Preparation of Sr2AlTaO6 thin films by metalorganic chemical vapor deposition

Sr₂AlTaO₆ (SAT) thin films were prepared by metalorganic chemical vapor deposition (MOCVD) using a double-metal alkoxide TaAl(O-iC₃H₇)₈ and Sr(DPM)₂-2tetraene as precursors. The former precursor was found to be stable for more than 300 h to prepare nearly stoichiometric thin films with the Ta/Al ratio of 1.0-1.3. High crystallinity of the films on SrTiO₃ substrates with the Sr/Al ratio slightly smaller than 2.0 was confirmed by X-ray diffraction. Moreover, 200 nm-thick SAT thin films were deposited on YBa₂Cu₃O _7-δ thick films grown by liquid phase epitaxy. Measurements of dielectric properties using a parallel capacitor structure 200 μm in diameter confirmed the conductance of the film lower than 10^-8 S as well as an almost temperature-independent dielectric constant of approximately 24. These results indicate that SAT films grown by MOCVD are promising to be incorporated in high-T_c multilayer structures for electronic devices