Title :
Improvement of average film quality in RBa2Cu3O7-x sputtered films
Author :
Simon, R.W. ; Platt, C.E. ; Daly, K.P. ; Lee, A.E. ; Wagner, M.K.
Author_Institution :
TRW Space & Technol. Group, Redondo Beach, CA, USA
fDate :
3/1/1989 12:00:00 AM
Abstract :
Thin films of RBa2Cu3O7-x (R includes Y, Er, and Nd) have been deposited by four-gun DC magnetron sputtering from metallic targets in a Xe-O2 gas mixture and postannealed in flowing O2. Extensive optimization of the film deposition process has been achieved for erbium-based films which can be produced with good characteristics on a variety of substrates. Fine-grained polycrystalline films with sharp resistive transitions are produced on single-crystal and polycrystalline YSZ, MgO, ZrO2-buffered sapphire, and silver-buffered sapphire. Broader transitions are observed on buffered silicon wafers. These erbium films often show grain sizes as small as 20-30 nm and, with the addition of an RF oxygen glow discharge in the deposition system, are quite smooth despite furnace postannealing. Highly-oriented 1-2-3 film growth is observed on SrTiO3 and LaAlO3 single-crystal substrates. Four-point resistivity measurements show transitions as narrow as 1 K, while magnetization and RF frequency-shift measurements show more detail about film quality. Films are characterized by XRD, SNMS, Auger, XPS, and cross-sectional EDX profiling. The authors also report on the use of in-situ deposition of silver as a passivation layer for the 1-2-3 surface
Keywords :
Auger effect; X-ray chemical analysis; X-ray diffraction examination of materials; X-ray photoelectron spectra; annealing; barium compounds; grain size; high-temperature superconductors; magnetisation; rare earth compounds; sputter deposition; superconducting thin films; superconducting transition temperature; Ag-buffered sapphire; Auger studies; ErBa2Cu3O7-x; MgO; NdBa2Cu3O7-x; RBa2Cu3O7-x sputtered films; RF frequency-shift; SNMS; XPS; XRD; Xe-O2 gas mixture; YBa2Cu3O7-x; ZrO2-buffered sapphire; average film quality; cross-sectional EDX profiling; film deposition process; fine/grained films; four point resistivity; four-gun DC magnetron sputtering; glow discharge; grain sizes; high temperature superconductors; magnetization; oriented film growth; passivation layer; polycrystalline YSZ; polycrystalline films; post-annealing; sharp resistive transitions; Conductivity measurement; Erbium; Furnaces; Glow discharges; Grain size; Neodymium; Radio frequency; Silicon; Sputtering; Substrates;
Journal_Title :
Magnetics, IEEE Transactions on
