Large-area MgB2 thin films were deposited on silicon nitride and sapphire substrates by co-deposition of Mg and B. After a post-annealing in Ar atmosphere at temperatures between 773 and 1173K depending on the substrate, the films exhibited a critical temperature higher than 35K with a transition width less than 0.5K. The X-ray diffraction pattern suggested a c-axis preferential orientation in films deposited on amorphous substrate. The smooth surface and the good structural properties of these MgB2 films allowed their reproducible patterning by a standard photolithographic process down to dimensions of the order of 10µm and without a considerable degradation of the superconducting properties.

MgB2 Thin Films on Silicon Nitride Substrates Prepared by an in situ Method. E.Monticone, C.Gandini, C.Portesi, M.Rajteri, S.Bodoardo, N.Penazzi, V.Dellarocca, R.S.Gonnelli: Superconductor Science and Technology, 2004, 17, 649-52