Breakdown-induced negative charge in ultrathin SiO2 films measured by atomic force microscopy

Atomic-force-microscopy-based techniques have been used to investigate at a nanometer scale the dielectric breakdown (BD) of ultrathin (<6 nm) SiO2 films of metal-oxide-semiconductor devices. The results show that BD leads to negative charge at the BD location and the amount of created charge has been estimated. Moreover, the comparison of the charge magnitude generated during current-limited stresses and stresses without current limit demonstrates that the observed BD induced negative charge is related to the structural damage created by the oxide BD.