Atomistic model for E´ center generation during electrical stress

A model is proposed which addresses the effects of the oxide electric field and anode bias as well as discusses the role of hydrogen in the trap generation process. The oxide wear-out phenomenon is considered as a multi-step process initiated by the capture of injected electrons by localized states in SiO₂. The captured electron significantly weakens the corresponding Si-O bond, which becomes unstable with respect to the applied electric field and temperature. The hydrogen present in the oxide (due to the anode hydrogen release process) prevents restoration of the broken bond and leads to the generation of a neutral E´ center. The model describes the charge-to-breakdown dependence on the electron fluence and energy, electric field, temperature and oxide thickness.