Self-Selective Characteristics of Nanoscale $ \hbox{VO}_{x}$ Devices for High-Density ReRAM Applications

We herein present a hybrid-type memory device in which threshold switching and bipolar resistive switching are combined. The nanoscale vanadium oxide
$(\hbox{VO}_{x})$
device simultaneously exhibited self-selective performance and memory switching by electroforming. By using W instead of Pt for the top electrode, memory performance was improved in terms of cycling, pulse endurance, and retention properties attributed to a self-formed
$\hbox{WO}_{x}/\hbox{VO}_{x}$
interface. Such a phenomenon in a simple metal–oxide–metal structure provides a good potential for future high-density cross-point memory devices by avoiding the sneak-path problem.