The effect of high temperature―high pressure treatment on the annealing behavior of VO center in neutron-irradiated Czochralski silicon

摘要

It is known that the application of high hydrostatic pressure on Si during heat treatment produces substantial changes in the properties of oxygen precipitates, which in turn, affect the behavior of various defects present in the crystal lattice. In this work, the annealing behavior of the VO complexes in Si samples subjected, before neutron irradiation, to different High Temperature―High Pressure (HT―HP) treatments at temperatures around 900℃ and pressures up to 12kbar, for t = 5h, was investigated using Infrared spectroscopy. We found that (ⅰ) the samples pre-treated at T_1 = 870℃ and 7% = 957℃, at atmospheric pressure and (ⅱ) the samples pre-treated at P_1 = 1 bar and P_2 = 12kbar, at T_1 = 870℃, exhibit approximately the same difference in the annealing temperature of the VO complexes. The observed effect is explained by taking into account the impact of the HT―HP pre-treatment on the fraction of the self-interstitials bound at the SiO_x/Si interface of the oxygen precipitates and the Si matrix. We argue that the two regimes of pre-treatments (ⅰ) and (ⅱ), see above, produce the similar effects upon self-interstitial aggregation processes in the presence of oxygen precipitates.