Interface adhesion enhanced by MeV ions

The adhesion enhancement of Ag or Au films on Ta (with native oxide) and Ta2O5 (anodic oxidation) interfaces by bombarding with 1.5-18 MeV Si ions at both room temperature (RT) and low temperature (LT) (170 K) has been studied. The threshold doses Dth for these systems to pass the Scotch tape test at RT as a function of ion electronic stopping power dE/dX were measured. The power las Dth∝(dE/dx)n with various magnitudes and n values were observed for all these systems. SIMS measurements showed MeV ion-induced migration of silver into the tantalum substrate for the irradiated Ag/Ta and Ag/Ta2O5 systems. Significantly increased threshold doses were observed for samples irradiated at LT except for the Ag/Ta2O5 interface, which indicated that possible bonds between silver and oxygen atoms formed during MeV ion bombardment may inhibit the further migration of silver into the substrate. The preliminary results about Dth as a function of the thickness of the ultrathin silicon native oxide on Ag/SiOx/Si and Au/SiOx/Si systems showing the different behavior in adhesion enhancement between Ag and Au films are also compared and discussed. (orig.)