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

•The porosity of porous silicon (PSi) can be done by image-processing of top-view SEM micrographs.•The ratio of the total pores'area to the scanned area reflects the ratio of the total voids' volume to that of the PSi layer.•Image-processing assessment of the average pore-size gave comparable results to direct measurements on the PSi images.•The dependence of the pore-size on the current densities and of the HF concentrations was confirmed by image processing.•The porosity of PSi layers grows linearly with increasing the current density, starting at a certain porosity threshold.

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.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide