title: Metal-assisted chemical etching using sputtered gold: a simple route to black silicon.
abstract: We report an accessible and simple method of producing 'black silicon' with aspect ratios as high as 8 using common laboratory equipment. Gold was sputtered to a thickness of 8 nm using a low-vacuum sputter coater. The structures were etched into silicon substrates using an aqueous H2O2/HF solution, and the gold was then removed usingaqua regia. Ultrasonication was necessary to produce columnar structures, and an etch time of 24 min gave a velvety, non-reflective surface. The surface features after 24 min etching were uniformly microstructured over an area of square centimetres.
authors.affiliation: Department of Chemistry, Carleton University, 1125 Colonel By Drive, Ottawa, ON, Canada.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Kurek
authors.affiliation: Department of Chemistry, Carleton University, 1125 Colonel By Drive, Ottawa, ON, Canada.
authors.forename: Seán T
authors.initials: ST
authors.lastname: Barry
keywords: etching; gold; nanostructure; silicon; sputtering