CHARACTERIZATION OF BISRCACUO THIN-FILMS BY THE COMPLEMENTARY USE OF IBA AND AES ANALYTICAL TECHNIQUES

Standard IBA (RES, 2 MeV He normal incidence, theta = 165 degrees and NRA, O-16(d,p)O-17) analysis, and AES combined with ion erosion for d epth profiling have been performed on BiSrCaCuO thin films deposited o n Si substrates by ion beam sputtering, in order to have a complete ch aracterization of the elemental composition and concentration of the l ayers. While RES can give average cationic composition of elements in the film and NRA gives the oxygen content of the film with greater pre cision than RBS, AES can give complementary information concerning che mical state of cations, or finding trace amounts of impurities of heav y elements which are difficult to separate by RBS from other heavy ele ments constituents of the film (for instance the hypothetical presence of W coming from the incandescent filaments during the deposition and the Bi). Although the system is quite complicated due to the multiele mental character of the samples and there are problems due to the over lap of AES signals for the heaviest elements (Sr and Bi), the AES comp osition profiles are obtained after a careful analysis of the full ene rgy range of the AES spectra, and show variations which are not detect ed by RBS. The use of both types of analytical techniques, ions and el ectrons, allows for a more complete characterization of the films.