On the universality of the I-V switching characteristics in non-volatile and volatile resistive switching oxides.

The I-V switching curves of bipolar switching non-volatile ReRAM devices show peculiar characteristics, such as an abrupt ON switching and the existence of a universal switching voltage. This switching behavior has been explained by the presence of a filamentary process, in which the width of a conductive filament changes during switching resulting in different resistance states. Vice versa, similar (ON) switching behavior, e.g. that of volatile switching Cr-doped V2O3 devices, has been interpreted as an indication of the presence of similar filamentary switching. In this paper, we want to review the correlation between filamentary (width) switching and the (SET) I-V characteristics by discussing the existing models. For the Cr-doped V2O3 devices, on the other hand, it is argued that a different, constant filament width switching mode may be present.