Effect of annealing temperature of titanium dioxide thin films on structural and electrical properties

Abstract

Titanium dioxide (TiO2) thin films are deposited on silicon substrates by using sol-gel dip coating technique. Annealing temperature was varied to investigate its effect on the surface morphology, structural and electrical properties of the film. The crystalline structure, surface morphology and the electrical properties were investigated by X-ray diffraction, field emission scanning electron microscopy (FESEM), atomic force microscope (AFM), and four point probe. The results show that with an increase in annealing temperature, the value of the intensity of (101) peak increases while the value of the full-width at half maximum decreases. Thin films deposited at high annealing temperatures result in an increase in surface roughness and grain size. The electrical properties of these films show that the resistivity varies between 1.40 × 105 and 7.19 × 102 Ω.cm when the annealing temperature changes from 300 to 900°C, respectively. The TiO2 thin films annealed at 900°C exhibited lower resistivity than other films. It found that the annealing temperature influences the surface morphology, structural and electrical properties of TiO2 thin films.