Material parameters of rf magnetron sputtered SiO/sub 2/ thin films for temperature stable SiO/sub 2//LiNbO/sub 3/ saw devices

摘要

SAW propagation characteristics, velocity and temperature coefficient of delay (TCD) of a 128/spl deg/ Y-X LiNbO/sub 3/ SAW device integrated with an over-layer of rf magnetron sputtered SiO/sub 2/ film have been studied. A deviation in the experimental observations with respect to the theoretical calculations on the layered structure SiO/sub 2//LiNbO/sub 3/ are identified mainly due to the difference in the material parameters of the deposited SiO/sub 2/ film. Influence of deposition conditions on the materials parameters of SiO/sub 2/ thin film have been studied, and the representative values of density, dielectric constant, elastic constants (C/sub 11/ and C/sub 44/) and their temperature coefficients have been determined, required for the design of a temperature stable SAW device.