Fabrication and characterization of low loss ZnO optical waveguide

Both structural and optical characteristics of ZnO thin films have to be defined in order to fabricate optoelectronic devices. In this paper a complete study of the deposition parameters and optical properties of r. f. sputtered ZnO films, which have been deposited both on amorphous and crystalline substrates, is carried out. The structural properties have been studied by the reflection high energy electron diffraction (RHEED) analysis. X-ray diffraction was also performed as comparison. Scanning electron microscopy (SEM) observations were also used in the investigation of the morphology of the films. The optical properties have been studied by measuring the transmittance of the grown films and in-plane scattering levels at lambda=633 nm. Fiber-texture films have been deposited having a total optical attenuation <4 dB/cm measured on ZnO samples 5 cm long, grown on sapphire substrates