Oxygen atomic flux O* enhancement by gas-pulsed electron cyclotron resonance plasma

We have investigated an oxygen gas-pulsed plasma in conjunction with the enhancement of atomic oxygen radical O* flux and its application. The measured mean O* flux of 5.9×1015 atoms/cm2 s from the gas-pulsed plasma with a duty cycle of 50% (periodically opened for 0.3 s and closed for 0.3 s) at 32 sccm is 1.6 times enhanced compared to that of a continuous wave plasma and is in good agreement with the increment obtained with the time averaged value of transient optical emission profiles of O* at 777.6 nm. The generation of a higher O* flux was interpreted by the mitigation of a recombinative reaction process through the interruption of gas flow injections in the gas pulsed plasma. As a preliminary application, an increase in critical temperature of superconducting YBa2Cu3O7−x thin films was achieved by the gas-pulsed plasma oxidation with a duty cycle of 50%.