Ab initio study of oxygen interstitial diffusion near Si: HfO2 interfaces

The tendency of oxygen interstitials to diffuse and segregate to the Si:HfO2 interface is evaluated by performing first principles interstitial formation and migration energy calculations at various distances from the interface. A coherent Si:HfO2 heterostructure based on monoclinic HfO2 was used in this study. These computations indicate that strong thermodynamic and kinetic driving forces exist for the segregation of oxygen interstitials to the interface, providing for a mechanism for the subsequent formation of SiOx interfacial phases.