Laser-assisted atom probe tomography of 18O-enriched oxide thin film for quantitative analysis of oxygen

18O-enriched SiO2 thin film with the 16O:18O ratio of around 1:1 has been analyzed by laser-assisted atom probe tomography (LA-APT) using 343 nm-wavelength ultraviolet laser or 532 nm-wavelength green laser in order to investigate the quantitativeness of the oxygen concentration determined by LA-APT. No clear evidence for detecting 16O18O++ signals was found in mass spectra, implying that the peaks at mass/charge of 16 and 18 are dominated by O+, not by O2++. The calculated elemental composition indicated significant loss of oxygen in LA-APT analysis of SiO2.