On the morphology of stain-etched porous silicon films

Morphology of stain-etched porous silicon films was investigated by a non-d estructive technique, based on reflectance spectrometry: dielectric functio n profiles were computed by spectral reflectance via a finite difference mo del, and porosity was deduced by the effective medium approximation. Theore tical calculations were supported by high-resolution electron microscopy ob servations. The relations among oxidising species concentration in the etch ing solution, porosity profile and surface reflectance of the films were in vestigated. (C) 1999 Elsevier Science B.V. All rights reserved.