The tendency of O interstitials to diffuse and segregate to the Si:HfO2 interface was evaluated by performing first-principles interstitial formation and migration energy calculations at various distances from the interface. A coherent Si:HfO2 heterostructure based upon monoclinic HfO2 was used. These computations indicated that strong thermodynamic and kinetic driving forces existed for the segregation of O interstitials to the interface; providing a mechanism for the subsequent formation of SiOx interfacial phases.

Ab initio Study of Oxygen Interstitial Diffusion near Si:HfO2 Interfaces. C.Tang, R.Ramprasad: Physical Review B, 2007, 75[24], 241302