Deposition Of VO₂ Films And Design Of Its Based Planar Integrated Detector Arrays

Several oxides of vanadium, such as VO,V₂O₃,VO₂,V₃O₅,V₆O₁₃ and V₂O₅, undergo a transition from a metal to a semiconductor or insulator phase at a critical temperature (Tc). When the temperature below Tc, it is semiconductor with a monoclinic crystalline structure; while above Tc, it is metal with a rutile structure. As for VO2, Tc≈68℃. Accompanied by the structural transforms, large changes occur in electrical and optical properties. Therefore, due to its high temperature coefficient of resistance (TCR) at room temperature, VO2 is a promising material for uncooled microbolometer application.In this paper, we present the VO2 films deposited by reactive DC magnetron sputtering on silicon substrates using a high pure vanadium target. Through the XRD and SEM measurements, it is deduced that the substrate temperature is one of two key parameters to form a single VO2 phase and to decide their structure and properties by directly affecting their phase composition and grain sizes. With the increase of the substrate temperature, the compositions of the films change from one phase to other phases of the vanadium oxides, and their grain sizes increase when they are in the same phase composition. Oxygen pressure is another key parameter to affect the structure and properties because the different pressure also causes the different composition.In addition, we also present the design of 64×64 VO2 based planar integrated detector arrays. It includes the device structure, layout, the process modules, and mask designs. Moreover, we present the optimization of the structure ofα-SiN:H/ VO2/α-SiN:H/ Al/α-SiN:H with the upper layer ofα-SiN:H as infrared absorber in order to achieve an optimal absorbance.