defects during the thermal oxidation process.