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

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.
Authors:
; ; ; ;  [1] ; ; ;  [1] ;  [2] ;  [3]
  1. Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
  2. (United States)
  3. Fen Edebiyat Fakultesi, Fizik Bolumu, Inonu Universitesi, 44280 Malatya (Turkey)
Publication Date:
OSTI Identifier:
22283055
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 9; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
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