A radio-frequency nonequilibrium atmospheric pressure plasma operating with argon and oxygen

A capacitively coupled, atmospheric pressure plasma has been developed that produces a high concentration of reactive species at a gas temperature below 300 ° C . The concentration of ground-state oxygen atoms produced by the discharge was measured by NO titration, and found to equal 1.2 vol % , or 1.2 ± 0.4 × 10 17 cm − 3 , using 6.0 vol % O 2 in argon at 150 W ∕ cm 3 . The ozone concentration determined at the same conditions was 4.3 ± 0.5 × 10 14 cm − 3 . A model of the gas phase reactions was developed and yielded O atom and O 3 concentrations in agreement with experiment. This plasma source etched Kapton® at 5.0 μ m ∕ s at 280 ° C and an electrode-to-sample spacing of 1.5 cm . This fast etch rate is attributed to the high O atom flux generated by the plasma source.