No abstract

We report the fabrication of VO2-based two terminal devices with ∼125-nm gaps between the two electrodes, using a simple, cost-effective method employing optical lithography and shadow evaporation. Current-voltage characteristics of the obtained devices show a main abrupt metal-insulator transition (MIT) in the VO2 film with voltage threshold values of several volts, followed by secondary MIT steps due to the nanostructured morphology of the layer. By applying to the two-terminal device a pulsed voltage over the MIT threshold, the measured switching time was as low as 4.5 ns and its value does not significantly change with device temperature, supporting the evidence of an electronically driven MIT.

International audienceMicrowave switching devices based on the semiconductor-metal transition of VO2 thin films were developped on two types of substrates C-plane sapphire and SiO2 / Si, and in both shunt and series configurations. Under thermal activation, the switches achieved up to 30-40 dB average isolation of the radio-frequency rf signal on 500 MHz-35 GHz frequency band with weak insertion losses. These VO2-based switches can be electrically activated with commutation times less than 100 ns, which make them promising candidates for realizing efficient and simple rf switches