Top-down fabrication and transformation properties of vanadium dioxide nanostructures

The fabrication of nanostructures of vanadium dioxide ( VO2)- based films with critical dimensions down to 100 nm and the characterization of their phase transformation properties are presented. Starting materials are VO2 and V0: 99Mo0: 01O2 films that are deposited by magnetron sputtering. For nanofabrication, two top- down processes are investigated, in which the substrate is nanomachined either before or after film deposition. Electrical resistance measurements on V0: 99Mo0: 01O2 bridge nanostructures exhibit a semiconductor- metal transition similar to reference films. A detailed analysis of phase transition temperatures does not reveal any significant width- dependence as it may be expected when approaching the grain size of 100 nm. The absolute electrical resistance in the semiconducting state scales inversely proportional to the width reflecting homogeneous material characteristics. Yet, the resistance change at the semiconductor- metal transition tends to increase for decreasing width indicating reduced carrier scattering as the absolute number of grain boundaries decreases. Published under license by AIP Publishing.