Limits on vanadium oxide Mott metal–insulator transition field-effect transistors

There have been numerous proposals for use of metal–oxide materials as an alternative to semiconductors in field-effect transistors (FET), as current Si FET technology inevitably encounters intrinsic scaling limitations. We report on device-independent power–delay characteristics of potential VO2-based field induced Mott transistors and compare scaling limits to that of Si. Since the critical electric field for metal–insulator transition (MIT) in VO2 is similar to the breakdown field of Si, and due to the inherent possibility of further scaling along one direction in VO2, both materials exhibit similar lower bounds on switching energy. MIT in VO2 results in free carrier concentration several orders of magnitude larger than that of Si, easily overcoming the carrier transit time limits of conventional semiconductor MOSFETs. VO2 switching speed is constrained by the kinetics of the phase transition and more importantly limited thermal dissipation. Our simple model predicts an intrinsic VO2 material lower bound switching time of the order of 0.5 ps at a power transfer of 0.1μW.