Deposition of Alumina Films on Interdigital Transducer/ZnO/Glass Substrates by Electron Beam Evaporation to Improve the Characteristics of Surface Acoustic Wave Devices

Abstract

ZnO films with c-axis (0002) orientation have been successfully grown by radio frequency magnetron sputtering on glass substrates. The alumina films were deposited on interdigital transducers/ZnO/glass substrates by electron beam evaporation to enhance the performance of the ZnO thin film surface acoustic wave (SAW) devices. The crystalline structure and surface roughness of the films were investigated by X-ray diffraction and atomic force microscopy, respectively. The phase velocity and coupling coefficient of SAW device were apparently increased when we increased the thickness of alumina film. The experimental result is beneficial to improve the characteristics of the ZnO thin film SAW devices on cheap glass substrates.

Keywords:

• Zinc oxide (ZnO)
• sputtering
• alumina (Al₂O₃)
• electron-beam evaporation
• surface acoustic wave (SAW)