Energy-Efficient Resistive Switching in VO2 Mesostructure

Vanadium dioxide $\left(\mathrm{VO}_{2}\right)$ is a functional material in which, at a temperature of $68^{\circ} \mathrm{C}$, an ultrafast semiconductormetal phase transition occurs with a conductivity jump up to five orders in magnitude. This property makes VO
2
promising for creating energy-efficient resistive switches. For practical applications, an urgent task is to reduce operating voltages and energy consumption during electrical switching. The formation of structures of special geometry in which heat dissipation is reduced compared to classical planar and vertical switches makes it possible to improve its energy efficiency and stability. In this paper we compare two types of vertical two-contact resistive switches based on polycrystalline VO
2
films and on VO
2
mesostructure. In such mesostructures VO
2
was located directly between two contacts. It was formed using photolithography and subsequent plasma etching of VO
2
film. It is shown that in such mesostructures, electrical switching occurs at lower voltages and power, compared with switches based on a uniform $\mathbf{V O}_{2}$ film. By locally removing the part of the film, it was possible to reduce the amount of heat dissipation by an order of magnitude. Switches based on the formed VO
2
mesostructures can be integrated into ultrafast and energy efficient electrical and optical systems, such as sensors, memory elements and neuromorphic systems.