In-Situ Deposition And Optical Properties Of VO₂ Films

VO₂ is a special function material, which undergoes a semiconductor-metal phase transition approximately at 68℃. The transition is accompanied with abrupt changes in its electrical and optical properties. Because of the special properties, VO₂ can be used in many fields, such as thermal resistor of uncooled infrared (IR) focal plane arrays, electro-optical switching and erasable optical storage materials, etc.Some researchers have demonstrated that the phase transition can also be controllable by an external applied field, and thus results in significant changes in the electrical and optical properties of VO₂. When injected electron density by the field reaches to a critical value, approximately 10¹⁸–10¹⁹ cm^-3, the transition is triggered and the metallic phase is formed. The transition in VO₂ is a purely electronic Mott–Hubbard transition.In the thesis, the main process parameters are present, and their effect is also discussed on the quality of VO₂ deposited by in-situ reactive magnetron sputtering on silicon substrates. It is pointed out that the pressure of O₂ and Ar in sputtering chamber and the temperature of the substrate are key factors. The crystalline structures of VO₂ thin films are studied by XRD measurements, the properties of the thermochromic and the field induced the transition are investigated by FTIR spectroscopy, and their surface morphologies are observed by SEM. This thesis also illustrates a designed device of 64×64 MTFET arrays based on the VO₂ thin film and with no compatible issue with standard IC process, in which the MTFET will work as MOSFET-like logical device and IR detector.