Optical switching properties of VOx thin films deposited on Si3N4 substrates using ion beam sputtering

Vanadium dioxide (VO 2 ) thin films, for their property of metal-insulator transition (MIT), have drawn many researchers' attention on optical devices study. Nowadays it is complicated to fabricate single-phase VO 2 ) thin films. Ion beam sputtering is adopted to deposit VOx thin films (main component is VO 2 ) ) on Si 3 N 4 , while sputtering power, substrate temperature and partial oxygen pressure of VOx are adjusted. Then annealing technology is utilized to improve the parameter property of VO x thin films. The thin films are tested by AFM, XPS, XRD, Fourier transform infrared spectrometry, tunable semiconductor laser and optical power meter. Both temperature-driven phasetransition and photoexcitation phasetransition of VO x thin films are applied. The samples are heated from 20°C to 80°C, discovering that the phasetransition temperature is about 59°C and the value of resistance before the phasetransition is two orders of magnitude over the value of resistance after the phasetransition. At the wavelength of 1550 nm, the transmission is from 32% to 1%. Besides, the extinction ratio of the thin films sample is obtained. The optical properties show that the VO x thin films have an apparent switching effect in the optical communication fields.