Effects of thermal history on the formation of oxidation-induced stacking fault nuclei in Czochralski silicon during crystal growth

The formation of oxidation induced stacking fault (OSF) nuclei during Czochralski silicon crystal growth was investigated using crystals subjected to in situ annealing for either 1 or 4 hours by halt of pulling during crystal growth. The effects of in situ annealing at temperatures from about 1160 degrees C to 1030 degrees C can be summarized as follows. In positions held at about 1090 degrees C and 1030 degrees C. the radial distributions of OSFs, LSTDs (light scattering tomography defects), and OPs (oxygen precipitates after annealing) changed greatly. In the position held at about 1090 degrees C, large LSTDs were formed but the OSF-ring disappeared in the region where it should have been present if pulling was not halted. In the position held at about 1030 degrees C, the defects in the OSF-ring grew, its width increased, and the OP density both inside and outside the OSF-ring decreased with holding time. However, the radial distribution of defects at the position held at about 1160 degrees C was similar to that, for a reference crystal which was not subjected to halt of pulling. These results indicate that these defects were not formed until 1160 degrees C, the large LSTDs were formed at 1160-1090 degrees C, the OSF nuclei were formed at 1090-1030 degrees C. and the OP nuclei inside and outside the OSF-ring were formed below 1030 degrees C. We discussed the influence of point defects upon the formation of OSF nuclei.