Ultra-high aspect ratio functional nanoporous silicon via nucleated catalysts

Abstract

Large scale, sub-10 nm high aspect ratio nanoporous silicon is fabricatedviascalable sputtering and a solution-based process.

Low-Load Metal-Assisted Catalytic Etching Produces Scalable Porosity in Si Powders

“…In contrast, the boundary between tortuous pores and bulk Si for Pt and Au was remarkably flat despite different Pt and Au particle morphologies (Figure ). The observation of both etch track and tortuous pores is consistent with previous results such as those of Hochbaum et al, who were the first to observe porous nanowire formation, Chiappini et al, and Patil et al…”

Nanoporous Silicon-Assisted Patterning of Monolayer MoS2 with Thermally Controlled Porosity: A Scalable Method for Diverse Applications

“…Robust large-area NPSi membrane masks were fabricated for the first time via a modified technique which was previously used for generating a partially nanoporous silicon substrate with high aspect ratio dead-end pores. 15 In brief, silver films of 1 angstrom nominal thickness were sputtered onto a (100) Si surface, resulting in the nucleation of hemispherical nanoislands.…”

“…Robust large-area NPSi membrane masks were fabricated for the first time via a modified technique which was previously used for generating a partially nanoporous silicon substrate with high aspect ratio dead-end pores. 15 In brief, silver films of 1 Å nominal thickness were sputtered onto a (100) Si surface, resulting in the nucleation of hemispherical nanoislands. Samples were then submerged in a solution of hydrogen peroxide and hydrofluoric acid (HF) for varying amounts of time, facilitating the etching of nanopores via a process known as metal-assisted chemical etching (MACE), 16 whereby oxidation occurs locally at the silicon−catalyst interface, and oxide is subsequently consumed by HF.…”

Nanostructuring of Si substrates by a metal-assisted chemical etching and dewetting process

“…Lithographic methods are based on fabrication of desirable catalytic metal pattern. 1,12 Non-lithographic methods use various ways to depose catalytic metal into the form of a discontinuous layer, islands 7,8,10,13 or particles from a colloidal suspension. [14][15][16][17] Density of particles, islands and cracks in a metal layer determines whether the obtained structures are more like porous material or nanowires.…”