Growth and nanomechanical characterization of nanoscale 3D architectures grown via focused electron beam induced deposition

Abstract

Nanomechanical measurements of platinum-carbon 3D nanoscale architectures grown via focused electron beam induced deposition (FEBID) were performed using a nanoindentation system in a scanning electron microscope (SEM) for simultaneous in situ imaging. Compression tests were used to estimate the modulus of the platinum-carbon deposits to be in the range of 8.6-10.5 GPa. Cantilever arm bend tests resulted in a modulus estimation of 15.6 GPa. Atomic layer deposition was used to conformally coat FEBID structures with a thin film of AlO, which strengthened the structures and increased the measured modulus. Cycled load-displacement testing at various load rates of nano-truss structures was also performed, demonstrating a viscoelastic response in the FEBID material. Finally, load-displacement tests of a variety of 3-dimensional nanoarchitectures with and without AlO coatings were measured.

Tunable 3D Nanoresonators for Gas‐Sensing Applications

“…While sp 2 ‐hybridized crystalline graphite reveals an in‐plane modulus of about 36 GPa, the here observed value lies by a factor of 3 lower, which is in the same order as reported for fine‐grained graphite (12.8 GPa) (see also Table ). Hence, we suggest a loose network of mainly sp 2 ‐hybridized molecules inside the carbon matrix, containing additionally precursor molecule fragments bonded via weak van der Waals forces in agreement with recent interpretation by Lewis et al who also observed a viscoelastic component supporting this assumption . Once the e‐beam curing starts, graphitization ensues as experimentally confirmed in this study (Figure e).…”

“…Both of these indicate a regime shift toward diffusion enhanced conditions, situated between electron and molecule limited growth, in agreement with the current variation trends observed in Figure b. Summarily, electrostatic experiments reveal an as‐deposited Young's modulus in the range of 9–13 GPa for Pt–C nanopillars fabricated at different primary electron energies at the lowest possible beam currents which is in good agreement with recent results measured via nanoindentation …”

“…By that, we can conclude this section as follows: first, Pt–C nanopillars fabricated via FEBID reveal a Young's modulus in the range of 9–13 GPa depending on the fabrication parameters, which lead to different metal content due to slight shifts in the working regime. This is in agreement with recently reported values accessed via nanoindentation which determined a value of about 14 GPa, however, claiming a slight overestimation due to the nature of the experiments . Second, Pt–C nanopillars are described by the Euler–Bernoulli formalism for a single clamped situation with a slightly modified proportionality factor c NP , which accounts for morphological deviations from a perfect cylinder and slightly varying composition along the pillar's main axis.…”

Mechanical Properties of 3D Nanostructures Obtained by Focused Electron/Ion Beam-Induced Deposition: A Review

“…Cases of free-rotating, pinned, and hinged can be distinguished and change the pre-factor K in Equation (7) from 0.5 to 1, which seems the largest error in this type of measurement. Figure 13c shows Pt-C FEBID pillar nanocompression by a flat diamond punch from Lewis et al [48]. The dotted line was the initial pillar shape.…”

“…The initial shape was straight as indicated, modified from Hao et al [90]. (c) Pt-C FEBID pillar nanocompression by a flat diamond punch (not shown), modified from Lewis et al [48]. (d) FEBID Co-C pillar with Ga-FIB milled flat top for compression experiments.…”