Micro and Nano Structure of Electrochemically Etched Silicon Epitaxial Wafers

Gamulin, Ozren; Balarin, Maja; Ivanda, Mile; Kosović, Marin; Derek, Vedran; Mikac, Lara; Serec, Kristina; Furić, Krešimir; Ristić, Davor; Krilov, Dubravka (2012) Micro and Nano Structure of Electrochemically Etched Silicon Epitaxial Wafers. Croatica Chemica Acta, 85 (1). pp. 101-106. ISSN 0011-1643

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Abstract

Silicon epitaxial wafers, consisting of 280 mu m thick n-type substrate layer and 4-5 mu m thick epitaxial layer, were electrochemically etched in hydrofluoric acid ethanol solution, to produce porous silicon samples. The resistivity of epitaxial layer was 1 Omega cm, while the substrate was much better conductor with resistivity 0.015 Omega cm. By varying the etching time, the micro- and nano-pores of different sizes were obtained within the epitaxial layer, and on the substrate surface. Due to the lateral etching the epitaxial layer was partially detached from the substrate and could be peeled off. The influence of etching time duration on the optical and structural properties of porous samples was investigated by Raman, infrared and photoluminescence spectroscopy. The samples were analysed immediately after the etching and six months later, while being stored in ambient air. The Raman spectra showed the shift in positions of transversal optical (TO) phonon bands, between freshly etched samples and the one stored in ambient air. Infrared spectra indicated the presence of SiHx species in the freshly etched samples, and appearance of oxidation after prolonged storage. Photoluminescence spectra were very weak in freshly etched samples, but their intensity has increased substantially in six month period.

Item Type:	Article
Uncontrolled Keywords:	nano materials; silicon; electrochemistry; raman; infrared; porous silicon; raman; photoluminescence
Subjects:	NATURAL SCIENCES > Chemistry
Divisions:	Division of Materials Physics
Projects:	Project title Project leader Project code Project type Mehanizmi narušavanja strukture lipoproteina djelovanjem vanjskih čimbenika [23525] Dubravka Krilov 108-1080134-3105 MZOS Fizika i primjena nanostruktura i volumne tvari [135746] Mile Ivanda 098-0982904-2898 MZOS
Depositing User:	Mile Ivanda
Date Deposited:	14 Oct 2013 15:11
URI:	http://fulir.irb.hr/id/eprint/785
DOI:	10.5562/cca1971

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