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 electrochemical corrosion of n- and p-type silicon substrates in 0.25 M dilute HF solutions, and the influence of fluoride ions or proton additives. All experiments were conducted in both the dark and under constant light flux, with solutions thoroughly degassed by high purity argon bubbling. Polarization resistance measurements near an open-circuit potential lead to the value of the corrosion current, while scanning the potential in the range of anodic and cathodic reactions permitted evaluation of the kinetics of charge transfer as a function of the majority carriers density in the semiconductor and the ionic composition of the solution. The influence of these parameters on the surface roughness of the silicon samples was also examined by ex situ atomic force microscopy profile measurements. (C) 1999 The Electrochemical Society. S0013-4651(98)03-123-1. All right reserved.