SNS Josephson junctions with tunable Ta-N barriers

We report on the fabrication and characterization of Nb/Ta-N/Nb Josephson junctions grown by room temperature magnetron sputtering on 150-mm diameter Si wafers. Junction characteristics depend upon the Ta-N barrier composition, which was varied by adjusting the N2 flow during film deposition. Higher N 2 flow rates raise the barrier resistance and increase the junction critical current. This work demonstrates the viability of Ta-N as an alternative barrier to aluminum oxide, with the potential for large scale integration.