Effects of Ne+ and Ar+ ion bombardment on Fe/SiO2 bi-layers studied using RBS

Ion beam mixing of Fe with SiO2 has been studied in details, using Rutherford backscattering spectroscopy (RBS) technique. Fe thin films of different thicknesses ranging from 23 to 49 nm were deposited on SiO2 by thermal evaporation method. Specimens were irradiated with Ne+ and Ar+ ions at different fluences (ranging from 5x1015 to 2x1017 ions/cm2) and at different temperatures (RT, 423 and 573 K). It is found that the square of diffusion length is proportional to the ion fluence implying that mixing is due to ballistic effects when irradiated with Ne+ and Ar+ ions. Long-range diffusional type of mixing similar to that observed in Fe/Si system is insignificant in case of Fe/SiO2 system. As the temperature is increased, keeping other parameters same (the ion mass, fluence and Fd), there is minor increase in the diffusion length