Study of preferred orientation of zinc oxide films on the 64° LiNbO₃ substrates and their applications as liquid sensors

The growth of (002) orientation of zinc oxide (ZnO) films on 64° LiNbO₃ substrates using rf magnetron sputtering system was demonstrated. It was shown that the film orientations and crystallinity were strongly dependent on the rf power, total chamber pressure, ratio of argon to oxygen and substrate temperature. The crystalline structure of the films was investigated using X-ray diffraction and scanning electron microscopy. It was demonstrated that the highly oriented (002) films were obtained under a total chamber pressure of 1.33 Pa, containing 40% oxygen and 60% argon and a substrate temperature around 120°C.