Title :
Improved on-axis DC magnetron sputtering for large-area deposition of YBa/sub 2/Cu/sub 3/O/sub 7/-films
Author :
Kruger, U. ; Kutzner, R. ; Wordenweber, R.
Author_Institution :
Inst. fur Schicht- & Ionentech., Forschungszentrum Julich, Germany
fDate :
3/1/1993 12:00:00 AM
Abstract :
A method of stabilizing the plasma during high-pressure DC sputter-deposition of YBa/sub 2/Cu/sub 3/O/sub 7/ is introduced. The plasma is monitored by optical emission spectroscopy and Langmuir probes. Strong changes of the plasma intensity and intensity profile above the target, which lead to unstable and inhomogeneous deposition of high-T/sub c/ material, can be observed. These changes are counteracted by an adequate variation of the process gas composition (Ar-O/sub 2/ mixture) at the target. The intensity of the plasma flicker is thus reduced by a factor of 4-5, and long-term drifts in the plasma intensity are eliminated. By this method a stable, reproducible and uniform deposition of epitaxial, c-axis-oriented YBa/sub 2/Cu/sub 3/O/sub 7/-films with extremely smooth surfaces over a 2-in wafer area was achieved.<>
Keywords :
barium compounds; high-temperature superconductors; sputter deposition; superconducting epitaxial layers; transmission electron microscope examination of materials; vapour phase epitaxial growth; yttrium compounds; 2 inch; Ar-O/sub 2/ mixture; Langmuir probes; TEM; YBa/sub 2/Cu/sub 3/O/sub 7/ epitaxial film; high temperature superconductor; high-pressure DC sputter-deposition; intensity profile; large-area deposition; on-axis DC magnetron sputtering; optical emission spectroscopy; plasma flicker; plasma intensity; process gas composition; wafer area; Optical films; Plasma materials processing; Plasma stability; Plasma waves; Probes; Semiconductor films; Sputtering; Stimulated emission; Substrates; Superconducting films;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
