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.
specific capacitance
Nb/Al-AlN/Nb SIS junctions
SIS junctions thermal stability
AlN tunnel barrier
superconducting circuits
millimeter/submillimeter mixers
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
Fujitsu Ltd
National Astronomical Observatory of Japan
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