The microstructural properties of sputtered zinc oxide SAW transducers

2014 The microstructural properties of sputtered zinc oxide, ZnO, were investigated and related to their effective surface acoustic wave, SAW, transducer capabilities. SAW transducer films were fabricated on glass using different deposition parameters to produce different levels of transducer efficiency. The ZnO film microstructure was analysed using X-ray diffraction, surface profilometer and scanning electron microscope equipment. Etch techniques were used to further delineate the microstructural properties. The low coupling factor films had a low crystalline content, rougher surface topography and high etch rates. High coupling factor films were highly ordered, structurally dense, smooth surfaced films with etch properties characteristic of single crystal zinc oxide. The differences relate to growth conditions which produce a low defect density film structure of uniform polarity with a minimum of fibre grain inversions and weak intergrain boundaries. Revue Phys. Appl. 20 (1985) 319-324 JUIN 1985, PAGE