Etching of uranium oxide with a non-thermal, atmospheric pressure plasma

The etching of uranium oxide films was investigated with a non-thermal, atmospheric pressure plasma fed with a mixture of 2.0 kPa carbon tetrafluoride, 880.0 Pa oxygen and 97.2 kPa helium. Etching rates of up to 4.0 μm/min were recorded at a 200 °C sample temperature. X-ray photoemission spectroscopy revealed that the etched surface was highly fluorinated, containing UOF4 species during the etching process. An average surface reaction rate was estimated to be 1.9 × 1019 UF6 molecules/m2 s.