% IMPORTANT: The following is UTF-8 encoded. This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.
@INPROCEEDINGS{Faley:1047361,
author = {Faley, Michael and Arzeo, M. and Denneulin, Thibaud and
Kovacs, Andras and Ummethala, Govind and Tavabi, Amir
Hossein and Mukhanov, O. and Dunin-Borkowski, Rafal},
title = {{M}icrostructural analysis of corrosion inhibition in
sub-100nm-scale {J}osephson circuits},
reportid = {FZJ-2025-04255},
year = {2025},
abstract = {We have studied sub-100nm-scale nanobridge Josephson
junctions (nJJs) and nJJ-based circuits using
microstructural analysis and measurements of electron
transport properties to reveal the possible origins of a
spread in superconducting parameters (Tc, Ic, etc.) and
long-term stability. The structures were prepared by dc
magnetron sputtering from Nb, Ti and TiN targets, with
electron beam exposure of HSQ resist and reactive ion
etching in pure SF6 gas. Microstructural characterization
was performed using aberration-corrected scanning
transmission electron microscopy imaging and elemental
mapping using energy-dispersive X-ray spectroscopy (FEI
Titan G2 80-200 ChemiSTEM). The distributions of elements in
nanostructures based on Ti-Nb-Ti heterostructures and TiN
films were compared. Oxygen-free TiN nJJs, which have been
reported previously [1, 2] are of interest for the
realization of corrosion-resistant superconducting circuits,
including qubits with operating temperatures down to 10 mK.
Ti-Nb-Ti heterostructures, including nanoSQUIDs described in
a recent paper [3], contain oxygen that has been chemisorbed
by the Ti layers and are intended primarily for operation at
4.2 K. Superconducting through-silicon vias (TSVs) between
circuits on opposite sides of a wafer will also be realized
by using direct writing of superconducting current leads
with focused-ion-beam-induced deposition and sputter
deposition of superconducting films. Particular emphasis
will be paid to the inhibition of oxygenation and corrosion
on the nanometer scale by using new materials and methods,
which promise to bring superconducting chip manufacture
closer to circular economy objectives. Our work helps to
realize the large-scale integration of long-term-stable
superconducting circuits that include nanoSQUIDs, qubits and
classical superconducting digital circuits, such as Single
Flux Quantum (SFQ) based circuits and the Josephson digital
phase detector (JDPD) described in ref. [4].References1. M.
I. Faley, Y. Liu and R. E. Dunin-Borkowski, Nanomaterials
11, 466 (2021).2. M. I. Faley, H. Fiadziushkin, B. Frohn, P.
Schüffelgen and R. E. Dunin-Borkowski, Supercond. Sci.
Technol. 35, 065001 (2022).3. M. I. Faley, J. V. Vas, P.-H.
Lu and R. E. Dunin-Borkowski, IEEE Transactions on Appl.
Supercond. 35, 1600105 (2025).4. L. Di Palma, A. Miano, P.
Mastrovito, D. Massarotti, M. Arzeo, G. P. Pepe, F. Tafuri
and O. Mukhanov, Phys. Rev. Applied 19, 064025 (2023).},
month = {Sep},
date = {2025-09-21},
organization = {The 17th European Conference on
Applied Superconductivity, Porto
(Portugal), 21 Sep 2025 - 26 Sep 2025},
subtyp = {After Call},
cin = {ER-C-1},
cid = {I:(DE-Juel1)ER-C-1-20170209},
pnm = {5351 - Platform for Correlative, In Situ and Operando
Characterization (POF4-535) / ReMade-at-ARI - RECYCLABLE
MATERIALS DEVELOPMENT at ANALYTICAL RESEARCH INFRASTRUCTURES
(101058414)},
pid = {G:(DE-HGF)POF4-5351 / G:(EU-Grant)101058414},
typ = {PUB:(DE-HGF)6},
url = {https://juser.fz-juelich.de/record/1047361},
}