Fabrication of single-crystal silicon nanotubes with sub-10 nm walls using cryogenic inductively coupled plasma reactive ion etching

Abstract

Single-crystal silicon nanostructures have attracted much attention in recent years due in part to their unique optical properties. In this work, we demonstrate direct fabrication of single-crystal silicon nanotubes with sub-10 nm walls which show low reflectivity. The fabrication was based on a cryogenic inductively coupled plasma reactive ion etching process using high-resolution hydrogen silsesquioxane nanostructures as the hard mask. Two main etching parameters including substrate low-frequency power and SF6/O2 flow rate ratio were investigated to determine the etching mechanism in the process. With optimized etching parameters, high-aspect-ratio silicon nanotubes with smooth and vertical sub-10 nm walls were fabricated. Compared to commonly-used antireflection silicon nanopillars with the same feature size, the densely packed silicon nanotubes possessed a lower reflectivity, implying possible potential applications of silicon nanotubes in photovoltaics.

Attenuated Glial Reactivity on Topographically Functionalized Poly(3,4‐Ethylenedioxythiophene):P‐Toluene Sulfonate (PEDOT:PTS) Neuroelectrodes Fabricated by Microimprint Lithography

“…A range of techniques have been explored to create defined microstructures on electrode surfaces, including laser ablation, focused ion beam, sputter etching, reactive ion etching, deep reactive ion etching, hot embossing, and electron beam lithography . Complementary to these techniques, imprint lithography is an especially attractive approach due to its simplicity, nondestructive character, and feasibility of patterning large areas with features down to 10 nm using elevated temperature and/or pressure processes to transfer a pattern into typically thermoplastic materials .…”

CMOS-Compatible Silicon Nanowire Field-Effect Transistor Biosensor: Technology Development toward Commercialization

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Metasurface Fabrication by Cryogenic and Bosch Deep Reactive Ion Etching

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“…However, Cryo etch has so far been less prevalent in industry than Bosch due to its dependence on very accurate temperature control of the wafer and etched structures towards achieving process controllability, uniformity and repeatability. There are nevertheless indications that Cryo is gaining interest also in industry [ 9 ]. Taking on the advantages of cryogenic etching, Yao and Wu demonstrated the feasibility of manufacturing an all-dielectric metasurface with positive sloped sidewalls, showing more than 90% reflection in the 600 to 800 nm wavelength range [ 12 ].…”

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