Beyond the solid on solid model: An atomic dislocation formation mechanism

Abstract

We investigate the growth of mismatched thin films by a kinetic Monte Carlo computer simulation. The strain is introduced through an elastic energy term based on a valence force field approximation and stress is relaxed along “atomic chains” at each step of the simulation. The calculations use a set of elementary atomic processes including, besides well-known standard processes, the collective incorporation of atoms. This leads us to introduce a new “hanging” position with only one bond created toward the substrate contrary to solid on solid models. This position plays a role of defects initiation, and thus an atomic dislocation nucleation mechanism is described. Finally, we present the influence of a step in the dislocations creation.