Novel Method of Controlling the Metal–insulator Transition Anisotropy of VO₂ Thin Films by Using Step and Terrace Structures

Vanadium dioxide (VO2) thin films exhibit a metal–insulator transition (MIT) near room temperature with sensitivity to the lattice strain. MIT property has been tuned by W-doping, fabrication of nanowires, etc. In addition to these methods, use of step and terrace structures could be a prospective candidate to control the MIT property since VO2 is sensitive to the lattice strain at the interface between thin films and substrates. In this study, VO2/TiO2 microwires were fabricated following the thin film growth to investigate the in-plane crystal orientation dependence of the MIT property. The VO2/TiO2 microwires with step and terrace structures exhibited a more significant MIT anisotropy, which is promising for strain engineering in device applications.