Fabrication of silicon nanowire arrays by near-field laser ablation and metal-assisted chemical etching

D. Brodoceanu, H Z Al Hmoud, R. Elnathan, B. Delalat, N. H. Voelcker, T. Kraus

Research output: Contribution to journalArticleResearchpeer-review

24 Citations (Scopus)

Abstract

We present an elegant route for the fabrication of ordered arrays of vertically-aligned silicon nanowires with tunable geometry at controlled locations on a silicon wafer. A monolayer of transparent microspheres convectively assembled onto a gold-coated silicon wafer acts as a microlens array. Irradiation with a single nanosecond laser pulse removes the gold beneath each focusing microsphere, leaving behind a hexagonal pattern of holes in the gold layer. Owing to the near-field effects, the diameter of the holes can be at least five times smaller than the laser wavelength. The patterned gold layer is used as catalyst in a metal-assisted chemical etching to produce an array of vertically-aligned silicon nanowires. This approach combines the advantages of direct laser writing with the benefits of parallel laser processing, yielding nanowire arrays with controlled geometry at predefined locations on the silicon surface. The fabricated VA-SiNW arrays can effectively transfect human cells with a plasmid encoding for green fluorescent protein.

Original languageEnglish
Article number075301
Pages (from-to)1-8
Number of pages8
JournalNanotechnology
Volume27
Issue number7
DOIs
Publication statusPublished - 18 Jan 2016
Externally publishedYes

Keywords

  • laser nanopatterning
  • metal-assisted chemical etching
  • near-field ablation
  • porous silicon
  • silicon nanowire array

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