Title :
Nb-based SNS junctions with Al and TaO/sub x/ barriers for a programmable Josephson voltage standard
Author :
Lacquaniti, V. ; Gonzini, S. ; Maggi, S. ; Monticne, E. ; Steni, R. ; Andreone, D.
Author_Institution :
Ist. Elettrotecnico Nazionale Galileo Ferraris, Torino, Italy
fDate :
6/1/1999 12:00:00 AM
Abstract :
We report results achieved in the fabrication of two different Nb-based SNS devices which can be used for the development of a programmable Josephson voltage standard. Junctions with an Al metal barrier, 5 to 100 nm thick, have been fabricated obtaining devices with I/sub C/R/sub N//spl ap/0.5 mV. A second kind of junction has been fabricated using 10 nm thick non-stabilized TaO/sub x/ as a barrier, deposited by bias sputtering. For these devices, using the bias voltage as the main process parameter, I/sub C/R/sub N//spl ap/0.1 mV was obtained. Measurements of the electrical properties of the Nb/Al/Nb and the Nb/TaO/sub x//Nb junctions are reported.
Keywords :
Josephson effect; aluminium; measurement standards; niobium; programmable circuits; superconducting arrays; superconducting microwave devices; superconductor-normal-superconductor devices; tantalum compounds; voltage measurement; 10 nm; 5 to 100 nm; Nb-Al-Nb; Nb-TaO-Nb; SNS junctions; bias sputtering; electrical properties; process parameter; programmable Josephson voltage standard; Damping; Electric variables measurement; Josephson junctions; Microwave frequencies; Niobium; Sputtering; Stability; Standards development; Superconducting devices; Voltage;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
