Study of Thermal Annealing Effect on the Properties of Silver Thin Films Prepared by DC Magnetron Sputtering

Silver nanoparticles have potential applications in fields of nanosicence and technology. In this work, polycrystalline silver (Ag) thin films were deposited on quartz substrates by DC magnetron sputtering method at the same deposition conditions and then, the Ag films were annealed in oxygen atmosphere for 65 min at different annealing temperatures namely 300, 400, 500 and 600°C. The crystal structure of the films was evaluated by X-ray diffraction. The atomic force microscopy and scanning electron microscopy were employed for surface morphological studies of the films. Normal-incidence transmittance over the wavelength range of 200-2500 nm was measured using a spectrophotometer. The results show that the crystallization of the films increases after annealing and that the Ag films without annealing have lowest roughness. Annealing temperature effectively influences the surface morphology of the films. Optical studies reveal that the as-deposited Ag film has metallic behavior with zero transmittance and after annealing, the transmittance increases due to the formation of silver oxide phases in the films.