Modelling (100) hydrogen-induced platelets in silicon with a multi-scale molecular dynamics approach

We introduce a multiscale molecular dynamics (MD) approach to study the thermal evolution of (100) hydrogen-induced platelets (HIPs) in silicon. The HIPs are modelled by 10 nm long planar defects in a periodically repeated crystalline model system containing are stabilized by saturating the resulting surface dangling bonds with hydrogen atoms. The time evolution of the defects is studied by finite-temperature MD using the Learn On The Fly (LOTF) technique. This hybrid scheme allows us to perform accurate density-functional-tight-binding (DFTB) force calculations only on the chemically reactive platelet zone, while the surrounding silicon crystal is described by the Stillinger-Weber (SW) classical potential. Reliable dynamical trajectories are obtained by choosing the DFTB zone in a way which minimizes the errors on the atomic forces.