Quantitative analysis of morphology of porous silicon nanostructures formed by metal-assisted chemical etching

Abstract

Morphology features of porous layers consisting of silicon nanowire arrays, which were grown by metal-assisted chemical etching, have been analyzed by means of digital processing of their scanning electron microscopy (SEM) images. Informational-entropic and Fourier analysis have been applied to quantitatively describe the degree of order and chaos in nanostructure distribution in the layers. Self-similarity of the layer morphology has been quantitatively described via its fractal dimensions. The applied approach allows us to distinguish morphological features of as-called "black" (more ordered) and "white" (less ordered) silicon layers characterized by minimal and maximal optical reflection, respectively.