A self-aligned nano-fabrication process for vertical NbN–MgO–NbN Josephson junctions. (22nd August 2017)

• Record Type: Journal Article
• Authors: Grimm, A; Jebari, S; Hazra, D; Blanchet, F; Gustavo, F; Thomassin, J-L; Hofheinz, M
• Is Part Of: Superconductor science & technology. Volume 30:Number 10(2017:Oct.)
• Publication Date: 2017-08-22
• Subjects: superconducting circuits -- nanofabrication -- niobium nitride -- Josephson junction; Superconductivity -- Periodicals; Superconductors -- Periodicals; 537.623
• DOI: 10.1088/1361-6668/aa8007
• Languages: English
• ISSNs: 0953-2048

Abstract

Abstract: We present a new process for fabricating vertical NbN–MgO–NbN Josephson junctions using self-aligned silicon nitride spacers. It allows for a wide range of junction areas from 0.02 to several 100 μ m 2 . At the same time, it is suited for the implementation of complex microwave circuits with transmission line impedances ranging from < 1 Ω to > 1 k Ω . The constituent thin films and the finished junctions are characterized. The latter are shown to have high gap voltages ( > 4 mV ) and low sub-gap leakage currents.