High temperature annealing effects on low energy iron implanted SiO2

15 keV Fe ions were implanted into a thermally grown silica film with a fluence of 1 × 1016 at./cm2 resulting in a near Gaussian concentration profile peaking at 8 at.% about 15 nm under the surface. High vacuum (∼10−7 mbar) furnace annealing and electron beam annealing at high temperature resulted in diffusion of Fe inside the oxide film. Segregation of Fe atoms at the SiO2 surface and SiO2/Si interface was observed in both cases. EBA resulted in faster precipitation and lower out-diffusion of Fe. In-situ Rutherford Backscattering Spectrometry was performed during high vacuum annealing and is shown to be an appropriate method to investigate the diffusion rate. The differences observed between the methods are explained by the effect of excess electrons and ionization induced by the electron beam on the oxygen-vacancy mediated displacement mechanism and on the reduction of Fe oxides.