Boundary conditions for formation of Er-O optical centers in Er- and O-coimplanted Si

Photoluminescence (PL) of a variety of samples co-implanted with erbium and oxygen in FZ Si has been investigated to determine boundary conditions for the formation of Er-luminescent centers. Within a limited range of anneali ng temperatures, the formation of these centers can be controlled by the re lative concentration of Er and O. As the annealing temperature increases fr om 600 degrees C to 900 degrees C for samples implanted with 1x10(19) Er/cm (3), the minimum concentration ratio of O/Er required for obtaining a PL in tensity of the main line at 0.8068 eV from Er-centers increases from 0.1 at 700 degrees C annealing to 10 at 900 degrees C. We give evidence that oxyg en migration is involved in enhancing the PL intensity of Er-optical center s. Preliminary Rutherford Backscattering spectroscopy and channeling (RBS/C ) measurements give an experimental result on the lattice location of the E r3+ ions in samples dominated with cubic symmetry optical centers. (C) 1999 Elsevier Science B.V. All rights reserved.