Fabrication of YBCO multi-layer wiring with a polished PBCO insulator

In this study we have fabricated YBa/sub 2/Cu/sub 3/O/sub 7-x/ (YBCO)/PrBa/sub 2/Cu/sub 3/O/sub 7-x/ (PBCO)/YBCO multi-layer wiring and investigated its properties. We found that a polishing technique is extremely effective in the elimination of precipitates on the films without degradation in film properties. YBCO/polished-PBCO/polished-YBCO crossover with 50 (mu)m square of overlap showed resistance of a degree of k(omega) at 4.2 K while a contact of two YBCO layers through a 10 (mu)m square of hole in the PBCO layer exhibited good superconductivity.