11-11
I.A.
Shah, Q.D. Nguyen, H.G.G. Philipsen, B.M.A. van der
Wolf, R.G. Algra, P. Tinnemans, A.J. Koekkoek, N. Panina, F.J.M. van
den Bruele, W.J.P. van Enckevort
, E. Vlieg,
X-ray
diffraction analysis of the silicon (111) surface during alkaline etching,
Surface
Science 605 (2011) 1027-1033
Abstract
We present a surface X-ray diffraction determination of the silicon
(111)-liquid interface structure during alkaline etching. Preparation of an
atomically smooth surface was realized by an in-situ procedure using an aqueous
NH(4)F solution devoid of oxygen. Using diluted aqueous potassium hydroxide
(KOH) and ammonium fluoride (NH(4)F) etchant, we have observed that the crystal
surface is hydrogen terminated and is not reconstructed at open circuit
potential. In addition, a partial liquid ordering of two water layers on top of
the crystal surface was found, indicating a weak interaction with the
hydrophobic, hydrogen terminated surface. We have followed in-situ the
development of the oxide layer by a birth and spread mechanism during anodic passivation of the silicon surface. (C) 2011 Elsevier B.V.
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