A theoretical study was made of the evolution of point defects in the first stages of porous sample formation via the anodization of crystalline material in a HF acid solution. A model was proposed for the interactions between intrinsic point defects and impurities in the near-surface region of semiconductors during the formation of pores. It was shown that a redistribution of defects, and the formation of areas with differing concentrations of vacancy-type defects, could be a reason for the formation of a porous structure. The generation rate of vacancies, due to the reaction of Si surface states with HF, was determined as a function of the hole concentration, HF concentration, and anodic current.

J.W.Corbett, D.I.Shereshevskii, I.V.Verner: Physica Status Solidi A, 1995, 147[1], 81-9