Growth and ripening of oxygen precipitation in neutron-irradiated Czochralski silicon

The effects of the vacancy-related defects introduced by neutron irradiation on oxygen precipitation in Czochralski silicon have been elaborately investigated. It is found that the vacancy-related defects significantly enhance the nucleation of oxygen precipitates as well as the growth of the grown-in oxygen precipitates. The Ostwald ripening of oxygen precipitates in neutron-irradiated silicon wafers is observed during a low-high two-step annealing. It is interpreted that the vacancy-related defects facilitate the formation of platelet-like oxygen precipitates, which continue to grow at the expense of small-sized oxygen precipitates during the high temperature annealing process. However, when subjected to the subsequent rapid thermal annealing at higher temperature, the platelet-like oxygen precipitates in the neutron-irradiated silicon exhibit lower stability due to the large surface free energy.