V. Konoplev et A. Grasmarti, MOLECULAR-DYNAMICS SIMULATION OF LOW-ENERGY COLLISION CASCADES AND ATOMIC MIXING IN SILICON, Philosophical magazine. A. Physics of condensed matter. Defects and mechanical properties, 71(6), 1995, pp. 1265-1279
We investigate atomic relocation processes in silicon at OK, initiated
by an internal 100 eV silicon recoil. The molecular dynamics code MOD
YSEM is used, based on a Tersoff potential for silicon. A fitting proc
edure was used far the generation of a potential valid over the whole
energy range of interest. The contribution of the collisional, spontan
eous relaxation and thermalization stages to the atomic relocation pro
cess are discussed. A threshold distance for the definition of relocat
ed atoms is determined, which separates atomic displacements into stab
le and unstable (or transient) groups. The atomic mixing process is qu
antified in terms of the first and second spatial moments over the rel
ocation cross-section. These moments depend on the criterion used to d
efine a relocated Si atom, with short-distance thermal-like atomic dis
placements, which appear during the thermalization stage, dominating t
he values of the spatial moments. However, the moments of the relocati
on cross-section calculated by considering only the stable displacemen
ts are generated mainly by collisional atomic relocations.