Numerical investigation of depth profiling capabilities of helium and neon ions in ion microscopy.

The analysis of polymers by secondary ion mass spectrometry (SIMS) has been a topic of interest for many years. In recent years, the primary ion species evolved from heavy monatomic ions to cluster and massive cluster primary ions in order to preserve a maximum of organic information. The progress in less-damaging sputtering goes along with a loss in lateral resolution for 2D and 3D imaging.

Experimental and simulation-based investigation of He, Ne and Ar irradiation of polymers for ion microscopy.

Secondary ion mass spectrometry (SIMS) on the helium ion microscope (HIM) promises higher lateral resolution than on classical SIMS instruments. However, full advantage of this new technique can only be obtained when the interaction of He(+) or Ne(+) primary ions with the sample is fully controlled. In this work we investigate how He(+) and Ne(+) bombardment influences roughness formation and preferential sputtering for polymer samples and how they compare to Ar(+) primary ions used in classical SIMS by combining experimental techniques with Molecular Dynamics (MD) simulations and SD_TRIM_SP modelling.

Molecular dynamics simulations of sputtering of Langmuir-Blodgett multilayers by keV C(60) projectiles.

Coarse-grained molecular dynamics computer simulations are applied to investigate fundamental processes induced by an impact of keV C(60) projectile at an organic overlayer composed of long, well-organized linear molecules. The energy transfer pathways, sputtering yields, and the damage induced in the irradiated system, represented by a Langmuir-Blodgett (LB) multilayers composed from molecules of bariated arachidic acid, are investigated as a function of the kinetic energy and impact angle of the projectile and the thickness of the organic system. In particular, the unique challenges of depth profiling through a LB film vs.