Characterization of Silicon Surfaces Implanted with Antimony Ions and Submitted to Annealing and Ageing Treatments

In this work, we study the effect of annealing and ageing treatments on the behavior of antimony atoms implanted in Si(111) targets. The ion implantation was performed at 120 keV energy to a dose of 2.3×10 ¹⁵ Sb⁺ cm⁻². Concerning the annealing treatment, it has been carried out at 900 °C during 30 minutes (under vacuum). The samples have been analyzed in two steps: immediately after their elaboration and after an ageing period of 4 years and 4 months. Several techniques have been applied for samples analysis: Rutherford backscattering spectroscopy (RBS), X-ray diffraction (XRD) and electrical measurements. Before the ageing period, a good recovery of radiation damage has been obtained and ∼50% of the dopant was redistributed into substitutional silicon sites. However, ∼22% of antimony has been lost from the Si substrates. After the ageing period, the fraction of substituted atoms remained unchanged but a quantity of ∼20% has again been lost from the specimens. This quantity provided from antimony atoms which remained into irregular positions of Si lattice.