Epitaxial aluminum nitride tunnel barriers grown by nitridation with a plasma source
Abstract
High critical current-density (10to420kA/cm2) superconductor-insulator-superconductor tunnel junctions with aluminum nitride barriers have been realized using a remote nitrogen plasma from an inductively coupled plasma source operated in a pressure range of 10-3-10-1mbar. We find a much better reproducibility and control compared to previous work. From the current-voltage characteristics and cross-sectional transmission electron microscopy images it is inferred that, compared to the commonly used AlOx barriers, the polycrystalline AlN barriers are much more uniform in transmissivity, leading to a better quality at high critical current densities.
- Publication:
-
Applied Physics Letters
- Pub Date:
- December 2007
- DOI:
- 10.1063/1.2819532
- arXiv:
- arXiv:0711.2221
- Bibcode:
- 2007ApPhL..91w3102Z
- Keywords:
-
- 74.50.+r;
- 74.25.Sv;
- Tunneling phenomena;
- point contacts weak links Josephson effects;
- Critical currents;
- Condensed Matter - Mesoscopic Systems and Quantum Hall Effect;
- Condensed Matter - Superconductivity
- E-Print:
- 3 pages, 3 figures, accepted for publication in APL