Investigating the relation between the secondary yield enhancement and the structure of the metallic overlayer in Metal-Assisted SIMS

Pristine and Au-covered molecular films have been analyzed by ToF-SIMS for different amounts of evaporated gold. In contrast to other MetA-SIMS studies, the metallization of the high-mass polymers (polycarbonate and polystyrene) was carried out in situ. The evaporation flux was monitored with a quartz-crystal microbalance, and the exact quantity of deposited gold was determined by XPS. It was found that the sticking coefficient of gold on these polymers is less than one. The evolution of the secondary ion yield using Argon ion bombardment is studied as a function of the total amount of deposited metal. Furthermore, the SIMS results are accompanied by a detailed characterization of the sample surfaces morphology, in order to check any possible relation between the structure of the deposited metallic film and the yield enhancement of S-SIMS signals.