Snapback behaviour and its similarity to the switching behaviour in ultra-thin silicon dioxide films after hard breakdown

Snapback behaviour, with well-defined conduction states involved, has been observed in the ramped-current current-voltage (I-V) characteristics of ult ra-thin silicon dioxide films after the occurrence of hard breakdown. The c omparison of the snapback behaviour with the switching behaviour observed i n the ramped-voltage measurement shows that the two behaviours are similar, suggesting that they can be explained by the same mechanism. The I-V relat ionship of each conduction state involved in either the snapback or the swi tching behaviours was found to follow a power law. These observations are c onsistent with the percolation model, and they can be easily explained in t erms of the on/off of conductive percolation paths due to detrapping/trappi ng or neutral trap generation at certain SiO2 lattice sites (strategic posi tions) during the measurements.