Presentation Information
[3P92]Deposition of Vanadium dioxide thin films by reactive High-Power Pulsed Magnetron Sputtering and improvement of crystallinity by adjusting the duty cycle
*Haruki Sato1, Kosuke Kasugai1, Md. Suruz Mian1, Takeo Nakano1 (1. Graduate School of Science and Technology, Seikei University)
Vanadium dioxide (VO2) shows reversible insulator-to-metal transition (IMT) which accompanies an abrupt resistance change of more than 3–4 orders of magnitude at around 68°C, originating from a change in crystal structure. To prepare a VO2 film showing IMT characteristics, precise control of the stoichiometry is necessary. We have been trying the deposition of VO2 by reactive high-power pulsed magnetron sputtering (r-HPPMS). In our previous study, we modified the oxygen gas flow rate dynamically during the deposition to switch the metal and oxide modes of the reactive sputtering and to adjust the VO2 composition. The optimized VO2 films showed a resistance change of one order of magnitude by the temperature change. In this study, we aimed to improve the VO2 crystallinity and resistance-temperature (R-T) characteristics by adjusting the duty ratio of the pulse discharge in the r-HPPMS process. As a result, with a 7% duty ratio, a VO2 film showing the three orders of magnitude change in resistance could be obtained. The remarkable improvement of the crystallinity of the film was also confirmed.