Characteristics of sub-keV atom-Si(111) surface collisions

Abstract

Molecular-dynamics (MD) simulations, using the potential developed by Tersoff, are reported for Si bombardment of Si(111) in the collisional energy range 15--520 eV. A comparison between ordinary MD and a modified version that includes a model for electronic stopping power and electron-phonon coupling is made. It is found that such modification does not significantly change the results for penetration depth and surface damage. However, electronic stopping does lead to energy dissipation and approximately 10--15% of the collisional energy is transferred to the electrons. The surface damage reaches deeper than the penetration of the projectile and is identified as single atom displacements or small-sized amorphous regions.