Fabrication and characterization of Nb/Al-AlN/Nb superconducting tunnel junctions
Artikel i vetenskaplig tidskrift, 2026
We report a Nb/Al-AlN/Nb superconducting tunnel junction process in which the AlN barrier is formed by plasma nitridation using a compact microwave electron cyclotron resonance (ECR) nitrogen plasma source integrated into a standard sputter cluster. This enables growth of uniform tunnel barriers across a broad range of specific resistances, with RnA down to similar or equal to 3 Omega mu m2. Junctions maintain excellent quality, exhibiting Rj/Rn >= 25 at the highest barrier transparencies. We characterize resistivity, specific capacitance, and the evolution of junction parameters under room temperature aging and thermal annealing. A consistent calibration of the junction specific capacitance Cs versus RnA is established and independently validated by the performance of demonstrator SIS mixers designed using the extracted Cs.
SIS junctions thermal stability
specific capacitance
AlN tunnel barrier
Nb/Al-AlN/Nb SIS junctions
millimeter/submillimeter mixers
superconducting circuits
Författare
Alexei Pavolotski
Chalmers, Rymd-, geo- och miljövetenskap, Onsala rymdobservatorium
François Joint
Chalmers, Rymd-, geo- och miljövetenskap, Onsala rymdobservatorium
Udupa Sujit Manjunatha
Indian Institute of Science
Victor Belitsky
Chalmers, Rymd-, geo- och miljövetenskap, Onsala rymdobservatorium
Denis Meledin
Chalmers, Rymd-, geo- och miljövetenskap, Onsala rymdobservatorium
Takafumi Kojima
National Astronomical Observatory of Japan
Fujitsu FTP Corporation
Sho Masui
National Astronomical Observatory of Japan
Ravishankar Narayanan
Indian Institute of Science
Vincent Desmaris
Chalmers, Rymd-, geo- och miljövetenskap, Onsala rymdobservatorium
Superconductor Science and Technology
0953-2048 (ISSN) 1361-6668 (eISSN)
Vol. 39 1 015005Ämneskategorier (SSIF 2025)
Nanoteknik
Fysik
DOI
10.1088/1361-6668/ae2f33