High critical current-density (10 to 420 kA/cm^2) superconductor-insulator-superconductor tunnel junctions with aluminium nitride barriers have been realized using a remote nitrogen plasma from an inductively coupled plasma source operated in a pressure range of 10^{-3} to 10^{-1} mbar. We find a much better reproducibility and control compared to previous work. From the current-voltage characteristics and cross-sectional TEM images it is inferred that, compared to the commonly used AlO_x barriers, the poly-crystalline AlN barriers are much more uniform in transmissivity, leading to a better quality at high critical current-densities.
@article{arxiv.0711.2221,
title = {Epitaxial aluminium-nitride tunnel barriers grown by nitridation with a plasma source},
author = {T. Zijlstra and C. F. J. Lodewijk and N. Vercruyssen and F. D. Tichelaar and D. N. Loudkov and T. M. Klapwijk},
journal= {arXiv preprint arXiv:0711.2221},
year = {2008}
}
Comments
3 pages, 3 figures, accepted for publication in APL