The Storing Matter technique: application to polymer samples using Ag collectors

Abstract

Abstract The Storing Matter technique has been developed to perform quantitative surface analysis with high sensitivity. This technique consists in decoupling the sputtering of the specimen from the subsequent analysis step. In the recently developed prototype instrument, the sample surface is sputtered by an ion beam and the emitted particles are deposited at submonolayer level on a dedicated collector under UHV conditions. In a second step, the matter deposited on the collector is analyzed by SIMS in dynamic or static mode. The chemical nature of the collector surface is chosen with regard to the subsequent SIMS analysis (high or low work function to enhance positive or negative ionization, metallic overlayer for optimized organic information by cationization, etc.) by depositing thin films by electron beam evaporation. This paper presents the first results obtained on polymer samples (PMMA, PVC and PS) with the Storing Matter prototype instrument. The chosen collector surface was Ag, which is known to enhance cationization in static SIMS. The positive mass spectra obtained from Storing Matter deposits on Ag collectors were compared to those recorded on polymer reference samples and on the pristine Ag collectors. This study showed that the Storing Matter technique allows for a clear identification of the PMMA and PVC deposits while enhancing the secondary ion intensities in the higher‐mass range with respect to a conventional static SIMS analysis of the polymer. Copyright © 2010 John Wiley & Sons, Ltd.