The tendency of O vacancies to diffuse and segregate to the Si/HfO2 interface was evaluated by performing first-principles vacancy formation and migration energy calculations at various distances from the interface. The results indicated that strong thermodynamic and kinetic driving forces existed for the segregation of O vacancies to the interface; thus providing a mechanism for the subsequent formation of interfacial phases.

Diffusion of O Vacancies Near Si:HfO2 Interfaces - an ab initio Investigation. C.Tang, B.Tuttle, R.Ramprasad: Physical Review B, 2007, 76[7], 073306 (4pp)