Ultra-low-angle microtomy to back up S-SIMS molecular depth profiling with C60+ and Bin+ for the nanoscale analysis of high-tech industrial materials

• Published in: Surface and interface analysis 2011-01, Vol.43 (1-2), p.389-392
• Main Authors: De Mondt, R., Vercammen, Y., Dardenne, R., Vangaever, F., Van Luppen, J., Van Vaeck, L.
• Format: Article
• Language: English
• Subjects: Atomic, molecular, and ion beam impact and interactions with surfaces; Chemical composition analysis, chemical depth and dopant profiling; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Depth profiling; Electron and ion emission by liquids and solids; impact phenomena; Exact sciences and technology; Feasibility studies; Impact phenomena (including electron spectra and sputtering); Materials science; Materials testing; Microtomy; molecular depth profiling; Nanocomposites; Nanomaterials; Nanostructure; organics; Physics; Polymethyl methacrylates; Projectiles; SIMS
• ISSN: 0142-2421; 1096-9918; 1096-9918
• DOI: 10.1002/sia.3593

Polyatomic projectiles such as C60+ have been used for molecular sputter depth profiling in time‐of‐flight static secondary ion mass spectrometry (ToF‐S‐SIMS). However, the practical application for nanoscale analysis problems still depends on the likely change of secondary ion yield with depth. Therefore, ultra‐low‐angle microtomy (ULAM) has been applied in conjunction with dual beam depth profiling (Bi3+C60+ + +) on polymer systems relevant to printing industry. Sputter depth profiles have been recorded from two 200 nm poly(methyl methacrylate) (PMMA) layers with additives. Furthermore, also a poly(vinyl pyrrolidone) (PVP)‐PMMA bilayer on Si (thickness of each layer 200 nm) was analyzed using sputter depth profile measurements. Identical samples have been prepared using UV‐cured acrylate as substrate allowing ULAM to be performed. The exposed surfaces have been analyzed using Binq+ liquid metal ion gun (LMIG). Use of a cutting angle of 0.3° and 0.1° makes that, in principle, surface analysis off the section with a spot of 150 nm characterises a depth range of 0.3–0.8 nm in the initial sample. The results show that ULAM is a valuable tool to complement the exploratory use of direct sputter depth profiling. To the best of our knowledge, this feasibility study is the first to show the experimental verification of molecular C60+ sputter depth profiles. Copyright © 2010 John Wiley & Sons, Ltd.