Corrosion rate of n- and p-silicon substrates in HF, HF+HCl, and HF+NH4F aqueous solutions

A research program was initiated in order to investigate the electrochemica l corrosion of n- and p-type silicon substrates in 0.25 M dilute HF solutio ns, and the influence of fluoride ions or proton additives. All experiments were conducted in both the dark and under constant light flux, with soluti ons thoroughly degassed by high purity argon bubbling. Polarization resista nce measurements near an open-circuit potential lead to the value of the co rrosion current, while scanning the potential in the range of anodic and ca thodic reactions permitted evaluation of the kinetics of charge transfer as a function of the majority carriers density in the semiconductor and the i onic composition of the solution. The influence of these parameters on the surface roughness of the silicon samples was also examined by ex situ atomi c force microscopy profile measurements. (C) 1999 The Electrochemical Socie ty. S0013-4651(98)03-123-1. All right reserved.