Epitaxial VO₂ thin-film-based radio-frequency switches with electrical activation Jaeseong Lee1

Vanadium dioxide (VO₂) is a correlated material exhibiting a sharp insulator-to-metal phase transition (IMT) caused by temperature change and/or bias voltage. We report on the demonstration of electrically triggered radio-frequency (RF) switches based on epitaxial VO₂ thin films. The highly epitaxial VO₂ and SnO2 template layer was grown on a (001) TiO2 substrate by pulsed laser deposition (PLD). A resistance change of the VO₂ thin films of four orders of magnitude was achieved with a relatively low threshold voltage, as low as 13V, for an IMT phase transition. VO₂ RF switches also showed high-frequency responses of insertion losses of %3 dB at the on-state and return losses of %4.3 dB at the off-state over 27GHz. Furthermore, an intrinsic cutoff frequency of 17.4 THz was estimated for the RF switches. The study on electrical IMT dynamics revealed a phase transition time of 840 ns.