Density functional theory study of the SiF molecule adsorption and decomposition on p(2×2) reconstructed Si(001) surface

Abstract

The adsorption of the F and Si atoms as well as the SiF molecule on the Si(001)-p(2×2) surface is studied using first-principle calculations. Our results show that the fluorine atom saturates the dangling bond of the surface while the silicon adatom forms two bonds with the surface atoms. For the adsorption of the SiF molecule, we obtained one dissociative state which is the most stable one and seven non-dissociative states. The minimum energy paths for F diffusion and SiF decomposition on the silicon surface are explored using the nudged elastic band (NEB) method. Our study reveals that it is energetically favorable for the fluorine atom to diffuse from the SiF molecule to a surface site than the diffusion from surface site to another one.