Influence of oxygen flow rate on metal-insulator transition of vanadium oxide thin films grown by RF magnetron sputtering

摘要

High-quality vanadium oxide (VO_2) films have been fabricated on Si (111) substrates by radio frequency (RF) magnetron sputtering deposition method.The sheet resistance of VO_2 has a significant change (close to 5 orders of magnitude) in the process of the metal-insulator phase transition (MIT).The field emission-scanning electron microscope (FE-SEM) results show the grain size of VO_2 thin films is larger with the increase of oxygen flow.The X-ray diffraction (XRD) results indicate the thin films fabricated at different oxygen flow rates grow along the (011) crystalline orientation.As the oxygen flow rate increases from 3 sccm to 6 sccm,the phase transition temperature of the films reduces from 341 to 320 K,the width of the thermal hysteresis loop decreases from 32 to 9 K.The thin films fabricated in the condition of 5 sccm have a high temperature coefficient of resistance (TCR) -3.455%/K with a small resistivity of 2.795 p/Ω cm.