Title :
Fabrication of all-NbN Josephson tunnel junctions using single crystal NbN films for the base electrodes
Author_Institution :
Electrotech. Lab., Ibaraki, Japan
fDate :
3/1/1991 12:00:00 AM
Abstract :
All-NbN Josephson tunnel junctions with sputter-deposited magnesium oxide barriers have been fabricated using single-crystal NbN films for the base electrodes. Fabricated Josephson junctions have shown good tunneling characteristics with large gap voltages (5.6-5.8 mV), narrow gap widths (0.1-0.2 mV, from 30 to 70%), and small subgap leakage currents (Vm=20-30 mV, measured at 3 mV). The results of a measurement of a subgap structure for a fabricated junction suggest that the excess leakage currents of fabricated junctions are due to multiparticle tunneling through locally thin areas in the MgO barriers
Keywords :
leakage currents; magnesium compounds; niobium compounds; sputter deposition; superconducting junction devices; 5.6 to 5.8 mV; Josephson tunnel junctions; NbN-MgO-NbN; base electrodes; fabrication; gap voltages; leakage currents; locally thin areas; multiparticle tunneling; narrow gap widths; single crystal NbN films; sputter deposition; tunneling characteristics; Electrodes; Fabrication; Leakage current; Niobium; Optical films; Sputtering; Substrates; Superconducting films; Temperature; Tunneling;
Journal_Title :
Magnetics, IEEE Transactions on
