Formation and Thermochromism of V O₂Films Deposited by RF Magnetron Sputtering at Low Substrate Temperature

Abstract

Thermochromic VO 2 films were deposited on substrates of silicon and Pyrex glass by reactive rf magnetron sputtering and characterized by thin-film X-ray diffraction (XRD), Rutherford backscattering spectrometry (RBS), atomic force microscopy (AFM) and spectrophotometry. Films with a VO 2 single phase were formed above a fairly low temperature of 300° C by controlling precisely the oxygen flow ratio. The use of a nucleated substrate improved the crystallinity of the VO 2 films deposited at low temperature. A negative substrate bias appeared to have an effect of favoring the formation of a VO 2 single phase at a substrate temperature as low as 250° C.