In situ preparation of superconducting Y1Ba2Cu3O7−δ thin films by on-axis rf magnetron sputtering from a stoichiometric target

Superconducting Y1Ba2Cu3O7−δ 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 (≤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 Tc’s as high as 88 K with transition widths ΔTc (90%–10%) of about 2 K, residual resistivity ratios R(300 K)/R(100 K) of 2.5, and critical current densities greater than 106 A/cm2 at 14 K.