Controlled Growth of Si Nanowire Arrays for Device Integration

TLDR

Silicon nanowires were synthesized in a controlled manner to facilitate their practical integration into devices. By controlling various aspects of nanowire growth, these methods will enable their efficient and economical incorporation into devices. Gold colloids served as seeds in a vapor–liquid–solid process using SiCl₄ in a chemical vapor deposition system to grow vertically aligned nanowire arrays. The authors achieved highly controlled, vertically aligned silicon nanowire arrays with narrow size distributions (average diameters down to 39 nm), tunable densities (∼0.1–1.8 wires µm⁻²), and spatial confinement via patterned colloid deposition, including growth directly into microchannels.

Abstract

Silicon nanowires were synthesized, in a controlled manner, for their practical integration into devices. Gold colloids were used for nanowire synthesis by the vapor−liquid−solid growth mechanism. Using SiCl4 as the precursor gas in a chemical vapor deposition system, nanowire arrays were grown vertically aligned with respect to the substrate. By manipulating the colloid deposition on the substrate, highly controlled growth of aligned silicon nanowires was achieved. Nanowire arrays were synthesized with narrow size distributions dictated by the seeding colloids and with average diameters down to 39 nm. The density of wire growth was successfully varied from ∼0.1−1.8 wires/μm2. Patterned deposition of the colloids led to confinement of the vertical nanowire growth to selected regions. In addition, Si nanowires were grown directly into microchannels to demonstrate the flexibility of the deposition technique. By controlling various aspects of nanowire growth, these methods will enable their efficient and economical incorporation into devices.