Wear-out of Al-Ta2O5/SiO2-Si structures under dynamic stress

Wear-out of Al-Ta2O5/SiO2-Si stacked layers under dynamic current stresses was studied. It was found that a detrapping of negative charges occurs between the pulses, similarly to SiO2 and SiOxNy films. Additional consumption of the SiO2 interfacial layer results in a decrease of the gate voltage in some stages of the stress, depending upon the stress time and current density.