AN IMPROVED MULTILAYER FABRICATION PROCESS FOR YBA2CU3O7-X-BASED CIRCUITS

Improved via connections in structures of YBa2Cu3O7-x/SrTiO3/YBa2Cu3O7 -x (YBCO/STO/YBCO) multilayers have been made using a combined HF wet- etching and ion-milling process. The critical current density J(C) of the via is as high as 2 x 10(6) A/cm(2) at 76 K, and is dominated by e dge contacts in the ab-plane. YBCO and Sr2AlNbO6 (SAN) multilayer test circuits were also made with this process. The 4 degrees crossovers i n a SAN test chin had a critical temperature T-C of 88 K and J(C) of 1 .5 x 10(6) A/cm(2) at 81 K, very close to those of the planar film, sh owing no evidence of weak links in the YBCO crossing low angle SAN ste ps.