Etching characteristics of aluminum oxide and Inconel 600 Ni-based alloy by energetic fluorine and chlorine ion beams

Etching yields of sputter-deposited aluminum oxide (Al2O3) by mono-energetic fluorine (F+), chlorine (Cl+), and argon (Ar+) ion beams were evaluated as functions of the ion incident energy in an energy range of up to 2,000 eV. The results showed that the etching yields of Al2O3 by Cl+ and Ar+ ions are higher than those by F+ ions over the energy range examined in this study. Ex situ X-ray photoelectron spectroscopy confirmed the formation of some aluminum fluoride (AlF3) on the Al2O3 surface exposed to energetic F+ ion beams. The etching yields of Inconel 600 alloy by F+, Cl+, and Ar+ ion beams were also evaluated similarly and found to be much higher than those of Al2O3 under the corresponding conditions examined in this study. The results suggest that Al2O3 is likely more corrosion-resistant than Inconel against F or Cl-based chemically reactive plasmas.