General Postionization of Sputtered and Desorbed Species by Intense Untuned Radiation

Abstract

Since HONIG [1] first used electron bombardment ionization to examine the neutral material sputtered from a sample, there has been a general realization that detection of sputtered neutrals could and should be performed. Although the convenience of detecting sputtered or desorbed secondary ions led to a much more intense development of secondary ion detection techniques, the motivation for examining the neutrals is more than just the fundamental interest in the emission process and its ion-to-neutral branching ratios. A prime practical motivation is the difficulty in quantifying the secondary ion yields in SIMS and laser desorption mass spectrometry. Since the neutrals are generally the major component of the sputtered or desorbed material, their intensities are much less dependent on matrix effects that can vary the ionization fraction over a wide range.