Abstract
Potassium niobate (KNbO3) thin films are promising materials for the surface acoustic wave devices (SAW). It is found from computed results that the layered structure, c-axis oriented KNbO3 thin film on SiO2/ (100) Si, will exhibit high phase velocity (4013 m/s) of SAW with high coupling coefficient (1%). The KNbO3 thin films were deposited on the SiO2/ (100) Si substrate by the electron beam evaporation system. It is important to have stoichiometric KNbO3 thin films. Relations between the composition of evaporation sources and quality of the thin films were examined. Without substrate heating, KNbO3 thin films with stoichiometry have been obtained at the K/Nb ratio for evaporation source of 0.2. When the substrate temperature was higher than 400°C, film composition almost corresponded with stoichiometry.
