Preparation, transport properties and patterning of superconducting YBCO thin films

Abstract The preparation of YBCO thin films by coevaporation and magnetron sputtering is reported. The coevaporated films were fabricated on SrTiO 3 substrates by the codeposition of Y, BaF 2 and Cu at elevated substrate temperature and an ex situ annealing process. Zero resistance T c was as high as 88 K and the critical current density was j c (77K)≈10 5 A/cm 2 . The superconducting sputtered films were fabricated in situ using an inverted cylindrical target on Y-stabilized ZrO 2 substrates with T c near 85 K and j c (77K)≈10 6 A/cm 2 . The films were structured by a conventional photolithographic technique and chemical etching. The temperature dependence of the resistance R(T) and critical current I c (T) were measured for bridges with different line widths w. Line widths down to 3 μm were patterned on sputtered films by EDTA without any degradation of the superconducting properties, whereas due to the intrinsic surface roughness of the coevaporated films, degradation in the superconducting properties was observed for w