MOCVD OF HIGH QUALITY YBA2CU3O7-DELTA THIN FILMS USING A FLUORINATED BARIUM PRECURSOR

摘要

MOCVD of superconducting YBa2Cu3O7-delta thin films using the novel fluorinated barium beta-diketonate complex [Ba(TDFND)(2) . tetraglyme](1) in combination with [Y(TMHD)(3)](2) and [Cu(TMHD)(2)] is reported. The Ba complex has a low melting point (72 degrees C), is thermally stable to 200 degrees C and allows reproducible and reliable film deposition even when maintained at 145 degrees C for several weeks, Conversion of the fluoride to the oxide is achieved by in situ hydrolysis. Films deposited on SrTiO3 (100) were characterised by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, rocking curve, ac susceptibility and secondary ion mass spectrometry. Homogeneous layers of YBa2Cu3O7-delta, similar to 0.25 mu m thick, were grown at similar to 0.13 mu m h(-1). The films are epitaxial with good c axis orientatior. Critical temperatures T-c are typically 91 K and critical current densities J(c) (at 77 K) of similar to 5 MA cm(-2) are reported, SIMS results showing levels of residual fluorine do not exceed 250 ppm. [References: 22]