Direct observation of the thickness distribution of ultra thin AlOx barriers in Al/AlOx/Al Josephson junctions
Artikel i vetenskaplig tidskrift, 2015

We have directly measured the thickness distribution of the tunnel barriers in state-of-the-art Al/AlOx/Al tunnel junctions. From the distribution we can conclude that less than 10% of the junction area dominates the electron tunnelling. The barriers have been studied by transmission electron microscopy, specifically using atomic resolution annular dark field (ADF) scanning transmission electron microscopy (STEM) imaging. The direct observation of the local barrier thickness shows a Gaussian distribution of the barrier thickness variation along the junction, from ~1 to ~2nm. We have investigated how the thickness distribution varies with oxygen pressure (Po) and oxidation time (to) and we find, in agreement with resistance measurements, that an increased to has a larger impact on barrier thickness and its uniformity compared to an increased Po.

TEM

Tunnel barriers

Aluminum

Josephson junctions

Författare

Lunjie Zeng

Chalmers, Teknisk fysik, Eva Olsson Group

Samira Mousavi Nik

Chalmers, Teknisk fysik, Eva Olsson Group

Tine Greibe

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

Philip Krantz

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

Christopher Wilson

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

Per Delsing

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

Eva Olsson

Chalmers, Teknisk fysik, Eva Olsson Group

Journal of Physics D: Applied Physics

0022-3727 (ISSN)

Vol. 48 39 395308- 395308

Styrkeområden

Nanovetenskap och nanoteknik

Ämneskategorier

Nanoteknik

Den kondenserade materiens fysik

DOI

10.1088/0022-3727/48/39/395308

Mer information

Skapat

2017-10-07