Effects of low-energy ion bombardment on the growth of Cu films

This thesis presents an experimental study on the interaction of low-energy ions with solid surfaces and its implications in the growth of Cu films. The experimental method is provided by a high-vacuum thin-film growth technique, referred to as partially ionized beam (PIB) deposition technique, which involves a physical vapor deposition process with a concurrent ion bombardment of the substrate. The ions (0-5% of the depositing beam) are derived from the depositing materials and have energies less than 5 keV. A study of the surface impurity sputtering is carried out on the PIB Du deposition on Si(111) substrate which contains a thin layer of impurities on the surface. A reduction of impurities at the Cu/Si interface is observed as a function of the ion-bombardment parameters. The energy dependences of the sputtering cross sections of oxygen, carbon and hydrogen at the Cu/Si interface by Cu ions are calculated and compared to experimental data. A theoretical study of the thermal spike effect induced by ion bombardment, with particular emphasis on the ion energy dependence of the substrate surface temperature, is carried out