Saturation effects observed in high fluence heavy ion implantation at few tens of keV

Effect of implantation fluence on the total number of metal atoms incorporated in a host matrix at few tens of keV beam energy has been studied experimentally using Rutherford backscattering spectrometry (RBS) as well as using simple calculations, taking Au and Ag ions for host matrices Si and silica glass. In all the cases, calculations showed that the total number of retained metal atoms are identical to the implantation fluence upto 3 × 10¹⁶ ions cm⁻² above which the metal content retained in the matrix shows a saturation. The variation in the number of metal atoms as a function of the implantation fluence extracted from the RBS measurements has been found to be in good agreement with the results of the calculation expect for the high fluence implantation case of Ag in Si. This observed difference is attributed to the irradiation induced in-diffusion of Ag atoms in Si matrix due to the low diffusion activation energy of Ag in Si. Effect of saturation on the number of metal atoms incorporated in the matrix is reflected in the Raman scattering data of the implanted Si samples as well as the optical absorption data of the implanted silica glass samples.