Ion-beam deposition of Nb and Ta refractory superconducting films

Journal Article · Fri Apr 01 04:00:00 EST 1983 · J. Vac. Sci. Technol., A; (United States)

DOI:https://doi.org/10.1116/1.572125· OSTI ID:5767908

Face, D W; Ruggiero, S T; Prober, D E

A Kaufman ion-beam source has been used to sputter deposit high quality superconducting Nb (T/sub c/ = 9.1 K) and Ta (T/sub c/ = 4.3 K) films. Superconducting and electrical properties were studied as a function of deposition conditions and an optimum set of conditions was found. Nb films always had the bulk bcc crystal structure. The Nb film deposition rates ranged from 1 to 5 A/s with a Xe or Ar sputtering gas pressure of approx.1 to 4 x 10-4 Torr and a beam current density of 5--20 mA/cm/sup 2/. Values of T/sub c/ above 8.3 K for Nb films were obtained with the use of Xe rather than Ar gas. In the case of Ta films, the deposition of a thin (> or =3 A) Nb underlayer was required for the nucleation and growth of Ta in the bulk bcc crystal structure. Ta films deposited without a Nb underlayer always had high resistivity, approx.150 ..mu cap omega.. cm, and a tetragonal ..beta..-Ta crystal structure. The Nb and Ta targets and Si substrates all remained below 70 /sup 0/C during deposition and the films were easily patterned by standard photoresist liftoff.

• Research Organization: Section of Applied Physics, Yale University, New Haven, Connecticut 06520
• OSTI ID: 5767908
• Journal Information: J. Vac. Sci. Technol., A; (United States), Journal Name: J. Vac. Sci. Technol., A; (United States) Vol. 1:2; ISSN JVTAD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101 -- Metals & Alloys-- Preparation & Fabrication
360102 -- Metals & Alloys-- Structure & Phase Studies
360104 -- Metals & Alloys-- Physical Properties
420201* -- Engineering-- Cryogenic Equipment & Devices
656102 -- Solid State Physics-- Superconductivity-- Acoustic
Electronic
Magnetic
Optical
& Thermal Phenomena-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ARGON
BCC LATTICES
COATINGS
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CUBIC LATTICES
DEPOSITION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELEMENTS
FILMS
FLUIDS
GASES
LOW TEMPERATURE
MASKING
MEDIUM VACUUM
METALS
NIOBIUM
NONMETALS
NUCLEATION
OPTIMIZATION
PHYSICAL PROPERTIES
RARE GASES
SEMIMETALS
SILICON
SPUTTERING
SUPERCONDUCTING FILMS
SUPERCONDUCTIVITY
SURFACE COATING
TANTALUM
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENTS
TRANSITION TEMPERATURE
ULTRALOW TEMPERATURE
VERY LOW TEMPERATURE
XENON