On a universal parameter of intrinsic oxide breakdown based on analysis of trap-generation characteristics

It is found, even at room temperature, that hole fluence to breakdown Q_p of wet oxides is not a constant value for different oxide fields, but has a strong stress-electric-field dependence. Based on the neutral trap-generation characteristics related to SILC, this oxide-breakdown behavior dependent on the stress-electric field is analyzed. A novel model is proposed in which oxide breakdown is triggered when the current level of steady-state SILC via electron tunneling between traps reaches a critical value. From the spatial distribution of traps, we have concentrated on the critical trap pair whose electron-tunneling probability has the smallest value in the middle of the SiO₂ films. To verify this model, the convoluted trap density which is related to the electron-tunneling probability between the critical trap pair is investigated. As a result, it is found that this convoluted trap density remains constant regardless of stress-electric field and oxide thickness. This means that this convoluted trap density is a universal parameter for oxide breakdown