Ab initiostudy of oxygen interstitial diffusion nearSi:HfO2interfaces

Abstract

The tendency of oxygen interstitials to diffuse and segregate to the $\mathrm{Si}:\mathrm{Hf}{\mathrm{O}}_{2}$ interface is evaluated by performing first principles interstitial formation and migration energy calculations at various distances from the interface. A coherent $\mathrm{Si}:\mathrm{Hf}{\mathrm{O}}_{2}$ heterostructure based on monoclinic $\mathrm{Hf}{\mathrm{O}}_{2}$ 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 $\mathrm{Si}{\mathrm{O}}_{x}$ interfacial phases.