QUANTIFICATION OF OXYGEN AND CARBON IN HIGH T(C) SUPERCONDUCTING FILMS BY (ALPHA,ALPHA) ELASTIC RESONANCE TECHNIQUE

The quantification of oxygen and carbon in high-temperature (T(c)) superconducting oxide thin films was made by employing elastic resonance in He backscattering analysis. A method combining the oxygen resonance technique and channeling was presented for measuring the nature of the oxygen disorder near the surface and the interface in a YBCO superconducting film grown on an MgO substrate. The oxygen resonance technique was used to quantify the oxygen profiling in the metal/YBCO contacts, showing that Zr and Nb act as sinks to oxygen from YBCO films and are oxidized in the forms Zr/ZrO2/YBCO/MgO and Nb0.2O/YBCO/MgO after annealing in a vacuum at 350-degrees-C. We combined the carbon and oxygen resonances to determine the carbon contamination and oxygen concentration changes on the YBCO surface after coating and baking the photoresist. Residual carbon on the surface and a thin layer of oxygen depletion near the YBCO surface have been observed. The residual carbon in Bi2Sr2CaCu2O8 films made by the decomposition of metallo-organic precursors was quantified using carbon resonance.