A1 Journal article (refereed)
Normal Metal-Insulator-Superconductor Tunnel Junctions with Pulsed Laser Deposited Titanium Nitride as Superconductor (2021)
Torgovkin, A., Ruhtinas, A., & Maasilta, I. (2021). Normal Metal-Insulator-Superconductor Tunnel Junctions with Pulsed Laser Deposited Titanium Nitride as Superconductor. IEEE Transactions on Applied Superconductivity, 31(5), Article 1100604. https://doi.org/10.1109/TASC.2021.3058594
JYU authors or editors
Publication details
All authors or editors: Torgovkin, Andrii; Ruhtinas, Aki; Maasilta, Ilari
Journal or series: IEEE Transactions on Applied Superconductivity
ISSN: 1051-8223
eISSN: 2378-7074
Publication year: 2021
Volume: 31
Issue number: 5
Article number: 1100604
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Publication country: United States
Publication language: English
DOI: https://doi.org/10.1109/TASC.2021.3058594
Publication open access: Not open
Publication channel open access:
Abstract
Here we report the fabrication of normal metal - insulator - superconductor (NIS) tunnel junctions using superconducting titanium nitride grown by pulsed laser deposition (PLD). The films for NIS junction fabrication were deposited on two different substrates: silicon nitride film and magnesium oxide. TiN films were characterized by means of electrical transport measurements, and films with superconducting transition temperatures above the liquid helium boiling point were chosen for fabrication of NIS junctions. Tunnel junction devices were successfully fabricated using electron beam lithography and shadow evaporation techniques. The insulator layer formation was performed using two different approaches: the tunnel barrier was either formed by direct oxidation of TiN, or by fabrication of an additional aluminum oxide layer. Devices fabricated by direct oxidation showed much more transparent barriers and slightly higher subgap currents, but both types of devices could be used for thermometry. Further optimization of the direct oxidation process may allow electric cooling applications in the future.
Keywords: superconductors; superconductivity; titanium; thin films
Contributing organizations
Related projects
- Coherent and Incoherent Heat Transport with Nanophononics
- Maasilta, Ilari
- Research Council of Finland
Ministry reporting: Yes
Reporting Year: 2021
JUFO rating: 1