Patent ID: 8864957

Claim:
A method comprising: placing a substrate in a sputtering chamber and heating the substrate prior to sputtering; placing a VO 2 target material in a sputtering gun inside the sputtering chamber, the target material including a crystalline oxide; introducing into the sputtering chamber an inert gas at a first flow rate, then a reactive gas at a second flow rate; applying a voltage within the sputtering chamber to create a plasma within the sputtering chamber; activating the sputtering gun at a distance from the substrate so as to cause the crystalline oxide in the target material to react with the reactive gas, and so as to cause a layer of a compound of the reactive gas and the crystalline oxide to be deposited on the substrate, thereby creating a single stoichiometric phase, polycrystalline VO 2 thin film; keeping the substrate at a temperature between 300° C. and 550° C. during sputtering, and cooling down the deposited VO 2 thin film to a temperature of about 150° C. after the deposition; wherein the first flow rate is 29 sccm and the second flow rate is 7.8 sccm, so that the ratio of vanadium to oxygen in the thin film allows the thin film to undergo a metal-insulator transition (MIT) of four orders of magnitude in resistance at an MIT temperature between 61° C. and 71° C.