It was shown how the kinetic Monte Carlo (KMC) technique was able to model successfully the defects and diffusion of dopants in Si-based materials for advanced microelectronic devices, especially under non-equilibrium conditions. Charge states of point defects and paired dopants were also simulated, including the dependency of the diffusivities on the Fermi level and charged particle drift coming from the electric field. The KMC method was used to simulate the diffusion of the point defects, and formation and dissolution of extended defects, whereas a quasi-atomistic approach was used to take into account the carrier densities. The simulated mechanisms include the kick-out diffusion mechanism, extended defect formation and the activation/deactivation of dopants through the formation of impurity clusters. Damage accumulation and amorphization were also taken into account. Solid phase epitaxy regrowth was included, and also the dopants redistribution during recrystallization of the amorphized regions. Regarding the charged defects, the model considers the dependencies of charge reactions, electric bias, pairing and break-up reactions according to the local Fermi level. Some aspects of the basic physical mechanisms had also been taken into consideration: how to smooth out the atomistic dopant point charge distribution, avoiding very abrupt and unphysical charge profiles and how to implement the drift of charged particles into the existing electric field. The efficiency, accuracy and relevance of the method were considered, together with its implementation into a computer-aided design process simulator.

Modeling Charged Defects, Dopant Diffusion and Activation Mechanisms for TCAD Simulations using Kinetic Monte Carlo. I.Martin-Bragado, S.Tian, M.Johnson, P.Castrillo, R.Pinacho, J.Rubio, M.Jaraiz: Nuclear Instruments and Methods in Physics Research B, 2006, 253[1-2], 63-7