Impact of the filament morphology on the retention characteristics of Cu/Al 2 O 3 -based CBRAM devices

In this paper, we demonstrate that the morphology of the conductive filament is the key parameter to control the data retention characteristics of CBRAM devices. In particular, we prove that the evolution of the LRS and HRS distributions is qualitatively related to the filament shape, whereas it is influenced quantitatively by the materials constituting the CBRAM stack, and we propose the peculiar hourglass filament shape as a solution for enabling optimal retention performances. Further analysis of the effect of cycling on retention confirms the key role of the filament morphology in the CBRAM data retention trend.