Structure of a Nb oxide tunnel barrier in a Josephson junction

Journal Article · Mon Nov 01 04:00:00 EST 1982 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.330118· OSTI ID:7081185

Kuan, T S; Raider, S I; Drake, R E

Oxides grown on the surface of a polycrystalline Nb thin film using rf plasma cleaning and plasma oxidation processes were examined by transmission electron microscopy. The oxides were prepared on the Nb surface using the same rf plasma processes developed for fabricating the tunnel barriers of Nb/Nb oxide/Pb alloy Josephson tunnel junctions. Transmission electron diffraction patterns obtained from the tunnel barrier formed on the Nb surface indicated the presence of a crystalline NbC/sub 0.25/O/sub 0.75/ layer between the amorphous Nb/sub 2/O/sub 5/ tunnel barrier layer and the Nb base electrode. The thickness of this transition layer was found to be sensitive to the rf plasma cleaning conditions prior to the tunnel barrier formation. The formation of this NbC/sub 0.25/O/sub 0.75/ layer of proper thickness is correlated to good junction quality. An epitaxial relationship between the NbC/sub 0.25/O/sub 0.75/ layer and the underlying Nb crystal was also observed.

• Research Organization: IBM Thomas J. Watson Research Center, Yorktown Heights, New York 10598
• OSTI ID: 7081185
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 53:11; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

420201* -- Engineering-- Cryogenic Equipment & Devices
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AMORPHOUS STATE
CHALCOGENIDES
CHEMICAL REACTIONS
CLEANING
COHERENT SCATTERING
CRYSTALS
DIFFRACTION
DIMENSIONS
ELECTRON DIFFRACTION
ELECTRON MICROSCOPY
EPITAXY
FILMS
JOSEPHSON JUNCTIONS
JUNCTIONS
MICROSCOPY
NIOBIUM COMPOUNDS
NIOBIUM OXIDES
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PLASMA
POLYCRYSTALS
POTENTIALS
SCATTERING
SUPERCONDUCTING JUNCTIONS
THICKNESS
TRANSITION ELEMENT COMPOUNDS
TRANSMISSION ELECTRON MICROSCOPY
TUNNEL EFFECT