Tunable Electrical Properties of Vanadium Oxide by Hydrogen-Plasma-Treated Atomic Layer Deposition

Abstract

In this study, a plasma-modified process was developed to control the electrical properties of atomic layer deposition (ALD)-grown vanadium dioxide (VO₂), which is potentially useful for applications such as resistive switching devices, bolometers, and plasmonic metamaterials. By inserting a plasma pulse with varying H₂ gas flow into each ALD cycle, the insulator-to-metal transition (IMT) temperature of postdeposition-annealed crystalline VO₂ films was adjusted from 63 to 78 °C. Film analyses indicate that the tunability may arise from changes in grain boundaries, morphology, and compositional variation despite hydrogen not remaining in the annealed VO₂ films. This growth method, which enables a systematic variation of the electronic behavior of VO₂, provides capabilities beyond those of the conventional thermal ALD and plasma-enhanced ALD.