Deposition of preferred-orientation ZnO films on the ceramic substrates and its application for surface acoustic wave filters

The preferred oriented ZnO films deposited on PT-ceramic substrates with the c-axis normal to the surface was demonstrated using the rf magnetron sputtering method. A systematic study was also undertaken on the effects of growth parameters on the crystal structure of the films. The film surfaces which were examined using atomic force microscopy (AFM) and scanning electron microscopy (SEM) were found to exhibit good morphology. It was also found that the film's orientation was strongly dependent on the argon-oxygen gas ratio, rf power, and sputtering time. The results show that the preferred orientated ZnO film is beneficial for improving the electromechanical coupling coefficient of surface acoustic wave (SAW) devices.