p- and n-type silicon electrochemical properties in dilute hydrofluoric acid solutions

After a systematic study of the factors influencing the electrochemical characteristics of the silicon/HF solution junction, we have obtained reproducible and reliable values of the electrochemical kinetic parameters of the interface. One of the features of this system is that the corrosion reaction on anodic and cathodic sites is equivalent to two redox reactions, one at the energy level of the conduction band, the other at the level of the valence band. Then, we supported the assumption that the junction with Si can be treated by the electrochemical model. Data have been obtained using n- and p-type silicon with different doping levels, in contact with deoxygenated or oxygen-saturated 5% HF aqueous solution, in the dark and under illumination. The electrochemical reaction kinetics are expressed as a corrosion rate in atom cm(-2) s(-1) for different Si substrates.