Proximal probe-like nano structuring in metal-assisted etching of silicon

Ersin Bahceci, Brian Enders, Zain Yamani, Serekbol Tokmoldin, Aman Taukenov, Laila Abuhassan, Munir Nayfeh

Research output: Contribution to journalArticlepeer-review


We use silicon having multiple crystalline orientation domains and high metal doping in metal assisted chemical etching (MACEtch) in HF/H2O2. In device-quality silicon, MACEtch produces high-aspect ratio anisotropic (1-D) structures (wires, columns, pores or holes) and to a lesser degree non-high-aspect ratio luminescent (0-D) nano structures. While the 1-D structure symmetry is understood in terms of crystallography axis-dependent etching, predominantly along the <100> direction, the isotropic 0-D spherical symmetry etching is not understood. We observe in silicon having multiple crystalline orientation domains formation of metal tips (needles or whiskers) of diameters as small as 2-3 nm that bridge the metal to silicon and cause AFM/STM-like nanofabrication, producing 0-D mounds, indentations, or clusters. The formation of sharp needles can be understood in terms of charge injection/electric breakdown between metal clusters and silicon due to charge build-up. Silicon with high degree of impurities as well as with multiple crystalline orientation domains allow imaging these effects using electron spectroscopy without cross sectional cuts.

Original languageEnglish (US)
Article number055228
JournalAIP Advances
Issue number5
StatePublished - May 1 2019
Externally publishedYes

ASJC Scopus subject areas

  • General Physics and Astronomy


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