Parametrization of the Stillinger-Weber potential for Si/N/H system and its application to simulations of silicon nitride film deposition with SiH4/NH3

Abstract

We determined the Stillinger-Weber interatomic potential parameters for Si/N/H system based on first principles density functional calculations. This new potential can be used to perform classical molecular dynamics simulation for silicon nitride deposition on Si substrate. During the first principles calculations, cluster models have been carefully and systematically chosen to make sampling of the interatomic potential supersurface more thoroughly. Global optimization method was used to fit the ab initio data into Stillinger-Weber form. We used a recursive method to perform the classical molecular dynamics simulations for silicon nitride (SiN) film growth on Si substrate with SiH4/NH3 gas mixtures. During the simulation, we could clearly observe the silicon nitride film growth progress. In this paper, we present the details of potential derivation and simulation results with different SiH4:NH3 ratios. It is demonstrated that this new potential is suitable to describe the surface reactions of the Si/N/H system and allows us to explore more complex SiN growing process such as plasma-enhanced chemical vapor deposition.