Two-dimensional macroscopical simulations of porous silicon growth

A simulator aimed at the prediction of the porous silicon profiles produced by anodization of samples with arbitrary doping profiles is presented. An equivalent non-linear electrical network is used to calculate the current density in the sample in order to estimate the etch rate along the electrolyte–silicon interface. The simulations have been devoted to study the anisotropy of silicon growth in the presence of p-doping gradients. A structure of practical interest in micromechanical and optical device fabrication has been simulated. The role of the anodization current density in determining the degree of anisotropy has been satisfactorily predicted as proven by comparison with experimental data.