Nb/Al-AlN/Nb SIS junctions grown with substrate bias during plasma nitridation of the tunnel barrier

Paper in proceeding, 2025

We investigate the influence of substrate bias on the plasma nitridation process to form tunnel barriers in superconducting tunnel junctions, especially focusing on the bias effects on the barrier transparency. In addition, we assess the role of substrate bias in the nitridation process in the enhancement of the reproducibility of AlN-SIS fabrication process. We find that this parameter is critical to optimize the fabrication of high-performance tunnel-junctions for superconducting mixer technology.