Development of a Nb/Al technology for SNS Josephson junctions

We report here the status of development of our Nb/Al/Nb SNS Josephson junctions to be used as superconducting D/A converters. The electrical behaviour and the morphology of these Nb/Al/Nb junctions are strongly dependent on the deposition rate of the AL barrier. Junctions fabricated at a high rate of 5 nm/s have stable and reproducible properties. A possible interpretation of the effect of the Al morphology on the electrical behaviour of the junctions is given.