Internal energy distribution change of sputtered Al atom under several hundreds of eV oxygen ion-beam bombardment by resonant laser ionization sputtered neutral mass spectroscopy

It is important to evaluate the internal energy of the sputtered neutral particles to optimize their resonant ionization efficiency. In this study, the internal energy of the sputtered Al atom, especially the ground state $P1∕22$ and the lowest-lying excited state $P3∕22$ $(112cm−1)$⁠, was monitored by using resonant laser postionization sputtered neutral mass spectrometry. The results of the authors showed the density of the ground state of the sputtered Al atom drastically decreased due to surface oxidation, as well as the enhancement of the secondary $Al+$ yield.