A theoretical model of the formation morphologies of porous silicon

Abstract

In this paper a qualitative theoretical model describing the mechanism and formation morphology of porous silicon is presented. The model is based on the diffusion limited aggregation models of Witten and Sanders. The validity of this model is verified by performing small scale computer simulations to construct various porous silicon structures. These structures are compared with the known properties of bulk silicon and morphologies of porous silicon. The postulates of the model are sufficiently rich to explain the relationship between pore density, pore diameter, porosity as well as crystallographic etch selectivity and electropolishing.