The influence of aging and annealing on the properties of Nb/Al-AlOx/Nb tunnel junctions
Paper in proceedings, 2010

This paper presents results of our studies on aging and annealing properties of Nb/Al-AlOx/Nb junctions. We performed a long room temperature aging with subsequent annealing at different temperatures up to 250°C. A distinct change of the junctions' normal-state resistance has been observed. Aging at room temperature results in a slight decrease of the normal-state resistance combined with improved junction quality, characterised by a better subgap-to-normal resistance ratio. Annealing at moderate temperatures in air increases the normal-state resistance and leads to improvement of the junction quality followed by degradation at higher annealing temperatures. The increase in the junction quality after long-term aging at room temperature is attributed to relaxation of the internal junction structure and interfaces, thus, resulting in a lower density of interface traps. The deterioration at higher annealing temperatures could be a consequence of diffusion processes at the Al/Nb interface. We observe a sufficiently clear difference between the behaviour of preliminary aged and newly fabricated junctions after annealing: for the aged high-quality junction, the degradation was negligible up to temperatures of 200°C, while non-aged junctions show a much faster and abrupt degradation at lower annealing temperatures.

Author

Dimitar Milkov Dochev

Chalmers, Department of Radio and Space Science, Advanced Receiver Development

Alexey Pavolotskiy

Chalmers, Department of Radio and Space Science, Advanced Receiver Development

Zonghe Lai

Chalmers, Microtechnology and Nanoscience (MC2), Nanofabrication Laboratory

Victor Belitsky

Chalmers, Department of Radio and Space Science, Advanced Receiver Development

Journal of Physics: Conference Series

17426588 (ISSN) 17426596 (eISSN)

Vol. 234 4

Subject Categories

Electrical Engineering, Electronic Engineering, Information Engineering

Condensed Matter Physics

DOI

10.1088/1742-6596/234/4/042006

More information

Created

10/7/2017