AES, XPS AND SIMS CHARACTERIZATION OF YBA2CU3O7 SUPERCONDUCTING HIGH-TC THIN-FILMS

High Tc superconducting YBa2Cu3O7- x (YBCO) films 100-200 nm thick have been grown in situ by ion beam sputter co-deposition using four Kaufman ion beam sources. As-deposited films have Tc (R = 0) at 74K. Postannealing improved Tc (R = 0) to 79 K. The critical current exceeded 5 × 104 A cm-2 at 77 K. Films were deposited on SrTiO3, or on Si with an intermediate layer of SiO2 or Y2O3. Auger Electron Spectroscopy (AES), X-Ray Photoelectron Spectroscopy (XPS) and Secondary Ion Mass Spectroscopy (SIMS) were used to depth profile films deposited at 350 and 650°C. For quantification of XPS and AES analysis, standards of BaF2, BaCo3, BaO, BaO2, CuO, Cu2O, and Y2O3, and monocrystals of BaCuO2 and YBa2O3O7 - x were measured. XPS binding energies and AES sensitivity factors were determined. Using the YBa2Cu3O7 - x monocrystal new AES sensitivity factors differing from handbook factors have been established. Static SIMS data of the monocrystal was compared to thin film spectra of the first 1-2 monolayers showing almost identical cracking patterns. © 1990.