Characterization of Nb/Nb oxide structures in Josephson tunnel junctions

Journal Article · Sun May 01 04:00:00 EDT 1983 · IEEE Trans. Magn.; (United States)

DOI:https://doi.org/10.1109/TMAG.1983.1062281· OSTI ID:5483111

Raider, S; Drake, R; Johnson, R; Kuan, T; Pollak, R

The subgap conductance of Nb/Nb oxide/Pb-alloy Josephson tunnel junctions was found to strongly depend on the rf plasma processing used to form the Nb oxide tunnel barrier. The authors have therefore studied the Nb/Nb oxide structures after rf plasma processing using x-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) data. A crystalline Nb-C-O layer was formed as a transition region between the polycrystalline Nb base electrode and the Nb/sub 2/O/sub 5/ tunnel barrier. The thickness of this transition region is sensitive to the rf plasma cleaning conditions prior to the tunnel barrier formation. An unexpected relation between junction electrical properties and the Nb/Nb oxide structure exists. The lowest subgap conductances are those obtained for tunnel junctions with transition regions about 30A thick. An abrupt interface between Nb and Nb/sub 2/O/sub 5/ leads to junctions with high subgap conductances.

• Research Organization: IBM, Thomas J. Watson Research Center, Yorktown Heights, NY 10598
• OSTI ID: 5483111
• Journal Information: IEEE Trans. Magn.; (United States), Journal Name: IEEE Trans. Magn.; (United States) Vol. 19:3; ISSN IEMGA
• Country of Publication: United States
• Language: English

Related Subjects

420201* -- Engineering-- Cryogenic Equipment & Devices
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALLOYS
CARBON
CHALCOGENIDES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTROMAGNETIC RADIATION
ELECTRON MICROSCOPY
ELECTRON SPECTROSCOPY
ELEMENTS
IONIZING RADIATIONS
JOSEPHSON JUNCTIONS
JUNCTIONS
LEAD ALLOYS
METALS
MICROSCOPY
NIOBIUM
NIOBIUM COMPOUNDS
NIOBIUM OXIDES
NONMETALS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
PHYSICAL PROPERTIES
PLASMA
RADIATIONS
SPECTROSCOPY
SUPERCONDUCTING JUNCTIONS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
TRANSMISSION ELECTRON MICROSCOPY
TUNNELS
UNDERGROUND FACILITIES
X RADIATION