First-principle simulations of molecular processes at semiconductor surfaces

We present an overview of basic adsorption and dynamical processes at semiconductor surfaces, studied by first-principle simulations. We have considered prototypical semiconductor surfaces such as GaAs(110), which is the cleavage plane of GaAs, and Si(100), which is the most common orientation for silicon from epitaxial growth. We present an adsorption path and the stable configurations of a Cl-2 molecule on GaAs(110), as well as the equilibrium state for complete and partial monolayer adsorption of H on the same surface. We also show the dynamical evolution of Sit dimers on the Si(100) face: they alternate their buckling in a correlated way producing different reconstructions.