Film thickness effect on the properties of interconnection between YBCO and Si for superconductor and semiconductor integration

YBa2Cu3O7-delta (YBCO) films were grown on Si using a buffer layer of yttria-stabilized zirconia (YSZ) by pulsed laser deposition. Interconnections between the YBCO film and the Si substrate using Au have been fabricated by lithography. The YBCO films showed zero-resistance critical temperatures in the range of 80-85 K and were found to be grown in the c-axis orientation. The structural properties of the films of various thicknesses were analyzed by XRD, SEM and Raman spectroscopy. Because of very different thermal expansion coefficients of Si and YBCO, there is a tendency to crack formation for films. The crack formation interrupts the current flow and increases the normal state resistance of the films. The effect of cracks on the contact resistances between YBCO films of various thicknesses and Si substrates through Au interconnections is reported. (C) 1998 Elsevier Science Ltd. All rights reserved.