İnvestigation of correlation between 1/f electronic noise and structural properties in nano sized vanadium oxide films

Vanadium oxide thin films are used in microbolometer pixels as the sensing layer. Their electrical properties such as resistivity, the temperature coefficient of resistance and 1/f electronic noise are closely related to their structural properties. In this study, VOx thin films were deposited on Si3N4/SiO2/Si substrates by pulsed DC reactive magnetron sputtering technique. Some of the films were post-deposition annealed at 200°C and 300°C under pure N2 atmosphere for three hours. The post-annealing effects on the films' structures were investigated by transmission electron microscopy, selected area electron diffraction, electron spectroscopic imaging, Grazing-Incidence X-Ray diffraction, Raman spectroscopy, and X-Ray photoelectron spectroscopy techniques. For electrical characterization, four-point probe technique was used. The correlation between electrical and structural properties of the films was discussed within the framework of the obtained results. The 1/f noise-structure correlation was discussed on the basis of the 1/f noise results obtained by our research group in a previous study. As a result of these discussions, it was concluded that the different 1/f noise values of as-deposited, 200°C and 300°C annealed films are mainly caused by the different VO2 grain size of these films. In addition, the electrical conduction mechanism of 200°C annealed film was explained by charge hopping.