LIGHT-SCATTERING FROM POROUS SILICON

Citation
G. Lerondel et al., LIGHT-SCATTERING FROM POROUS SILICON, Thin solid films, 276(1-2), 1996, pp. 80-83
Citations number
8
Categorie Soggetti
Physics, Applied","Material Science","Physics, Condensed Matter
Journal title
ISSN journal
00406090
Volume
276
Issue
1-2
Year of publication
1996
Pages
80 - 83
Database
ISI
SICI code
0040-6090(1996)276:1-2<80:LFPS>2.0.ZU;2-F
Abstract
Light scattering from porous silicon Layers has been investigated. It reveals that scattering depends strongly, first, on the layer thicknes s and secondly on the doping level of the substrate. During the format ion of porous silicon (PS) on p-type Si material, the bottom of the PS layer develops a roughness which is responsible for the observed scat tered light. The two other possible contributions to the scattering, t he bulk PS and the interface between PS and air were found to be negli gible (< 1%) compared with the first one and independent of the layer thickness. Mechanical roughness and optical scattering measurements gi ve a bottom interface flatness of the order of 100 Angstrom per micron of layer and a mean lateral spatial frequency of the oscillations of 1 mu m(-1), independent of the sample thickness. In contrast the back interface of layers from a heavily doped p + substrate remains almost hat and the level of scattering is low.