Tunneling spectroscopy of superconducting MoN and NbTiN grown by atomic layer deposition

Journal Article · Mon Mar 03 00:00:00 EST 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4867880· OSTI ID:22283055

Klug, Jeffrey A.; Claus, Helmut; Pellin, Michael J.; Proslier, Thomas ^[1]; Cao, Chaoyue; Becker, Nicholas G.; Zasadzinski, John F. ^[1]; Altin, Serdar ^[2]

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1. Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
2. Fen Edebiyat Fakultesi, Fizik Bolumu, Inonu Universitesi, 44280 Malatya (Turkey)

A tunneling spectroscopy study is presented of superconducting MoN and Nb{sub 0.8}Ti{sub 0.2}N thin films grown by atomic layer deposition (ALD). The films exhibited a superconducting gap of 2 meV and 2.4 meV, respectively, with a corresponding critical temperature of 11.5 K and 13.4 K, among the highest reported T{sub c} values achieved by the ALD technique. Tunnel junctions were obtained using a mechanical contact method with a Au tip. While the native oxides of these films provided poor tunnel barriers, high quality tunnel junctions with low zero bias conductance (below ∼10%) were obtained using an artificial tunnel barrier of Al{sub 2}O{sub 3} on the film's surface grown ex situ by ALD. We find a large critical current density on the order of 4 × 10{sup 6} A/cm{sup 2} at T = 0.8T{sub c} for a 60 nm MoN film and demonstrate conformal coating capabilities of ALD onto high aspect ratio geometries. These results suggest that the ALD technique offers significant promise for thin film superconducting device applications.

• OSTI ID: 22283055
• Journal Information: Applied Physics Letters, Vol. 104, Issue 9; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALUMINIUM OXIDES
ASPECT RATIO
CRITICAL CURRENT
CRITICAL TEMPERATURE
MOLYBDENUM NITRIDES
NIOBIUM COMPOUNDS
SPECTROSCOPY
SUPERCONDUCTING DEVICES
SUPERCONDUCTING JUNCTIONS
SUPERCONDUCTIVITY
SUPERCONDUCTORS
THIN FILMS
TITANIUM NITRIDES
TUNNEL EFFECT