We studied the growth and oxidation of niobium nitride (NbN) films that we used to fabricate superconductive tunnel junctions. The thin films were deposited by dc reactive magnetron sputtering using a mixture of argon and nitrogen. The process parameters were optimized by monitoring the plasma with an optical spectroscopy technique. This technique allowed us to obtain NbN as well as good quality AlN films and both were used to obtain NbN/AlN/NbN trilayers. Lift-off lithography and selective anodization of the NbN films were used, respectively, to define the main trilayer geometry and/or to separate electrically, different areas of the trilayers. The anodized films were characterized by using Auger spectroscopy to analyze compounds formed on the surface and by means of a nano-indenter in order to investigate its mechanical and adhesion properties. The transport properties of NbN/AlN/NbN Josephson junctions obtained as a result of the above described fabrication process were measured in liquid helium at 4.2 K.

Lucci, M., Ottaviani, I., Cirillo, M., DE MATTEIS, F., Francini, R., Merlo, V., et al. (2017). Anodization-based process for the fabrication of all niobium nitride Josephson junction structures. BEILSTEIN JOURNAL OF NANOTECHNOLOGY [10.3762/bjnano.8.58].

Anodization-based process for the fabrication of all niobium nitride Josephson junction structures

LUCCI, MASSIMILIANO;OTTAVIANI, IVANO;CIRILLO, MATTEO;DE MATTEIS, FABIO;FRANCINI, ROBERTO;MERLO, VITTORIO;DAVOLI, IVAN
2017

Abstract

We studied the growth and oxidation of niobium nitride (NbN) films that we used to fabricate superconductive tunnel junctions. The thin films were deposited by dc reactive magnetron sputtering using a mixture of argon and nitrogen. The process parameters were optimized by monitoring the plasma with an optical spectroscopy technique. This technique allowed us to obtain NbN as well as good quality AlN films and both were used to obtain NbN/AlN/NbN trilayers. Lift-off lithography and selective anodization of the NbN films were used, respectively, to define the main trilayer geometry and/or to separate electrically, different areas of the trilayers. The anodized films were characterized by using Auger spectroscopy to analyze compounds formed on the surface and by means of a nano-indenter in order to investigate its mechanical and adhesion properties. The transport properties of NbN/AlN/NbN Josephson junctions obtained as a result of the above described fabrication process were measured in liquid helium at 4.2 K.
Pubblicato
Rilevanza internazionale
Articolo
Esperti anonimi
Settore FIS/03 - Fisica della Materia
English
Con Impact Factor ISI
Josephson effect; superconductors; thin films; tunneling
Lucci, M., Ottaviani, I., Cirillo, M., DE MATTEIS, F., Francini, R., Merlo, V., et al. (2017). Anodization-based process for the fabrication of all niobium nitride Josephson junction structures. BEILSTEIN JOURNAL OF NANOTECHNOLOGY [10.3762/bjnano.8.58].
Lucci, M; Ottaviani, I; Cirillo, M; DE MATTEIS, F; Francini, R; Merlo, V; Davoli, I
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2108/173515
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