X‐Ray Diffraction Study of Thin Porous Silicon Layers

High resolution X‐ray diffraction measurements are performed on porous silicon samples (p+ type, 40% porosity) of various thicknesses (from 0.03 to 20 μm). In the thicker samples narrow Bragg peaks are observed for as‐formed samples, with profiles close to those of dynamical diffraction theory. For thin samples (in the 0.1 μm range) the Bragg peak of the porous layer is not resolved, but appears as a shoulder on the substrate peak. Thickness fringes are observed, from which simulations give information on these thin PS layers, showing that the porous layer surfaces are well defined.