Preparation of NbN-AlN-NbN Josephson junctions by atomic layer deposition

Josephson junctions, as the cornerstone of superconducting quantum computing, are extensively studied across various material platforms. Among these, Al/AlOx/Al junctions are widely used due to their well-established fabrication techniques. However, these junctions are susceptible to two-level-system losses in the AlOx barrier and are limited by the low transition temperature of aluminum. In this work, we employ a novel trilayer thin film, NbN/AlN/NbN, grown by atomic layer deposition, to make junctions for applications at temperatures exceeding 1K. A flip-chip technique is utilized to simplify fabrication and minimize damage during processing. Preliminary current-voltage characteristics of junctions across multiple wafers will be presented in the talk.