Optimizing the growth conditions of Al mirrors for superconducting nanowire single-photon detectors

We investigate the growth conditions for thin ( ${\leqslant}200$ nm) sputtered aluminum films. These coatings are needed for various applications, e.g. for advanced manufacturing processes in the aerospace industry or for nanostructures for quantum devices. Obtaining high-quality films, with low rou...

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Bibliographic Details
Main Authors: Rasmus Flaschmann, Christian Schmid, Lucio Zugliani, Stefan Strohauer, Fabian Wietschorke, Stefanie Grotowski, Björn Jonas, Manuel Müller, Matthias Althammer, Rudolf Gross, Jonathan J Finley, Kai Müller
Format: Article
Language:English
Published: IOP Publishing 2023-01-01
Series:Materials for Quantum Technology
Subjects:
Online Access:https://doi.org/10.1088/2633-4356/ace490
Description
Summary:We investigate the growth conditions for thin ( ${\leqslant}200$ nm) sputtered aluminum films. These coatings are needed for various applications, e.g. for advanced manufacturing processes in the aerospace industry or for nanostructures for quantum devices. Obtaining high-quality films, with low roughness, requires precise optimization of the deposition process. To this end, we tune various sputtering parameters such as the deposition rate, temperature and power, which enables 50 nm thin films with a root mean square roughness of less than 1 nm and high reflectivity. Finally, we confirm the high-quality of the deposited films by realizing superconducting single-photon detectors integrated into multi-layer heterostructures consisting of an aluminum mirror and a silicon dioxide dielectric spacer. We achieve an improvement in detection efficiency at 780 nm from 40% to 70% by this integration approach.
ISSN:2633-4356