Toward local growth of individual nanowires on three-dimensional microstructures by using a minimally invasive catalyst templating method

M. G. Jenke; D. Lerose; C. Niederberger; J. Michler; S. Christiansen; I. Utke

Nano Letters 11 (2011) 4213-4217

We present a novel minimally invasive postprocessing method for catalyst templating based on focused charged particle beam structuring, which enables a localized vapor-liquid-solid (VLS) growth of individual nanowires on prefabricated three-dimensional micro- and nanostructures. Gas-assisted focused electron beam induced deposition (FEBID) was used to deposit a SiOx surface layer of about 10×10 μ2 on top of a silicon atomic force microscopy cantilever. Gallium focused ion beam (FIB) milling was used to make a hole through the SiOx layer into the underlying silicon. The hole was locally filled with a gold catalyst via FEBID using either Me 2Au(tfac) or Me2Au(acac) as precursor. Subsequent chemical vapor deposition (CVD)-induced VLS growth using a mixture of SiH4 and Ar resulted in individual high quality crystalline nanowires. The process, its yield, and the resulting angular distribution/crystal orientation of the silicon nanowires are discussed. The presented combined FIB/FEBID/CVD-VLS process is currently the only proven method that enables the growth of individual monocrystalline Si nanowires on prestructured substrates and devices. © 2011 American Chemical Society.