title: Solid-Liquid-Vapor Etching of Semiconductor Nanowires.
abstract: The vapor-liquid-solid (VLS) mechanism enables the bottom-up, or additive, growth of semiconductor nanowires. Here, we demonstrate a reverse process, whereby catalyst atoms are selectively removed from the eutectic catalyst droplet. This process, which is driven by the dicarbonyl precursor 2,3-butanedione, results in axial nanowire etching. Experiments as a function of substrate temperature, etchant flow rate, and nanowire diameter support a solid-liquid-vapor (SLV) mechanism. An etch model with reaction at the liquid-vapor interface as the rate-limiting step is consistent with our experiments. These results identify a new mechanism to in situ tune the concentration of semiconductor atoms in the catalyst droplet.
authors.affiliation: School of Chemical & Biomolecular Engineering, Georgia Institute of Technology , Atlanta 30332, Georgia United States.
authors.forename: Ho Yee
authors.initials: HY
authors.lastname: Hui
authors.affiliation: School of Chemical & Biomolecular Engineering, Georgia Institute of Technology , Atlanta 30332, Georgia United States.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Filler
keywords: Semiconductor nanowire; etching; germanium; silicon; vapor−liquid−solid mechanism