INSITU PREPARATION OF SUPERCONDUCTING Y1BA2CU3O7-DELTA THIN-FILMS BY ON-AXIS RF MAGNETRON SPUTTERING FROM A STOICHIOMETRIC TARGET

Superconducting Y1Ba2Cu3O7-delta thin films have been fabricated in situ by on-axis rf reactive magnetron sputtering from a single stoichiometric 1-2-3 target. By using high total sputtering pressures (> 400 mTorr) and low oxygen pressures (less-than-or-equal-to 10 mTorr), negative ion resputtering is almost eliminated and high quality oriented films on (100) MgO are realized with excellent reproducibility. Such films display zero resistance T(c)'s as high as 88 K with transition widths DELTA-T(c) (90%-10%) of about 2 K, residual resistivity ratios R(300 K)/R(100 K) of 2.5, and critical current densities greater than 10(6) A/cm2 at 14 K.