In-situ preparation of Y-Ba-Cu-O thin films on silicon single crystals

This paper reports on superconducting Y-Ba- Cu-O thin films with critical temperatures exceeding 80 K deposited on silicon single crystal substrates using the pulsed laser deposition technique. Deposition from a sintered Y1Ba2Cu3O7 target in oxygen ambient of 0.1 - 5 mbar onto substrates kept at 700 degrees C to 820 degrees C results in crystalline films in which the target composition of the metallic constituents is preserved. No post deposition treatments are required to obtain high values for the zero resistance. X-ray analysis as well as Raman spectroscopy reveal that specimens prepared at optimum conditions are single phase c-axis oriented. In contrast to films prepared on LaAlO3 or SrTiO3 the surface morphology shows a granular structure. The films prepared by this technique are quite stable against chemicals used in conventional lithographic patterning, however, a strong correlation between film quality before patterning and some degradation after patterning is observed