Executive Summary : | Vanadium dioxide (VO₂) is a phase transition material with a reversible insulator to metal transition at 68 ˚C, making it useful in electronic and optical switching applications. Synthesis of VO₂ with good phase-transition properties is challenging due to multiple valence states of Vanadium and the complex V-O phase diagram. Most VO₂ synthesis methods require precise control of oxygen partial pressure and temperature, which can lead to mixed phases of Vanadium oxides, resulting in poor switching properties. One approach to obtain high-quality VO₂ films is oxidation of V films in open air using high power lasers. This method can be used to directly write VO₂ devices and pattern V as contact and interconnect to form an integrated circuit (IC). However, there are only a few publications exploring laser induced oxidation of V for developing VO₂ devices and circuits. This proposal aims to contribute to worldwide efforts in this field by developing a Direct Laser Writing (DLW) system capable of writing VO₂ and V₂O₅ spots, lines, and areas, along with mesa isolation patterns on V films using laser induced oxidation/ablation. The optimized writing parameters will be used to write any pattern of choice, and two integrated circuits (relaxation oscillator and series/shunt RF switch) will be demonstrated to prove the feasibility of the approach to fabricate full circuits. This study will significantly add to our knowledge about direct laser writing of VO₂ devices and contribute to the development of VO2 technology. It would also be a unique facility for researchers working on these important materials for various applications. |