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

Abstract

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 × 10(5) and 1 × 10(2) Ω/cm(2). The application potential of such VO2 films in integrated optics is deemed high.

Vanadium Oxide Compounds: Structure, Properties, and Growth from the Gas Phase

“…The photochromism of V 2 O 5 was attributed to the photo‐reduction of V 5+ with a visible laser light that turns the yellow V 2 O 5 into blue‐black . Thermally induced chromism was also observed for V 2 O 5 , and intensively investigated along the structural transition in VO 2 . Electrochromism was reported for VO 2 and V 2 O 5 ‐based coatings .…”

“…[2,3] Thermally induced chromism was also observed for V 2 O 5 , [4] and intensively investigated along the structural transition in VO 2 . [5][6][7] Electrochromism was reported for VO 2 [8] and V 2 O 5 -based coatings. [9][10][11][12] The above-mentioned optical properties emphasize the suitability of vanadium oxide as a material of choice for optoelectronics [4,13] such as optical switching, [14][15][16][17][18] and also for energy-saving smart windows.…”

Sputter deposition of thermochromic VO2 films on In2O3:Sn, SnO2, and glass: Structure and composition versus oxygen partial pressure

“…Films of VO 2 can be made in many different ways, 6 and recent investigations include films prepared by physical techniques such as molecular beam epitaxy, 9 pulsed laser deposition, 10 and magnetron sputtering [11][12][13][14][15] (including high power impulse magnetron sputtering known as HiPIMS); 16 other studies have used chemical methods such as atomic layer deposition, 15 chemical vapor deposition, 17 sol-gel deposition, [18][19][20][21] and spin coating, 22,23 as well as hydrothermal 24 and colloidal techniques. 25 It has been known for many years that the characteristics of the substrate material play a large role for the thermochromism of VO 2 films.…”

Effect of O2 flow rate in the annealing process on metal–insulator transition of vanadium oxide thin films

“…Especially, the property that VO 2 thin film can transform its resistivity by some excitations promotes its application to electronic devices. At present, lots of methods are applied to growing VO 2 thin film, such as chemical vapor deposition [12][13][14], sputtering [15][16][17], pulsed laser deposition [18][19][20], electron beam evaporation [21,22] and sol-gel process [23][24][25]. Of all the methods, magnetron sputtering method is widely used because of numerous advantages.…”