ZnO films have been prepared by radio frequency magnetron sputtering on sapphire substrates. The effect of the annealing temperature on the structure and optical properties of the ZnO films are studied using XRD

SEM and photoluminescence. The results indicate that the ZnO thin films have hexagonal wurtzite single phase structure and a preferred orientation with the

c

axis perpendicular to the substrates. With increasing annealing temperature the intensities of the XRD (002) diffraction peaks increases

the grain size and intensity of the UV photoluminescence peaks increase while the FWHM of (002) peaks decreases

which demonstrates that the high quality of the ZnO films deposited by RF magnetron sputtering can be obtained by properly controlling annealing temperature.