|
We have fabricated non-superconducting mesoscopic tunnel junctions by
oxidation of Ti. The fabrication process uses conventional
electron-beam lithography and shadow deposition through an organic resist
mask. Superconductivity in Ti is suppressed by performing the deposition
under a suitable background pressure.
We have employed this method to make
single-electron transistors which operated at T < 0.4 K and had a moderate
charge noise of 2.5 x 10^(-3) e / sqrt(Hz) at 10 Hz. Based on nonlinearities
in the current-voltage characteristics at higher voltages, we deduce the
oxide barrier height of approximately 110 mV. The non-superconducting Ti
junctions can be useful in several applications.
Physica E 15, 41 (2002) |
Above: IV-characteristics of Ti SET in the Coulomb blockade regime,
with two extreme gate voltages giving the largest and the smallest width
of the Coulomb gap. Inset: image of a sample similar to the measured one.
The tunnel junctions are marked by arrows.
|
