Effect of Deposition Temperature on I-V Characteristics of Vanadium Oxide Film

In this paper, the effects of deposition temperatures on the resistive switching characteristics of polycrystalline vanadium oxide thin films have been investigated. VOx thin films were prepared by reactive sputtering at various deposition temperatures (RT, 250 °C, 350 °C, and 450 °C, respectively). X-ray photoelectron spectroscopy revealed the compositions of VOx thin films. Electrical switching has been observed in Cu(tip)/VOx/Cu memory units by Semiconductor Device Analyzer. Crystalline characterizations revealed that as-deposited (RT) film was amorphous, the films crystallized into different phases (e.g. VO₂, V₂O₅, VO_1.86 etc.) with increasing the deposition temperatures. The VOx memory units have low V_set and V_reset. Furthermore, their set voltage decreased from 1.52 V to 0.45 V and reset voltage decreased from 1.01 V to 0.41 V with increasing the deposition temperatures from 250 °C to 450 °C, respectively. The thin films have three orders of change in resistivity between ON-state and OFF-state except as-deposited film. The vanadium oxide thin film can be a promising material for low power nonvolatile memory applications.