Templated dewetting of single-crystal sub-millimeter-long nanowires and on-chip silicon circuits

• Published in: Nature communications 2019-12, Vol.10 (1), p.5632-10, Article 5632
• Main Authors: Bollani, Monica, Salvalaglio, Marco, Benali, Abdennacer, Bouabdellaoui, Mohammed, Naffouti, Meher, Lodari, Mario, Corato, Stefano Di, Fedorov, Alexey, Voigt, Axel, Fraj, Ibtissem, Favre, Luc, Claude, Jean Benoit, Grosso, David, Nicotra, Giuseppe, Mio, Antonio, Ronda, Antoine, Berbezier, Isabelle, Abbarchi, Marco
• Format: Article
• Language: English
• Subjects: 639/925/357/1016; 639/925/927/1007; Circuits; Condensed Matter; Crystal defects; Drying; Humanities and Social Sciences; Materials Science; multidisciplinary; Nanotechnology; Nanowires; Physics; Science; Science (multidisciplinary); Silicon; Single crystals
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-019-13371-3

Large-scale, defect-free, micro- and nano-circuits with controlled inter-connections represent the nexus between electronic and photonic components. However, their fabrication over large scales often requires demanding procedures that are hardly scalable. Here we synthesize arrays of parallel ultra-long (up to 0.75 mm), monocrystalline, silicon-based nano-wires and complex, connected circuits exploiting low-resolution etching and annealing of thin silicon films on insulator. Phase field simulations reveal that crystal faceting and stabilization of the wires against breaking is due to surface energy anisotropy. Wires splitting, inter-connections and direction are independently managed by engineering the dewetting fronts and exploiting the spontaneous formation of kinks. Finally, we fabricate field-effect transistors with state-of-the-art trans-conductance and electron mobility. Beyond the first experimental evidence of controlled dewetting of patches featuring a record aspect ratio of ~ 1/60000 and self-assembled ~ mm long nano-wires, our method constitutes a distinct and promising approach for the deterministic implementation of atomically-smooth, mono-crystalline electronic and photonic circuits. Fabricating defect-free micro- and nano-circuits over large scales with controlled interconnections remains a challenge. Here, Bollani et al. show a dewetting strategy for engineering arrays of parallel Si-based nanowires up to 0.75 mm and complex interconnected circuits of monocrystalline Si on a chip.