Determination of chemical composition in multilayer polymer film using ToF-SIMS

摘要

Time-of-flight secondary ion mass spectrometry is a widely used surface analytical technique, which can provide chemical information from both the uppermost surface and underneath the surface for various materials. For identification of the structure of a multilayer polymer film with unknown chemical composition, it is generally not practical to perform depth profiling using atomic ion sputtering because it will destroy the chemical information and it is difficult to obtain accurate chemical depth distributions. In this study, we present an alternative approach to microtome the polymer film to reveal the multilayer cross-section followed by imaging the cross-section with bismuth liquid metal ion gun (LMIG). To identify the spatial distribution of the thin inorganic layer in the multilayer film, bismuth sputtering was employed on the same analysis area to remove organic mass interference. Overlaid images from two separate analyses allow us to determine both inorganic and organic layers chemically and laterally with high lateral resolution.