Fabrication of ZnO Waveguide Films Deposited on Sapphire and MgO Substrates by RF Magnetron Sputtering

Abstract

ZnO waveguide films were fabricated on sapphire (001) and MgO (100) substrates by the radiofrequency (RF) magnetron sputtering technology using ZnO ceramic as the target. Properties of the films were investigated by prism coupling method, X-ray diffraction (XRD) and Rutherford backscattering spectrometry (RBS). The results demonstrated that the ZnO nano-films have planar waveguide structure and have nearly stoichiometric composition with c-axis preferred orientation growth. The growth rates of the films were slightly influenced by the substrates. The effective refractive indices of the films were smaller than the bulk material and were affected by substrates. The relationships between the average grain sizes, substrates, and film thickness were analyzed.