Oxidized treatment of high Tc superconducting thin films by plasma-ion doping technique

Gd-Ba-Cu-O superconducting thin films were oxidized by an ion doping technique using a microwave electron-cyclotron-resonance (ECR) plasma with AC(20kHz) substrate bias at a substrate temperature of 330 degree C. Under conditions with the lowest emission intensity ratio of molecular oxygen ions(O2+) to oxygen atoms(O) observed by optical emission from O2 plasma, superconducting films did not exhibit superconductivity after treatment. X-ray diffraction indicated that bonded oxygen atoms were removed from the films by oxygen radical. Under conditions with high O2+/O ratio, the superconducting thin films were not remarkably changed. The effect of oxygen ion doping could be observed