Preparation of VO2 Films with Metal–Insulator Transition on Sapphire and Silicon Substrates by Inductively Coupled Plasma-Assisted Sputtering

Abstract

We have achieved single phase crystalline VO2 film growth on sapphire (0001) and Si(100) substrates by the introduction of inductively coupled plasma (ICP)-assisted sputtering with an internal coil. The VO2 film on Si substrate showed a metal–insulater (M–I) transition at a temperature of 60°C with three orders of change in resistivity, with a small hysteresis width of 2.2°C for temperature. On the other hand, we could not eliminate vanadium oxides with excess oxygen such as V2O5 and V3O7 from stoichiometric VO2 in conventional reactive magnetron sputtering, regardless of the control maintained over the deposition conditions. The growth of VO2 film under a relatively wide range of deposition conditions in ICP-assisted sputtering is expected to aid in the development of integrated devices based on the M–I transition that is due to strong electron correlation.