T. Kikuchi et al., FABRICATION AND CHARACTERISTICS OF VERTICALLY STACKED NBCN MGO/NBCN JOSEPHSON-JUNCTIONS WITH THIN INTERMEDIATE ELECTRODES/, IEEE transactions on applied superconductivity, 7(2), 1997, pp. 2426-2429
Vertically stacked NbCN/MgO/NbCN Josephson junctions with thin interme
diate electrodes (2 nm similar to 11 nm) have been fabricated on a sil
icon wafer in a computer-controlled sputtering system. The tunneling c
haracteristics of fabricated junctions have been evaluated as function
s of the number of stacks and thickness of intermediate electrodes d.
As a result, it has been found that the energy gap for intermediate el
ectrodes reduced with d linearly depending on 1/d. The junction qualit
y parameter R-SG/R-N gradually decreased with d.