Dynamics of the ion beam induced nitridation of silicon

Abstract

High-resolution Rutherford backscattering and channeling has been used to study the energy and angular dependence of the ion beam induced nitridation of Si in a secondary ion mass spectrometry system. The nitridation of Si is characterized by two critical angles θc1 and θc2, corresponding to the formation of stoichiometric and overstoichiometric Si-nitride layers, respectively. For the N₂⁺ bombardment in the 10 to 13.5 keV range, θc1 changes from 40° to 45°, while θc2 changes from 28° to 30°. Further, strong oscillations in the secondary ion signal, observed for angles of incidence below θc2, are directly related to charging of the Si-nitride surface. We demonstrate that the response of the Si-nitride layer under ion bombardment during the transient stage of nitridation can be described by a second order differential equation. Show more