Author:

Keywords:

Science & Technology, Physical Sciences, Technology, Electrochemistry, Materials Science, Coatings & Films, Materials Science, ACID, 0303 Macromolecular and Materials Chemistry, 0306 Physical Chemistry (incl. Structural), 0912 Materials Engineering, Energy, 3406 Physical chemistry, 4016 Materials engineering

Abstract:

The wet etching behavior of CoSi2 films in HF-based solutions is investigated for a wide 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 = kRΘH+ΘHF, where kR = 2.5 · 107 exp (-10500/RT) nm/s (0.416 at 293 K), ΘH+ ≈ [H+]0.135 and ΘHF ≈ [HF]i0.310. It is shown that the induction period increases in the etching process of CoSi2 in diluted HF, which is attributed to the presence of a thin surface layer on top of the CoSi2.