JOSEPHSON-JUNCTIONS, INTERCONNECTS, AND CROSSOVERS ON CHEMICALLY ETCHED EDGES OF YBA2CU3O7-X

A technique of ultraviolet photolithography of YBa2Cu3O7-x and PrBa2Cu3O7-x films combined with nonaqueous Br-ethanol chemical etching was developed. Josephson junctions, interconnects, and crossovers on the basis of chemically etched edges of c-axis oriented YBa2Cu3O7-x thin films were prepared and investigated. For the Josephson junctions with a PrBa2Cu3O7-x barrier, the I(c)R(n) product values of about 10 mV at 4.2 K and up to about 0.6 mV at 77 K were achieved. Shapiro steps were observed in the temperature range up to about 89 K. Critical current spreads of about +/-10% were observed. At 77 K, the electrodes of crossovers carried more than 10(6) A/cm2. For a 160-nm-thick SrTiO3 intermediate layer in crossovers, a resistivity of more than 10(9) OMEGA cm was achieved at T less-than-or-equal-to 100 K.