Figure 14.

TEM images of FEBID nanopillars using differing precursors and post-treatments. (a) Amorphous dielectric Si-O-C tip from tetraethoxysilane (TEOS), fabricated at 25 keV/100 pA. (b) shows an Au-C nanopillar shaft fabricated at 30 keV/21 pA using Me₂Au(acac) precursor, revealing 3–5 nm Au nanograins (dark), which are embedded in a carbon matrix (bright). (c) shows the same pillar after full purification using 5 keV/1.2 nA in 10 Pa H₂O environments, where the highly crystalline Au character becomes evident. Of particular relevance is the widely maintained morphology, although diameters are strongly reduced (see scale bars). The remaining surface contamination by carbon due to the imaging is only about 1 nm, which becomes essential for plasmonic applications [75].