Deposition of YBa 2Cu 3O x by laser ablation on Si(100) using different buffer layers

Abstract

Superconducting YBa 2Cu 3O x (YBCO) thin films have been obtained on Si(100) substrates with yttria-stabilized zirconia (YSZ), CeO 2 and SrTiO 3 buffer layers. The YBCO and the buffer films were deposited by laser ablation. The films were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), scanning electron microscopy (SEM), secondary ion mass spectrometry (SIMS), and four-contact electrical resistivity. X-ray diffraction spectra show well oriented buffer layers and secondary ion mass spectrometry results indicate low interdiffusion between YBCO, buffer layers and Si. YBCO films with the c-axis perpendicular to the substrate are obtained for the three materials used as buffers. The best films show a normal state metallic behaviour with zero resistance around 84 K. The crystalline and electrical properties of the films are related with the substrate temperature. The substrate temperature range for the best properties depends on the nature of the buffer layer.