Metal-assisted SIMS with hypervelocity gold cluster projectiles

The feasibility of metal-assisted secondary ion mass spectrometry (MetA-SIMS) for increasing secondary ion yields from massive gold projectile impacts is investigated using polymeric and plastic additive test molecules. Poly(methyl methacrylate) (PMMA) and Irganox 1010 surfaces were deposited with various amounts of gold and silver and then analyzed using both Bi+ and Au-400(4+). The Bi+ primary ion displays a fivefold ion yield increase for some species while the massive gold cluster exhibits significant suppression due to the metal overlayer, with more than a tenfold decrease in ion yields for most species. Consequently, MetA-SIMS does not lead to enhanced secondary ion yields when using the Au-400(4+) projectile. Overall, the Au-400(4+) projectile leads to secondary ion yields that are similar to 2 orders of magnitude larger than for Bi+, even when MetA-SIMS is employed. (C) 2013 Elsevier B.V. All rights reserved.