X-ray scattering study of porous silicon layers

X-ray reflectivity is used to study the mesoscopic structure of porous sili con layers. For a porous silicon thin film, we present measurements of the specular and the diffuse scattering together with their best fits. The anal ysis of the scattered intensity within the distorted-wave Born approximatio n based on a model of rough fractal interface yields new structural informa tion. Furthermore, an overview of experimental results obtained for several thick porous silicon samples (either as-formed or etched) is presented. Th e diffuse scattering exhibits characteristic effects due to large surface r oughness and the porous structure. (C) 2000 Elsevier Science B.V. All right s reserved.