Atomic-scale effects behind structural instabilities in Si lamellae during ion beam thinning

Author(s)

E. Holmström, J. Kotakoski, L. Lechner, U. Kaiser, K. Nordlund

Abstract

The rise of nanotechnology has created an ever-increasing need to probe

structures on the atomic scale, to which transmission electron

microscopy has largely been the answer. Currently, the only way to

efficiently thin arbitrary bulk samples into thin lamellae in

preparation for this technique is to use a focused ion beam (FIB).

Unfortunately, the established FIB thinning method is limited to

producing samples of thickness above ˜20 nm. Using atomistic

simulations alongside experiments, we show that this is due to effects

from finite ion beam sharpness at low milling energies combined with

atomic-scale effects at high energies which lead to shrinkage of the

lamella. Specifically, we show that attaining thickness below 26 nm

using a milling energy of 30 keV is fundamentally prevented by atomistic

effects at the top edge of the lamella. Our results also explain the

success of a recently proposed alternative FIB thinning method, which is

free of the limitations of the conventional approach due to the absence

of these physical processes.

Organisation(s)

Physics of Nanostructured Materials

External organisation(s)

University of Helsinki, Universität Ulm

Journal

AIP Advances

Volume

ISSN

2158-3226

DOI

https://doi.org/10.1063/1.3698411

Publication date

2012

Peer reviewed

Yes

Austrian Fields of Science 2012

103009 Solid state physics, 103018 Materials physics

Portal url