Investigation of PECVD silicon nitride films for surface wave devices

Silicon nitride thin films deposited by plasma enhanced chemical vapor deposition (PECVD) are investigated for application to surface acoustic wave (SAW) devices. A matrix of deposition conditions is investigated and the deposition parameters for high-quality films applicable to SAW technology are found. It is confirmed that films having low optical attenuation also have correspondingly good acoustic properties. The experimental procedures for depositing the silicon nitride films, the parameters for high-quality film deposition, and experimental results on the acoustic loss and velocity dispersion are presented. Results indicate low SAW propagation loss and velocity dispersion correlated well with previous investigations.<>