The effect of annealing under hydrostatic pressure on the visible photoluminescence from Si+-ion implanted SiO2 films

We have studied the influence of the hydrostatic pressure during annealing on the intensity of the visible photoluminescence (PL) from thermally grown SiO2 films irradiated with Si (+) ions. Post-implantation anneals have been carried out in an Ar ambient at temperatures T-a of 400 degrees C and 450 degrees C for 10 h and 1130 degrees C for 5 h at hydrostatic pressures of I bar-15 kbar. It has been found that the intensity of the 360, 460 and 600 nm PL peaks increases with rising hydrostatic pressure during low-temperature annealing. The intensity of the short-wavelength PL under conditions of hydrostatic pressure continues to rise even at T-a = 1130 degrees C. Increasing T-a leads to a shift in the PL spectra towards the ultraviolet range. The results obtained have been interpreted in terms of enhanced, pressure-mediated formation of =Si-Si= centres and small Si clusters within metastable regions of the ion-implanted SiO2. (C) 1999 Elsevier Science B.V. All rights reserved.