New Silicon Architectures by Gold-Assisted Chemical Etching

Abstract

Silicon nanowires (SiNWs) were produced by nanosphere lithography and metal assisted chemical etching. The combination of these methods allows the morphology and organization control of Si NWs on a large area. From the investigation of major parameters affecting the etching such as doping type, doping concentration of the substrate, we demonstrate the formation of new Si architectures consisting of organized Si NW arrays formed on a micro/mesoporous silicon layer with different thickness. These investigations will allow us to better understand the mechanism of Si etching to enable a wide range of applications such as molecular sensing, and for thermoelectric and photovoltaic devices.

Evidences for redox reaction driven charge transfer and mass transport in metal-assisted chemical etching of silicon

“…The only difference may be the diffusion process of the ions whereby MacEtch will rely on solid-state diffusion instead. This new understanding will also explain discrepancies between the work from Mikhael et al 46,. who observed the presence of Au particles on the sidewalls of fabricated SiNWs, and that from Chiappini et al 47,.…”

Gold-thickness-dependent Schottky barrier height for charge transfer in metal-assisted chemical etching of silicon

“…In fact, n-doped Si was found to be etched faster than p-doped Si [17,23], and the etching rate decreases with increasing dopant concentration for both n- and p-doped Si [11,17,24]. Meanwhile, Li et al reported that the etching rate showed only small variation for a Au-coated p + , p − , and n + Si substrate and a Pt-coated Si was etched faster compared with a Au-coated Si [25].…”

“…The crystallographic orientation and the doping properties of the Si substrate, the type and the structure of a noble metal, the component and the concentration of the etching solution, temperature, illumination, and so on were reported to have a substantial effect on the etching rate [11,12,14-17]. In the present study, the thickness of the Au catalyst film, which is a new control dimension, was found to affect the etching rate of Si during the fabrication of SiNWs by a method that combines the anodic aluminum oxide (AAO) template and the metal-assisted chemical etching.…”

Electrical characterization of organic/inorganic hybrid solar cells based on silicon nanopillars-poly(3,4-ethylenedioxythiophene):Poly(styrenesulfonate)

“…The detailed fabrication procedure can be found elsewhere [8,9]. The ALD of Al 2 O 3 was carried out with a Cambridge Nanotech Savanah 200 system.…”