Small-angle X-ray scattering study of the microstructure of highly porous silicon

Abstract

Small-Angle X-ray Scatterin is well suited to the study of porous silicon microstructure since the pore radii range (2-10 -5 corresponds to the small-angle scattering range (1-100 nm).In all the studies realized till now, the porous silicon layers were always supported by the substrate. Recently, it has been possible to detach the porous silicon layer from the substrate. We performed small-angle X-ray scattering measurements, on such P-type samples, at a synchrotron radiation source. Close to the origin, the scattering pattern shows an anisotro ic behaviour when tilting the sample surface with respect to the X-ray beam. This anisotropy is di ferent from the one observed previously in the case of P+ samples.

Morphology of ion irradiation induced nano-porous structures in Ge and Si1−xGex alloys

“…Indeed, when the porous layer thickness become less than 20% of the thickness of amorphous layer, there was a continuous modification in the shape of the scattering profiles. 31 Fig. 10 shows the effect of Ge content on the feature size of the nano-pores.…”