Nanoscale electrical characterization of trap-assisted quasibreakdown fluctuations in SiO2

Abstract

The nanoscale spatial distribution of trap-assisted quasibreakdown fluctuations in thin SiO2 films was discussed, using conductive atomic force microscopy. A model to study the conduction through SiO2 film by trap-assisted tunneling and the characterization of the leakage path in tunnel barriers was developed. The characterization of the effective trap sites which gave rise to local random telegraph signals in the film was studied using a semiquantative analysis. The results show that trap-assisted quasibreakdown fluctuations in tunnel current arise from charge-noise effects in trap states within conduction paths.