Atomistic Modeling of Point and Extended Defects in Crystalline Materials

Abstract

Atomistic process modeling, a kinetic Monte Carlo simulation technique, has the interest of being both conceptually simple and extremely powerful. Instead of reaction equations it is based on the definition of the interactions between individual atoms and defects. Those interactions can be derived either directly from molecular dynamics or first principles calculations, or from experiments. The limit to its use is set by the size dimensions it can handle, but the level of performance achieved by even workstations and PC's, together with the design of efficient simulation schemes, has revealed it as a good candidate for building the next generation of process simulators, as an extension of existing continuum modeling codes into the deep submicron size regime. Over the last few years it has provided a unique insight into the atomistic mechanisms of defect formation and dopant diffusion during ion implantation and annealing in silicon. Object-oriented programming can be very helpful in cutting software development time, but care has to be taken not to degrade performance in the critical inner calculation loops. We discuss these techniques and results with the help of a fast object-oriented atomistic simulator recently developed.

Kinetic Monte Carlo simulations for transient thermal fields: Computational methodology and application to the submicrosecond laser processes in implanted silicon

“…Consequently, a great number of codes based on KMC and continuous models have been developed, most of them daily used in academic and industrial research [7]. In this section a brief generic description of the KMC method will be given, focusing on the modifications of the numerical formalism which make possible the kinetic simulation in the case of a transient nonuniform thermal field.…”

“…An interesting application of the KMC approach concerns the simulation of the damage evolution in ion-implanted samples [6,7] for technological applications in the field of microelectronics. Several works have demonstrated the prediction power of this method when it is applied to postimplantation annealing processes at high uniform temperature.…”

Internally consistent approach for modeling solid-state aggregation. I. Atomistic calculations of vacancy clustering in silicon

“…In atomistic simulation, the only required input is the interatomic potential that governs the dynamical evolution of the atomic trajectories. In between these limits are methods, such as Kinetic Monte Carlo 14,15 , that attempt to retain atomistic-level detail, but coarse-grain the details of the atomic motion to allow for much larger and longer simulation scope. Once again, Kinetic Monte Carlo requires that an interaction and transport description for each cluster be specified a priori.…”

Feature activated molecular dynamics: An efficient approach for atomistic simulation of solid-state aggregation phenomena

“…In order for a direct connection between material properties and experimental observables to be feasibly made, such simulators often rely on a continuum, or at least mesoscopic scale models of the relevant physical and chemical processes. Continuum simulators typically are comprised of a system of Master and/or Fokker-Planck equations 12,13,14 , while mesoscale tools can be based on a variety of approaches such as Kinetic Monte Carlo (KMC) 15,16,17,18 . While computationally efficient relative to atomistic simulation methods such as molecular dynamics (MD), the implementation of such models requires the specification of microscopic, or atomic scale, physics and parameters in one form or another in order for them to be predictive.…”