Fabrication of High-Quality VO2 Thin Films by Ion-Assisted Dual ac Magnetron Sputtering

The technique of cathodic ac dual magnetron sputtering along with the high energy ionic bombardment is known to yield high-quality thin films in terms of their uniformity and high density. This technique has been applied for the first time to achieve thermochromic VO2 thin films that show a high optical and electrical contrast between normal and switched states. In this two-step process Vanadium metal films were deposited and subsequently oxidized in optimum conditions to achieve stoichiometric VO2 films. Typical films switched between more than 40 % to less than 5 % transmission in the infrared region while undergoing an electrical sheet resistance change between 1 × 105 and 1 × 102 Ω/cm2. The application potential of such VO2 films in integrated optics is deemed high.