Secondary-ion emission from GaN(0001) and dodecanethiol/Au(111) surfaces irradiated with Arq+ (q = 4-8)

Abstract

Secondary-ion mass spectroscopic (SIMS) studies have been performed to investigate desorption or sputtering processes of various solid surfaces interacting with highly charged ions (HCIs). We have recently developed an HCI-SIMS apparatus capable of detecting secondary ions, secondary electrons and scattered atoms/ions simultaneously. This apparatus allows us to analyze solid surfaces in four different operation modes: 1) low-energy ion scattering spectroscopy (LEIS), 2) SIMS in coincidence with LEIS, 3) SIMS triggered by scattered neutral atoms and 4) SIMS triggered by secondary electrons. The coincidence experiments with two different operation modes 2) and 4) were conducted with a GaN(0001) and a dodecanethiol/Au(111) self-assembled monolayer surface, respectively, in collisions with Arq+ (q = 4-8) (2.5×q keV). It was successful to measure two different SIMS spectra which were taken by triggering with the scattered Ar+ ions and the secondary electrons in Ar6+ collisions.