Effect of Ar/O2 gas ratio and annealing temperature on the structure and properties of ZnO film

Zinc oxide (ZnO) film is deposited on Si (001) substrate by radio-frequency (RF) reactive magnetron sputtering method. Then the samples are annealed at different temperatures. The effects of the ratio of Ar/O
₂
and annealing temperature are investigated. Crystal structures of the films are characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM). The results indicate that the ratio of Ar/O
₂
and the annealing temperature have great influence on the crystal orientation and the surface morphology. The crystalline orientation of ZnO thin film is in direct proportion to the Ar/O
₂
gas ratio. While less than 750°C;, the crystal orientation of ZnO thin film increases with the annealing temperature increasing. As higher than 750°C, the crystalline orientation of ZnO thin film is inversely proportional to the annealing temperature.