Institut de Physique Nucléaire de Lyon, IN2P3-CNRS/Université Claude Bernard 43, Bd. du 11 Novembre 1918,69622, Villeurbanne Cedex, France
Abstract:
The evolution of damages at a Cu/Al2O3 device interface after Ar+ irradiation, depending on alumina structure, and the effect of surface roughness on sputtering have been studied. A polycrystalline Cu/Al2O3 bilayer and polycrystalline Cu on amorphous alumina were irradiated with 400 keV Ar+ ion beam at doses ranging from 5 × 1016 to 1017 Ar+/cm2 at room temperature. The copper layer thicknesses were between 100 and 200 nm. RBS analysis was used to characterize the interface modification and to deduce the sputtering yield of copper. The SEM technique was used to control the surface topography. A RBS computer simulation program was used to reproduce experimental spectra and to follow the concentration profile evolutions of different elements before and after ion irradiation. A modified TRIM calculation program which takes into account the sputtering yield evolution as well as the concentration variation versus dose gives a satisfactory reproduction of the experimental argon distribution. The surface roughness effect on sputtering and the alumina structure influence at the interface on mixing mechanisms are discussed.