Sputtering Deposition of VO$lt;inf$gt;2$lt;/inf$gt; Film Using Plasma Emission Monitor as Reactive Gas Flow Rate Feedback Control

Monoclinic VO2 film was deposited on quartz substrate by reactive sputtering using the plasma emission monitor (PEM) system as reactive gas flow rate feedback control. Relationship between oxygen flow rate and plasma emission intensity was studied. It was found that single-phase VO2(M) could be obtained steadily at specific relative emission intensity (REI), which were determined as 0.6-0.65, 0.65 and 0.6 for total deposition pressure of 0.8 Pa, 0.5 Pa and 0.2 Pa, respectively. XRD measurement indicated that the deposited VO2 films were strongly oriented of (011) and the XPS measurements verified stoichiometry of the films as VO2.02. Optical transmission measurement of VO2 film exhibited an abrupt change of transmittance from 81% to 16% as VO2 film switched from semiconductor state to metallic state, at transition temperature of 66℃.