The influence of aging and annealing on the properties of Nb/Al-AlOx/Nb tunnel junctions
Paper i proceeding, 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.

Författare

Dimitar Milkov Dochev

Chalmers, Institutionen för radio- och rymdvetenskap, Avancerad mottagarutveckling

Alexey Pavolotskiy

Chalmers, Institutionen för radio- och rymdvetenskap, Avancerad mottagarutveckling

Zonghe Lai

Chalmers, Mikroteknologi och nanovetenskap (MC2), Nanotekniklaboratoriet

Victor Belitsky

Chalmers, Institutionen för radio- och rymdvetenskap, Avancerad mottagarutveckling

Journal of Physics: Conference Series

1742-6588 (ISSN)

Vol. 234 4

Ämneskategorier

Elektroteknik och elektronik

Den kondenserade materiens fysik

DOI

10.1088/1742-6596/234/4/042006