As an alternative to the shadow evaporation method for the preparation of ultrasmall tunnel junctions we have established the so-called self-aligned in-line technique. It was applied to the fabrication of common Al/AlO/sub x//Al-type and, for the first time, Nb/AlO/sub x//Nb-based single-electron transistors. The characterization of the samples at temperatures in the range of a few hundred millikelvins reveals charging effects (Coulomb blockade and gate modulation) of the quasiparticle current.
Published in:
Applied Superconductivity, IEEE Transactions on
(Volume:7
,
Issue:
2
)
Date of Publication: June 1997