The wet etching behavior of CoSi2 films in HF-based solutions is investigated for a nide range of experimental conditions. It is established that the etching rate of CoSi2 depends on the concentrations of H+ ions and on the initial concentration of HF ([HF](i)). Interaction of H+ and HF with the CoSi2 occurs in the adsorption layer. The concentration of adsorbed particles is described by the equation of the Freundlich adsorption isotherm. The kinetic equation of the etching rate is R = k(R) Theta(H+)Theta(HF), where k(R) approximate to 2.5 . 10(7) exp (-10500/RT) nm/s (0.416 at 293 K), Theta(H+) approximate to [H+](0.135) and Theta(HF) approximate to [HF](0.310)(i). It is shown that the induction period increases in the etching process of CoSi, in diluted HF, which is attributed to the presence of a thin surface layer on top of the CoSi2.