Journal of Vacuum Science & Technology B, Vol.15, No.6, 2379-2381, 1997
Fabrication of high-temperature superconductor Josephson junctions by focused ion beam milling
We have fabricated high-critical-temperature Josephson junctions using a focused ion beam (FIB) milling to define the gap, in a-axis oriented YBa2Cu3O7 (YBCO) films. A good quality normal metal/YBCO interface is obtained by in situ Au deposition. The effect of FIB milling has been studied with different milling conditions and the resulting devices exhibit different I-V characteristics, i.e., flux flow or superconductor/normal/superconductor Josephson junction behavior. The junctions exhibit Shapiro steps in their I-V characteristics under microwave irradiation. The critical current and normal resistance product (IcRn) of the order of 1 mV has been obtained. We also show that there is a voltage modulation in the superconducting quantum interference devices as a function of an applied magnetic flux up to 80 K.
Keywords:FILMS