Properties of NbN thin films deposited on ambient temperature substrates

Journal Article · Tue Nov 01 04:00:00 EST 1983 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.331881· OSTI ID:5598406

Bacon, D D; English, A T; Nakahara, S; Peters, F G; Schreiber, H; Sinclair, W R; van Dover, R B

The preparation of cubic NbN films by reactive dc magnetron sputtering is described. These superconductive films are deposited at a sufficiently low temperature (<90 /sup 0/C) that photoresist liftoff techniques and can be used in fabricating Josephson junctions. The superconducting transition temperature has been measured as a function of gas composition and pressure. It reaches a maximum of 14.2 K at 15% N/sub 2/--85% Ar and 1.06 Pa total pressure. The resistivity ratio of these films is close to unity. Structural studies by transmission electron microscopy and electron diffraction show that films 100-nm thick or less are randomly oriented, and noncolumnar with a crystallite diameter of 5 nm and a lattice parameter of 4.46 A, which is significantly higher than the bulk value for cubic NbN. The films are dense with void diameters no larger than 0.7 nm. Films 300-400 nm thick show a small degree of texturing in x-ray studies with a Read camera. Auger analysis shows a monotonic increase in the N/Nb ratio with increase in the N/sub 2//Ar ratio in the sputtering ambient up to 30% N/sub 2/. From 30% to 50% N/sub 2/ in the sputtering mixture the N/Nb ratio is constant. Small amounts of carbon impurity are found in all films.

• Research Organization: Bell Laboratories, Murray Hill, New Jersey 07974
• OSTI ID: 5598406
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 54:11; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
&amp; Refractories-- Preparation &amp; Fabrication
360202 -- Ceramics
Cermets
&amp; Refractories-- Structure &amp; Phase Studies
360204 -- Ceramics
Cermets
&amp; Refractories-- Physical Properties
656102 -- Solid State Physics-- Superconductivity-- Acoustic
Electronic
Magnetic
Optical
&amp; Thermal Phenomena-- (-1987)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
AUGER ELECTRON SPECTROSCOPY
COHERENT SCATTERING
CRYSTAL STRUCTURE
DIFFRACTION
DIMENSIONS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRON DIFFRACTION
ELECTRON MICROSCOPY
ELECTRON SPECTROSCOPY
ELEMENTS
FABRICATION
FILMS
JOSEPHSON JUNCTIONS
JUNCTIONS
LATTICE PARAMETERS
LOW TEMPERATURE
MEDIUM VACUUM
MICROSCOPY
NIOBIUM COMPOUNDS
NIOBIUM NITRIDES
NITRIDES
NITROGEN
NITROGEN COMPOUNDS
NONMETALS
PHYSICAL PROPERTIES
PNICTIDES
SCATTERING
SPECTROSCOPY
SPUTTERING
SUPERCONDUCTING FILMS
SUPERCONDUCTING JUNCTIONS
SYNTHESIS
THERMODYNAMIC PROPERTIES
THICKNESS
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
TRANSMISSION ELECTRON MICROSCOPY
VERY LOW TEMPERATURE