Can swift heavy ions create latent tracks in silicon?

Abstract

In this paper we make attempts to clarify the contradictory results for latent track formation in silicon by single heavy ions in the electronic regime of their slowing down. We show by Monte Carlo calculations that, in contrast to the assumption used by the inelastic thermal spike model, the interactions of electrons excited by ions cannot cause fast heating of the lattice at the early stage of the track evolution. In addition, thermal balance equations do not confirm the reality of latent track creation. We believe that, on an ultra short time scale, the damage introduced in the lattice by the ion is rather caused by non-thermal processes, similar to those that occur in silicon irradiated by femto-second lasers ( fs-lasers). The characteristics of the damaged zone, the radius of this cylindrical zone, and the effective stopping power related to the non-thermal process for different ions of energy 1–10 MeV/amu are presented. The calculations have also shown that Auger recombination does not influence significantly the density of the e–h pairs which is the most important quantitative characteristic of the non-thermal process.