The role of silicon self-interstitial supersaturation in the retardation of oxygen precipitation in Czochralski silicon

The retardation phenomenon of oxygen precipitation in Czochralski silicon has been studied simultaneously with the growth of surface stacking faults under a silicon nitride capping layer. The surface faults were intentionally introduced to monitor the bulk self-interstitial supersaturation in the crystal during precipitate growth. It was observed that an increase in the low-temperature nucleation anneal time resulted in a reduced rate of oxygen precipitation and an enhanced rate of surface stacking fault growth at high temperatures. This indicates that as the nucleation anneal time increases, silicon self-interstitials, which must be generated for precipitation to proceed, reach a high level of supersaturation and cause the annihilation of most nuclei generated during the nucleation anneal.