Ultra-low-angle microtomy to back up S-SIMS molecular depth profiling with C-60(+) and Bi-n(+) for the nanoscale analysis of high-tech industrial materials

作者：De Mondt R^*; Vercammen Y; Dardenne R; Vangaever F; Van Luppen J; Van Vaeck L

来源：Surface and Interface Analysis, 2011, 43(1-2): 389-392.

DOI：10.1002/sia.3593

• SIMS
• molecular depth profiling
• organics

Polyatomic projectiles such as C-60(+) 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 (Bi-3(+)-C-60(+++)) 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 Bi-n(q+) liquid metal ion gun (LMIG). Use of a cutting angle of 0.3 degrees and 0.1 degrees 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 C-60(+) sputter depth profiles.

• 出版日期2011-2