On the switching behaviour of post-breakdown conduction in ultra-thin SiO2films

Switching between well defined states of post-breakdown conduction in ultra -thin SiO2 films is observed in both I-V and time-domain voltage (current) measurements under constant low bias current (voltage). Using I-V measureme nts, single switching with two conduction states and multi le switching wit h more than two states was observed. The I-V characteristic of each state c an be well modelled by the power law, and a convincing linear dependence is observed for each state when the I-V characteristics are plotted on a log- log scale. The switching behaviour is explained in terms of the on/off stat e of percolation paths of neutral electron traps due to de-trapping/trappin g of the traps at certain SiO2 lattice sites (strategic positions) during t he measurements.