Stacked Niobium-MoSi2-Niobium Josephson Junctions for AC Voltage Standards
Paul Dresselhaus, Yonuk Chong, Samuel Benz
Superconductor-normal metal-superconductor (SNS) Josephson junctions have proven to be a critical technology for voltage standards. NIST has used SNS junctions for both programmable DC and AC voltage standards. Previous devices have primarily used PdAu as a normal metal barrier material. In this paper we present results of circuits having MoSi2 barriers. The main advantages of MoSi2 are that it can be etched in a low energy plasma, which enables the fabrication of vertically stacked junctions, and the reproducibility of its barriers produces consistent electrical properties. Stacking enables the junctions to be packed more densely, thus increasing design flexibility and margins for the microwave circuits. In this work, results are presented from two and three junction stacks for application to ac Josephson voltage standards.
, Chong, Y.
and Benz, S.
Stacked Niobium-MoSi<sub>2</sub>-Niobium Josephson Junctions for AC Voltage Standards, IEEE Transactions on Applied Superconductivity, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=31824
(Accessed December 3, 2023)