Effects of substrate temperature on properties of vanadium oxide thin films on Si substrate

We prepared the vanadium oxide thin films on Si substrates by magnetron sputtering , using different substrate temperatures, 300℃, 350℃, 400℃. The effects of substrate temperature on film composition, micro morphology, resistance temperature characteristics, TCR (temperature coefficient of resistance) and other thin film characteristics were analyzed by XRD (X-Ray Diffraction), FESEM (Field emission scanning electron microscopy), and four-probe method. Results show that the increase of substrate temperature is conducive to the promotion of V2O5 (101) crystal formation in the films, meanwhile it is beneficial to reduce the gap and improve the uniformity of grain size, so as to increase the density of the films. The variation range of the film resistance was 500~1700 KΩ·cm,200~550 KΩ· cm and 30~160 KΩ· cm when the substrate temperature was 300 ℃ ,350 ℃ and 400 ℃ . With the increase of substrate temperature, the room temperature resistance and high temperature resistance of the thin film are greatly reduced, and the TCR performance has been optimized at the same time. The room temperature TCR of the film is about -2.4%/℃ under 400 ℃ substrate temperature, and the average TCR is about -1.98%/℃ in the process of temperature change.