Application of X-ray diffraction methods in the study of micrometer-sized porous Si layers

An X-ray analysis of porous silicon layers (Sb-doped n ⁺-Si(111)) obtained by anodic oxidation for different times with a current of 50 mA/cm² is performed by the methods of double-crystal rocking curves and total external reflection. A nondestructive method for monitoring the stationary process of the formation of micrometer-sized porous silicon layers and estimating their porosity and thickness is proposed. The parameters obtained for porous silicon layers with a thickness of ～6 μm are confirmed by the joint processing of diffraction curves for the 111 and 333 reflections on the basis of the developed model of dynamic scattering from layers while taking into account the strain profiles Δd(z)/d, the static Debye-Waller factor f(z), and the porosity P(z). The advantages and drawbacks of the proposed method are discussed.