Atomistic modeling of strain and diffusion at theSi/SiO2interface
Résumé
In this paper, we present a theoretical study of the elastic deformations arising in the vicinity of the Si/ SiO 2 interface upon oxidation of a silicon substrate. The oxidation is modelized using an algorithm which alternates the inclusion of oxygen atoms and Molecular Dynamics simulations at high temperature. We find that the SiO 2 film undergoes an overall compressive state while a more complex strain field is found in the first few Si layers under the interface where tensile and compressive microstructures coexist, the former being definitely larger than the latter. The analysis of the formation energies of the main defects responsible for Si diffusion reveals that, in spite of the complexity of the deformation field at the Si/ SiO 2 interface, their dependence with respect to the local deformation obeys the same laws as those derived from the application of a simple biaxial stress.
Domaines
Physique [physics]
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