SIMS depth profiling multi-layer materials with polyatomic cluster ion beams

Advanced materials incorporating reduced feature sizes and interface widths present new challenges for depth-profiling and 3D imaging analysis.  Detailed characterisation of such samples is crucial in the development of materials for energy storage, biomedical and quantum devices etc. 

One approach is ion beam sputtering, combined with direct analysis of secondary ions by mass spectrometry (SIMS) [1] or in combination with other analytical methods such as X-ray photoelectron spectroscopy (XPS) [2]. Sputtering with polyatomics such as C₆₀ and gas cluster ion beams (GCIBs) has been shown to preserve molecular chemistry and provide high etch-rates and depth resolution. However, performance greatly depends on the material type and experimental parameters including beam energy, cluster size and sample temperature.  Determining ‘optimal’ conditions for high-resolution practical analysis require systematic study [3,4].  

Here we present systematic time-of-flight SIMS depth-profiling studies of model materials comprised of inorganic, organic and hybrid multilayer structures using C₆₀ and GCIB sputtering.  We explore the influence of cluster size, energy and chemistry on the quality of the depth-profiles obtained.   For each material type, results are discussed in terms of sputter rates, beam-induced chemical damage and interface widths.

References.

[1] Secondary ion mass spectrometry. N.P. Lockyer, S. Aoyagi, J.S. Fletcher et al. Secondary ion mass spectrometry. Nat Rev Methods Primers 4, 32 (2024)

[2] X-ray Photoelectron Spectroscopy Equipped with Gas Cluster Ion Beams for Evaluation of the Sputtering Behavior of Various Nanomaterials. H-Y. Chang, W-C. Lin, P-C. Chu, Y-K. Wang, M. Sogo, S. Iida, C-J. Peng, and T. Miyayama, ACS Applied Nano Materials 5 (3) (2022) pp 4260-4268.

[3] Hybrid Perovskites Depth Profiling with Variable-Size Argon Clusters and Monatomic Ions Beams. C. Noël, S. Pescetelli, A. Agresti, A. Franquet,V. Spampinato, A. Felten, A. di Carlo, L. Houssiau, Y. Busby, Materials 12, (2019) pp726.

[4] Impact of cluster size on sputtering effects in hybrid organic/inorganic materials during cluster SIMS depth profiling. N. Sano, J.F. Messinger, M.R. Fitzsimmons, K. McHardy, P. Blenkinsopp, S.D. Stranks, J. Vac. Sci. Technol. B 44 (1) (2026) pp 014203.