Investigation of high rate magnetron sputtering of niobium films for Josephson integrated circuits

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

DOI:https://doi.org/10.1109/TMAG.1983.1062556· OSTI ID:5718467

Villegier, J; Veler, J

High rate Dc-magnetron sputtering of 30 nm niobium thin films is shown to be a very good technique to achieve reproducible and stable ground plane, tunnel junctions electrodes, control lines and even resistors for Josepson Integrated Circuits. Pure niobium films have low residual resistivity (p /SUB 10K/ approx. = 2/sigma phi/..cap omega..cm), low stresses, and are no longer in the ''dirty limit''. High quality ratio (R /SUB J/ /R /SUB N/ approx. = 20 at 4 K). Josephson Junctions were performed with niobium base electrode. Critical temperatures either below 4.2K used for resistors or between 4.2K and 16K can be controlled accurately by reactive magnetron sputtering in an argon-nitrogen plasma. Homogeneous low critical temperature can be also selectively obtained by liquid cathodization or by RF plasma post-treatments on a pure niobium film through a photoresist mask. Nb, Nb(N), Nb(O) and Nb (H) films are studied by TEM and X ray diffraction. The critical temperature change obtained can be explained by lattice BCC structure dilatation or distorsion and by impurities inclusion.

• Research Organization: LETI, Comissariat a L'energie Atomique, 85X - 38041 Grenoble
• OSTI ID: 5718467
• 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
CRITICAL TEMPERATURE
CRYSTAL LATTICES
CRYSTAL STRUCTURE
ELECTRON TUBES
ELECTRONIC CIRCUITS
ELECTRONIC EQUIPMENT
ELEMENTS
EQUIPMENT
FABRICATION
FILMS
INTEGRATED CIRCUITS
JOSEPHSON JUNCTIONS
JUNCTIONS
MAGNETRONS
METALS
MICROELECTRONIC CIRCUITS
MICROWAVE EQUIPMENT
MICROWAVE TUBES
NIOBIUM
PHYSICAL PROPERTIES
SPUTTERING
SUPERCONDUCTING JUNCTIONS
THERMODYNAMIC PROPERTIES
THIN FILMS
TRANSITION ELEMENTS
TRANSITION TEMPERATURE