Determination of the average pore-size and total porosity in porous silicon layers by image processing of SEM micrographs

This work describes a method for measuring the average pore size and the determination of the porosity of porous silicon (PSi) layers, which involves image processing of top-view SEM micrographs. The processing program can measure the total area of the pores and calculate its proportion to the total scanned area. In cases where the pores are longitudinal, uniform and non-branched, as evident from cross-section images, it is assumed that it represents also the ratio between the total volume of the pores to the volume of the entire layer, which defines the porosity of the layer. Our results are in good agreement with the literature values that were obtained by two physical methods.