Xe distribution in amorphous SiO2 as a function of implantation and thermal annealing parameters

• We studied the distribution of implanted Xe in amorphous SiO2.
• Various energies and fluencies as well as thermal annealing were considered.
• RBS and TEM characterizations were undertaken.
• We demonstrated that Xe can be located at vacancy peak or at ion projected range.
• When a dense layer of bubbles is formed, Xe is shifted to stable bubbles region.

We studied the distribution of implanted Xe in amorphous SiO2. Our results clearly showed that Xe profile is energy and fluence dependent. By varying ion energy from 50 to 300 keV, we found that its thermal out-diffusion is very conventional for the first two energies and unexpected for the highest energy. In that last case Xe main peak increases with thermal annealing. Instead of out-diffusing, Xe seems to be driven toward the main peak. The effect of ion fluence is similar to energy one with a conventional out-diffusion for lower fluences (5 × 1015 and 1 × 1016 cm−2) while higher fluences (3.5 × 1016 and 5 × 1016 cm−2) display an increase of the main peak with annealing. Such a behavior can be linked to the formation (or not) of a high density of stable bubbles.