Preparation of small-area Al/AlOx/Al tunnel junctions in a self-aligned in-line technology and observation of the Coulomb blockade

M. Götz; P. Thieme; K. Blüthner; W. Krech; D. Born; S. Götz; H.-J. Fuchs; E.-B. Kley; Th. Wagner; G. Eska

doi:doi:10.1051/jp4:1994636

Issue		J. Phys. IV France Volume 04, Number C6, Juin 1994 WOLTE 1 Proceedings of the First European Workshop on Low Temperature Electronics


Page(s)		C6-223 - C6-228
DOI		https://doi.org/10.1051/jp4:1994636

WOLTE 1
Proceedings of the First European Workshop on Low Temperature Electronics

J. Phys. IV France 04 (1994) C6-223-C6-228
DOI: 10.1051/jp4:1994636

Preparation of small-area Al/AlO_x/Al tunnel junctions in a self-aligned in-line technology and observation of the Coulomb blockade

M. Götz¹, P. Thieme¹, K. Blüthner¹, W. Krech¹, D. Born¹, S. Götz¹, H.-J. Fuchs², E.-B. Kley², Th. Wagner³ and G. Eska³

¹ Institute of Solid State Physics, Friedrich-Schiller-University of Jena, Max-Wien-Platz I, D-07743 Jena, Germany
² Institute of Applied Physics, Friedrich-Schiller-University of Jena, Max-Wien-Platz I, D-07743 Jena, Germany
³ Institute of Physics, University of Bayreuth, D-95448 Bayreuth, Germany

Abstract
We have demonstrated the suitability of a self-aligned in-line (SAIL) technique for the preparation of ultra-small high-ohmic tunnel junctions as required for the investigation of single-charge tunneling phenomena. The Coulomb blockade has been observed at 14mK by means of a series array of five Al/AlO_x/Al tunnel junctions operated in the normal-conducting state. We have applied this conception to the fabrication of single junctions in a Nb/NbO_x/PbAuIn system as well. At 4.2K these samples show the typical I-V behaviour of Josephson tunnel junctions as expected. The compatibility of this process with several thin film deposition techniques, evaporation as well as sputtering, extremely small parasitic capacitances and excellent integrability promise interesting applications in both single-charge electronics and Josephson physics.