Multiple resistive states in vanadium dioxide (VO2) memristive devices

Vanadium dioxide (VO2) has been widely studied for its prominent insulator-metal transition (IMT) near room temperature and potential applications in novel memory devices and brain-inspired computing. We report on the fabrication of in-plane VO2 metal-insulator-metal (MIM) structures and reproducible switching measurements in these two-terminal devices. The VO2 film grown on TiO2 substrate by pulsed laser deposition (PLD) was etched into bridge structures with different sizes. Resistive switching can be achieved by applying current/voltage bias, which creates Joule heating in the device and triggers the IMT. We observe repeatable unipolar switching and a clear correlation between the switching power and device size. This approach provides a gateway to mimic neurons and synapses with hardware components, allowing for much denser and complex neural networks.