The effect of various annealing cooling rates on electrical and morphological properties of TiO$_{2}$ thin films

This paper investigates the effect of various postannealing cooling rates on structural and electrical properties of Titanium Dioxide (TiO$_{2}$) thin films. TiO$_{2}$ thin films were deposited on a silicon substrate using DC magnetron sputtering technique. After annealing TiO$_{2}$ thin films at 600$^\circ$C, to investigate the effect of different cooling rates on TiO$_{2}$ thin films, samples were cooled down from 600$^\circ$C to room temperature under 3 different rates: 2$^\circ$C/min, 6$^\circ$C/min, and 8$^\circ$C/min. The Surface morphology, crystal structure, and electrical properties of the samples were characterized by atomic force microscope (AFM), X-ray diffraction (XRD) and Four-point probe (FPP) techniques. It is found that the rate of decreasing temperature after annealing can affect the morphology structure and electrical resistivity of TiO$_{2}$. The sample with 2$^\circ$C/min cooling rate has the largest grain size and highest electrical resistivity, while the sample with 8$^\circ$C/min cooling rate has the smallest grain size and lowest electrical resistivity.