Influence of pre-existing and generated traps on reliability in HfSiON/SiO2 stacks with fluorine incorporation

In this paper, we investigate the correlation between traps and the degradation of reliability in HfSiON/SiO₂ stacks with F incorporation. It was found that the nature of generated traps corresponds to that of pre-existing traps. Namely new traps cannot be generated if there is no seeds traps which can be eliminate by F incorporation. The controlling pre-existing electron traps which work as seeds traps is effective for suppression of degradation. As TDDB and BTI lifetime strongly depends on trap characteristics, such as positions and their levels, the dominant traps concerning the degradations differ for each reliability characteristic, and also depending on stress polarities in FETs.